Welcome to Weekly Health Update

“A critical weekly review of important new research findings for health-conscious readers”

SOY, CURCUMIN & PROSTATE CANCER RISK

Because chronic inflammation within the prostate gland is through to be an important risk factor for prostate cancer, anti-inflammatory dietary supplements and medications may be able to reduce the risk of prostate cancer by reducing inflammation.

Isoflavones from soy-based foods are known to act as a weak form of estrogen (the dominant female sex hormone).  Based upon this estrogen-like behavior, as well as potential anti-inflammatory properties, soy isoflavones are being studied as possible prevention and treatment agents for prostate cancer, and other types of cancer. 

Curcumin, which is present in the Indian curry spice turmeric, is also known to have potent anti-inflammatory properties, and has also been the subject of considerable cancer prevention and cancer treatment research.

A newly published prospective, randomized, blinded, placebo-controlled research study, published in the current issue of the journal Prostate, suggests that the combination of soy isoflavones and curcumin may have important potential prostate cancer prevention properties.

In the first part of this study, human prostate cancer cells were treated with a combination of soy isoflavones and curcumin.  Treatment of these human cancer cells with soy isoflavones and curcumin resulted in a significant reduction of prostate-specific antigen (PSA) production by these malignant cells (PSA is a marker of both prostate gland inflammation and prostate gland cancer).

As regular readers of this column are already aware, treatments performed in the laboratory that have beneficial effects on cancer cells, or on mice or rats, do not always have the same positive effects on living, breathing human beings.  Therefore, the findings of the second part of this study are of particular interest.  A total of 85 men with elevated PSA levels, but without prostate cancer (as confirmed by prostate biopsy), were enrolled in the second phase of this intriguing small study.  These 85 men were divided into two groups, and one group received daily supplements containing both soy isoflavones and curcumin, while the second (control) group of men received placebo (sugar) pills that were identical in appearance to the supplement pills (neither the 85 men, nor the nurses who dispensed the supplement pills and placebo pills, were aware of which pills each study volunteer was receiving until after the research study had been completed).

PSA blood levels were tested at the beginning of the clinical portion of this study, and once again 6 months later.  As was observed in the prostate cancer cells during the first part of this study, men with a PSA level of 10, or higher, experienced a significant reduction in their blood PSA levels 6 months after starting daily supplementation with soy isoflavones and curcumin.

Although this brief study cannot definitively confirm that soy isoflavone and curcumin supplements reduce the risk of prostate cancer, their ability to reduce elevated PSA levels in men with chronic prostate inflammation, but without evidence of prostate cancer, at least suggests a potential role in the prevention of prostate cancer (presumably through a reduction in prostate gland inflammation).

While there are multiple human research studies underway that are evaluating the effectiveness of soy isoflavones as cancer prevention agents, currently, there are no major human studies looking at the effects of curcumin on prostate cancer risk.  Based upon the findings of this small, interesting study of soy isoflavones and curcumin, which suggest a potential additive effect on PSA reduction when both of these dietary supplements are taken together, human research trials should be developed to look at the long-term impact, if any, of combined soy isoflavone and curcumin supplementation on prostate cancer risk.

For additional research information on soy isoflavones and curcumin in cancer prevention and cancer treatment, please review the following previous columns:

Soy Foods & Stomach Cancer Risk

Cruciferous Vegetables, Soy & Breast Cancer Risk

Soy Isoflavones & Recurrent Prostate Cancer

Soy Isoflavones Decrease Breast Cancer Recurrence Risk

Genistein (Soy Isoflavone) & Prostate Cancer

Diet, Soy & Breast Cancer Risk

Viagra & Sexual Function in Women; Patient-Reported Adverse Hospital Events; Curcumin & Pancreatic Cancer

Disclaimer: As always, my advice to readers is to seek the advice of your physician before making any significant changes in medications, diet, or level of physical activity

Dr. Wascher is an oncologic surgeon, a professor of surgery, a cancer researcher, an oncology consultant, and a widely published author  

http://www.youtube.com/watch?v=7-Tdv7XW0qg

I and the staff of Weekly Health Update would like to take this opportunity to thank the more than 100,000 new and returning readers who visit our premier global health information website every month.  As always, we enjoy receiving your stimulating feedback and questions, and I will continue to try and personally answer as many of your inquiries as I possibly can.

Welcome to Weekly Health Update

“A critical weekly review of important new research findings for health-conscious readers” 

SOY FOODS & STOMACH CANCER RISK

There is a great deal of interest regarding the potential effects of soy-based foods (like tofu and soy beverages) on cancer risk.  As discussed in my forthcoming book (“A Cancer Prevention Guide for the Human Race”), there is a growing body of laboratory and human research data suggesting that dietary soy isoflavones might be able to reduce the risk of prostate and breast cancer.

Now, a newly published clinical research study from Korea suggests that high levels of soy isoflavones in the blood may also be linked to a reduced risk of stomach cancer, as well.  (Korea has one of the highest incidences of stomach cancer in the world.)  This study appears in the current issue of the journal Cancer Epidemiology, Biomarkers & Prevention.

As most of the published research in the area of cancer prevention is based upon the subjective recall of patient volunteers regarding their diet (and other habits), the authors of this study chose, instead, to directly measure the levels of soy isoflavones in the blood of patient volunteers.  This study included 131 patients with recently diagnosed stomach cancer, and 393 “control” patients who did not have stomach (gastric) cancer.  Blood levels of the two major dietary soy isoflavones (genistein and daidzein) were directly measured in all 524 of these research volunteers, and these results were compared between the patients with stomach cancer and the “control” patients without gastric cancer.

Study volunteers with the highest levels of genistein in their blood, when compared with those with the lowest levels, were found to be 46 percent less likely to be diagnosed with stomach cancer.  Even more impressive was the finding that study volunteers with the highest daidzein blood levels were 79 percent less likely to be diagnosed with stomach cancer when compared to the volunteers with the lowest levels of daidzen in their blood

While there may be other health-related factors at work among the study volunteers with high levels of soy isoflavones in their blood that could explain the much lower stomach cancer risk observed in these same patients, this study’s results are nonetheless intriguing enough to justify a large scale, prospective, randomized, placebo-controlled soy isoflavone clinical research study to confirm the findings of this relatively small Korean public health study.

To learn more about the role of soy isoflavones as potential cancer prevention nutrients, look for the publication of my new landmark evidence-based book, “A Cancer Prevention Guide for the Human Race,” in the summer of this year.

Welcome to Weekly Health Update

“A critical weekly review of important new research findings for health-conscious readers” 

CRUCIFEROUS VEGETABLES, SOY & BREAST CANCER RISK

The role of soybean-derived isoflavones in cancer prevention is not entirely clear at this time.  However, there has been intense interest in tofu, and other soy-derived foods, as potential breast cancer prevention agents.  At the same time, because genistein, and other soy isoflavones, are known to variably act as both inhibitors and mimics of estrogen (the primary female sex hormone), cancer experts remain divided regarding the safety of regularly consuming soy isoflavones by women who are at an increased risk of developing breast cancer (chronic estrogen stimulation of the breast is a known risk factor for breast cancer).  Meanwhile, the high level of tofu consumption among women in the Far East, coupled with the much lower incidence of breast cancer in those countries when compared to the United States and other western countries, has fuelled speculation that tofu and other soy-derived foods may actually be associated with a reduced risk of breast cancer. 

In addition to soy isoflavones, there is also research data available suggesting that the frequent consumption of cruciferous vegetables, like broccoli and cauliflower, may also be associated with a decreased risk of at least some types of cancer, including breast cancer.

A newly published public health study from Singapore evaluated the impact of the regular intake of vegetables, fruit, and soy-derived foods on the risk of breast cancer within the large Chinese population in that country.  This enormous prospective epidemiological study, which began in 1993, and which appears in the current issue of the American Journal of Clinical Nutrition, included more than 34,000 women volunteers.  All of the 34,018 women in this study underwent detailed evaluation of their diets when they entered into this prospective public health study.  Among this very large group of women, 629 new cases of breast cancer were diagnosed during the course of this ongoing study. 

Based upon their self-reported dietary patterns, the women participating in this large epidemiological study were divided into two groups.  The first group consisted of women who regularly consumed cruciferous vegetables, fruit, and tofu.  The second group of women generally favored meat and starchy foods (such as dim sum), and consumed far fewer portions of vegetables, fruit, and tofu when compared to the first group.

The results of this study indicated that increasing levels of vegetable, fruit and tofu intake were associated with a significant decrease in breast cancer risk in postmenopausal women.   Among the women reporting the highest levels of intake of these foods, there was, on average, a 30 percent reduction in the risk of breast cancer when compared to the women who rarely ate these healthy foods.  Moreover, among the postmenopausal women who frequently consumed vegetables, fruit, and tofu, and who were observed for 5 or more years in this study, the apparent reduction in the risk of breast cancer grew even stronger, and these women were found to be 43 percent less likely to develop breast cancer when compared to women who rarely consumed vegetables, fruit, and tofu in their diets.

Therefore, in this large diet survey-based, prospective public health study,  a diet rich in vegetables (and cruciferous vegetables, such as broccoli and cauliflower, in particular), fruit, and tofu was strongly associated with a significant reduction in breast cancer risk in postmenopausal Chinese women living in Singapore.

Although there remains some concern that soy isoflavones may, under some conditions, actually stimulate the growth of either new or previous breast cancers (or cancers of the ovary or uterus), this public health study’s favorable findings are additive to a growing body of research data suggesting that both cruciferous vegetables and soy-derived isoflavones may be associated with a substantial decrease in the risk of breast cancer in women. 

To learn more about the potential role of cruciferous vegetables and soy isoflavones as part of a cancer prevention lifestyle, look for the publication of my new landmark evidence-based book, “A Cancer Prevention Guide for the Human Race,” in the summer of this year.

Dr. Wascher is an oncologic surgeon, a professor of surgery, a cancer researcher, an oncology consultant, and a widely published author

http://www.youtube.com/watch?v=7-Tdv7XW0qg

In view of the extreme devastation and human misery brought about in Haiti and Chile by the recent earthquakes, Weekly Health Update asks our tens of thousands of caring readers to give generously to established charities that are currently working in those countries to assist the injured, the ill, and the homeless.  There are many such legitimate charities, including the following two:

http://www.redcross.org/

http://www.imcworldwide.org/haiti 

Welcome to Weekly Health Update

“A critical weekly review of important new research findings for health-conscious readers” 

AVODART (DUTASTERIDE) & PROSTATE CANCER PREVENTION

Because most prostate cancers, like breast cancer, are fueled by sex hormones, the prevention of prostate cancer through the use of hormone-blocking medications is an attractive potential strategy.

Two medications, finasteride (Proscar) and dutasteride (Avodart), are FDA-approved to treat the benign enlargement of the prostate that commonly occurs with increasing age (also known as benign prostatic hypertrophy, or BPH).  Both of these medications have recently been evaluated in prospective, randomized, placebo-controlled clinical research trials as potential prostate cancer prevention agents.  Finasteride and dutasteride are 5-alpha-reductase inhibitors, and function by blocking the conversion of testosterone into dihydrotestosterone by this enzyme (dihydrotestosterone is the biologically active male sex hormone within the prostate gland).  Finasteride inhibits one of the two known forms of 5-alpha-reductase, while dutasteride (Avodart) inhibits both forms.

Finasteride (Proscar) has previously been evaluated in the Prostate Cancer Prevention Trial, which enrolled nearly 19,000 men (55 years of age and older) who were without any clinical evidence of prostate cancer at the time they entered the study.  These men were randomly assigned to receive either finasteride or an identical placebo pill, and the entire cohort of men was then followed for a period of 7 years.  After 7 years of follow-up, 18 percent of the men who had been secretly randomized to receive finasteride were diagnosed with prostate cancer, while 24 percent of the men who had received the placebo pill (unknown to them at the time) developed prostate cancer.  Thus, taking finasteride for 7 years was associated with a 25 percent reduction in the relative risk of prostate cancer during the relatively brief course of this clinical study.  However, a potentially significant downside was also observed in this study, as the men who received finasteride, and who still went on to develop prostate cancer, tended to have more aggressive tumors when compared to the men in the placebo group (37 percent versus 22 percent, respectively).  Moreover, and not surprisingly, since finasteride blocks the active metabolite of testosterone, sexual dysfunction and breast enlargement were more common among the men taking finasteride when compared to the men in the placebo group. 

Following the intriguing results with finasteride (Proscar) in the Prostate Cancer Prevention Trial, there has been a great deal of anticipation building for results of the recently completed dutasteride (Avodart) prostate cancer prevention trial.  Now, the results of this important cancer prevention study have just been published in the New England Journal of Medicine.  This prospective, randomized, blinded, placebo-controlled study lasted for 4 years, and included 6,729 men at high risk of developing prostate cancer.  These men, all of whom were between 50 and 75 years of age, were secretly randomized to receive either 0.5 mg of dutasteride (Avodart) per day or an identical placebo pill.  As part of this research study’s protocol, all of these men underwent needle biopsies of the prostate gland at 2 years and 4 years after entering the study.  By the end of the study, 20 percent of the men who had received dutasteride (Avodart) had developed prostate cancer, while 25 percent of the men in the placebo (control) group were diagnosed with prostate cancer.  Thus, there was an observed 25 percent decrease in the relative risk of prostate cancer among the group of men that was randomized to receive dutasteride (Avodart) for 4 years (and a 5 percent absolute reduction in prostate cancer risk with Avodart).  As was observed in the finasteride (Proscar) study, however, there was also a higher incidence of more aggressive (i.e., higher grade) tumors observed among the men who took dutasteride (Avodart) when compared to the men in the placebo group, although only a very small number of these high grade tumors were identified in either group of men.  Finally, and not surprisingly, the symptoms of benign prostatic hypertrophy (BPH), including difficulties in passing urine, were much improved among the men randomized to take dutasteride (Avodart).

Because it is still too soon to determine whether or not finasteride or dutasteride are able to significantly reduce the risk of death due to prostate cancer, there is no consensus at this time, among most prostate cancer experts, regarding the use of these hormone-blocking agents as prostate cancer prevention agents.  However, for men with significant prostate cancer risk factors, it may be prudent to consider the use of Proscar or Avodart.

To learn more about the potential role of 5-alpha-reductase inhibitors in cancer risk reduction, look for the publication of my new landmark book, “A Cancer Prevention Guide for the Human Race,” in the spring/summer of this year.

http://www.youtube.com/watch?v=7-Tdv7XW0qg

http://www.redcross.org/

http://www.imcworldwide.org/haiti

Welcome to Weekly Health Update

“A critical weekly review of important new research findings for health-conscious readers” 

SOY ISOFLAVONES & RECURRENT PROSTATE CANCER

The interest level in natural and complementary treatments for cancer has never been higher in the medical and scientific communities than it is now.  For decades, now, this area of research was often relegated to the fringes of the clinical research community, while most mainstream academic research centers and Big Pharma companies focused on the design and testing of new biochemical therapies with improved therapeutic and safety profiles.  With the 5-year overall survival rate among all patients with cancer approaching a record 65 percent, we have, unquestionably, made enormous improvement in our ability to cure many of the cancers that, not too long ago, were associated with a very high risk of death.  Cancer physicians also have far more effective medications available now to control the noxious side effects of many of our “front-line” cancer therapies, which have had the beneficial effect of further reducing suffering and morbidity among thousands of cancer patients as they undergo their daily treatments. 

Despite the  admirable (and ongoing) progress that has been achieved over the past four decades in cancer care, however, nearly 600,000 cancer patients will still succumb to their disease this year in the United States, alone.  Thus, more effective cancer prevention strategies are necessary to reduce the number of new cases of cancer, and more effective (and less toxic) cancer therapies must be identified.  Moreover, with the annual cost of many new cancer therapies now running into the hundreds-of-thousands of dollars per patient, per year, our already unsustainable (and still rising) health care costs demand that the cancer care community rigorously evaluate less costly approaches to cancer prevention and treatment.

Because so-called “natural products” are relatively inexpensive, widely available, and generally non-toxic, there is a growing interest in studying these agents using the same high-level prospective, randomized clinical trials that are routinely used by pharmaceutical companies and academic medical centers to evaluate promising new drug therapies.  Because of their great complexity and high cost, however, randomized clinical trials are best reserved for studying novel therapies for which there is at least some laboratory (“preclinical”) or early-phase clinical data available that suggests some potential benefit to humans.  Until recently, however, and most likely due to inherent biases against natural products by the mainstream clinical research community in the past, very little high-level clinical research has been performed to definitively evaluate natural products as disease prevention and treatment agents.  Fortunately, and despite shrinking research funding over the past decade, there has been a recent surge in the number of large randomized, prospective, controlled clinical research trials reporting their findings of the effects of natural products on disease prevention and treatment.

As the vast majority of natural products and lifestyle-related research in the past has been based upon low-powered research methods, it should come as no surprise that recent high-level prospective clinical research studies have, more often than not, found little or no benefit associated with the use of many of these supplements and products.  (Moreover, in some cases, several very popular and highly recommended vitamins and dietary supplements have actually been found to be potentially harmful.)   However, a great deal of promising high-level clinical research has yet to be done in order to fully and accurately assess the, literally, hundreds of natural products for which there is at least some preclinical data supporting potentially beneficial health effects.  (In my forthcoming book, “A Cancer Prevention Guide for the Human Race,” I will be comprehensively reviewing and analyzing the available laboratory and clinical research data on natural products and lifestyle strategies as an integral approach to a cancer prevention lifestyle.  The publication of this groundbreaking and authoritative evidence-based cancer prevention guide is tentatively scheduled for May of this year.)

In many respects, prostate cancer is the male counterpart of breast cancer in women.  Analogous to breast cancer in women, prostate cancer is the most common cancer that occurs in men (excluding minor skin cancers), and the second most common cause of cancer death.  In 2009, an estimated 192,000 new cases of prostate cancer were diagnosed in the United States alone, and approximately 27,000 American men died of this disease in the same year.  In most industrialized nations, prostate cancer accounts for approximately 25 percent of all cancer diagnoses in men (similar to the percentage of breast cancer cases among all cancer cases diagnosed in women).

A newly published prospective, early-phase, clinical pilot study from Canada evaluated the effects of a soy beverage (“soy milk”) on the progression of recurrent prostate cancer in 29 men following radiation therapy for their cancers.  This study, which has just been published in the journal Nutrition and Cancer, was not a placebo-controlled randomized study, however, this small phase II clinical study prospectively followed these patient volunteers for 6 months, during which time serial measurements of the level of prostate-specific antigen (PSA) in their blood was performed (PSA is the primary prostate tumor marker that is measured both to detect early prostate cancer and to identify recurrences of this type of cancer.)

The time interval during which the level of PSA in the blood doubles is an important indicator of the rate of progression of recurrent prostate cancer.  In this small prospective clinical pilot study, the consumption of approximately 500 ml of soy beverage per day, for 6 months, was associated with an actual decline in PSA levels in 4 (14 percent) of these patient volunteers, while another 8 (28 percent) of these recurrent prostate cancer patients experienced a greater than 100 percent increase in their PSA doubling times.  However, another 5 patients (17 percent) experienced a 50 percent or greater decrease in their PSA doubling times during the 6 month duration of this study, which was an unfavorable development.  Thus, during the brief duration of this intriguing small pilot study, 42 percent of men with early recurrence of their prostate cancer experienced either a decrease in the biochemical extent of their recurrent cancers or a significant biochemical slowing of the progression of their recurrent disease.

Whether or not longer durations of soy intake will be able to sustain the impressive results of this study is not clear at this time.  More importantly, whether or not these observed favorable effects of daily soy intake on PSA levels and PSA doubling times will actually translate into prolonged survival (or not) is also unknown at this time.  It will require several larger and longer-term randomized, placebo-controlled, blinded, prospective clinical trials of soy foods and soy isoflavone supplements to answer these critical questions (several of which are already underway).  Meanwhile, the overall safety profile for moderate amounts of soy intake in men appears to be quite favorable, and so many prostate cancer experts are cautiously recommending soy-derived foods for men with prostate cancer, and for men who are at an increased risk of developing prostate cancer, pending the completion of these larger prostate cancer research studies.

For a much more detailed and comprehensive evaluation of the role of soy foods, and other dietary supplements and lifestyle modifications, in the prevention of prostate cancer (and other cancers), look for the publication of “A Cancer Prevention Guide for the Human Race” in the spring of this year.

I and the staff of Weekly Health Update would like to take this opportunity to thank the more than 100,000 new and returning readers who have visited our premier global health information website this month, alone.  As always, we enjoy receiving your feedback and questions, and I continue to try to personally answer as many of your inquiries as I possibly can.

In view of the extreme devastation and human misery brought about in Haiti and Chile by the recent earthquakes, Weekly Health Update asks our tens of thousands of caring readers to give generously to established charities that are currently working in that country to assist the injured, the ill, and the homeless there.  There are many such legitimate charities, including the following two:

http://www.redcross.org/

http://www.imcworldwide.org/haiti

For a somewhat lighter perspective on Dr. Wascher, please click on the following YouTube link: 

http://www.youtube.com/watch?v=7-Tdv7XW0qg

Welcome to Weekly Health Update

“A critical weekly review of important new research findings for health-conscious readers”

BREAST CANCER, PHYSICAL THERAPY &

LYMPHEDEMA

Arm lymphedema, or chronic swelling of the arm, occurs in 10 to 30 percent of women following treatment for breast cancer.  When the lymphatic drainage network in the arm and hand has been disrupted by the surgical removal of axillary (armpit) lymph nodes, or by radiation therapy to the axilla (or, sometimes, following both types of treatment), the delicate network of lymphatic vessels that return excess tissue fluid back to the heart can become obstructed. This lymphatic obstruction can then result in chronic swelling of the hand and arm.  Patients with significant lymphedema of the arm following breast cancer treatment may experience considerable swelling (edema), heaviness, stiffness and discomfort of the affected hand and arm.

Unfortunately, there are no known effective methods available to prevent lymphedema, and once significant lymphedema does develop, compression sleeves and soft tissue massage are the primary treatment modalities currently available.  Unfortunately, currently available lymphedema treatments are often not highly effective for many patients, and there is no known cure for lymphedema once it develops.

Now, a newly published research study, in the British Medical Journal, suggests that physical therapy, when initiated early after breast cancer surgery, can significantly decrease the risk of arm and hand lymphedema.  In this prospective randomized clinical research study, 120 women who underwent removal of their axillary lymph nodes for breast cancer were randomized to one of two groups.  Women assigned to the experimental group underwent physical therapy 3 times per week, for a total of 3 weeks.  Physical therapy techniques used in this group included manual lymph drainage and soft tissue massage techniques, as well as progressive shoulder exercises.  Both groups of women also underwent the same lymphedema management educational course, but the control group of women did not receive any physical therapy interventions.

Among the 116 women who completed at least one year of follow-up, 18 women (16 percent) went on to develop lymphedema.  Fourteen of the women who developed lymphedema were in the control group, while the remaining 4 women were in the experimental group.  Thus, in this clinical study, early physical therapy following axillary lymph node dissection (ALND) was associated with a very significant 72 percent reduction in the risk of developing lymphedema, at least within the first year following breast cancer surgery.

Whether or not the use of early postoperative physical therapy can reduce the incidence of arm lymphedema over periods longer than one year is unknown at this time, and additional follow-up of the patients who participated in this clinical research study will be required to answer this very important question.  However, this is one of the very few studies available that suggests a role for physical therapy in the actual prevention of arm and hand lymphedema following ALND for breast cancer.  If additional, mature follow-up of these patients confirms a long-term benefit from early postoperative physical therapy in preventing arm lymphedema, then a strong case could be made for the routine use of early physical therapy in women who undergo ALND, and perhaps, as well, women who undergo sentinel lymph node biopsy with subsequent radiation therapy to the breast and armpit (axilla) area.

For additional information and resources related to cancer-associated lymphedema, please click on the links below:

http://www.cancersupportivecare.com/Abstracts/asbdpbtps.html

http://meeting.ascopubs.org/cgi/content/abstract/23/16_suppl/8185

http://www.annalssurgicaloncology.org/cgi/content/abstract/15/7/1996

http://www.cancerlynx.com/sln.html

http://doctorwascher.com/Archives/11-23-08.htm

http://doctorwascher.com/Archives/8-16-09.htm

For a somewhat lighter perspective on Dr. Wascher, please click on the following YouTube link: 

http://www.youtube.com/watch?v=7-Tdv7XW0qg

Welcome to Weekly Health Update

“A critical weekly review of important new research findings for health-conscious readers”

PREVENTION OF SURGICAL SITE INFECTIONS

(SSIs) AFTER SURGERY

Infections following surgery in the United States occur in approximately 3 to 5 percent of all cases, and in more than 10 percent of certain types of operations.  In view of these statistics, surgical site infections (SSIs) are a major public health problem throughout the world.  On average, patients in the United States who develop an SSI will remain in the hospital for an additional week, resulting in an average of more than $25,000 in additional healthcare costs per affected patient.  Patients who develop SSIs are also 60 percent more likely to be admitted to the ICU, and are twice as likely to die, when compared to patients who do not develop SSIs following surgery.   Moreover, at a time when profound changes in the United State’s health care system are being proposed to control skyrocketing health care costs, SSIs are estimated to add an additional $10 billion in national health care costs, annually.   In addition to the economic costs associated with SSIs, serious infections following surgery often cause considerable suffering among affected patients; and in severe cases, SSIs can also result in permanent disability or death.

The known causes of SSIs are complex and multiple and, therefore, no single or simple solution is capable of eliminating all cases of SSIs.  However, there is ample research data available suggesting that a number of opportunities exist whereby the risk of SSIs can be further reduced.  For example, one major (and preventable) cause of potentially life-threatening SSIs is the increasing prevalence of antibiotic-resistant strains of bacteria that have developed following decades of excessive and inappropriate antibiotic use.  Among these resistant bacteria, few have raised more concern than methicillin-resistant Staphylococcus aureus (more commonly known by its acronym, MRSA).  MRSA is capable of causing limb- and life-threatening infections, particularly in very ill patients, and in the very young and very old.  When I began my medical career, more than 20 years ago, MRSA was an exceedingly rare cause of bacterial infections.  When MRSA first began to appear, this bacterium primarily caused infections among seriously ill hospitalized patients, and was rarely a source of infection among generally healthy nonhospitalized patients.

In a landmark study by the Centers for Disease Control, and published in the Journal of the American Medical Association in 2007, a remarkable 58 percent of invasive infections caused by MRSA in 2004 and 2005 occurred in nonhospitalized patients, while 27 percent of MRSA infections arose among hospitalized patients.  This tectonic shift in the epidemiology of MRSA (and other emerging strains of antibiotic-resistant bacteria and fungi, as well) has grave implications for preventing SSIs, as the majority of SSIs are known to arise from the surgical patient’s own native bacteria.

Two important new studies related to SSI prevention, and just published in The New England Journal of Medicine, offer important new ammunition in the ongoing fight against potentially deadly SSIs.

In the first study, from the Netherlands, patients being admitted to the hospital for elective surgery were tested for the presence of Staphylococcus aureus bacteria in their nasal passages.  In this prospective, randomized, placebo-controlled, double-blind, multi-center clinical research trial, 6,771 patients were screened for the presence of nasal Staphylococcus aureus, and 1,251 of these patients were confirmed to be nasal carriers of this bacterium.  A total of 917 of these patients were subsequently enrolled into this clinical research trial. These 917 patients were then divided into an “experimental” group and a “control” group, although neither the patients nor the research assistants in this double-blind study were permitted to know which group any patient was assigned to until after the study had been completed.  Patients randomized to the “experimental” group were treated, before surgery, with antibacterial ointment (mupirocin) applied to their nasal passages, and with showers using antibacterial soap (chlorhexidine), in an effort to eradicate surface bacteria (including Staphylococcus aureus) from their noses and skin.  The “control group” of patients received identical-appearing nasal ointment and skin soap, but without mupirocin or chlorhexidine.

All study patients were tracked following surgery, and the incidence of SSIs was then analyzed.  In this highly-powered randomized, controlled clinical research trial, there was a 58 percent overall reduction in the relative risk of SSIs among the “experimental group” of patients when compared to the patients who received only placebo ointment and placebo soap.  The benefit of preoperative treatment with mupirocin ointment and chlorhexidine soap was even more pronounced for SSIs involving deep body spaces, in this study: the relative risk of deep body space SSIs was reduced by 79 percent in the “experimental group” of patients.  Therefore, the results of this powerful prospective clinical trial suggest that SSIs following elective surgery can be significantly reduced by, first, testing patients for evidence of colonization with Staphylococcus aureus bacteria and, secondly, by “decolonizing” the nasal passages and skin of already-colonized patients with antibacterial ointment and soap, respectively.  Many hospitals already selectively apply nasal cavity testing for MRSA (either before or following surgery), and recommend a shower with chlorhexidine soap prior to surgery.  The results of this important public health study suggest that the incidence of SSIs can probably be further lowered by more rigorous and more universal preoperative screening programs for nasal Staphylococcus aureus (including both MRSA and non-MRSA Staphylococcus aureus) directed at all patients who are undergoing elective surgery.

The second, and related, study evaluated the impact of two different preoperative skin prep solutions on the incidence of SSIs.

For decades, now, iodine-based skin cleansing solutions have been applied to skin surfaces just prior to the start of surgery, in an effort to kill skin-surface bacteria that can lead to SSIs.  While these traditional iodine-based antibacterial skin prep solutions are active against many bacteria and fungi that are known to cause SSIs, their antibacterial and antifungal activity rapidly dissipates after being applied.  Newer surgical skin prep agents that contain alcohol and chlorhexidine have been shown by recent research studies to not only have a wider spectrum of activity against skin bacteria and fungi than traditional iodine-based prep solutions, but these newer surgical prep solutions also sustain their antibacterial and antifungal activity over a much longer duration than their iodine-based counterparts.  In this new prospective, randomized clinical research study, 849 patients undergoing elective surgery were randomized to one of two groups.  One group of patient volunteers underwent preoperative skin preparation with a commercially available chlorhexidine-alcohol solution, while the second group was randomized to undergo skin preparation with the traditional povidone-iodine solution.

Following surgery, 16 percent of the patients who had their skin prepped with povidone-iodine solution developed SSIs within 30 days of surgery, while just under 10 percent of the patients who received the chlorhexidine-alcohol skin prep solution subsequently developed SSIs.  (This 41 percent reduction in the relative risk of SSIs was found to be highly statistically significant.)    Although use of the chlorhexidine-alcohol skin prep, alone, did not appear to protect against deep organ-space infections (when compared with the use of povidone-iodine skin prep solutions) in this study, both superficial and deep SSIs of the surgical incision were significantly reduced following use of the chlorhexidine-alcohol skin prep solution.  In this study, the use of a chlorhexidine-alcohol prep solution cut the risk of superficial incisional infection by one-half, while deep incisional infections were reduced threefold.  Thus, the use of chlorhexidine-alcohol skin prep solutions, just prior to making the incision, was associated with a highly significant reduction in the incidence of both superficial and deep infections of surgical incisions when compared to traditional iodine-based prep solutions.

Taken together, these two very important prospective randomized clinical research trials offer clinically valuable lessons for patients, physicians, and hospitals in our crucial quest to drive down the incidence of SSIs to the lowest achievable level.  In view of the recent and ongoing emergence of highly virulent strains of bacteria and fungi that have become resistant to many of our most powerful antibiotic and antifungal drugs, respectively, it is imperative that we find new ways to reduce the risk of SSIs, and particularly new methods that do not involve the continued inappropriate or excessive utilization of broad spectrum antibiotic drugs.

If you are scheduled to undergo elective surgery in the near future, I would advocate that you share the findings of these two clinically important research studies with your surgeon (if they are not already aware of them).

For a somewhat lighter perspective on Dr. Wascher, please click on the following YouTube link: 

http://www.youtube.com/watch?v=7-Tdv7XW0qg

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SOY ISOFLAVONES REDUCE BREAST CANCER

RECURRENCE RISK

Regular readers of this column are already aware of the controversy surrounding soy isoflavone intake and breast cancer risk.  As happens frequently in clinical research (unfortunately), contradictory research findings have made it difficult to understand the true relationship between dietary soy intake and breast cancer risk (if one exists).  There is, for example, both laboratory and clinical data suggesting that a diet rich in soybean-derived products may be associated with a lower risk of developing breast cancer.  At the same time, because genistein and other dietary isoflavones are known to weakly mimic the effects of estrogen, there has been some concern that a diet rich in isoflavone “phytoestrogens” may increase both the risk of developing a new breast cancer and the risk of developing a recurrence of a previous breast cancer.  (In fact, there is data from laboratory research studies showing that genistein can indeed fuel the growth of human breast cancer cells growing in culture dishes, when exposed to high concentrations of this soy-derived isoflavone.)

A growing body of public health research, primarily from Asian countries where tofu and other soy-based foods are frequently consumed, appears to link increased soy consumption with a decreased lifetime breast cancer risk, particularly when soy-based foods are consumed during adolescence, during the time when development of the female breast is most active (Soy & Breast Cancer Risk).  (Interestingly, there is also recent research suggesting that soy products might also reduce the risk of prostate cancer, which is another hormonally driven cancer:   Genistein & Prostate Cancer Cells, Dietary Soy & Prostate Cancer Risk.)

Although epidemiological research is, increasingly, suggesting that a diet rich in soybean-derived foods might lower a woman’s lifetime risk of developing breast cancer, many breast cancer experts have remained apprehensive regarding dietary isoflavone intake in women with a prior history of breast cancer, in view of the estrogen-like effects of these “phytoestrogens.”  As I have already noted, there is considerable research data available to suggest that soy-derived isoflavones can, at least under certain laboratory conditions, stimulate estrogen-sensitive breast cancer cells to grow and divide.  These research findings have left many oncologists feeling uncomfortable in recommending soy-based foods to their breast cancer patients.  Now, a newly publish public health study in the Journal of the American Medical Association suggests that soy-based foods may actually reduce the risk of breast cancer recurrence, and death due to any cause, in women who have previously been diagnosed with this very common form of cancer.

In this study, which was performed in Shanghai, China, 5,042 female breast cancer survivors (ages 20 to 75 years) were followed for an average of almost 4 years.  All of these patient volunteers underwent detailed surveys regarding their lifestyle habits, including their diets.  These patients, who were originally diagnosed with breast cancer between 2002 and 2006, were surveyed at 6, 18, 36 and 60 months following their original diagnosis with breast cancer.  

The results of this study indicate that the breast cancer survivors who consumed the greatest amount of soy-based foods in their daily diets were 32 percent less likely to experience a recurrence of their breast cancer when compared to the women who consumed the least amount of soy-based isoflavones.  Moreover, the women who consumed the greatest amount of soy were also 29 percent less likely to die, from any cause, when compared to the women who consumed the least amount of soy-derived foods.

A particularly interesting and unexpected finding of this study was that both women with estrogen sensitive breast cancers and women with tumors that were not sensitive to estrogen appeared to experience a significantly decreased risk of breast cancer recurrence if they frequently consumed soy products.  Another important finding of this study was that women who were taking the estrogen-blocking cancer treatment drug tamoxifen also appeared to enjoy a reduced risk of breast cancer recurrence with higher levels of dietary soy intake.  Additionally, the researchers noted that high levels of soy intake appeared to be about as effective in reducing the risk of breast cancer recurrence as the breast cancer prevention drug tamoxifen, alone.

The results of this very important study mirror the findings of the only other prospective clinical study that has looked at the impact of soy-based foods on breast cancer recurrence (the “Life After Cancer Epidemiology,” or “LACE,” study).  The LACE study, which was performed in the United States, followed nearly 2,000 breast cancer survivors for, on average, more than 6 years.  In the LACE study, women who were taking tamoxifen, and who also consumed the highest amount of soy-based dietary isoflavones, were 50 percent less likely to develop a recurrence of their breast cancer when compared to women who reported the lowest consumption of soy-derived foods.

As I have pointed out previously, epidemiological research studies based upon dietary surveys are susceptible to several types of bias which, in turn, can cause researchers to draw the wrong conclusions.  In this case, however, there are now two large prospective cohort studies that have reached essentially the same conclusions (albeit with a rather limited duration of patient follow-up).  Both studies strongly suggest that high levels of soy-based isoflavones in the diet may be able to significantly reduce the risk of breast cancer recurrence.  Based upon the findings of this large Chinese study, the apparent cancer risk reduction effect associated with high levels of soy intake also appears to benefit premenopausal and postmenopausal women, as well as women who are taking the estrogen-blocking drug tamoxifen, women with estrogen-sensitive tumors, and women with (counter-intuitively) estrogen-resistant tumors.

In view of the limited duration of patient follow-up in both of these clinical breast cancer studies, as well as the limitations of survey-based epidemiological research in general, I would like to see updated data from both of these studies after at least 10 years of patient observation before I would be willing to tell my breast cancer patients that they should significantly increase their dietary soy intake.  On the other hand, the rather compelling data presented by both of these clinical research studies will also make me less anxious when any of my breast cancer patients decide, of their own accord, to increase their intake of soy-derived isoflavones.

Note:  Weekly Health Update is currently undergoing an extensive upgrade to better serve its tens of thousands of health-conscious readers around the world.  Beginning in January 2010, newly archived columns will be available by selecting the “Archives” tab on the right side of your screen (all archived columns prior to January 2010 will continue to be available by selecting the “Archives 2007-2009” tab at the top of the screen.)

Disclaimer: As always, my advice to readers is to seek the advice of your physician before making any significant changes in medications, diet, or level of physical activity

Welcome to Weekly Health Update

“A critical weekly review of important new research findings for health-conscious readers”

EXERCISE & PROSTATE CANCER RISK

There is an increasing body of research evidence to suggest that many cases of cancer can be prevented through lifestyle and diet modifications.  Indeed, even conservative estimates suggest that more than 60 percent of new cancer cases could be prevented simply by abstaining from unhealthy lifestyle and dietary habits.  (More enthusiastic cancer prevention experts have suggested that 80 percent of cancer cases, or more, might be preventable with rigorous lifestyle and diet changes.)   Given that, in the best case, modern cancer treatment results in the long-term survival of only about 60 percent of all cancer patients, and that the survival rate for many of the most lethal cancers still remains far more dismal, an ounce of cancer prevention is certainly worth much more than a pound of cancer cure.  (This simple yet profound realization is the central theme of my new book, “A Cancer Prevention Guide for the Human Race,” which will be published in the spring of 2010.) 
 
As a practicing comprehensive Surgical Oncologist, I routinely treat patients with highly lethal cancers, many of which are, sadly, incurable by the time they are diagnosed.  While not every case of cancer can be prevented through lifestyle and diet modification, many of the terrible, and ultimately fatal, cancer cases that I routinely see might have been prevented with reasonably moderate alterations in the way that people choose to live their daily lives.
 
Prostate cancer is the most common non-skin cancer that occurs in men, and the second most common cause of cancer death in men.  In 2009, an estimated 192,000 new cases of prostate cancer will be diagnosed, and approximately 27,000 men will die of this disease.  Prostate cancer currently afflicts 1 out of every 6 American men during their lifetimes, and accounts for 25 percent of all cancer diagnoses in men (similar, I might add, to the percentage of breast cancer cases among all cancer cases diagnosed in women).  Most prostate cancers are stimulated to grow and spread by testosterone and other androgens produced by the testes, and by other tissues in the body. 
 
The relationship between prostate cancer risk and exercise has not been entirely clear, thus far, as various clinical studies have produced contradictory findings.  Some of these studies have suggested that high levels of daily physical activity may reduce the risk of prostate cancer, while other studies have not confirmed a link between prostate cancer risk and physical activity levels.
 
A new prospective public health study, just published in the British Journal of Cancer, adds further important evidence that increased levels of physical activity may indeed reduce the risk of developing prostate cancer.  In this newly published study, nearly 46,000 men between the ages of 45 and 70 years were prospectively followed between 1998 and 2007.  All of these male volunteers completed extensive questionnaires regarding their daily levels of physical activities at 30 years of age and at 50 years of age, as well as at the time or their entry into this clinical study.  These questionnaires specifically included questions regarding walking or bicycling; current waist, hip and height measurements; education level; cigarette smoking; alcohol consumption; diabetes; family history of prostate cancer; and other lifestyle factors.  Six predefined activity levels for occupational activity (from “mostly sitting down” to “heavy manual labor”), and additional predefined categories for time spent on different activities, were specifically included in the questionnaire, such as walking or bicycling (“hardly ever” to “more than 90 min per day”), home or household work (“less than 1 hour per day” to “more than 8 hours per day”), inactive leisure time (“from 2 hours per day or less” to “5 hours per day or more”), and active leisure-time exercising (“from less than 1 hour per week” to “more than 5 hours per week”).  The patient volunteers were also queried regarding the average number of hours per day they spent sleeping. 
 
Importantly, the researchers conducting this study took the extra step of conducting 7-day physical activity evaluations to verify that the study’s participants actually engaged in the levels of physically activity that they claimed on the questionnaires.  (This additional validation step confirmed the accuracy of the questionnaire information supplied by the study’s volunteers.)  The incidence of prostate cancer, and the death rate associated with prostate cancer, among these 45,887 middle-aged and elderly men were then analyzed at the conclusion of this very large prospective epidemiological study. 
 
When the men who engaged in physical activity at the highest levels were compared with those at the lowest levels, some very important differences in prostate cancer risk emerged.  Overall, very high levels of physical activity were associated with a 16 percent reduction in the risk of developing prostate cancer.  Additionally, among the men who spent at least half of their work days being physically active, the risk of prostate cancer was 20 percent lower when compared to men who spent most of their work day sitting down.  Specifically, and very importantly, there appeared to be a linear and progressive decrease in prostate cancer risk with each additional 30 minutes of walking or bicycling per day over the course of the adult lifetimes of these men (this linear relationship was noted within a range of 30 to 120 minutes of walking or bicycling per day).  Additionally, the risk of developing advanced prostate cancer appeared to be further lessened by regular daily physical activity. 
 
The results of this study mirror those of other high-quality cancer prevention studies for other types of cancer (including, most notably, breast cancer).  While clinical research studies such as this one are prone to various forms of bias, and in particular, biases that arise from patients “self-reporting” their personal health and lifestyle information on study questionnaires, the authors of this study appear to have taken very significant and effective steps to reduce the risk of including such biases in the data that they collected from these nearly 46,000 men.  Therefore, although a small degree of residual error cannot be completely excluded from the results of this impressive epidemiological study, its findings that progressively higher levels of daily physical activity (and, it must be stressed, throughout one’s lifetime) are associated with a decreasing level of prostate cancer risk are very likely to be valid even in the presence of small errors in the study’s data (if they exist).
 
Cardiovascular disease remains the most common cause of premature death in most societies.  Cancer is the number two cause of premature death when including people of all ages, and the number one cause of premature death below the age of 80 in the United States.  Regular exercise, including relatively moderate activities such as brisk walking or bicycling, have been shown to significantly reduce the risk of death due to cardiovascular disease, as well as, increasingly, the risk of developing or dying from multiple different types of cancer.  Based upon the results of this well designed and well executed prospective clinical research study, it would appear that prostate cancer can be added to the list of life-threatening illnesses for which the risk can be decreased through regular and frequent physical activity (and both at work and at home).

Disclaimer: As always, my advice to readers is to seek the advice of your physician before making any significant changes in medications, diet, or level of physical activity