Chemotherapy for Breast Cancer & Memory Loss
May 2, 2010 by admin
Filed under Breast Cancer, Cancer, Weekly Health Update, dementia, memory
Welcome to Weekly Health Update“A critical weekly review of important new research findings for health-conscious readers”
CHEMOTHERAPY FOR BREAST CANCER & MEMORY LOSS “Chemo Brain” is a term often used by breast cancer patients to describe the decreased memory, and other cognitive dysfunctions, associated with chemotherapy for this common form of cancer. However, there has been very little prospective, objective clinical research into this phenomenon. Furthermore, what little research that has been done in this area, to date, has primarily focused upon subjective self-assessments, by breast cancer patients, of their own level of cognitive function following chemotherapy. Moreover, until recently, the complaints of breast cancer patients regarding their self-perceived memory loss following chemotherapy were often dismissed by many physicians. Now, a newly published prospective clinical research study from the M.D. Anderson Cancer Center suggests that physicians may have vastly underestimated the frequency, severity, and duration of cognitive dysfunction following standard breast cancer chemotherapy. This clinical study, which appears in the current issue of the journal Cancer, prospectively enrolled 42 women with newly diagnosed breast cancer. All of these women then underwent standardized neuropsychological evaluation before, during, and after chemotherapy. Importantly, this study not only tested these breast cancer patients in the early period after they completed their chemotherapy, but also one year after their chemotherapy had ended. The findings from this small study strikingly illustrate just how common, and how enduring, memory loss and other forms of cognitive dysfunction are following chemotherapy for breast cancer. Prior to beginning chemotherapy, 21 percent of these patients had some detectable degree of cognitive dysfunction. By the end of their chemotherapy treatments, a whopping 65 percent of these 42 patients displayed measurable declines in memory function, organizational ability, and cognitive processing speed. One year later, 61 percent of these women continued to display measurable declines in cognitive function. Worse yet, among this group of women with persistent cognitive dysfunction one year after completion of their chemotherapy, 71 percent continued to display progressively worsening of cognitive function when compared to their level of function immediately after finishing chemotherapy. Finally, the remaining 29 percent of this group of women with long-term evidence of cognitive dysfunction actually displayed a delayed-onset of cognitive decline when they were tested one year after chemotherapy (i.e., when compared to the results of their neuropsychological testing immediately after chemotherapy). Although this clinical research study enrolled a small cohort of patients, its prospective nature, and its use of validated neuropsychological tests, make it a powerful research study for its size. The findings of this study also fit well with previous laboratory research studies that have shown both acute and delayed changes in the actual structure of the brains of animals treated, proportionately, with the same chemotherapy drugs commonly used to treat breast cancer in humans. Whether or not the significant declines in cognitive function that were observed, one year after chemotherapy in the 61 percent of women who participated in this study, will eventually stabilize, improve or worsen is unknown at this time. Longer follow-up of these 42 breast cancer patients will have to be performed to answer this important question. However, this small prospective study clearly indicates that the majority of women who undergo standard chemotherapy for breast cancer appear to experience significant and prolonged declines in their level of cognitive function, including memory loss, decreased organizational skills, and a general slowing of their cognitive processing speed, and that these adverse changes persist for at least a year after completion of chemotherapy. The findings of this study should spur additional research into the precise cause(s) of this chemotherapy-associated impairment in cognitive function, as well as strategies to reduce the severity and duration of these adverse health effects following chemotherapy for breast cancer. Meanwhile, it is important for me to stress that chemotherapy unquestionably extends survival, and saves lives, among women who are appropriately advised to undergo such treatment for breast cancer. In my opinion, no patient should read this column, and then go on to refuse chemotherapy that has been appropriately recommended because of the findings of this clinical research study.
To learn more about the prevention, screening, diagnosis and treatment of breast cancer, 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.
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 For a different perspective on Dr. Wascher, please click on the following YouTube link: 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 nearly 120,000 new and returning readers who visited our premier global health information website last 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. 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.imcworldwide.org/haiti |
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Pancreatic Cancer Risk, Sodas & Juice
Welcome to Weekly Health Update“A critical weekly review of important new research findings for health-conscious readers”
PANCREATIC CANCER RISK, SODAS & JUICE Pancreatic cancer is one of the deadliest of all types of cancer. Nearly 45,000 new cases of pancreatic cancer were diagnosed in 2009 in the United States, and more than 35,000 deaths due to this disease occurred during the same year. At the time of diagnosis, the vast majority of patients with this terrible disease are already incurable, and overall, 5-year survival rates remain a dismal 5 percent at this time. Even among the small minority of patients who are diagnosed with pancreas cancer at a relatively early stage, when the tumor is still confined to the pancreas, the 5-year survival rate is only in the 15 to 20 percent range. The only possible hope for pancreatic cancer cure is very radical surgery, which is often followed by chemotherapy and radiation therapy. For most patients with pancreatic cancer, however, surgery is not even an option due to the advanced stage of their cancer at the time of diagnosis. Therefore, efforts to prevent pancreas cancer are critically important in decreasing the death rate from this aggressive and treatment-resistant type of cancer. There are several known risk factors for pancreatic cancer. These include smoking, obesity, diabetes, chronic pancreatitis (inflammation of the pancreas), and chronic liver disease. Because of the known links between pancreatic cancer, diabetes and obesity, there is concern that regularly consuming foods that significantly elevate the level of glucose (sugar) in the blood may also increase the risk of developing pancreatic cancer. A new large-scale prospective public health study, just published in the journal Cancer Epidemiology, Biomarkers & Prevention, adds further evidence that the regular consumption of sugar-rich foods may indeed increase the risk of developing this deadly type of cancer. In this study, nearly 61,000 patient volunteers within the Singapore Chinese Health Study were followed for up to 14 years by researchers. All of these volunteers were extensively surveyed regarding their consumption of juices, sugary sodas (“soft drinks”), and other dietary items. Additionally, other lifestyle factors and environmental exposures linked to various types of cancer were assessed within this very large group of patients. Within 14 years of the beginning of this very large epidemiological study, 140 new cases of pancreatic cancer were diagnosed within this cohort of patient volunteers. When the researchers analyzed all of their data, they discovered that the consumption of 2 or more sodas per week was associated with nearly twice the risk of developing pancreatic cancer when compared to not drinking any sodas at all (fortunately, there appeared to be no link between juice intake and pancreatic cancer risk). The findings of this study add further evidence to previous similar studies regarding the intake of so-called “high glycemic index” foods and pancreatic cancer risk. As these same sugar-rich foods also directly contribute to the development of both diabetes and obesity, it is not surprising that scientists have begun to identify common biochemical pathways that link excessive calorie intake from sugar-rich foods with all three of these life-threatening diseases. I will be discussing the known risk factors (and evidence-based prevention strategies) for pancreatic cancer, and for many other cancers, in much greater detail in my new book, “A Cancer Prevention Guide for the Human Race,” which is due to be published in the spring of this year. Meanwhile, if you currently drink sodas containing sucrose or fructose on a regular basis, you might want to seriously consider eliminating these soft drinks from your diet altogether.
In view of the extreme devastation and human misery brought about in Haiti by the recent earthquake, 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.imcworldwide.org/haiti 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 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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CT Scans & Cancer Risk
December 20, 2009 by admin
Filed under CT Scans, Cancer, Cancer Prevention
Welcome to Weekly Health Update“A critical weekly review of important new research findings for health-conscious readers”
HAPPY HOLIDAYS FROM WEEKLY HEALTH UPDATE!
CT SCANS & CANCER RISK
CT (computed tomography) scanners have revolutionized the practice of medicine since they were first introduced into routine clinical practice in 1974. CT scanners utilize a rotating x-ray device to create hundreds of individual images that can then be reconstructed into a complex three dimensional view of the body by computers. Current generation CT scanners are able to image the entire human body within seconds, and these high definition images provide physicians with an incredibly detailed view of the organs and tissues deep within us.
CT scanners have become an indispensible diagnostic tool within virtually every medical and surgical specialty, and an estimated 75 million CT scans are now performed annually in the United States, alone. As the popularity of these complex and powerful diagnostic imaging machines has continued to grow, so has their use for clinically dubious reasons. For example, routine scans of the heart, and its coronary arteries, have, increasingly, been used for “screening purposes” in patients without any clinical evidence of heart disease. Likewise, there has been an explosion in the number of private radiology imaging centers offering fee-based “body scans” for clinically healthy people who are interested in having their internal organs examined for any early signs of diseases that can be detected by CT scans. Another area of concern regarding the use of CT scanners is that physicians have become so dependent on these machines, and the exquisite images of the human body that they provide, that many (if not most) doctors have a very low threshold to order CT scans as a routine part of their diagnostic work-up of patients. (For example, in my own specialty of Surgery, the diagnosis of appendicitis is now routinely made with a CT scanner, rather than by the traditional method of the surgeon’s clinical evaluation of the patient.)
While CT scanners have become essential diagnostic tools, they also expose patients to much higher doses of radiation than most conventional x-ray examinations. It has long been known that exposure to radiation increases the risk of developing cancer, and that the risk of developing cancer is proportional to the dose of radiation received by patients. (Based upon recent estimates, it has been estimated that at least 2 percent of all cancer cases may be caused by prior exposure to medical x-rays.) Moreover, there is no known “safe” dose of radiation in terms of radiation-induced cancer risk. As if this was not already bad enough, there has been a growing concern regarding the actual dose of radiation that is being delivered to patients from CT scanners across the country, as there is a great deal of variability in the radiation dose settings being used among different CT scan imaging facilities. (This alarming point was recently brought to the public’s attention when it was revealed that Cedars Sinai Medical Center, a prestigious private hospital in the Beverly Hills area, was being investigated after multiple patients who had undergone CT scans of their brain there began to notice that their hair was falling out. Authorities subsequently determined that these patients had received grossly excessive radiation doses during their scans.)
Two very important public health studies have just been published in the Archives of Internal Medicine, and the findings of these two related studies have significantly raised the level of concern regarding the current use of CT scanners among public health experts.
The first of these two studies quantified the amount of radiation dose delivered to 1,119 patients for 11 common types of CT scan examinations that were performed at 4 different hospitals in the San Francisco area. In addition to calculating the radiation doses received by these patients, the authors also estimated the probable lifetime cancer risk associated with these CT scans. As the Cedars Sinai case has already shown, there appears to be considerable variability in the amount of radiation used at different institutions to conduct the same exact type of CT scan. However, the sheer magnitude of this variability in radiation doses, as measured by these researchers, is both mind-boggling and disturbing. Not only was there an enormous difference in radiation doses associated with performing the same exact type of CT scan between the 4 different institutions that were studied, but significant radiation exposure differences were also present within each individual institution when performing the same type of CT scan examination on different patients. When the researchers had finished their calculations, they noted an almost unbelievable 13-fold difference, on average, in radiation exposure for the same type of CT scan between the highest and lowest observed radiation doses for each individual type of CT examination.
Based largely upon cancer incidence data collected after the Hiroshima and Nagasaki atomic bombings, this clinical study’s researchers calculated that an estimated 1 in 270 women who underwent a CT scans of their coronary arteries at age 40 will eventually develop cancer as a direct result of these CT scans (versus 1 in 600 men), while 1 in 8,100 women who underwent CT scans of the brain at age 40 will develop cancer from these scans (versus 1 in 11,080 men). For men and women who underwent CT scans at age 20 (instead of age 40), the projected lifetime risk of CT scan-associated cancer was nearly double the projected risk of the 40 year-old patients.
The findings of this study indicate that the variability in radiation exposure between hospitals for the same type of CT scan examination is much greater than was previously believed. Perhaps even more surprising was the finding that identical CT scan examinations performed within a single hospital also subjected patients to significantly different amounts of radiation exposure. Finally, the calculated range of radiation exposure for CT scans revealed that, in general, patients are receiving far higher doses of radiation from routine CT scans than has generally been appreciated. (For example, a single CT coronary artery angiogram delivers the same amount of radiation as 310 chest x-rays!)
The second research study used public health data to estimate the average number of radiation-induced cancers caused by CT scans in the United States. Based upon current CT scan use, these researchers predicted that approximately 29,000 future cases of cancer could be expected to arise from CT scans performed in 2007 in the United States, resulting in approximately 15,000 deaths due to cancers caused directly by CT scans!
These two studies are eye-openers that should cause all of us, physicians and patients alike, to reconsider the benefits versus the risks of each and every CT scan that is considered before such scans are performed. Although most CT scans are performed because they offer vitally important clinical information on patients that could only otherwise be obtained by surgical exploration, too many CT scans are still being ordered and performed for far less compelling reasons (one of them being, unquestionably, the tendency of many physicians to order multiple unnecessary tests on patients as part of their practice of “defensive medicine,” in the absence of tort reform throughout most areas of the United States…). Moreover, the striking variation in CT-associated radiation doses, and the unexpectedly high level of these radiation doses in general, points to the need to improve standardization and compliance at every one of the thousands of institutions in the United States that operates a CT scanner. As a dedicated cancer specialist, I am already well aware of the potential for radiation-induced cancers, and I have, for many years, tried to be very selective in ordering CT scans on my patients. In cases where I can gather the necessary clinical information without resorting to radiographic imaging, then I try to avoid obtaining any form of x-ray examination (including CT scans). In other cases, where I must obtain some sort of imaging examination, then I will often initially use ultrasound or MRI studies in place of CT scans, when appropriate. Even so, the dramatic findings of these two studies suggest to me that all physicians need to further decrease their routine use of CT scans whenever possible.
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
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Soy Isoflavones Reduce Breast Cancer Recurrence Risk
December 13, 2009 by admin
Filed under Breast Cancer, Cancer, Cancer Prevention, Isoflavones, Nutrition, Soy, diet, health
Welcome to Weekly Health Update“A critical weekly review of important new research findings for health-conscious readers”
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 Dr. Wascher is an oncologic surgeon, a professor of surgery, a cancer researcher, an oncology consultant, and a widely published author
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Exercise & Prostate Cancer Risk
November 29, 2009 by admin
Filed under Cancer, diet, health, prostate cancer
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.)
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
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