Welcome to Weekly Health Update

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

OBESITY, DIABETES AND BREAST CANCER RECURRENCE RISK

Obesity and diabetes have both been linked to an increased risk of certain types of cancer (including breast cancer), as discussed in detail in my new book, A Cancer Prevention Guide for the Human Race.  (The single greatest risk factor for adult-onset diabetes is obesity.)

Not only have obesity and diabetes been strongly linked to an increased risk of developing cancer, but these two chronic illnesses, which have become epidemic in our modern culture, also appear to increase the risk of breast cancer recurrence, and death due to recurrent breast cancer.  Two newly published clinical research studies, which appear in the current issue of the Journal of Clinical Oncology, reveal just how strongly obesity and diabetes impact the incidence of breast cancer recurrence, and death due to breast cancer, among women who have previously been diagnosed with this common form of cancer.

In the first study, the impact of obesity on breast cancer recurrence, and the risk of death due to breast cancer, was assessed among 18,967 women with a previous diagnosis of breast cancer in Denmark.   Using body mass index (BMI) scores, which indicate whether a person is obese or not, the findings of this study were quite concerning.  (A BMI between 18.5 and 24.9 indicates a healthy weight, while a BMI of 25 to 29.9 indicates that a person is overweight, and a BMI of 30 or more indicates obesity.)

In this very large public health study with long-term follow-up, female breast cancer survivors with a BMI of 30 or more (when compared to women with a BMI below 25) were, stage-for-stage, 46 percent more likely to be diagnosed with metastatic breast cancer within 10 years of their original diagnosis, and 38 percent more likely to die of metastatic breast cancer within 30 years of their original breast cancer diagnosis.

In the second study, 604 women with a prior diagnosis of breast cancer were evaluated with a blood test that measures insulin secretion levels (serum C-peptide).  Fasting C-peptide levels were measured in these breast cancer survivors 3 years after their initial cancer diagnosis, and this group of research volunteers was then followed for about a decade.  In this study, a 1nanogram per milliliter (ng/mL) increase in serum C-peptide levels, even among women without diabetes, was associated with a 31 percent increase in the risk of death from any cause over the duration of this study.  This same miniscule 1 ng/mL increase in C-peptide blood levels was also associated with a 35 percent increase in the risk of death specifically due to breast cancer.  (The increased risk of death associated with rising C-peptide levels among women with diabetes was even higher.)  Thus, this study is one of the first ever to show that rising levels of insulin secretion in women either with or without diabetes is associated with a significantly higher risk of death due to recurrent breast cancer.

Taken together, the findings of these two very important clinical studies add to the findings of previous studies that have linked both obesity and diabetes with an increased likelihood of breast cancer recurrence and death due to recurrent breast cancer.  These, and other, clinical studies also continue to show that the chemotherapy and hormonal therapy that is routinely given following the diagnosis of breast cancer appears to be less effective in obese women and in diabetic women, when compared to women without either of these chronic illnesses.  The findings of these studies also mirror cancer risk and cancer prevention studies that have linked breast cancer risk with both obesity and diabetes.

If you have a history of breast cancer, and you are significantly overweight, then it is essential that you discuss a prudent weight loss program with your doctor, including a healthy diet and a regimen of regular aerobic exercise (as discussed in my new book).  Likewise, if you have diabetes, both weight loss interventions and tight control of your diabetes are essential for reducing your risk of breast cancer recurrence, and your overall risk of premature death from cancer and other serious illnesses associated with diabetes.

For a complete discussion of the role of obesity, diabetes, diet, and exercise in cancer prevention, and other important evidence-based approaches to cancer prevention, order your copy of my new book, A Cancer Prevention Guide for the Human Race, now!  For the price of a cheeseburger, fries, and a shake, you can purchase this landmark new book, in both paperback and e-book formats, and begin living an evidence-based cancer prevention lifestyle today!

GIVE  THE  GIFT  OF  HEALTH  THIS  HOLIDAY  SEASON!  For a groundbreaking overview of cancer risks, and evidence-based strategies to reduce your risk of developing cancer, order your copy of my new book, “A Cancer Prevention Guide for the Human Race,” from Amazon, Barnes & Noble, Books-A-Million, Vroman’s Bookstore, and other fine bookstores! 

On Thanksgiving Day, 2010, A Cancer Prevention Guide for the Human Race was ranked #6 among all cancer-related books on the Amazon.com “Top 100 Bestseller’s List” for Kindle e-books!  On Christmas Day, 2010, A Cancer Prevention Guide for the Human Race was the #1 book on the Amazon.com “Top 100 New Book Releases in Cancer” list!

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: 

Texas Blues Jam

I and the staff of Weekly Health Update would again like to take this opportunity to thank the more than 100,000 health-conscious people, from around the world, who visit this premier global health information website every month.  (As of 9/16/2010, more than 1,000,000 health-conscious people had logged onto Weekly Health Update in 2010!)  As always, I 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.

Click the following link to join Dr. Wascher on Facebook

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

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

http://www.redcross.org/

http://www.imcworldwide.org/haiti