Could 50% of Breast Cancer Cases be Preventable?

Dr. Graham Colditz, associated director for prevention and control at Siteman Cancer Center and Washington University in St. Louis, a co-author of the report, stated that breast cancer prevention work needed to be started at a young age. He added that women had to have a better access to understanding the accumulation of breast cancer risk and how it increases through the addition of these lifestyle factors.

Further to their research on effective treatments and early detection methods, Colditz and his Washington University colleague Dr. Kari Bohlke stress that more importance should be attributed to the known facts about what raises breast cancer risk. In their report they note that of those women who could benefit from the breast-cancer-preventing medications tamoxifen and raloxifene, only a small number of them actually take these drugs.

Additionally they write that strategies for preventing breast cancer have received "far less attention" than efforts to improve treatment and early detection of the disease, yet women can dramatically reduce their breast cancer risk by avoiding alcohol or drinking very moderately; being physically active and maintaining a healthy weight; eating plenty of fruits, vegetables and whole grains; and, if they have children, breastfeeding them.

As the researchers point out, accumulation of the risk associated with lifestyle factors begins in early life, with evidence highlighting the time between a girl's first period and her first pregnancy as a specifically important in influencing breast cancer risk.

As an example, it has been found that in comparison to their peers who had at least one drink in the past 30 days, teenagers may reduce their future breast cancer risk by 20-30% if they do not drink alcohol. The same reduction can be achieved by young adult women who consume less than one alcoholic beverage a day, opposed to those who drink at least four per week.

It is known that a diet filled with vegetables, plenty of fruits, and whole grains contributes to the reduction of future risk of a number of cancer types, including breast cancer, and according to Dr. Colditz, it is never too late to start exercising, as physical activity has the most breast-cancer-preventing benefit when women sustain it throughout their lifetimes.

Obesity following menopause is a key risk factor for breast cancer, however the loss of weight in post-menopausal years will bring down the disease’s risk for women who adopt these strategies. Properly adhered to, they substantially reduce the onset of new cases and even deaths from breast cancer in postmenopausal women as well as premenopausal women, as Colditz explained.

The Siteman Cancer Center offers eight tips for breast cancer prevention on its Web site here: bit.ly/1pxNx0l

Many women at high breast cancer risk could benefit from chemoprevention, yet they avoid this route due to the complex risk-benefit profile associated with the drugs, Dr. Colditz noted, since tamoxifen increases the risk of endometrial cancer and dangerous blood clots. He added that these issues were partially why these drugs were used less in older women, despite the magnitude of benefit that taking these preventive drugs actually delivers as it will cut an individual woman's risk of cancer in half.

As disovered in one study, the benefits of breast cancer chemoprevention outweigh the risks for nearly 8 million 50-60 year old US women, yet less than 120,000 US women aged 35 to 79 are taking tamoxifen or raloxifene.

Concluding, Colditz said that there was a much larger proportion of women who could be talking to their doctors about chemopreventive strategies, however identifying them and educating them about the tools to make the decision appeared to be one of the major gaps in the process strategy’s implementation. 

Source: Reuters Health

27 March 2014