Author: Joan Giblin, NP, Director of Survivorship, Winship Cancer Institute of Emory University.
Substantial research conducted over the last few decades demonstrates that being overweight at the time of a breast cancer diagnosis may result in less favorable outcomes. This information—coupled with the fact that many women are indeed overweight at the time of their breast cancer diagnosis and additional weight gain during treatment is frequently reported—means that for a woman diagnosed with breast cancer, achieving or maintaining a desirable weight may be one of the most important lifestyle pursuits they can make in the interest of their overall health and wellness.
Much of the research around breast cancer has supported the theory that excess weight at the time of diagnosis can lead to a worse prognosis. Recently, analyses conducted on a group of nonsmoking breast cancer survivors corroborated these findings. According to the study’s findings, women who increased their body mass index (BMI) by 0.5 to 2 units were found to have a 40% greater chance of breast cancer recurrence, and those who gained more than 2 BMI units had a 53% greater chance of recurrence. Data suggests that being overweight or obese adversely influences not only cancer-specific outcomes, but also overall health and quality of life. As a result, weight management is now considered a priority standard of care for overweight women diagnosed with early stage breast cancer.
Research around breast cancer also suggests that the weight gain experienced by women who have undergone chemotherapy or hormone treatments seems to be the result of increased tissue mass, with no change or a decrease in lean body mass. This unfavorable shift in body composition suggests that steps should be taken to not only curb weight gain during treatment, but also to preserve or rebuild muscle mass. Moderate physical activity (especially resistance training) during and after breast cancer treatment may help survivors maintain lean muscle mass while avoiding the accumulation of excess body fat.
Additional research is currently under way to evaluate the effects of dietary patterns on cancer-specific outcomes, as well as overall health. One observational study found that dietary pattern was important for overall survival among breast cancer patients, with those who ate a Western diet having poorer overall survival and those who ate a dietary pattern characterized by high amounts of fruits, vegetables, and whole grains having better survival rates overall. Furthermore, this theory is supported by data on breast cancer survivors participating in the Nurses’ Health Study. Participants were followed for nearly 10 years post-diagnosis, and study findings suggest that those who consume a healthy diet, with higher intakes of fruits, vegetables, and whole grains and lower intakes of added sugar, refined grains, and animal products, may not have had significantly lower rates of recurrence or cancer-specific mortality.
A topic of controversy as it relates to breast cancer risk and prognosis is alcohol consumption. Alcohol is an unusual factor, as it presents both risks and benefits to those with breast cancer. In the general population, clear and consistent evidence links moderate alcohol intake (1-2 drinks per day) with a lower risk of cardiovascular disease. For breast cancer survivors, however, the decision to drink alcoholic beverages at moderate levels is complex because they must consider their levels of risk for recurrent or second primary breast cancer as well as cardiovascular disease. See our post on the relationship between alcohol and breast cancer for more information.
It is important to remember that lifestyle, nutrition and physical activity recommendations to reduce the risks of a second primary breast cancer and heart disease are especially important for breast cancer survivors. Diet for those at high risk for breast cancer or with a breast cancer diagnosis should emphasize vegetables and fruits, have low amounts of saturated fats, and include sufficient dietary fiber. Most importantly, breast cancer patients and survivors should strive to achieve and maintain a healthy weight through eating a well-balanced diet and regular exercise. In addition, regular physical activity should be maintained regardless of any weight-related concerns.
|Table 1. American Cancer Society Guidelines on Nutrition and Physical Activity for Cancer Prevention and Cancer Survivorship.|
|Achieve and maintain a healthy weight.
• If overweight or obese, limit consumption of high-calorie foods and beverages and increase physical activity to promote weight loss. Engage in regular physical activity.
|Engage in regular physical activity.
• Avoid inactivity and return to normal daily activities as soon as possible following diagnosis.
• Aim to exercise at least 150 minutes per week.
• Include strength training exercises at least 2 days per week.
|Achieve a dietary pattern that is high in vegetables, fruits, and whole grains.
• Follow the American Cancer Society Guidelines on Nutrition and Physical Activity for Cancer Prevention.