Much research has shown that being overweight or obese increases the risk of breast and other cancers. A study found that being overweight or obese also can affect the type of breast cancer a woman may get, as well as length of survival after breast cancer diagnosis.
The researchers found that:
- Overweight and obese women were more likely than women of a healthy weight to develop a relatively rare but serious type of aggressive breast cancer called inflammatory breast cancer. Inflammatory breast cancer symptoms include redness, warmth, and tenderness of the breast. Inflammatory breast cancer usually is diagnosed at stage III or stage IV, and can be difficult to treat.
- Overweight and obese women were more likely than women of a healthy weight to have more aggressive forms of breast cancer. This means that the cancers are less likely to respond to treatment. It also means that the women had worse prognoses. Five years after breast cancer diagnosis, 58.6% of obese women and 58.3% of overweight women were alive. In comparison, about 70% percent of women at a healthy weight were still alive 5 years after diagnosis.
Fatty tissue can cause more inflammation in the body and this inflammation can make breast cancer more aggressive. Hormones such as estrogen are stored in fat cells and this may explain in part why breast cancer is more aggressive in overweight or obese women.
This study used body mass index (BMI) to classify the women's weight. BMI takes both height and weight into account. Losing weight is hard work, but keeping your BMI in the normal range is worth the effort. A healthy weight can improve your overall health, lower your risk of breast and other cancers, and make it more likely that you'll survive if you're diagnosed with breast cancer.
If your BMI is high, talk to your doctor about a safe and sensible plan to get your BMI in the normal range. The National Institutes of Health offers an online BMI calculator that allows you to calculate your BMI. For more information on creating a healthy diet plan that includes exercise, visit the breastcancer.org page on Balancing Your Diet in the Nutrition section.