Thirty percent of women who overcome breast cancer experience a recurrence
( Recently, scientists reviewed 67 studies to determine whether lifestyle choices—like physical activity, alcohol intake, diet and smoking—had links to recurrence. The goal was to help women make changes in lifestyle that might prevent the disease from returning.

The research review showed that women who were overweight or obese at the time of diagnosis had a higher likelihood of recurrence than those whose weight was normal. Women who gained weight during or after treatment had greater rates of recurrence and were more likely to die from the disease than women who did not gain weight. The researchers noted that most women do gain weight during treatment, and not many lose it after the process is complete. There was insufficient data on weight loss to say whether it was protective against breast cancer recurrence. The researchers did determine that regular physical
activity had the "most robust effect of all lifestyle factors on reducing breast cancer recurrence."

"A meta–analysis of 22 prospective cohort studies found that breast cancer mortality was significantly reduced among women who reported participating in recreational physical activity after their breast cancer diagnosis," the authors said. "The effect was stronger among women who met recommended levels of physical activity, postmenopausal women and women with a BMI greater than 25."

The authors suggested that the greatest protection against recurrence
coincides with meeting current physical activity recommendations.

"Patients should be encouraged to engage in at least 30 minutes of
moderate–intensity physical activity at least five days of the week, or 75 minutes of more vigorous exercise, along with two to three weekly strength training sessions, including exercises for major muscle groups," they advised.

The meta–analysis was published in the Canadian Medical Association Journal (2017; 189 [7], e268–74).