Incidents of breast cancer have been on the decline in the US since 2000. But that followed a steady increase over the two decades prior, and the prognosticators are still estimating another 255,180 new cases of invasive breast cancer will be diagnosed in women in the US in 2017. That’s in addition to another 63,410 new cases of non-invasive breast cancer this year. So we’re not out of the woods yet. In fact, only the lung cancer death rate is higher for American women.

What can women already suffering from breast cancer do to reduce the risk of cancer recurrence and death? At the risk of sounding like a broken record, exercise and diet are still your best bets. The latest research comes out of the Sunnybrook Health Sciences Center in Toronto. Scientists there looked at all the lifestyle choices that a woman could make, and diet and exercise beat out even smoking and alcohol use as influencers.

"Of all lifestyle factors, physical activity has the most robust effect on breast cancer outcomes," writes Dr. Ellen Warner, a co-author study. "Weight gain of more than 10 percent body weight after a breast cancer diagnosis increases breast cancer mortality and all-cause mortality. However, there are good reasons to discourage even moderate weight gain because of its negative effects on mood and body image.”

The study recommends that breast cancer patients take in at least 30 minutes of moderate exercise daily, five days a week, or 75 minutes of vigorous exercise weekly. Two to three sessions of strength training are also suggested.

No specific type of diet has any advantage over another when it some to minimizing the recurrence of breast cancer, all that matters is that women keep their weight down. The researchers debunked the notion that consuming soy products raised the risk of breast cancer, to the extent of even recommending soy as a low-calorie source of protein. Vitamin D supplementation was recommended for women already being treated for breast cancer, as chemotherapy and hormonal treatments can reduce bone density, which vitamin D supplementation augments.

What about smoking and alcohol? It was unclear to the scientists whether stopping smoking after a breast cancer diagnosis affects recurrence. But the well-documented risks of death from smoking-related health issues make ceasing smoking during breast cancer treatment a no-brainer. The researchers also noted that limiting consumption to one or fewer alcoholic drinks per day may help reduce the risk of recurring breast cancer.

It is worth pointing out that no amount of lifestyle adjustment is one hundred percent effective; some breast cancers are particularly aggressive and may recur despite anyone’s best efforts.

The research was published in CMAJ.