Lifestyle and breast cancer: what advice for the management of post-cancer?

Abstract

It is widely admitted that after adjuvant therapy, about one half of women with localized breast cancer experience a weight gain of 3 kg. It can however reach 8 to 10 kg in numerous cases. Risk factors associated with weight gain are unclear, but women undergoing chemotherapy seem to have an increased risk, especially before the menopause. Retrospective studies suggest that post-treatment weight gain might increase the risk of relapse. Furthermore, the only intervention trial in adjuvant breast cancer, though impaired by methodological pitfalls, suggests that limiting weight gain could increase disease free survival. The use of nutritional complements by cancer patients is usually underestimated. Several compounds, such as vitamins C and, E, selenium or carotenoids, have been investigated in clinical trials whose quality is usually poor. Available date nevertheless suggest a deleterious effect of supplementation with anti-oxydants, in particular at supraphysiological doses. The WHEL trial is the only large randomised trial investigating an healthy diet with vegetables, fruits and fiber after localized breast cancer. An effect of survival is observed in the experimental arm only in patients with sufficient level of physical activity. Physical activity, when practiced regularly, improves asthenia, quality of life and even survival, without any detrimental effect. It should however be initiated after an evaluation of patient’s ability and comorbidities, and be realized in specific centers with careful medical follow-up. Its mechanisms of action include regulation of estrogen, insulin, IGF1 and adipokines. Adapted physical activity should be proposed to patients fulfilling precise inclusion criteria.