Impact of nutrition on breast cancer mortality and risk of recurrence, a review of the evidence

Introduction > There is a growing interest in diets and their effects on cancer prognosis. In 2014, a report from the World Cancer Research Fund on diet and women with a history of breast cancer did not demonstrate a major effect on breast cancer prognosis. The aim of this literature review was to provide an update of knowledge in this area. Methods > Randomized trials, prospective cohorts and meta-analyses published between 2012 and 2018 examining the impact of diet on recurrence risk and/or mortality after breast cancer were included, to achieve the objective. We evaluated study quality (according to Haute Autorite de Sante criteria) and the studied diets were categorized: macronutrients, micronutrients and selective foods. Results > We selected eighteen articles that met levels of evidence 1 to 3. For macronutrients, a low-fat diet was associated with better survival. With regard to micronutrients, a diet rich in phytoestrogen reduced the risk of cancer recurrence. Finally, the adoption of a healthy diet was not associated with an improved prognosis for breast cancer but with an improvement in overall survival and risk of death from cardiovascular disease. Discussion > This review suggests that nutrition influences the prognosis of breast cancer. Nevertheless, the level of evidence of the results was insufficient to make recommendations. Ultimately, a healthy and balanced diet could be encouraged in order to reduce global mortality.