Healthy Eating Index/Alternative Healthy Eating Index and Breast Cancer Mortality and Survival: A Systematic Review and Meta-analysis

OBJECTIVE Breast cancer is the most common cancer in women worldwide. The effects of overall diet quality instead of single nutrients after breast cancer diagnosis on mortality have been a growing area of research interest. The aim of this systematic review was to investigate the relationship between the Healthy Eating Index (HEI)/the Alternative Healthy Eating Index (AHEI) and risk of breast cancer mortality or survival rates as a primary outcome, and some related inflammatory factors, as secondary outcomes among postdiagnosed women. METHODS This study methodology was performed based on the Preferred Reporting Item for Systematic Review and Meta-analysis statement recommendation and had been registered at PROSPERO (registration number: CRD42015015605). The systematic search was conducted in the electronic databases including PubMed, ISI, Scopus, Cochrane, and Google before July 2016. Researches that had not reported risk of breast cancer mortality or survival rates separately were excluded from the study. Similarly, this review excluded studies which only had examined the HEI or AHEI without reporting their association with the risk of mortality or survival rates. RESULTS After primary search, of 643 studies identified, 4 studies including eligible criteria were selected for the final assessment. All selected studies had been conducted in the USA and used self-report food-frequency questionnaire for diet quality assessment. In two studies HEI-2005, in one study AHEI, and in another study AHEI-2010 were applied. Meta-analysis result showed no significant association between these indexes and risk of breast cancer mortality/survival among women with this malignancy [relative risk: (RR) 1.04; 95% confidence interval (CI): 0.69-1.56; P = 0.87]. CONCLUSIONS Regarding the adherence HEI/AHEI, we found no association between mentioned indexes and risk of mortality or survival from breast cancer in women with breast cancer. However, evidence in this field is limited and inconsistence and further studies are needed.