The impact of pre-existed and SERM-induced non-alcoholic fatty liver disease on breast cancer survival: a meta-analysis

Background: Non-alcoholic fatty liver disease (NAFLD) is a common disorder and a frequent side effect of endocrine therapy (ET) for breast cancer treatment. This was the first meta-analysis to investigate the impact of NAFLD on breast cancer survival. Material and Methods: We searched Pubmed, Embase and Cochrane Central Register of Controlled Trials database for relevant studies that investigated the correlation between NAFLD and breast cancer survival. Fixed- and random-effect meta-analyses were conducted according to the heterogeneity of enrolled studies. Subgroup analyses were performed based on whether NAFLD was induced by ET administration Results: Eight cohorts from six studies including 3684 breast cancer patients were enrolled. NAFLD was significantly associated with advanced age (p < 0.001), obesity (p < 0.001), lymph node metastases (p = 0.003) and hormone receptor positivity (p < 0.001). NAFLD had no significant impact on disease free survival (DFS) [hazard ratio (HR) 1.07, 95% confidence interval (CI) = 0.64-1.77, p = 0.81] and overall survival (OS) (HR 1.29, 95% CI = 0.68-2.44, p = 0.44). In subgroup analyses, ET-associated NAFLD showed no significant impact on DFS and OS. Nonetheless, non-ET-associated NAFLD had a strong prognostic correlation with poor OS (HR 1.92, 95% CI = 1.09-3.41, p = 0.02). Conclusion: NAFLD had no significant impact on breast cancer survival. However, non-ET-associated NAFLD implied increasing death risk. Future large-scale studies are warranted to further elucidate the correlation between NAFLD and breast cancer prognosis.