Association between Non-alcoholic Fatty Liver Disease and Breast Cancer: A Systematic Review and Meta-analysis Study

Breast cancer (BC) is the most prevalent neoplasm in females globally, with an increasing incidence trend almost in all regions. Previous studies have indicated that non-alcoholic fatty liver disease (NAFLD) may be an emerging risk factor for extrahepatic cancers, including BC. This systematic review and meta-analysis study aimed to determine the association between NAFLD and the development of BC.

Data were systematically collected without time limitation until 21 April 2022, from the following electronic databases: PubMed, Scopus, Embase, Web of Science, and Google Scholar. The association between NAFLD and BC with odds ratio (OR) was calculated with a 95% confidence interval (CI) and presented via forest plots. Hazard ratios along with incidence rate ratios in the cohort studies transformed into OR.

According to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) and the inclusion criteria herein, 11 eligible studies were obtained from various countries. The pooled OR of NAFLD as a risk of developing BC, using a random-effects model, was estimated at 1.61 (95% CI: 1.30-2.00) (Q-value: 51.35, I2 = 80.52%, P < 0.0001). Multivariate meta-regression analysis showed that the publication year-, country-, detection method-, study design-, and body mass index-adjusted status did not cause heterogeneity. The Egger's regression (P = 0.32) and the symmetry in the funnel plot showed no publication bias in the studies.

The present research revealed that NAFLD had a significant association with BC, independent of traditional risk factors.