Systematic review and meta-analysis of breast cancer risks in relation to 2,3,7,8-tetrachlorodibenzo-p-dioxin and per- and polyfluoroalkyl substances.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) and per- and polyfluoroalkyl substances (PFAS) are endocrine disrupting chemicals that may cause breast cancer. However, there lacks consistent research on the association between TCDD, PFAS exposure, and breast cancer. To this end, a meta-analysis was carried out in this review to explore the relationship between these two endocrine disruptors and breast cancer. Relevant literature was searched from 5 databases: Medline, Scopus, Embase, PubMed, and Web of Science. Odds ratios (OR) with 95% confidence intervals (CIs) were pooled by fixed-effects and random-effects meta-analysis models. A total of 17 publications were finally included for quantitative evaluation. Meta-analysis showed that TCDD (OR = 1.00, 95% CI = 0.89-1.12, I = 39.3%, P = 0.144), PFOA (OR = 1.07, 95% CI = 0.84-1.38, I = 85.9%, P < 0.001), PFOS (OR = 1.01, 95% CI = 0.95-1.08, I = 65.7%, P < 0.001), PFNA (OR = 0.89, 95% CI = 0.67-1.19, I = 74.4%, P < 0.001), and PFHxS (OR = 0.90, 95% CI = 0.72-1.13, I = 74%, P < 0.001) were not significantly correlated with breast cancer. Internal exposure, however, showed a significant positive correlation between TCDD and BC (OR = 2.85, 95% CI = 1.23-6.59, I = 0.0%, P = 0.882). No statistically significant association between TCDD, PFAS exposure, and breast cancer was observed in this meta-analysis.