Organochlorines and breast cancer risk: revisiting evidence through a meta-analytic approach

The risk of breast cancer in human subjects is associated with the exposure to organochlorines, although the findings have somewhat been inconclusive. A meta-analysis of published peer-reviewed articles was conducted to draw a definitive conclusion about exposure to organochlorine compounds and the incidence of breast cancer, taking into account hospital and population-based case-control studies. Scopus, MEDLINE and Web of Science databases were examined to gather retrospective case-control studies, wherein 16 case-control studies meeting the criteria were included, involving 2960 cases and 2777 controls. Heterogeneity tests, publication bias, sensitivity analysis and trial sequence analysis test were also performed. Chlorinated compounds such as p,p' DDE (<i>p</i> = 0.000, SDM = 4.027: lipid-unadjusted; <i>p</i> = 0.001, SDM = 1.145: lipid adjusted), HCB (<i>p</i> = 0.002, SDM = 2.718), <i>cis</i>-Nonachlor (<i>p</i> = 0.006, SDM = 3.558) and p,p' DDT (<i>p</i> = 0.015, SDM = 1.536: lipid-unadjusted), imposed a significant and positive association with breast cancer. Although compounds like Heptachlor, Dieldrin, γ-HCH, Oxychlordane, and <i>trans</i>-Nonachlor did not reach significant levels, they indicated a possible role in the risk of breast carcinoma. This meta-analysis supports the hypothesis that several organochlorine compounds contribute to an increased incidence of breast cancer.