A meta-analysis of exposure to phenoxy acid herbicides and chlorophenols in relation to risk of soft tissue sarcoma

This analysis combines the results of the epidemiologic studies which appeared in the literature from 1979-1987 concerning the associations between phenoxy acid herbicides (PH) and chlorophenols (CP) and the occurrence of soft tissue sarcoma. Cohort studies and case-control studies are considered separately. After specifying criteria for inclusion, the total number of deaths due to cancer occurring in selected cohorts of people exposed to PH or CP was determined. The proportion of soft tissue sarcoma cases observed versus expected in the cohort studies, calculated using United States SEER registry data, resulted in a proportional mortality ratio of 3.5 (95% confidence interval of 0.7-10.3). Excluding the initial reports, the selected case-control studies had homogeneous risk estimates with a summary odds ratio of 1.1 (95% confidence interval of 0.9-1.4). Other attempts to assess the combined data did not yield results indicating an association. These meta-analyses do not provide strong support for an association between the specified herbicides and soft tissue sarcoma.