Organophosphate Pesticide Exposure and Breast Cancer Risk: A Rapid Review of Human, Animal, and Cell-Based Studies.

Kailynn June Yang,Jennifer Lee,Hannah Lui Park

doi:10.3390/ijerph17145030

Abstract

Background: Organophosphate pesticides (OPs) are one of the most commonly used classes of insecticides in the U.S., and metabolites of OPs have been detected in the urine of >75% of the U.S. population. While studies have shown that OP exposure is associated with risk of neurological diseases and some cancers, the relationship between OP exposure and breast cancer risk is not well understood. Methods: The aim of this rapid review was to systematically evaluate published literature on the relationship between OP exposure and breast cancer risk, including both epidemiologic and laboratory studies. Twenty-seven full-text articles were reviewed by searching on Pubmed, EMBASE, and Cochrane databases. Results: Some human studies showed that malathion, terbufos, and chlorpyrifos were positively associated with human breast cancer risk, and some laboratory studies demonstrated that malathion and chlorpyrifos have estrogenic potential and other cancer-promoting properties. However, the human studies were limited in number, mostly included agricultural settings in several geographical areas in the U.S., and did not address cumulative exposure. Conclusions: Given the mixed results found in both human and laboratory studies, more research is needed to further examine the relationship between OP exposure and breast cancer risk, especially in humans in non-agricultural settings.

Highlights

Breast cancer is the most common type of cancer among women worldwide after skin cancer, and approximately one in eight women will be diagnosed with invasive breast cancer in their lifetime [1].Studies have suggested that only 5–10% of breast cancer cases are hereditary [2,3]
Registry in two time periods, 1988–1994 and 1995–2001, and exposure to Organophosphate pesticides (OPs) was estimated based on work histories supplied to the United Farm Workers (UFW) linked to data from the California Department of Pesticide
The authors found that medium use of malathion by farm workers during 1988–1994, quantified in terms of pounds of malathion applied to a crop in a given county, month, and year, was significantly associated with increased breast cancer risk; there was no statistically significant difference in breast cancer risk for cases diagnosed during 1995–2001, which may be explained by differing patterns of usage within the two time periods or by chance due to the relatively small sample size

Summary

Introduction

Breast cancer is the most common type of cancer among women worldwide after skin cancer, and approximately one in eight women will be diagnosed with invasive breast cancer in their lifetime [1].Studies have suggested that only 5–10% of breast cancer cases are hereditary [2,3]. Lifestyle and environmental factors have a significant impact on breast cancer risk. A recent study comprised of 68,946 individuals found that a high consumption of organic foods was correlated with a decreased risk of postmenopausal breast cancer [7], suggesting that pesticide exposure may increase breast cancer risk. While studies have shown that OP exposure is associated with risk of neurological diseases and some cancers, the relationship between OP exposure and breast cancer risk is not well understood. Methods: The aim of this rapid review was to systematically evaluate published literature on the relationship between OP exposure and breast cancer risk, including both epidemiologic and laboratory studies.

Objectives

Methods

Results

Discussion

Conclusion