Background: The association between occupational pesticide exposure and the risk of head and neck cancer remains debated. Available evidence comes mostly from studies conducted among agricultural workers, although other occupational groups are also exposed to pesticides in the workplace.
Objective: We investigated the role of occupational pesticide exposure in head and neck cancer risk using data from the ICARE study.
Methods: ICARE is a population-based case–control study conducted in France between 2001 and 2007, including 2,415 cases of head and neck cancers and 3,555 controls from the general population. Pesticide exposure was assessed using a job-exposure matrix. Associations between pesticide exposure and head and neck cancer risk were examined using conventional unconditional logistic regression models as well as more advanced statistical methods designed to investigate exposure mixtures. All analyses were adjusted for age, sex, area of residence, tobacco smoking, and alcohol consumption.
Results: Increased risks of head and neck cancer were observed among participants ever exposed to herbicides, insecticides, fungicides, and other phytosanitary products considered individually (ORs ~1.20), with a slight indication of increasing risk with duration and level of exposure for oropharyngeal and laryngeal cancers. Three exposure profiles reflecting combined exposure to pesticides were identified: one characterized by exposure levels lower than the overall sample average (profile 1, reference category), and two others characterized by moderately (profile 2) and markedly higher exposure levels (profile 3) compared with the mean levels in the total sample. No association was found between the profiles of combined exposure to pesticides and head and neck cancer risk, overall or by cancer subsite. The simultaneous increase in pesticide exposure levels showed no association with head and neck cancer risk.
Conclusion: Our results provide limited evidence of an association between occupational pesticide exposure and head and neck cancer risk across a wide range of workers beyond the agricultural sector.