Introduction High-quality epidemiological evidence on the relationship between the occupational environment and ovarian cancer risk is limited. Most studies had very few cases, did not adjust for important confounders, and lacked information on specific workplace exposures.

Objectives To investigate the relationship between occupation, specific workplace exposures, and ovarian cancer risk.

Methods In a population-based case-control study conducted in Montreal, Canada (2011–2016), lifetime occupational histories were collected for 492 cases and 897 controls. For each job held by a participant, occupational and industrial classification codes were coded by an industrial hygienist. To identify specific workplace exposures, job codes were linked to the Canadian job-exposure matrix. Twenty-three agents with relatively high prevalence were selected. Occupations were examined by comparing participants ever employed in a given occupation for at least ten years vs. never employed in that occupation. For specific exposures, ever exposure, exposure duration, and cumulative exposure to selected agents were analyzed. Odds ratios (OR) and 95% confidence intervals (CI) for associations with ovarian cancer risk were estimated using logistic regression.

Results Elevated ORs were observed for accountants (OR=2.03, 95% CI: 1.09–3.76); hairdressers, barbers, and beauticians (OR=3.22, 95% CI: 1.25–8.28); sewers and embroiderers (OR=1.89, 95% CI: 0.78–4.59); saleswomen, shop assistants, and demonstrators (OR=1.42, 95% CI: 0.70–2.89); and occupations in retail trade (OR=1.59, 95% CI: 1.05–2.39). For specific exposures, increased risks were suggested for cosmetic talc, ammonia, hydrogen peroxide, hair dust, propellant gases, fluorocarbons, ethanol, cellulose, and polyester fibres. Hairdressers, barbers, and beauticians were the most frequent occupation exposed to six out of nine specific workplace exposures among participants.

Conclusion Study results suggest that certain occupations may be associated with increased ovarian cancer risks, but it is difficult to determine specific exposures that may contribute to the increased risks. Future larger studies with expert assessments of specific occupational exposures may better characterize co-exposures.