Skiftarbeid og risiko for aggressiv prostatakreft blant norske offshorearbeidere.

Forskere fra Universitetet i Oslo, Kreftregisteret i Norge, Oslo universitetssykehus, Albert Einstein College of Medicine-USA og National Cancer Institute-USA har i denne studien undersøkt risiko for utvikling av prostatakreft blant offshorearbeidere med roterende skiftarbeid, og som var eksponert for klorerte avfettingsmidler som er mye brukt i oljeindustrien. Resultatene i studien viste at arbeidere med roterende skiftskiftarbeid hadde større risiko for utvikling av prostatakreft sammenlignet med arbeidere som kun jobbet dagskift, og risikoen økte med antall år med roterende skiftarbeid. Det ble ikke funnet sammenheng mellom klorerte avfettingsmidler og risiko for prostatakreft.

Leon A M Berge​, Fei-Chih Liu, Tom K Grimsrud, Ronnie Babigumira, Nathalie C Støer, Kristina Kjærheim, Trude E Robsahm, Reza Ghiasvand, H Dean Hosgood, Sven Ove Samuelsen, Debra T Silverman, Melissa C Friesen, Nita K Shala, Marit B Veierød, Jo S Stenehjem

Studien er publisert i International Journal of Epidemiology

Background: Night shift work may acutely disrupt the circadian rhythm, with possible carcinogenic effects. Prostate cancer has few established risk factors though night shift work, a probable human carcinogen, may increase the risk. We aimed to study the association between night shift work and chlorinated degreasing agents (CDAs) as possible endocrine disrupters in relation to aggressive prostate cancer as verified malignancies.
Methods: We conducted a case-cohort study on 299 aggressive prostate cancer cases and 2056 randomly drawn non-cases in the Norwegian Offshore Petroleum Workers cohort (1965-98) with linkage to the Cancer Registry of Norway (1953-2019). Work history was recorded as years with day, night, and rollover (rotating) shift work, and CDA exposure was assessed with expert-made job-exposure matrices. Weighted Cox regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for aggressive prostate cancer, adjusted for education and year of first employment, stratified by 10-year birth cohorts, and with 10, 15, and 20 years of exposure lag periods.
Results: Compared with day work only, an increased hazard of aggressive prostate cancer (HR = 1.86, 95% CI 1.18-2.91; P-trend = 0.046) was found in workers exposed to ≥19.5 years of rollover shift work. This persisted with longer lag periods (HR = 1.90, 95% CI 0.92-3.95; P-trend = 0.007). The exposure-hazard curve for a non-linear model increased linearly (HRs ≥1.00) for 18-26 years of rollover shift work. No association was found with CDA exposure.
Conclusions: Long-term exposure to rollover shift work may increase the hazard of aggressive prostate cancer in offshore petroleum workers.