Background Circadian disruption caused by night work has been associated with hormonal-related cancers such as breast and prostate cancer. Data on the role of circadian factors in the aetiology of endometrial cancer, an oestrogen-associated cancer, are scarce.
Methods We examined the association between endometrial cancer and night shift work, chronotype (a characteristic correlating with preference for morning or evening activity) and sleep duration, in 180 incident cases and 218 hospital controls. Participants were interviewed face-to-face by trained interviewers to collect information on sociodemographic factors, familial, medical, occupational history (including work shifts), sleep duration and chronotype, and other lifestyle factors. We used logistic regression models adjusted for potential confounders to estimate ORs and 95% CIs.
Results After adjustment by potential confounders, we found an inverse not statistically significant association between ever worked in night shifts and endometrial cancer (OR=0.64; 95% CI=0.35 to 1.16). Associations were irrespective of shift type (permanent or rotating nights) or duration of night work. We did not observe any statistically significant association between endometrial cancer and sleep duration, while inconsistent patterns were observed for chronotype and endometrial cancer risk.
Conclusions These data do not support a role for circadian disruption in the carcinogenesis of endometrial cancer.
- shift work schedule
- circadian rhythm
- medical oncology
Data availability statement
Data are available upon reasonable request.
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Contributors Conceptualisation—LC. Methodology—LC and MK. Formal analysis—LC. Resources—JdF, VC and JMM. Data curation—JF-G. Writing (original draft preparation)—LC. Writing (review and editing)—all authors. Supervision—LA. Project administration—LC. Funding acquisition—LC, SDS, XM-G, JP and JB. All authors have read and agreed to the published version of the manuscript.
Funding This work was conducted with the contribution of the Carlos III Health Institute through projects PIE16/0049, PI17/01179 and PI19/01835, as well as through CIBERESP CB06/02/0073 and CIBERONC CB16/12/00401, CM19/00216, FI20/00031, MV21/00061 and MV20/00029, co-financed by the European Regional Development Fund (ERDF), a way to build Europe. It also counts with the support of the Secretariat for Universities and Research of the Department of Business and Knowledge of the Generalitat de Catalunya, Roche Diagnostics, AECC Grupos estables coordinados, grants to support the activities of research groups 2017SGR01085, 2017SGR01718 and 2017SGR00735 and also with funding from the Health Department of the Generalitat de Catalunya (PERIS SLT006/17/76). We thank CERCA Programme/Generalitat de Catalunya for institutional support.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.
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