LAUSR

Breast cancer is the leading malignancy in females and flight attendants seem to have an elevated risk for it. This paper synthesizes the current evidence on the association of occupational exposure to cosmic radiation and circadian rhythm disruption and breast cancer risk in this population. Objective We conducted a systematic review and meta-analysis to investigate occupational exposures and their role in breast cancer (BC) risk among female flight attendants (FFAs). Methods We systematically searched PubMed and EMBASE and included all observational studies reporting on the outcome BC incidence among FFAs. The exposures of interest were cosmic radiation and circadian rhythm disruption. Study quality was assessed using the Newcastle-Ottawa Scale. Results Nine studies met the inclusion criteria, of which four were included in the meta-analysis for BC incidence (pooled standardized incidence ratio, 1.43; 95% confidence interval, 1.32 to 1.54). Three studies suggested a possible association between BC and cosmic radiation, whereas none found an association with circadian rhythm disruption. Conclusion Neither exposure to cosmic radiation nor circadian rhythm disruption seems to explain the elevated risk of BC among flight attendants. Further studies reporting individual information on occupational exposures are needed.