Night shift and breast cancer

Objective The aim of this review was to synthesize the evidence on the potential relationship between nightshift work and breast cancer. Methods We searched multiple databases for studies comparing women in shift work to those with no-shift work reporting incidence of breast cancer. We calculated incremental risk ratios RR per five years of night-shift work and per night shift increases in exposure and combined these in a random effects dose—response meta-analysis. We assessed study quality in ten domains of bias.

Javascript is currently disabled in your browser. Several features of this site will not function whilst javascript is disabled. Received 25 December Published 21 August Volume Pages — Review by Single-blind. Peer reviewers approved by Dr Amy Norman.

The purpose of this study was to review epidemiologic evidence on the relationship between night work and breast cancer. We reviewed 21 original articles and 5 meta analyses on relationship between nightwork and breast cancer, and investigated the compensation criteria of Denmark. The association between breast cancer and night work has been reported by numerous epidemiologic studies, including cohort studies, case-control studies, and meta-analysis. Although there are some limitations to the epidemiological studies so far, further consideration of breast cancer cases in patients with high exposure to night work is needed to assess breast cancer as a work-related disease. This decision, made in , was based on sufficient evidence from experimental studies, but limited evidence from epidemiological studies.

By New Scientist staff and Press Association. Night shifts do not increase the risk of breast cancer , a ten-year study of more than , UK women suggests. One theory is that artificial lighting means that night workers produce less of the of the night-hormone melatonin, which increases oestrogen production, which can affect the growth of breast tumours. But an analysis of data from , women suggests this many not be the case.