There is a positive association between long-term night shift work and the risk of several common cancers for women, with evidence of a dose-response correlation, according to a study published online in Cancer Epidemiology, Biomarkers & Prevention.
Xia Yuan, from West China Hospital in Chengdu, and colleagues reviewed 61 articles involving 114,628 cases and 3,909,152 participants to examine whether long-term night shift work increases the risks of common cancers in women. A dose-response analysis was performed to estimate the cumulative effect of night shift work on breast cancer risk.
The researchers observed a positive correlation between long-term night shift work and the risks of breast, digestive system, and skin cancers (odds ratios, 1.316, 1.177, and 1.408, respectively). The risk of breast cancer was increased by 3.3% for every 5 years of night shift work (odds ratio, 1.033). For nurses, long-term night shift work was associated with increased risk of breast cancer, digestive system cancer, and lung cancer (odds ratios, 1.577, 1.35, and 1.28).
“We identified that cancer risk of women increased with accumulating years of night shift work, which might help establish and implement effective measures to protect female night shifters,” the authors write.