Shift Work and Prostate Cancer Incidence in Industrial Workers

In 2007 the International Agency for Research on Cancer (IARC) classified shift work involving circadian disruption as a probable human carcinogen (1). Most of the evidence for this is based on animal experiment models and only a few reliable epidemiological studies. The cancer best described to date is breast cancer; this has mainly been investigated in female nurses and flight attendants (2, 3). Shift work can also increase the incidence of prostate cancer, as plausibly described in a review article published in 2012 (4). Mechanistically, it is possible that nocturnal light exposure and disrupted circadian rhythms cause cancer, or that tumor growth is favored by hormonal mediation. Noctur…