Shift rotation cancer link remains unproven says Cancer Research UK
Cancer Research UK has said that a study which reported a link between rotating shift work and prostate cancer should not be taken as definitive evidence.
The researchers examined the incidence of cancer among 14,052 Japanese men from data gathered between 1988 and 1998. This was then-compared with their working patterns.
The researchers found that, adjusted for age, the risk of prostate cancer was increased three-fold among workers who regularly switched between working night and day shifts.
Henry Scowcroft of Cancer Research UK said that there were a number of questions surrounding the study's findings, however.
"There have been several previous reports that disturbances to natural body rhythms might be linked to cancer, and this report adds to that evidence," he said.
"But it has never been shown that the actual sleep disturbance itself is responsible for the slight increase in risk observed in these studies.
"It might be that people with abnormal sleep patterns are more likely to be doing something else, such as smoking or eating unhealthily that increases their risk.
"As the authors of this study point out, this was a relatively small study with several limitations, not least the fact that the researchers only saw 31 cases of prostate cancer over the ten year study.
"So there is a long way to go before we can say for sure whether sleep disturbance is linked to prostate cancer."
The study was conducted by the University of Occupational and Environmental Health in Japan and is published in the American Journal of Epidemiology.
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