Is there any correlation between working Night Shift and Breast Cancer in Women? Many Nurses work night shift and for some it has been for extended periods. The enclosed article titled Night work and breast cancer in women: a Swedish cohort was recently published in BMJ open access and provides some interesting information.
In part the article identifies the following:
In 2007, the International Agency for Research on Cancer (IARC) carried out a review of available knowledge on the link between breast cancer in women and shift work, and concluded that six of the eight studies showed excessive risk for female shift workers with night work to develop breast cancer
Duration of exposure seems important, particularly at levels exceeding 15 years
The mechanism of the relation between night work and cancer is hypothesised to be influences of light night on the level of melatonin, as well as disturbances of the circadian rhythm
The results showed a significant association between the exposure to night work for >20 years and breast cancer in women who were followed up to the age of 60 years. For the complete group, independent of exposure duration, there was a trend in the same direction. The article also identifies a number of variables that may have impacted the findings.