Breast cancer risk linked to night shifts

Picture Source: Doctor Oz

WORKING night shifts for more than 30 years could double women's risk of developing breast cancer

A new study has found that online journalist, Nurses, cleaners, care workers, call centre operators and others who work nights for a long term can have a twice as high risk of developing the disease than those who don't.

Canadian researchers examined 1,134 women with breast cancer and 1,179 women without the disease, but of the same age.

Women were questioned about their work and shift patterns and researchers also assessed the hospital records for the women who suffered from the disease.

About a third of the women had a history of night shift work.

The study, published in Occupational and Environmental Medicine, found that those who had worked nights for 30 or more years were twice as likely to have developed the disease, after taking account of potentially influential factors, although the numbers in this group were comparatively small.

No such relationship was found if women worked for less than 30 years doing shift work.

Previous research has linked the disease with shift work done by nurses but the latest study found that the associations were similar among those who worked in healthcare and those who did not.

"As shift work is necessary for many occupations, understanding of which specific shift patterns increase breast cancer risk, and how night shift work influences the pathway to breast cancer, is needed for the development of healthy workplace policy," the authors said.

However, Jane Green, clinical epidemiologist at the University of Oxford, has expressed caution.

She says the finding adds to similar results from some previous studies.

"But (it) does not change the existing consensus: that while there is some evidence to associate increased risk of breast cancer with very long term shift work, the evidence is not yet sufficient to be sure, and certainly not sufficient to give a public health message about working shifts," Dr Green said.

But experts have cautioned that an increased cancer risk is yet to be confirmed.