Women with night shift work and breast cancer: the situation in Denmark

摘要

Electrical light, which has been a widespread benefit only during about the past 100 years, is new in an evolutionary perspective, and has among priceless advantages given humans the ability to work during the normal dark part of the day (evening, night and early morning). In the late 1980s Stevens1 suggested that exposure to light at night may increase the risk of breast cancer. The initial hypothesis was that exposure to light at night suppresses pineal melatonin secretion, potentially reversing the normally onco-static properties of the hormone and increasing circulating oestrogens associated with breast carcinogenesis.