Association between night-work and breast cancer risk

Our  study has the following clinical implications: 1) Overall, this study further strengths the evidence for an association between night-work and breast cancer risk. Now, 10 out of 13 epidemiological studies have supported this link, which was evaluated by the International Agency for Research on Cancer in 2007 as “possibly carcinogenic”.  2) The breast cancer risk seems  minimal, if any, for less than 3 consecutive night shifts per week. 3) Diurnal preference seems to be an indicator of breast cancer risk. 4) Especially women  with morning preference should avoid or limit night shift work. 5) Further studies are needed and ongoing, also in other potential target organs such as the prostate and colo-rectal. "

Bibliographic Reference:

Hansen J et al.: "Nested case-control study of night shift work and breast cancer risk among women in the Danish military", Occup Environ Med. 2012 May 29. [Epub ahead of print]

Johnni Hansen

Institute of Cancer Epidemiology, Danish Cancer Society, Copenhagen, Denmark