Correlation of the risk of breast cancer and disruption of the circadian             rhythm (Review).
Breast cancer is the worldwide leading cause of cancer incidence among women.             Night shift work exposure has been recently considered one of the significant             breast cancer risk factors in industrialized countries. The mechanisms by which             this work exposure may be responsible for cancer development is still discussed.             In the last 15 years, many authors have paid attention to the relationship between             night shift work and breast cancer risk. In the current study, eight case-control             studies and four prospective epidemiological studies describing such relationship             are discussed. A positive correlation between night shift work and breast cancer             risk was described in 8 out of 12 studies. However, different reasons suggest             that some of these studies have an Achilles heel according to the International             Agency of Cancer (IARC) indications. Both the circadian system alteration and             the melatonin output reduction, related to the exposure to light-at-night during             night shift work, remain the most valid hypotheses on the causal relation of shift             work and breast cancer. Overall, the results of the present study suggest that             there is an association between night shift work and breast cancer development             in western countries. However, further studies are needed to confirm such association             and to understand which biomolecular mechanisms may be involved in the pathogenesis             of cancer diagnosed in patients with night shift work exposure.
Laboratory of Translational Oncology and Functional Genomics, Section of Pathology and Oncology, Department of Bio-medical Sciences, University of Catania, and Senology Unit, Cannizzaro Hospital, Catania, Italy.
Giulia Costanza
GC
Leonardi
Venerando
V
Rapisarda
Andrea
A
Marconi
Aurora
A
Scalisi
Francesca
F
Catalano
Lidia
L
Proietti
Salvo
S
Travali
Massimo
M
Libra
Concettina
C
Fenga
D001943:Breast Neoplasms / Q000503:physiopathology*; D016022:Case-Control Studies; D002940:Circadian Rhythm / Q000502:physiology*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D012307:Risk Factors