Risk of breast cancer among Norwegian women with visual impairment.
Experimental studies suggest that melatonin has a protective effect against breast cancer. Exposure to light suppresses melatonin secretion, but to a lesser degree in totally blind persons. Breast cancer was investigated in a cohort of 15 412 Norwegian visually impaired women. The risk among totally blind women was 0.64 (95% CI = 0.21-1.49, 5 cases only), and for those who became blind before age of 65, the SIR was 0.51 (95% CI = 0.11-1.49). Our findings give support to the 'melatonin hypothesis'.
Kliukiene
J
J
The Cancer Registry of Norway, Montebello N-0310, Oslo, Norway.
Tynes
T
T
Andersen
A
A
D000293:Adolescent; D000328:Adult; D000368:Aged; D001766:Blindness / Q000150:complications; D001943:Breast Neoplasms / Q000150:complications*; D005260:Female; D006801:Humans; D017533:Marital Status; D008875:Middle Aged; D009664:Norway; D012307:Risk Factors; D014786:Vision Disorders / Q000150:complications*