Risk factors for benign proliferative breast disease.
BACKGROUND
As part of a nested case-control study of benign proliferative breast disease (BPBD) conducted within the cohort of women participating in the Alberta breast screening programme, an analysis of all women who had a benign breast biopsy between 1990 and 1995 was undertaken to identify the epidemiological risk factors for BPBD.


METHODS
The breast biopsies of all eligible women were re-reviewed by a panel of four pathologists using Page's classification for benign breast disease. Cases were 165 women whose biopsies, upon review, showed benign breast tissue changes ranging from sclerosing adenosis to atypical ductal hyperplasia. Controls were 217 women whose biopsies showed no evidence of any proliferative or neoplastic changes. In-person interviews were conducted with all study subjects.


RESULTS
Women with >/=25% fibroglandular breast tissue density, as compared to women with <25% density, experienced nearly a doubling in risk of BPBD (OR = 1.91, 95% CI : 1.24-2.94). All other possible risk factors examined were not associated with BPBD.


CONCLUSIONS
This study suggests that fibroglandular tissue density may be a risk factor, or marker, for increased risk of BPBD.
Division of Epidemiology, Prevention and Screening, Alberta Cancer Board, 1331-29 St NW, Calgary, Alberta, Canada, T2N 4N2. chrisf@acb-epi.ucalgary.ca
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Friedenreich
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Bryant
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Alexander
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Hugh
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Danyluk
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D000368:Aged; D000416:Alberta / Q000453:epidemiology; D001941:Breast Diseases / Q000453:epidemiology / Q000473:pathology / Q000517:prevention & control*; D001943:Breast Neoplasms / Q000453:epidemiology / Q000473:pathology / Q000517:prevention & control*; D016022:Case-Control Studies; D005260:Female; D005348:Fibrocystic Breast Disease / Q000453:epidemiology / Q000473:pathology / Q000517:prevention & control*; D006801:Humans; D016015:Logistic Models; D008327:Mammography; D008875:Middle Aged; D016017:Odds Ratio; D012307:Risk Factors