Oral contraceptive use and risk of breast cancer by histologic type.
We examined the association between oral contraceptive use and risk of specific breast cancer histopathologies in a large, multi-center, population-based, case-control study. Women younger than age 75 with a new diagnosis of invasive breast cancer were identified from 4 statewide tumor registries. We compared women with lobular (n = 493) and ductal carcinoma (n = 5,510) to randomly selected controls (n = 9,311). Odds ratios (OR) and 95% confidence intervals (CI) for each histologic type were estimated using polytomous logistic regression, adjusted for other breast cancer risk factors. Current oral contraceptive use was associated with increased risk of lobular carcinoma (OR = 2.6, 95%CI = 1.0-7.1) and there was a significant trend (p = 0.017) of increased risk with more recent use. Oral contraceptive use was not clearly associated with ductal carcinoma (OR = 1.2, 95%CI = 0.8-1.9). These results suggest that the association between oral contraceptive use and risk of breast cancer may vary by histologic type.
Newcomer
Laura M
LM
Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA. lnewcome@fhcrc.org
Newcomb
Polly A
PA
Trentham-Dietz
Amy
A
Longnecker
Matthew P
MP
Greenberg
E Robert
ER
D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000209:etiology; D044584:Carcinoma, Ductal / Q000453:epidemiology* / Q000209:etiology; D018275:Carcinoma, Lobular / Q000453:epidemiology* / Q000209:etiology; D016022:Case-Control Studies; D003276:Contraceptives, Oral / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008875:Middle Aged; D012042:Registries; D012307:Risk Factors; D014481:United States / Q000453:epidemiology
D003276:Contraceptives, Oral