title: Risk factors for uncommon histologic subtypes of breast cancer using centralized pathology review in the Breast Cancer Family Registry.
abstract: Epidemiologic studies of histologic types of breast cancer including mucinous, medullary, and tubular carcinomas have primarily relied on International Classification of Diseases-Oncology (ICD-O) codes assigned by local pathologists to define histology. Using data from the Breast Cancer Family Registry (BCFR), we compared histologic agreement between centralized BCFR pathology review and ICD-O codes available from local tumor registries among 3,260 breast cancer cases. Agreement was low to moderate for less common histologies; for example, only 55 and 26 % of cases classified as mucinous and medullary, respectively, by centralized review were similarly classified using ICD-O coding. We then evaluated risk factors for each histologic subtype by comparing each histologic case group defined by centralized review with a common set of 2,997 population-based controls using polytomous logistic regression. Parity [odds ratio (OR) = 0.4, 95 % confidence interval (95 % CI): 0.2-0.9, for parous vs. nulliparous], age at menarche (OR = 0.5, 95 % CI: 0.3-0.9, for age ≥13 vs. ≤11), and use of oral contraceptives (OCs) (OR = 0.5, 95 % CI: 0.2-0.8, OC use >5 years vs. never) were associated with mucinous carcinoma (N = 92 cases). Body mass index (BMI) (OR = 1.05, 95 % CI: 1.0-1.1, per unit of BMI) and high parity (OR = 2.6, 95 % CI: 1.1-6.0 for ≥3 live births vs. nulliparous) were associated with medullary carcinoma (N = 90 cases). We did not find any associations between breast cancer risk factors and tubular carcinoma (N = 86 cases). Relative risk estimates from analyses using ICD-O classifications of histology, rather than centralized review, resulted in attenuated, and/or more imprecise, associations. These findings suggest risk factor heterogeneity across breast cancer tumor histologies, and demonstrate the value of centralized pathology review for classifying rarer tumor types.
authors.affiliation: Department of Epidemiology, Mailman School of Public Health, Columbia University, 722 W 168th St., 7th Floor, New York, NY 10032, USA.
authors.forename: Meghan E
authors.initials: ME
authors.lastname: Work
authors.forename: Irene L
authors.initials: IL
authors.lastname: Andrulis
authors.forename: Esther M
authors.initials: EM
authors.lastname: John
authors.forename: John L
authors.initials: JL
authors.lastname: Hopper
authors.forename: Yuyan
authors.initials: Y
authors.lastname: Liao
authors.forename: Fang Fang
authors.initials: FF
authors.lastname: Zhang
authors.forename: Julia A
authors.initials: JA
authors.lastname: Knight
authors.forename: Dee W
authors.initials: DW
authors.lastname: West
authors.forename: Roger L
authors.initials: RL
authors.lastname: Milne
authors.forename: Graham G
authors.initials: GG
authors.lastname: Giles
authors.forename: Teri A
authors.initials: TA
authors.lastname: Longacre
authors.forename: Frances
authors.initials: F
authors.lastname: O'Malley
authors.forename: Anna Marie
authors.initials: AM
authors.lastname: Mulligan
authors.forename: Melissa C
authors.initials: MC
authors.lastname: Southey
authors.forename: Hanina
authors.initials: H
authors.lastname: Hibshoosh
authors.forename: Mary Beth
authors.initials: MB
authors.lastname: Terry
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000145:classification / Q000453:epidemiology* / Q000473:pathology*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008875:Middle Aged; D012042:Registries; D012307:Risk Factors; D055815:Young Adult