CitationWilliams, Lindsay A.; Nichols, Hazel B.; Hoadley, Katherine A.; Tse, Chiu-Kit J.; Geradts, Joseph; Bell, Mary Elizabeth; Perou, Charles M.; Love, Michael I.; Olshan, Andrew F.; & Troester, Melissa A. (2018). Reproductive Risk Factor Associations with Lobular and Ductal Carcinoma in the Carolina Breast Cancer Study. Cancer Causes & Control, 29(1), 25-32. PMCID: PMC5903274
AbstractBACKGROUND: Invasive lobular breast tumors display unique reproductive risk factor profiles. Lobular tumors are predominantly Luminal A subtype, and it is unclear whether reported risk factor associations are independent of molecular subtype
METHODS: Polytomous logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (95% CIs) for the associations between risk factors and histologic subtype [ductal (n = 2,856), lobular (n = 326), and mixed ductal-lobular (n = 473)] in the Carolina Breast Cancer Study (1993-2013). Three-marker immunohistochemical clinical subtypes were defined as Luminal A (ER+ or PR+/HER2-), Luminal B (ER+ or PR+/HER2+), Triple Negative (ER-/PR-/HER2-), and HER2+ (ER-/PR-/HER2+).
RESULTS: In case-case analyses compared to ductal, lobular tumors were significantly associated with lactation duration > 12 months [OR 1.86, 95% CI (1.33-2.60)], age at first birth >/= 26 years [OR: 1.35, 95% CI: (1.03-1.78)], and current oral contraceptive use [OR: 1.86, 95% CI: (1.08-3.20)]. Differences in risk factor associations between ductal and lobular tumors persisted after restricting to Luminal A subtype.
CONCLUSIONS: Lobular tumors were associated with older age at first birth, increased lactation duration, and current oral contraceptive use. Etiologic heterogeneity by histology persisted after restricting to Luminal A subtype, suggesting both tumor histology and intrinsic subtype play integral parts in breast cancer risk.
Reference TypeJournal Article
Journal TitleCancer Causes & Control
Author(s)Williams, Lindsay A.
Nichols, Hazel B.
Hoadley, Katherine A.
Tse, Chiu-Kit J.
Bell, Mary Elizabeth
Perou, Charles M.
Love, Michael I.
Olshan, Andrew F.
Troester, Melissa A.