Tumor variants by hormone receptor expression in white patients with node-negative breast cancer from the surveillance, epidemiology, and end resultsdatabase

Purpose: Hormone receptor expression (presence-positive or absence-negative ) may reflect different stages of one disease or different breast cancer ty pes. Determining whether hormone receptor expression represents one or more breast cancer phenotypes would have important paradigmatic and practical i mplications. Methods: Breast cancer records were obtained from the National Cancer insti tute's Surveillance, Epidemiology, and End Results (SEER) database. The stu dy included 19,541 non-Hispanic white women with node-negative breast cance r. Standard tumor cell characteristics and breast cancer-specific survival were analyzed by independent estrogen receptor (ER+ and ER-), independent p rogesterone receptor (PR+ and PR-), and joint ERPR expression (ER+PR+, ER+P R-, ER-PR+, and ER-PR-), Results: Age frequency density plots by hormone receptor expression showed two overlapping breast cancer populations with early-onset and/or late-onse t etiologies. Independent ER+ and PR+ phenotype were associated with smalle r tumor sizes, better grade, and better cancer-specific survival than ER- a nd PR- breast cancer types. Joint ERPR phenotype exhibited biologic gradien ts for tumor rite, grader and cancer-specific survival, which ranked from g ood to worse for ER+PR+ to ER+PR- to ER-PR+ to ER-PR-, Conclusion: Variations of standard tumor cell characteristics and breast ca ncer-specific survival by hormone receptor expression in white patients wit h node-negative breast cancer suggested two breast cancer phenotypes with o verlapping etiologies and distinct clinical featured. J Clin Oncol 19:18-27 . (C) 2001 by American Society of Clinical Oncology.