title: Hormone receptor status does not alter the effect of trastuzumab in breast cancer.
abstract: Overexpression of human epidermal growth factor receptor 2 (HER2) predicts response to anti-HER2 therapy in breast cancer. We investigated whether hormone receptor (HR) status influences the treatment benefit of trastuzumab in patients with breast cancer. Data from 8338 patients with primary nonmetastatic breast cancer from the cancer registry of Saxony-Anhalt Germany were analyzed. A total of 5554 patients were eligible for analysis. The median follow-up of the study was 6 years. Of the 5554 patients investigated, 1128 (20.3%) showed HER2 overexpression and 656 (58.2%) of them received adjuvant trastuzumab. The 10-year overall survival (OS) in the study cohort according to HR, HER2 status, and trastuzumab treatment was as follows: 78.4% for HR-/HER2-, 85.0% for HR+/HER2-, 70.4% HR-/HER2+/TRA-, 71.4% for HR+/HER2+/TRA-, 80.9% for HR-/HER2+/TRA+, and 89.2% for HR+/HER2+/TRA+. Trastuzumab treatment improved OS in the HR- patients only in the first 3 years, whereas in the HR+ group the effect of trastuzumab was still apparent 5 years after diagnosis. Notably, the relative improvement in a patient outcome was higher for HR+ patients. Nevertheless, matching for age, histological type, tumor stage, tumor grade, and performance status between patients with HR- and HR+ tumors demonstrated that the survival effect of trastuzumab was not affected by HR status; P=0.890. Trastuzumab treatment improves patients' survival regardless of HR status and should be offered to all HER2+ patients.
authors.affiliation: Department of Obstetrics and GynecologyOtto-von-Guericke University, Magdeburg, Germany.
authors.forename: Tanja
authors.initials: T
authors.lastname: Ignatov
authors.affiliation: Department of Obstetrics and GynecologyOtto-von-Guericke University, Magdeburg, Germany.
authors.forename: Holm
authors.initials: H
authors.lastname: Eggemann
authors.affiliation: Institute of Biometry and Medical InformaticsOtto-von-Guericke University, Magdeburg, Germany.
authors.forename: Elke
authors.initials: E
authors.lastname: Burger
authors.affiliation: Department of Obstetrics and GynecologyOtto-von-Guericke University, Magdeburg, Germany.
authors.forename: Serban Dan
authors.initials: SD
authors.lastname: Costa
authors.affiliation: Department of Obstetrics and GynecologyOtto-von-Guericke University, Magdeburg, Germany atanas.ignatov@gmail.com.
authors.forename: Atanas
authors.initials: A
authors.lastname: Ignatov
mesh_terms: D000328:Adult; D000074322:Antineoplastic Agents, Immunological / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008875:Middle Aged; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D011987:Receptors, Steroid / Q000378:metabolism; D000068878:Trastuzumab / Q000627:therapeutic use*
chemical_list: D000074322:Antineoplastic Agents, Immunological; D018719:Erb-b2 Receptor Tyrosine Kinases; D011987:Receptors, Steroid; D000068878:Trastuzumab; C508053:ERBB2 protein, human
keywords: HER2; breast cancer; hormone receptor; trastuzumab