Oncology 2017 24;92(6):317-324. Epub 2017 Mar 24.
Department for Obstetrics and Gynecology, University of Würzburg Medical School, Würzburg, Germany.
Objective: To identify subgroups of patients with pT1 pN0 breast cancer (BC) who might not profit from adjuvant systemic therapy (AST).
Methods: Data of 3,774 pT1 pN0 BC patients from 17 certified BC centres within the BRENDA study group were collected between 1992 and 2008 and retrospectively analysed. Uni- and multivariate analyses were performed using Kaplan-Meier methods and Cox regression models.
Results: 279 (7.4%) of the pT1 pN0 BC patients were T1a, 944 (25.0%) were T1b and 2,551 (67.6%) were T1c. There was no significant difference (p > 0.1) in recurrence-free survival (RFS)/overall survival (OAS) between patients with pT1a, pT1b, and T1c. Patients receiving any type of AST had a better outcome compared to women without AST after adjusting for age, tumour size, and intrinsic subtypes (RFS: p < 0.001; OAS: p < 0.001). AST was the most important prognostic parameter for RFS followed by intrinsic subtypes and age.
Conclusion: Patients with pT1 pN0 BC profit from AST independently of molecular subtypes, tumour size, age or comorbidity, with 5-year RFS of more than 95%. The correct definition of subgroups of patients who do not need AST is still an open question.