Objective: To assess the treatment outcomes and to explore the determinants of clinical outcome in breast cancer patients with 1-3 positive nodes who did or did not receive postmastectomy radiotherapy (PMRT) in a tertiary care referral cancer center in Northern Thailand.
Methods: We investigated a retrospective cohort of registered breast cancer patients at the Faculty of Medicine, Chiang Mai University, Thailand from 2001-2007. Analysis was performed using Cox regression models to identify factors affecting the overall survival (OS) and relapse-free survival (RFS) rates.