Ten-Year Outcomes in a Population-Based Cohort of Node-Negative, Lymphatic, and Vascular Invasion–Negative Early Breast Cancers Without Adjuvant Systemic Therapies

Abstract

PurposeTo discuss the absolute benefits from adjuvant systemic therapy knowledge of long-term outcomes and baseline risks of relapse and disease-specific survival are required. We assessed the 10-year outcomes in a population-based cohort of node-negative (N−) lymphovascular negative (LV−) early breast cancers diagnosed from 1989 to 1991 who did not receive adjuvant systemic therapy.MethodsOne thousand one hundred eighty-seven cases of pT1–2N0LV− breast cancers with a median follow-up of 10.4 years were reviewed. Kaplan-Meier survival curves for relapse free survival (RFS), breast cancer–specific survival (BCSS) and overall survival (OS) were compared with log-rank tests with cohorts stratified for tumor size and grade.ResultsThe median age of this series was 62 years. Four hundred thirty tumors were ≤ 1 cm in diameter (cohort 1), 507 were 1.1–2 cm (cohort 2), and 250 were 2.1 to 5 cm in diameter (cohort 3). The 10-year outcomes for cohorts 1, 2, and 3, respectively, were significantly different: RFS, 82%, 75%, and 66%; BCSS, 92%, 90%, and 77%; and OS, 79%, 78%, and 66%. Tumor grade significantly altered outcome within size cohorts, particularly in pT1N0breast cancers.ConclusionThis study provides detailed information on the continued relapse and breast cancer death rate to 10 years of follow-up. Specifically, without adjuvant systemic therapy, patients with LV−, N − breast cancer had a ≥ 25% 10-year risk of relapse and a corresponding 10-year breast cancer death rate of ≥ 10% if they had either a grade 3 tumor ≤ 1 cm, a grade 2 to 3 tumor from 1.1 to 2 cm, or any grade tumor greater than 2 cm.