We performed a retrospective analysis of the pathological features of 1,065 cases of invasive breast cancer with one to three positive axillary lymph nodes. Patients underwent radical breast conserving surgery or mastectomy. A total of 45 % of patients received adjuvant chest wall/breast RT. No patients received adjuvant SCFRT. The primary outcome was SCFR. Secondary outcomes were chest wall/breast recurrence, distant metastasis, all death, and breast-cancer specific death. Kaplan-Meier estimates were used to calculate actuarial event rates and survival functions compared using log-rank tests. Multivariate analyses (MVA) of factors associated with outcome were conducted using Cox proportional hazards models.
Median follow-up was 9.7 years. SCFR rate was 9.2 % . Median time from primary diagnosis to SCFR was 3.4 years (range, 0.7-14.4 years). SCFR was associated with significantly lower 10-year survival (18 % vs. 65 % ; p?<?0.001). Higher grade and number of positive lymph nodes were the most significant predictors of SCFR on MVA (p < 0.001). 10 year SCFR rates were less than 1 % in all patients with Grade 1 cancers compared with 30 % in those having Grade 3 cancers with three positive lymph nodes. Additional factors associated with SCFR on univariate analysis but not on MVA included larger nodal deposits (p?= 0.002) and proportion of positive nodes (p?= 0.003).
Breast cancer patients with one to three positive lymph nodes have a heterogenous risk of SCFR. Patients with two to three positive axillary nodes and/or high-grade disease may warrant consideration of SCFRT.