The relative benefits of tamoxifen in older women with T1 early-stage breast cancer treated with breast-conserving surgery and radiation therapy

Small, hormone receptor-positive breast carcinomas in older women are associated with low local recurrence rates. The relative benefits of adjuvant hormonal therapy remain unclear in elderly women with small, node-negative breast cancer after breast-conserving surgery and adjuvant radiation therapy. From our institutional data base, 224 patients ≥65 years of age with T1N0M0 breast cancer treated with BCS+RT were identified. Of these, 102 patients (45.5%) received tamoxifen (TAM) and 122 patients (54.5%) did not (no-TAM). The median follow-up time was 62.6 months. The 10-year local relapse-free survival (LRFS) was 98% in both the TAM and no-TAM cohorts (p = 0.58); the 10-year DMFS was 83% TAM vs. 89% no-TAM (p = 0.91). There was no difference in 10-year contralateral breast relapse or overall survival (OS) between the two cohorts. In univariate and multivariate analysis, use of TAM was not associated with LRFS, distant metastases-free survival (DMFS), OS, or a reduction in contralateral breast cancers when compared with the no-TAM cohort. In this large cohort of T1N0 elderly breast cancer patients treated with CS+RT, the use of TAM did not appear to decrease ipsilateral breast relapse, contralateral breast relapse, distant metastasis, or OS.