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.