Omission of radiotherapy after breast conserving surgery among elderly women with favorable prognosis tumors

Abstract

9034 Background: Adjuvant radiotherapy after breast-conserving surgery is a standard therapy for invasive breast carcinoma. Controversy exists regarding the benefit of adjuvant radiotherapy for elderly women with favorable prognosis tumors. Methods: Using data from the Surveillance Epidemiology and End Results (SEER) registry, data were analyzed for 28,808 women ages = 65 years, with stage I and II, who underwent breast conservation therapy between 1998 and 2002. Relative survival rates (observed survival/expected survival) were calculated using Kaplan-Meier method for women who underwent radiotherapy and those for whom radiotherapy was omitted. Results: Among women = 65 years with stage I breast cancer who underwent breast conserving surgery (n = 20,400), 71.7% received adjuvant radiotherapy. Among those with stage II breast cancer (n = 8,408), 66.0% received adjuvant radiotherapy. Five-year relative survival rates among stage I patients were 1.000 (95% CI: 0.990, 1.010) for those receiving adjuvant radiotherapy, and 0.959 (95% CI: 0.932, 0.986) for those without adjuvant radiotherapy. Among stage II patients, the 5-year survival rates were 0.998 (95% CI: 0.978, 1.018) for those receiving adjuvant radiotherapy, and 0.832 (95% CI: 0.791, 0.873) for those without adjuvant radiotherapy. Conclusions: Adjuvant radiotherapy following breast conserving surgery may be safely omitted for elderly women with stage I breast carcinoma, especially for women ages 85–94 years. [Table: see text] No significant financial relationships to disclose.