Comparison of Recurrence Rate Between Re-Excision With Radiotherapy and Radiotherapy-Only Groups in Surgical Margin Involvement of In Situ Carcinoma

PURPOSE: (DCIS) in the resection margin after BCS, has not been reported previously. Therefore, in the present study, the clinical characteristics of DCIS involvement in the surgical resection margin between excision with RTx and RTx alone were investigated, and the IBTR rate was compared. METHODS: We analyzed 8,473 patients treated with BCS followed by RTx between January 2013 and December 2019. Patients were divided into 2 groups based on surgical resection margin status in permanent pathology, and superficial and deep margins were excluded. Patients who underwent re-excision with DCIS confirmed in the resection margin were identified and the IBTR rate was examined. RESULTS: = 0.262). CONCLUSION: The IBTR rate did not differ between the excision with RTx and RTx-only groups when DCIS was confirmed at the resection margins. This suggests that RTx and close observation without re-excision could be an option, even in cases where minimal involvement of DCIS is confirmed on surgical resection.