ESTRO 2022 - Abstract Book

S1004

Abstract book

ESTRO 2022

1 Puerta de Hierro University Hospital, Radiation Oncology, Madrid, Spain; 2 Puerta de Hierro University Hospital, Gynecology, Madrid, Spain; 3 Puerta de Hierro University Hospital, Pathology, Madrid, Spain Purpose or Objective We aimed to compare survival and local control rates between treatment with mastectomy or breast conservation surgery (BCS) plus adjuvant radiotherapy in patients with breast ductal carcinoma in situ (DCIS). Materials and Methods We conducted a retrospective study of 156 patients diagnosed with DCIS from January 2009 to December 2018. Among them, 83 were treated with mastectomy and 73 with BCS followed by radiotherapy. Clinical characteristics: Mean age 54 years (30-85); tumor grade: 1 (27 patients), 2 (48 patients), 3 (81 patients). Radiotherapy: 50Gy, 2Gy/fx (49 patients) or 42.56 Gy, 2.66 Gy/fx (24 patients); +/-10-16 Gy boost: (40 patients). Overall survival (OS), disease-free survival (DFS) and local recurrence-free survival (LRFS) rates were compared between the two treatment modalities. Statistics: Kaplan-Meier, log-rank. Results OS rates at 5 and 10 years was 100% in both groups. LRFS rates at 5 and 10 years was 98.7% for the mastectomy group and 98.1% for the BCS plus radiotherapy group (Figure 1). Rates of DFS in the mastectomy group were 95% and 90.8% at 5 and 10 years, respectively; and 93.9% at 5 and 10 years for BCS and radiotherapy (Figure 2). There were no significant differences between groups for DFS or LRFS. In the multivariate analysis, there were no significant differences; although young age, proximal margin (<3 mm) and grade III tumors showed a trend towards significance for recurrence for the whole series.