Clinical outcomes of ductal carcinoma in situ of the breast treated with partial mastectomy without adjuvant radiotherapy

Purpose: Some recent trials suggest that postoperative adjuvant radiotherapy (RT) may be safely omitted after breast-conserving surgery (BCS) for some patients with ductal carcinoma in situ (DCIS). In this study, we reviewed clinical outcomes of patients with DCIS treated with partial mastectomy (PM) without adjuvant RT. Materials and Methods: Medical records of 28 patients (29 breasts) with DCIS who were treated with PM, but without RT, between April 1991 and December 2010 were retrospectively analyzed. Based on established criteria (2.0 cm or less in size and no comedonecrosis), 18 patients were treated without RT after PM. Seven patients (8 breasts) who did not receive RT due to refusal were also included in this study. Three other patients were excluded because data concerning comedonecrosis were not available. Results: For the 25 patients included in this study, the mean age of the 18 patients who met the criteria was 47.9±6.2 years, and 47.6±12.7 years for the 7 patients who did not. The mean sizes of the primary tumors were 0.6±0.4 cm and 0.9±0.3 cm, respectively, in these two groups. Among these 25 patients (26 breasts) treated without RT, we observed no ipsilateral breast tumor recurrence or mortality within a mean follow-up of 84 months. Conclusion: Based on this small number of cases, patients with DCIS, who were selected for tumor size less than 2 cm and absence of comedonecrosis, may be treated successfully with BCS; adjuvant RT may be omitted.