Type of Recurrence, Cause of Death and Second Neoplasms among 737 Patients with Ductal Carcinoma In Situ of the Breast—15-Year Follow-Up

SIMPLE SUMMARY: A retrospective analysis of 737 consecutive DCIS patients with a 15-year follow-up was carried out. Sixty-six recurrences (42% DCIS, 58% invasive) were reported: 61 in the breast and 5 outside the breast. 79% of local recurrences were true recurrences. The highest number of recurrences was reported in patients after local excision without radiotherapy despite the fact that it was the lowest-risk group. Deaths due to DCIS progression were reported in 0.5% of all patients and in 10.5% of patients with invasive recurrences. The majority of deaths were linked to the age of the patients or other diseases, including other neoplasms. ABSTRACT: Aim: To assess the outcomes of 737 consecutive patients with DCIS, with particular attention to the type of recurrences, other malignancies and causes of deaths. Material and Methods: A retrospective analysis of 737 consecutive DCIS patients treated in one institution in the years 1996–2011 was carried out. The cumulative recurrence risk, DFS, OS depending on the method of treatment (mastectomy, breast-conserving treatment (BCT), breast-conserving surgery (BCS)) and cause of death were assessed. Results: Sixty-six recurrences (42% DCIS, 58% invasive) were reported: 61 in the breast and 5 outside the breast. The cumulative recurrence risk after a 15-year observation after mastectomy, BCT and BCS was 3.2%, 19.5% and 31.2%, respectively (p < 0.001). The 15-year DFS after mastectomy, BCT and BCS was 72%, 65% and 48%, respectively (p < 0.001). The 15-year OS after mastectomy, BCT and BCS was 75%, 83% and 70%, respectively (p = 0.329). Deaths due to DCIS progression were reported in four (0.5%) of the overall patients and in 10.5% of patients with invasive recurrences. The majority of deaths were linked to the age of the patients or other diseases, including other neoplasms, but not DCIS. Conclusions: The highest number of recurrences was reported in patients after BCS, despite the fact that it was the lowest-risk group. In total, 79% of local recurrences were true recurrences and 58% were invasive recurrences. Local recurrences were effectively treated without an influence on the OS. The percentage of deaths due to DCIS was low and mainly concerned patients with locoregional and distant failure.