Development of new cancers in patients with DCIS: The M.D. Anderson experience

Background: The purpose of this study was to describe clinical characteristics and outcome of mammographically and clinically detected new cancers in patients with previously diagnosed ductal carcinoma in situ (DCIS). Method: Our database was searched to identify patients with a primary diagnosis of DCIS. Those with prior evidence of invasive carcinoma were excluded from the analysis. Cumulative incidence of new cancers was estimated according to the method of Gray. Survival times were estimated using the Kaplan Meier product limit method. Results: A total of 799 patients diagnosed and treated for DCIS were included in the analysis. Median age at diagnosis was 54 years (range 22-88 years) and median tumor size was 1.4 cm (range 0.2-15 cm). After a median follow-up of 2.9 years, 45 patients (5.6%) had a second event: 14 (31%) with in-situ and 31 (69%) with invasive disease. Median disease-free interval was 3.5 years (range 0.5-20.8 years). The majority of second events (63%) occurred in the opposite breast (P = 0.048) and the cumulative incidence at 5 years was 6.6%. Overall survival at 5 years was 97.4%; that for the second event was 76.1%. For mammography and self-palpation, respectively, the 5-year survival by method of detection of the second event was 63.2% and 100% (P = 0.08 with a 33% power to detect a difference). Conclusion: Second events following DCIS occurs primarily in the opposite breast and have a negative impact on survival.