Ductal carcinoma in situ (DCIS) treated by mastectomy, or local excision with or without radiotherapy: A monocentric, retrospective study of 608 women

Abstract Objectives Since mammographic screening programmes, the proportion of DCIS has dramatically increased. Adjuvant radiotherapy (RT) after local excision (LE) has become a solid option for DCIS since 4 randomised trials have proven a decrease in local relapse (LR), though failing to prove a benefit on mortality rate. DCIS is a heterogeneous disease and it is unclear whether all patients uniformly benefit from radiotherapy. We report a descriptive analysis including all types of treatment. Materials and methods Our retrospective cohort describes 608 women treated for DCIS in our centre between 1983 and 2013. Mastectomy was recommended before 1992, or for multifocal or >3 cm DCIS. LE alone was an option for DCIS ≤10 mm, with low or intermediate grade, and clear margins (≥2 mm). LE + RT was recommended for all other cases. Results The median follow-up time was 6.7 years. Treatment consisted in mastectomy for 252 women, LE + RT for 269 and LE for 86. The major prognosis factor for LR rate was the type of treatment: LE + RT or LE was associated with a higher LR-rate than those treated by mastectomy (HR respectively 2.06; 95%CI 1.33–3.19; p = 0.001 and 2.12; 95%CI 1.20–3.65; p = 0.007). In our selected population, women treated by LE + RT versus LE showed no significant differences in LR (HR 0.97; 95%CI 0.61–1.7; p = 0.91). The overall survival rate was 99.7% after ten years, with no differences between the treatment groups. Conclusion Although retrospective, our monocentric study suggests that LE alone could be an option for DCIS with good prognosis factors. Confirmation by larger randomised studies is needed.