Systematic review and meta-analysis of outcomes of low-risk ductal carcinoma in situ

The current standard of treatment for ductal carcinoma in situ (DCIS) is surgery with or without adjuvant radiotherapy. With a growing debate about overdiagnosis and overtreatment of low-risk DCIS, active surveillance is being explored in several studies. A systematic review and meta-analysis of 33 studies, involving 47,696 women with low-risk DCIS found pooled 5-year and 10-year invasive ipsilateral breast tumor event rates (iIBTE) of 3.3% (95% CI 1.3-8.1) and 5.9% (3.8-9.0), respectively. The iIBTE rates were significantly lower in patients who underwent surgery compared with those who did not: at 5 years 3.5% versus 9.0% (p=0.003) and at 10 years 6.4% versus 22.7% (p=0.008). The 10-year breast cancer-specific survival rate was higher in the surgery group (99.6%) than in the no-surgery group (96.0%; p=0.010). In patients treated with breast-conserving surgery, additional radiotherapy significantly reduced IBTE risk. The authors conclude that among women with low-risk DCIS surgery was associated with lower risk of progression and better survival.