Long-term results of radiation versus observation after lumpectomy for good-risk ductal carcinoma in situ

The multicenter phase 3 NRG/RTOG 9804 trial randomized patients after lumpectomy for good-risk DCIS to radiation or observation. At 13.9 years’ median follow-up, the15-year cumulative incidence of IBR was 7.1% with radiation versus 15.1% with observation, and the cumulative incidence of invasive LR was 5.4% versus 9.5%. The authors conclude that radiotherapy significantly reduced all and invasive IBR for good-risk DCIS with durable results at 15 years.