Abstract
Baxter et al. ( 1 ) report that about half the women undergoing lumpectomy for ductal carcinoma in situ do not get radiotherapy. The authors consider this to be undertreatment, because several studies have shown that radiotherapy reduces the risk of local recurrence and of invasive cancer. But the effect on mortality is not encouraging ( 2 ), and I believe the 50–50 split reflects the considerable uncertainty about what to do with carcinoma in situ.