Surgery and outcomes of ductal carcinoma in situ of the breast: a population-based study in Australia.

We examined surgery and outcome in a population-based series of 2109 women newly diagnosed with ductal carcinoma in situ (DCIS) in 1995-2000 in New South Wales (NSW), Australia. The sole data source for the study was pathology records in the NSW Cancer Registry. Most DCIS was treated with breast-conserving surgery (BCS); use of breast conservation increased throughout the 6 years of the study. Women who were younger, had higher grade DCIS or had larger lesions were significantly and independently less likely to have BCS than other women. Eighteen percent of women had lymph nodes removed, most often with mastectomy. The NSW Cancer Registry does not collect information about radiotherapy. Based on cancer registrations alone, 97.7% of women were free of ipsilateral invasive cancer after three years; more women who had mastectomy were cancer-free (100%) than women who had breast-conserving surgery (97.2%; P=0.05).