CHANGES IN THE MANAGEMENT OF DUCTAL CARCINOMA IN SITU BEFORE THE RELEASE OF CLINICAL PRACTICE RECOMMENDATIONS IN AUSTRALIA: THE CASE IN VICTORIA

BACKGROUND: This study examines changes in the management of ductal carcinoma in situ between 1995 and 1999 in the Australian State of Victoria. This period was before the release of Australian treatment recommendations. METHODS: All new cases of ductal carcinoma in situ diagnosed between 1 April and 30 September in 1995 and 1999 were identified from the population cancer registry. Treating surgeons completed a questionnaire on the presentation and management of each case. In 1995, 64 out of 70 surgeons returned questionnaires for 137 cases (case response, 94%). In 1999, 68 surgeons treated 159 registered cases and 141 completed surveys were returned (case response, 89%). RESULTS: More cases underwent an image-guided biopsy in 1999 (54%) than in 1995 (34%). Breast-conserving surgery (BCS) was used to treat 69% of cases in 1999 and 63% in 1995. The use of axillary procedures (clearance or sampling) for women treated by mastectomy decreased from 61% in 1995 to 30% in 1999. More patients treated with BCS had margins simply described as "clear" in 1995 (49%) than in 1999 (21%). In 1995, only 7% of cases treated with BCS had radiotherapy, and this was 25% in 1999. CONCLUSION: In both 1999 and 1995, the majority of patients were treated by BCS, but only a minority received radiotherapy.