Definitive irradiation for intraductal carcinoma of the breast.

During the period from 1978 to 1985, 51 women with intraductal carcinoma of the breast were treated with definitive irradiation following breast-conserving surgery. Surgical treatment of the primary tumor in all patients consisted of excisional biopsy or wide resection. In general, definitive irradiation consisted of conventional breast tangents to 4500-5000 cGy followed by a breast boost to a total dose of 6000-6600 cGy (median = 6000 cGy; range = 4200-6600 cGy). No patient was treated with radiation to a supraclavicular or axillary field. For the 51 patients, the median follow-up was 68 months (range = 25-126 months). The 5-year actuarial rate of local failure was 6%. A total of five patients failed in the breast at 19, 35, 40, 79, and 119 months following definitive irradiation. Salvage treatment in these five patients consisted of mastectomy in all five patients plus adjuvant tamoxifen in one patient. All five of the patients with breast failures are alive and NED (no evidence of disease), although with limited follow-up (median = 12 months; range = 6-68 months). These results suggest that definitive irradiation is an acceptable alternative to conventional mastectomy for appropriately selected and staged patients with intraductal carcinoma of the breast. In view of the long natural history of this disease, prolonged and careful follow-up of these patients is required.