DUCT CARCINOMA INSITU - 227 CASES WITHOUT MICROINVASION

From 1979 to 1990, 227 patients with intraductal carcinomas (DCIS) without microinvasion were selectively treated; the least favourable (large lesions with involved biopsy margins) with mastectomy, the most favourable (small lesions with clear margins) with breast preservation. The preservation group was further subdivided into those who received radiation therapy (excision and radiation) and those who did not (excision alone). In the mastectomy group, there were 98 patients (43%) with an average lesional size of 3.3 cm; 41% had multifocal lesions, 15% had multicentric lesions. There has been one local invasive recurrence and no deaths. The 7-year actuarial disease-free survival is 98% with mastectomy. In the excision and radiation group, there were 103 patients (45%) with an average lesional size of 1.4 cm. 10 patients have had local recurrences (5 invasive and 5 noninvasive) one of whom has died. The 7-year actuarial disease-free survival is 84%, a statistically significant difference when excision and radiation is compared with mastectomy (P = 0.038). In the excision alone group, there were 26 patients (11%) with an average lesional size of 1.0 cm. There have been two local recurrences (8%), one of which was invasive and no deaths. The 7-year actuarial disease-free survival is 67%, but only 3 patients have been followed for more than 4 years. A total of 163 axillary node dissections were done; all were negative. Since DCIS without microinvasion rarely metastasises to axillary lymph nodes, routine dissection should not be performed. Patients in this series with intraductal carcinoma treated with excision and radiation recurred locally at a statistically higher rate than those treated with mastectomy, in spite of the fact that those chosen for excision and radiation had clinically more favourable lesions. 6 of 12 (50%) local recurrences in conservatively treated patients were invasive. There was, however, no significant difference in overall survival in any subgroup regardless of treatment.