External irradiation prior to conservative surgery for breast cancer treatment.

From 1981 to 1987, 138 patients with breast cancer unsuitable for primary tumorectomy received initial external radiotherapy (45 Gy/25f/35d) in order to reduce the tumor volume so that secondary limited surgery could be performed. There were 81 T2 and 57 T3. Fifty-seven percent of the patients had a tumor larger than 4.5 cm. After completion of the radiotherapy, 22 patients (16%) showed no more evidence of a tumor either clinically or radiologically and received a boost of 25 Gy. In 52 cases (38%) the tumor regression allowed for secondary tumorectomy followed by a boost of 20 Gy. Sixty-four patients (46%) showed either little or no tumor regression: radical surgery was performed in 14 cases (10%) and high dose boost curietherapy (37 Gy) in the 50 (36%) remaining patients who refused mastectomy. Breast conservation in good condition was thus obtained in 74 patients (54%). Sufficient tumor regression to allow secondary tumorectomy was more often observed in T2 than in T3, in poorly differentiated tumors or mucinous type, and in tumor with well defined mammographic aspects. Actuarial 5-year local control and disease-free survival rates after limited surgery were, respectively, 90% and 73%. No particular complications were observed after secondary tumorectomy. This therapeutic approach is encouraging in patients with large T2 and T3 breast tumors, but a longer follow-up is required to assess definitive conclusions.