[Conservative treatment of breast cancer (the Lyon experience during 1963-1983)].

Over a 20-year period (1969-1983), 570 infiltrating primary breast carcinomas were conservatively treated in Lyons. Two different protocols were used: a first group of 162 patients with T1 T2 less than 3 cm NO lesions was treated, between 1963 and 1973, by lumpectomy and external beam irradiation with 60cobalt. The 5 and 10 year overall survival rates are 86% and 66% respectively. Local and regional failure rates are 10% and 2.5%. Cosmetic result was good or excellent in 70% of patients with only 5% poor results; a second group of 408 patients with T1 T2 less than 3 cm lesions was treated between 1973 and 1983 by tumorectomy and axillary dissection, followed by cobalt irradiation and 192iridium boost. The 5-year overall survival rate was 90% and, at 5 years, the probability of failure is 5% in the breast and 2% in the axilla. Cosmetic results are comparable in the 2 groups. Comparison of these 2 groups indicates an improvement in local control with Iridium boost. No obvious change in axillary recurrence rate and overall survival rate was observed. Boost modalities are discussed, with regard to cosmetic results. A prospective randomized study was initiated in 1986, in order to assess the value of the boost in the conservative treatment of breast cancer.