The most recent analysis of the results of three major trials on breast conservation carried out at the Milan Cancer Institute between 1973 and 1988 showed that breast conservation consisting of a wide breast resection (quadrantectomy) plus radiotherapy is a safe procedure, and that there are no differences in long-term survival (up to 19 years) compared with women who have undergone Halsted's mastectomy. The studies also showed that reducing the extent of surgery from quadrantectomy to lumpectomy increases the risk of local recurrence by nearly three times, as does withdrawing radiotherapy. However, in women older than 55 years, quadrantectomy alone (without radiotherapy) may yield good results. Among the risk factors for local recurrence, a young age and the presence of an extensive intraductal component are the most significant.