Late breast recurrence after lumpectomy and irradiation.

For 276 patients with early breast cancer followed from 10-21 years after lumpectomy and radiotherapy, the recurrence rate in the treated breast was 15.6%, and 7.2% developed contralateral breast cancer. Only 63% of breast recurrences occurred within 5 years, and the remainder were "late failures," with 5 of the 43 recurrences observed after 10 years. The proportion of failures occurring late was greater for T1 than for T2 tumors (53% vs 25%). Twenty-six percent of early recurrences were inoperable, and an adverse impact of early recurrence on 10-year survival was clearly demonstrable. Late recurrences were all operable and did not appear to be associated with decreased survival. Only 16 of the 36 patients (44%) with operable breast recurrence ever developed metastatic disease, and 5 year survival following salvage therapy was 62%. Although the treated breast remains at continuous cancer risk even beyond 5 year, the prognosis of late recurrence appears quite similar to that of contralateral breast cancer. We do not consider the phenomenon of late recurrence to lend support to a policy of primary mastectomy, just as the existence of contralateral breast cancer does not justify routine "prophylactic" contralateral mastectomy.