Conservative surgery and radiation therapy in breast carcinoma: local recurrence and prognostic implications

Conservative surgery with radiation therapy has been used with increasing frequency at Yale-New Haven Hospital since the late 1960's, resulting in a minimum evaluable follow-up time of 5 years on 278 patients treated prior to 1982. The radiation therapy technique generally encompassed treatment to the breast and regional lymph nodes of 4600 cGy with an electron beam boost to the tumor bed of 6400 cGy. Axillary dissection was performed in 19%, adjuvant chemotherapy in 7.3%, and adjuvant hormonal therapy in 5.7%; 65% were clinical Stage I and 35% were clinical Stage II. As of July 1987, with a minimum evaluable follow-up of 5 years and a median follow-up of 7.46 years, the actuarial 5- and 10-year survival for all 278 patients was 83% and 67%, respectively. The breast recurrence-free rate was 91% at 5 years and 80% at 10 years. Whereas the 5-year survival was significantly greater for clinical Stage I patients (91% vs 68%, p = .01), the breast recurrence-free rates did not significantly differ between clinical Stage I & II (93% vs 88%). There were 31 patients who failed in the breast alone as the first site of failure; 67% were at or near the primary site whereas 33% were distinctly removed from the primary site. Salvage mastectomy was performed in 25 patients, repeat wedge resection in two patients, and biopsy only in four patients. Axillary nodes were positive in five (33%) of 15 evaluable patients undergoing axillary dissection at the time of recurrence. The 5-year actuarial survival following local recurrence for the 31 patients was 48% at a mean follow-up of 5.06 years. The local recurrences were further subclassified into localized breast recurrences (LBR), defined clinically as greater than 3 cm and/or with dermal involvement. The 22 patients experiencing localized breast recurrences tended to occur later (median time to recurrence 4.3 years) than the nine patients experiencing a diffuse breast recurrence (median time to recurrence 2.9 years). At last follow-up, three (14%) of the 22 localized breast recurrences had subsequently failed distantly and none had subsequent local failure, whereas four (44%) of nine diffuse breast recurrences had subsequent distant failure and five (55%) of the nine diffuse breast recurrences experienced further local disease. The 5-year actuarial survival following salvage treatment was 90% for the localized breast recurrences and only 13% for the diffuse breast recurrences.