DELAYING THE INITIATION OF INTACT BREAST IRRADIATION FOR PATIENTS WITH LYMPH-NODE POSITIVE BREAST-CANCER INCREASES THE RISK OF LOCAL RECURRENCE

Background. The impact of delaying irradiation to the intact breast fo r patients receiving chemotherapy for lymph node positive breast cance r is controversial. Methods. From 1974 to 1989, 474 patients underwent lumpectomy and intact breast irradiation for early stage invasive bre ast cancer. Chemotherapy was administered to 84 patients (1 patient wi th bilateral breast cancer) because of positive axillary lymph nodes. Time from definitive breast surgery (lumpectomy or reexcision) to the initiation of breast irradiation was 21-314 days, with a median of 124 days. Forty-two patients began receiving radiation therapy before 120 days (early) and 42 more than 120 days after surgery (delayed). In th e early group, cyclophosphamide/methotrexate/5-fluorouracil (CMF) was administered to 32 patients, doxorubicin, cyclophosphamide or cyclopho sphamide, doxorubicin, 5-fluorouracil (AC or CAF) to 6 patients, and o ther regimens to 4 patients; in the delayed group, CMF was given to 29 patients, CAF to 12 patients, and L-PAM/5-fluorouracil to 1 patient. Results. Median follow-up was 62 months. There was one breast recurren ce in the early group, compared with six in the patients receiving del ayed irradiation. The actuarial relapse rates for these groups at 5 ye ars were 2% and 14%, respectively (P = 0.05). Survival and distant dis ease free survival were not significantly different between the two gr oups. Conclusions. Delays in the initiation of irradiation are associa ted with increased risk of relapse in the breast. When possible, the i nterval between definitive breast surgery (lumpectomy or reexcision) a nd the initiation of radiation therapy should be fewer than 120 days.