THE EFFECT OF MASTECTOMY RADIOTHERAPY INTERVAL ON LOCAL CONTROL AND SURVIVAL IN BREAST CANCER PATIENTS

The effect of mastectomy-radiotherapy interval on local control and survival was retrospectively analysed in 672 breast cancer patients referred to our clinic from 1970 through 1992. In 189 (28%) patients, only peripheral lymphatic areas were irradiated, in 483 (72%) peripheral lymphatic and chest wall areas were irradiated. 298 (44%) patients have received chemotherapy; 74% of these had 6 cycles and 26% had 12 cycles. Fluorouracil, doxorubicin, cyclophosphamide combination was used in 22%, and fluorouracil, metotrexate, cyclophosphamide combination was used in 78%. Patients were grouped into two in terms of mastectomy-radiotherapy interval: Group A, patients irradiated within 8 weeks postoperatively and Group B, patients irradiated after 8 weeks. Patients were stratified according to the treatment modalities they received: Group 1, received radiotherapy only; Group 2, received first radiotherapy, then adjuvant chemotherapy; Group 3, received sandwich modality (3 cycles of chemotherapy, then radiotherapy, then 3 more cycles of chemotherapy). Mastectomy-radiotherapy interval (groups A and B) and various treatment modalities (radiotherapy first and sandwich treatments) were not found to be significantly impacting on local control or survival in multivariate analysis. We conclude that, 3 cycles of chemotherapy can be given safely before radiotherapy in breast cancer patients who need both of these adjuvant treatments.