THE ORDER OF ADMINISTRATION OF CHEMOTHERAPY AND RADIATION AND ITS EFFECT ON THE LOCAL-CONTROL OF OPERABLE BREAST-CANCER

Background. A delay in administration of radiation therapy has been su ggested to increase the risk of local recurrence after breast-conservi ng surgery. Methods. The data were retrospectively reviewed from 552 p atients in whom treatment consisted of total mastectomy (n = 467) or s egmental mastectomy (n = 85), irradiation, and combination chemotherap y. Of these, 463 patients received radiation therapy first, and 89 rec eived chemotherapy first. The pattern of failures was compared between the subgroups according to the order of administration chemotherapy a nd irradiation and its effect on the local control of disease. Results . The median follow-up time of the local mastectomy subgroup was 133 m onths; of the segmental mastectomy subgroup, it was 39 months. The inc idence of locoregional failure within each subgroup was not affected b y the order in which the chemotherapy and irradiation were administere d. Conclusions. These data suggest that delaying irradiation in an eff ort to reduce the risk of systemic relapse does not increase the risk of local failure.