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 suggested to increase the risk of local recurrence after breast‐conserving surgery. Methods. The data were retrospectively reviewed from 552 patients in whom treatment consisted of total mastectomy (n = 467) or segmental mastectomy (n = 85), irradiation, and combination chemotherapy. Of these, 463 patients received radiation therapy first, and 89 received chemotherapy first. The pattern of failures was compared between the subgroups according to the order of administration chemotherapy and irradiation and its effect on the local control of disease. Results. The median follow‐up time of the local mastectomy subgroup was 133 months; of the segmental mastectomy subgroup, it was 39 months. The incidence of locoregional failure within each subgroup was not affected by the order in which the chemotherapy and irradiation were administered. Conclusions. These data suggest that delaying irradiation in an effort to reduce the risk of systemic relapse does not increase the risk of local failure.