[Impact of the interval between surgery and radiotherapy in the initial phases of breast cancer in patients who did not receive systemic adjuvant therapy]. 
The purpose was to evaluate the effect of surgery-radiotherapy delay in the outcome of patients treated for early breast cancer, who did not receive adjuvant systemic therapy.  We retrospectively analyzed data from 623 patients with breast cancer diagnosis stage I and II and with clinically negative axillary node, treated over a 18 year period.  Patients were grouped in basis of the delay in the beginning of their radiation therapy, after surgery.  Group 1 (270 patients) began radiation within 4 weeks of surgery, group 2 (285 patients) began 5-8 weeks after surgery and group 3 (68 patients) had a delay greater than 9 weeks.  Median follow up in the total group was 64 months.  Patients received a dose of 50-60 Gy to the tumor bed and/or 50 Gy to the nodes.  Age, menopausal stage, clinical stage of disease, histological diagnosis, pathologic tumor size, and nodes metastasis, were similarly distributed among the 3 groups.  Comparisons of local-control, overall 10-year survival and disease free survival curves between the three groups were done, no differences were observed among group 1 and 3, showed no significant differences in overall survival or local-control, however disease free survival was negatively affected by a delay in the administration of radiation (p = 0.05).  It was concluded that delay in the beginning of radiation therapy longer than 8 weeks after surgery in breast cancer stage I and II patients treated without systemic therapy, decrease significantly disease free survival.