[en] In breast cancer patients with involved axillary nodes, it is now widely accepted to combine surgery, radiotherapy and systemic chemotherapy to minimize the risk of both local and distant failures. This multicentric study was carried out in order to analyse retrospectively the influence of delay between surgery and radiotherapy on both local and distant recurrences. From 1977 to 1987, 312 patients met the following criteria: unilateral tumors, no evidence of distant metastases, pathological involvement of at least one node in the axilla, therapeutic combination of surgery (mastectomy or tumorectomy with free margins), loco-regional radiotherapy and chemotherapy (CMF or anthracyclin containing regimen), 3 years minimal follow-up from the end of the treatments. The sequencing of treatments was not randomized. Radiation preceded chemotherapy in 125 patients (group I). Chemotherapy was given prior to radiotherapy in 187 patients (group II) allotted in different subgroups according to the length of interval in months (groups 112, 113, 114, 115, 116) have intervals between surgery and radiotherapy of 2, 3, 4 5, 6 months and more respectively. The median age was 45 (27 to 69) and 70% of patients were non-menopausal. TNM stagings did not significantly differ in group I and group II patients. The whole rate of local and distant relapse was 10% and 28% respectively. There were no statistically significant difference between the different subgroups. Delaying radiotherapy is not likely to increase the rate of local recurrence in node positive breast cancers. However, results should be considered with caution as far as the study is a multicentric and retrospective analysis and treatments are not homogenous particularly chemotherapy regimens. (author). 5 tabs., 24 refs