Between 1960 and 1980, 518 patients with T1, T2, N0, N1a, invasive breast cancer were treated by limited surgery at Institute Curie with (183 patients) or without (335 patients) axillary node dissection, followed by radiation therapy to breast and nodes. Median follow-up was 8.6 years (1.3 to 25 years). Fifty-six breast recurrences occurred, including 49 breast recurrences alone, 3 simultaneous breast and node recurrences, and 4 simultaneous breast recurrences and metastasis. Five-year, 10-year, and 15-year actuarial risks of breast recurrences were 7 +/- 1%, 11 +/- 1.5%, and 18 +/- 3%, respectively. Univariate analysis of 14 clinical and pathological prognostic factors revealed that local control in breast was significantly impaired by young age, premenopausal status, inadequate gross surgical excision, extensive ductal in situ component, and endolymphatic extension. On multivariate analysis with a Cox regression model, the most important contributors to local breast control in order of importance were age (p less than 10(-4), relative risk = 2.44), adequacy of surgery (p = 0.003, relative risk = 2.78), and endolymphatic extension (p = 0.03, relative risk = 2.98). The 5-year actuarial survival rate following breast recurrence was 73%, and was significantly worse when breast recurrence occurred in the first 3 years after treatment: 44% versus 87%, respectively (p less than 0.01). This study confirms the relationship between young age and low breast control rates, and demonstrates the importance of adequate initial surgical procedures. It emphasizes the adverse prognosis of early breast recurrences as compared to the relatively favorable outcome of late recurrences.