The pathological features of 236 clinical stage I and II invasive breast carcinomas treated by conservation were reviewed. On follow-up (minimum 2 years) 13 patients (6%) have developed breast relapse, 10 (4%) regional lymph node relapse and 26 (11%) distant metastases. Nineteen patients have died from breast carcinoma. On univariate analyses lymph node metastases, increasing amounts of non-invasive carcinoma and multiple foci of invasion were significant risk factors for breast relapse. A Cox's multivariate analysis showed the first two of these to be independently significant. The results are in agreement with other published series and confirm that assessment of non-invasive carcinoma is important. The study compares simple quantitation with the original method reported to define cases with an "extensive intraduct component".