Residual disease after excision of non-palpable breast tumours: analysis of tumour characteristics.

INTRODUCTION: A tumour-positive resection margin is a well-known prognostic factor for local recurrence. The aim of this study was to evaluate tumour characteristics that might be predictive for the presence of residual disease after excisional surgery. PATIENTS AND METHODS: Data of 295 patients, subjected to a wire-guided excisional breast biopsy were studied. Type and size of the primary tumour, the presence of DCIS and an extensive in situ component (EIC), multifocality of the tumour and nodal status were recorded. RESULTS: Residual disease was found in 51% of the patients undergoing a re-operation. 80% of the patients with positive margins were treated by mastectomy. Nodal status and the presence of an extensive in situ component were the only two variables that were statistically significant. CONCLUSION: In case of tumour positive margins axillary involvement and an extensive in situ component in the primary tumour were predictive for residual disease. No subgroups could be defined in whom additional surgery could be omitted. More 'aggressive' surgical therapy is justified in patients belonging to these risk groups