Clinical and radiological predictors of complete excision in breast-conserving surgery for primary breast cancer

Local recurrence after conservative surgery for breast cancer usually results from growth of residual cancer adjacent to the excised primary tumour or from multicentric disease. Complete local excision (CLE) confirmed histologically is essential to ensure that the risk of local recurrence is minimal. This study was undertaken to determine that clinical or radiological factors may assist the surgeon at the time of surgery to achieve this aim.

A retrospective review of 101 cases treated by conservative surgery identified 70 cases of CLE and 31 of incomplete local excision (ILE). Clinical, surgical and histopathological data were taken from hospital records. Mammographic features and those of specimen X-rays were evaluated without knowledge of the histopathological outcome of surgery.

Complete excision was significantly associated with type of operation (lumpectomy vs wide local excision/quadrantectomy, P < 0.003), absence of calcification (P < 0.03) and the presence of a mass on mammography (P = 0.05). Tumour size (> 2.5 cm) and the presence of extensive ductal carcinoma in situ (DCIS) were associated with incomplete excision (P = 0.0005). No relationship was demonstrated with patient age, breast size, breast density, tumour grade, receptor status, axillary nodal status or spicules on X-ray and completeness of excision. Specimen X-ray had a positive predictive value of 94% with CLE.

Clinical and pre-operative mammographic parameters are important for predicting CLE for breast cancers treated by breast-conserving surgery. Specimen radiology for palpable lesions can confirm excision of the cancer and permit re-excision of breast tissue at the time of initial surgery. Its role in determining CLE should be further evaluated.