[Predictive factors of invasion with initial diagnosis of ductal carcinoma in situ based on core biopsy].

Introduction: Previous studies suggest that sentinel lymph node biopsy (SLNB) should not be performed in case of pure ductal carcinoma in situ (DCIS) routinely. In order to avoid a second operation for invasive cancer detected postoperatively the chance of invasion need to be determined preoperatively. The purpose of our retrospective study was to evaluate the sensitivity of core biopsy and determine the predictive value of clinical and histological factors of invasion in cases when DCIS diagnosed preoperatively.

Material And Methods: Between January 2006 and December 2011, 1311 patients were treated for breast cancer in our institute, of whom preoperative core biopsy showed DCIS in 50 cases. Wide excision or quadrantectomy was performed in 41 cases, re-excision was necessary in 6 cases for positive surgical margins and mastectomy was carried out in four patients for multicentricity. In further 9 cases extensive tumour size indicated mastectomy straight away. SLNB was carried out in 31 patients, axillary block dissection (ABD) in 8 patients, while ABD for positive sentinel nodes in another two cases. Pathology showed invasion in 17 (34,7 %) cases.

Results: Multivariate analysis showed that tumour grade, symptomatic disease, patients' age were significant predictors of invasion. Although preoperative tumour size also showed correlation with invasiveness, this was statistically not significant.

Conclusion: Evaluation of a larger patient population might be helpful to identify women who should undergo tumour excision and SLNB as a single step operation due to increased risk of invasive disease despite the preoperative diagnosis of DCIS.