[Specimen radiography assessment of surgical margins status in subclinical breast carcinoma: a diagnostic study]

Abstract

Objective: This study aimed to determine the accuracy of specimen radiography in evaluating the surgical margins of impalpable breast carcinoma.

Design and setting: Retrospective study from June 2009 to June 2010 in Orleans Hospital Center.

Patients and methods: The study involved patients with impalpable in situ breast carcinoma diagnosed by mammography. Only patients with larger in situ carcinoma than invasive carcinoma were included. Patients underwent a breast conserving surgery after preoperative localization of the lesion.

Primary endpoint: Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the specimen radiography are determined by correlation between radiologic and histologic margins.

Results and discussion: The following results were obtained from 46 patients: 36 DCIS cases (78%), six DCIS with IDC cases (13%), two LCIS cases (4%) and two biopsy suggested DCIS (4%). A radiologic margin of 2mm (by analogy with the histological margins) results in a NPV of 73%. NPV, sensibility and specificity were respectively 79, 60 and 74% for a radiologic margin of 5mm. The measure or inter-rater reliability found a moderate agreement (kappa: 0.62). The systematic review on this topic found only eight articles (small samples and only two prospective studies). We could not make any recommendations from the literature review on a threshold to define excision margin status.

Conclusion: The specimen radiography is a useful tool to assess margins of impalpable breast carcinoma. However, further studies are necessary as this point to determine a threshold for those radiologic margins.