Evaluation of lumpectomy surgical specimen radiographs in subclinical, in situ and invasive breast cancer, and factors predicting positive margins.

PURPOSE: To determine the diagnostic performance of radiological evaluation of the margins of surgical specimens from lumpectomies for subclinical malignant breast lesions.
MATERIALS AND METHODS: Retrospective study in two French hospitals including all patients who had a non-palpable in situ (ISDC) or invasive (IDC) ductal carcinoma treated by lumpectomy after radiological localisation. For the analysis, the lesions were divided into two groups depending on the majority component in the definitive histological examination: ISDC or IDC. The radiological margin considered was 10mm.
RESULTS: For the 178 lumpectomies studied, the sensitivity of the radiographs of the surgical specimen was 33.3% for ISDC and 50% for IDC. The surgical revision rate was 27.41% for ISDC and 12.64% for IDC. The significant predictive factors for positive margins were the radiological size of the lesions (>10mm) for ISDC (P=0.02) and radiologically positive margins for IDC (P=0.01). Correlation was found between the histological and radiological sizes of the lesion for IDC, but not for ISDC.
CONCLUSION: Radiological examination of surgical specimens does not provide a satisfactory evaluation of the histological margins, in particular for ISDC, even with a radiological threshold of 10mm.