Karina Cox

Predictive factors for invasive cancer in surgical specimens following an initial diagnosis of ductal carcinoma in situ after stereotactic vacuum-assisted breast biopsy in microcalcification-only lesions

PURPOSEnThe aim of this study was to determine the incidence of invasive breast carcinoma in patients with preoperative diagnosis of ductal carcinoma in situ (DCIS) by stereotactic vacuum-assisted biopsy (SVAB) performed for microcalcification-only lesions, and to identify the predictive factors of invasion.nnnMETHODSnFrom 2000 to 2010, the records of 353 DCIS patients presenting with microcalcification-only lesions who underwent SVAB were retrospectively reviewed. The mammographic size of microcalcification cluster, presence of microinvasion within the cores, the total number of calcium specks, and the number of calcium specks within the retrieved core biopsy specimen were recorded. Patients were grouped as those with or without invasion in the final pathologic report, and variables were compared between the two groups.nnnRESULTSnThe median age was 58 years (range, 34-88 years). At histopathologic examination of the surgical specimen, 63 of 353 patients (17.8%) were found to have an invasive component, although SVAB cores had only shown DCIS preoperatively. The rate of underestimation was significantly higher in patients with microcalcification covering an area of 40 mm or more, in the presence of microinvasion at biopsy, and in cases where less than 40% of the calcium specks were removed from the lesion.nnnCONCLUSIONnInvasion might be underestimated in DCIS cases diagnosed with SVAB performed for microcalcification-only lesions, especially when the mammographic size of calcification is equal to or more than 40 mm or if microinvasion is found within the biopsy specimen and less than 40% of the calcifications are removed. At least 40% of microcalcification specks should be removed from the lesion to decrease the rate of underestimation with SVAB.

Use of preoperative breast MRI to determine disease extent

Breast MRI can be performed in the preoperative workup of patients with biopsy-proven breast cancer to size lesions, if there is discrepancy regarding the extent of disease from clinical, mammography or ultrasound assessment, and to identify multicentric or multifocal disease. The purpose of breast MRI is to plan the optimum surgical procedure, thus reducing the local tumour recurrence rate and the need for the patient to undergo additional surgery.