Predictive factors for complete excision and underestimation of one-pass en bloc excision of non-palpable breast lesions with the Intact® breast lesion excision system

Objective: Image-guided percutaneous biopsy is the recommended initial diagnostic procedure for suspicious mammographic lesions. This study was conducted to determine the accuracy of the Intact® breast lesion excision system (BLES) and to identify predictive factors for complete excision and underestimation. Material and methods: A prospective study was conducted between January 28, 2008 and April 30, 2009 on 166 biopsy procedures using Intact® biopsy device. Diagnoses obtained from biopsy specimen were compared with to final diagnosis on surgical excision specimen. Results: Of the 166 patients, 15 (9%) displayed lesions with cell atypia, 28 (17%) had an intra ductal carcinoma (IDC) and 9 (5%) had an invasive carcinoma. Eight of 15 patients with cell atypia had open surgical excision, and none showed underestimation. All patients with IDC underwent surgical excision: we found an invasive carcinoma in 6 cases (21.4% underestimation) and a complete removal of the lesion by the Intact® BLES in 11 cases (39%). All 9 patients with invasive carcinoma had a surgical excision, with 1 complete removal of the lesion by Intact® BLES. Multivariate analyses did not identify predictive factors for underestimation; clear margins ≥1 mm on biopsy specimen was the only independent predictive factor of complete excision (OR = 8.51, p = 0.02). Conclusions: Intact® BLES provides a safe alternative to vacuum assisted core needle biopsy (VACNB) with an underestimation rate comparable to those previously reported for VACNB. The high rate of complete removal of the lesions, particularly ISC, offers an interesting perspective of avoiding subsequent excisional surgery for small lesions and thus requires further confirmational study.