Clinicopathologic factors associated with involved margins after breast-conserving surgery for invasive lobular carcinoma

Introduction: Obtaining negative margins for patients undergoing breast-conserving surgery (BCS) for invasive lobular carcinoma (ILC) can be difficult because of the unique histologic pattern of ILC. Our goal was to determine whether any specific patient- or disease-related factors influenced margin status. Patients and Methods: We retrospectively reviewed 211 patients with ILC treated from 1994 through 2004 to determine if specific clinical and pathologic factors influenced the ability to obtain negative margins. Results: We identified 110 patients (52%) who underwent total mastectomy and 101 (48%) who underwent BCS. Among patients who underwent BCS, 50 (50%) had close or positive margins. Patients with close or positive margins were more likely to have architectural distortion on ultrasonography (vs. mass or calcifications; P = .049), to have undergone excisional biopsy (vs. core or fine-needle aspiration; P = .008), and to have associated ductal carcinoma in situ (P = .021). On multivariate analysis, only biopsy method retained significance (P = .006). Conclusion: Core needle biopsy is the preferred method of diagnostic biopsy before surgical intervention. With appropriate patient selection, most patients with early-stage ILC can undergo successful BCS.