[280] Significance of Lobular Carcinoma In Situ at Margins of Breast Conservation Specimens

EP Olsen, M Matin, NA Moatamed, SK Apple. UCLA Medical Center, Los Angeles, CA

Background: Lobular carcinoma in situ (LCIS) is a known risk factor for development of breast cancer. LCIS at the margin is frequently not reported because margins clear of LCIS are not a surgical goal. There is new emerging evidence of the biological significance of LCIS as possible precursor lesion. At our institution, LCIS with margin assessment is routinely performed as part of pathology report. Our aim is to review the impact of margin status and determine if LCIS found at a margin on breast conservation surgery was associated with an increased incidence of residual/recurrent disease.
Design: We retrospectively reviewed a total of 1334 breast surgical excision specimens at a single institution in a 10 year period. Inclusion criteria for positive group are as follows: primary breast conservation surgery containing invasive and/or in situ carcinoma with LCIS/ALH that had only positive margin with LCIS/ALH. We excluded all invasive carcinoma, DCIS and close margin (less than 1 mm) with LCIS/ALH. We identified 39 cases (2.9%) with LCIS/ALH was solely identified at a margin. A negative control group consisted of 46 cases of invasive carcinoma and/or in-situ carcinoma and clear margins including LCIS/ALH on primary surgical excision. No patients had re-excision. Both groups were matched to tumor type, stage and grade, lymph node status and patient age with clinical follow up in the patient's medical records.
Results: Of the 39 cases: 4 (10%) were lost to follow-up, 12 (30%) had no further procedures performed and 23 (59%) had subsequent pathology specimens which consisted of 11 mastectectomies and 12 re-excisions. Of 23 patients with re-excision, 11 (48%) had residual invasive carcinoma or DCIS, three (13%) had pleomorphic LCIS and five (22%) showed residual classic type LCIS after only LCIS/ALH was identified at a margin. Thirteen (33%) cases had negative residual diseases or no recurrence in their clinical follow up. Follow up months ranges from 1 to 109 months. From the 46 negative control groups, we found three (6.5%) patients with bone or brain metastasis and one local recurrence. Follow up months ranges from 4 to 152 months.
Conclusions: LCIS found at a margin on an excision specimen showed a significant residual and recurrent ipsilateral disease finding when residual invasive carcinoma/DCIS and pleomorphic LCIS were included. Our study showed 36% had significant diseases when compared to 6.5% from negative control groups. Our study supports the view that margin status may play a role in treatment of patients with positive margin with LCIS.
Category: Breast

Wednesday, March 24, 2010 9:30 AM

Poster Session V # 49, Wednesday Morning


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