Positive or involved margins result in higher rates of local recurrence in breast cancer patients and often need further operations. Identification of patients at increased risk for positive surgical margins may enhance clinical pre-operative decision-making.
A retrospective study of 1468 primary operable breast patients were enrolled in our current margin analysis study, and factors associated with positive surgical margin, re-excision, and residual cancer detection in the re-excision specimen were analyzed.
Among them, 103 (7%) patients were found to have positive surgical margin involvement. The positive surgical margin involved rate was 10.7% (78/730) in breast-conserving surgery patients, and 3.4% (25/743) in total mastectomy group (P < 0.0001). In multivariate analysis, the positive surgical margin involvement was associated with lower body surface area (BSA), larger tumor size (HR = 1.458, CI = 1.162-1.831), pathologic multifocal (HR = 2.801, CI: 1.160-6.762), and without MRI use (HR = 2.381, CI = 1.318-4.301).
No further re-excision was performed in the 25 margin-positive total mastectomy patients. Among the 78 breast-conserving surgery patients with positive surgical margin, 55(70.5%) received further re-excision. Patients without MRI pre-operative evaluation, or DCIS were factors related to re-operation.
Among the 55 patients with positive surgical margin and who had undergone further surgical excision, 31 (56.4%) were found to have residual tumor in the re-excision specimen. Compared with the no residual tumor in the second operation group, no difference in tumor size, lymph node status, Ki-67, pathologic multifocal, or MRI use was found. The only difference was that DCIS histologic subtype was associated with higher residual tumor than other types of breast cancer.
Lower BSA, larger tumor size, pathologic multifocal, and without MRI use were associated with increased risk for positive surgical margin involvement. Patients with DCIS who had positive surgical margin involvement were associated with increased risk for re-operation and residual cancer found at second operation.
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All authors have declared no conflicts of interest.