Clinicopathologic factors related to surgical margin involvement, reoperation, and residual cancer in primary operable breast cancer - An analysis of 2050 patients.

BACKGROUND: To evaluate whether clinicopathologic factors are related to surgical margin involvement, reoperation, and residual cancer in primary operable breast cancer.

METHODS: Identification of patients at increased risk for positive surgical margins may enhance clinical preoperative decision-making and lower the reoperation rate. In this retrospective study, we analyzed the factors associated with positive surgical margins, the need for re-excision, and residual cancer detection in re-excised specimens in a cohort of 2050 women who underwent either breast-conserving surgery (BCS) or mastectomy for primary operable breast cancer.

RESULTS: Positive surgical margins were detected in 151 (7.4%) of the 2050 patients. The incidence of positive surgical margins was 11.3% (118/1042) in the BCS group and 3.3% (33/1008) in the mastectomy group (P < 0.001). In multivariate analysis, lower body mass index (BMI), larger tumor size, and pathologic evidence of multifocal disease were associated with positive surgical margin involvement in the BCS group. Younger age and ductal carcinoma in situ (DCIS) histologic subtypes (Odds ratio (OR) = 2.165, 95% CI = 1.253-4.323) were associated with higher risk of re-operations. Preoperative MRI examination was associated with decreased risk for margin involvement in the BCS group (OR = 0.530, 95% CI = 0.332-0.842) and reoperation (OR = 0.302, 95% CI = 0.119-0.728). DCIS histologic subtypes were associated with higher residual tumor incidence than other types of breast cancer.

CONCLUSIONS: Lower BMI, larger tumor size, pathologic evidence of multifocal disease, and no preoperative MRI evaluation were associated with increased risk for positive surgical margin involvement. DCIS with positive surgical margins was associated with increased risk for reoperation and residual cancer detection at re-excision.