Abstract P2-12-19: Comparison between ultrasound-guided-vacuum-assisted excision and surgical excision of benign phyllodes tumor of the breast: A single center retrospective study

Abstract

Abstract Background: Wide local excision (WLE) is the recommended treatment for patients with phyllodes tumor of the breast, regardless of the tumor subtype (benign, borderline and malignant). However, the association between margin status and local recurrence is still controversial. In our institution, surgical excision (SE) alone (margin width<1cm) is the standard treatment for patients with benign phyllodes tumor. In addition, ultrasound-guided-vacuum-assisted excision (UGVAE) is also employed as an alternative, minimally invasive way to remove benign phyllodes tumor. We hypothesized that UGVAE alone is adequate and as safe as SE alone for benign phyllodes tumor. Method: We searched our database for patients with benign phyllodes tumor diagnosed in Sun Yat-sen Memorial Hospital between 2000 and 2014, and identified 136 patients with valid follow-up information. Formalin fixed slices of each patient were reviewed for pathology diagnosis. In UGVAE group, we used 8G Mammotome to remove all lesions detected by ultrasound and surgical re-excision after pathology diagnosis was not performed. In SE group, patients received SE with no intention to achieve a surgical margin >=1cm. Macroscopically negative margins is guaranteed by gross examination. Comparison of patients' features were performed using student t-test, Mann–Whitney u-test or Chi-sqaure test, when appropriate. Association between surgery (UGVAE & SE) and local recurrence was analyzed using univariate (Kaplan-Meier analysis) and multivariate approaches (Cox-regression analysis). Age, tumor size and the presence of accompanied fibroadenoma were included in the multivariate analysis. Results: Patients had significantly smaller tumor in the UGVAE group and those in the SE group (Median size: 2.1 vs. 3.0cm, P<0.01). There were more patients in the UGVAE group that had accompanied fibroadenoma, when compared with those in the SE group (67.2% vs. 29.1%, P<0.01). The median age was 38 and 37 in the UGVAE and SE group, respectively (P=0.66). With a median follow-up of 43 months, the 3-year and 5-year recurrence-free survival was 89.6% and 86.5% in UGVAE group, 97.3% and 90.0% in SE group, respectively (Log-rank test: P=0.26). In multivariate analysis, Surgery type (UGVAE or SE) (HR=0.37, P=0.19), age(HR=0.97, P=0.45), tumor size (HR=0.88, P=0.58) and the presence of accompanied fibroadenoma (HR=0.38, P=0.16) were not associated with recurrence-free survival. Conclusion: UGVAE alone did not significantly increase the local recurrence rate of benign phyllodes tumor, when compared with SE, in this study. A prospective study with more patients and longer follow-up is needed in future. Citation Format: Ouyang Q, Chen K, Zhu L, Song E, Su F. Comparison between ultrasound-guided-vacuum-assisted excision and surgical excision of benign phyllodes tumor of the breast: A single center retrospective study. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-12-19.