Benign Phyllodes Tumor of the Breast Diagnosed After Ultrasound-Guided Vacuum-Assisted Biopsy: Surgical Excision or Wait-and-Watch?

The role of tumor-free resection in the treatment of benign phyllodes tumors (PTs) is still unknown. Ultrasound-guided vacuum-assisted biopsy (UGVAB) has been used for complete removal of benign breast lesions. This retrospective study aimed to compare the risk of relapse between patients with benign PT who undergo UGVAB and those who receive surgical excision (SE). Benign PT patients with a pathology diagnosis who had received treatment between 2005 and 2013 at the authors' hospital were identified. The patients who received UGVAB did not receive any SE. In the SE group, wide local excision or mastectomy was performed when appropriate. The Kaplan-Meier curve and Cox proportional hazards regression were used to analyze and compare the relapse-free survival (RFS) between the patients in the two groups. The study enrolled 225 female patients with benign PT. The patients in the UGVAB group (n = 108) had significantly smaller tumors, more fibroadenoma, a higher body mass index (BMI), and a lower Breast Imaging-Reporting and Data System classification than the patients in the SE group (n = 117). The 5-year cumulative RFS was 81.6 and 88.7 % (p = 0.11) respectively for the patients receiving UGVAB and SE during a median follow-up period of 35.5 months. After adjustment for age, tumor size, BMI, or presence of fibroadenoma, treatment (UGVAB vs. SE) was not associated with increased risk for relapse events (hazard ratio 0.34; 95 % confidence interval 0.08-1.43; p = 0.14). No distant metastasis or death events occurred. The patients with benign PT who received UGVAB alone did not have a significantly more compromised RFS than those who underwent SE. A prospective, randomized study is needed to confirm this observation.