Is wide excision really needed? Correlation between resection margin and recurrence in benign phyllodes tumors of the breast

Purpose: Phyllodes tumors are similar to fibroadenomas in imaging and in pathological characteristics and are difficult to identify preoperatively. The purpose of this study was to analyze the recurrence rate after excision stratified by the surgical margin width and to propose and emphasize the "wait and watch" treatment strategy for benign phyllodes tumors. Methods: We performed a retrospective cohort study of patients diagnosed with benign phyllodes tumors by surgical excision between January 2000 and December 2022 at our institution. The medical and histopathological records were reviewed. Results: The results were obtained using the Cox proportional hazard regression and logistic regression. Resection margin status and recurrence were the independent variables. In each variable selection model, the resection margin was positive or less than 1 cm, and the recurrence rate was 3.7 and 1.04 times higher than the control group, but the difference was not statistically significant in 2 analyses. Conclusion: The surgical resection margin status of benign phyllodes tumors did not significantly affect locoregional recurrence. Therefore, follow-up imaging at short intervals without additional surgery is a feasible clinical option when the surgical resection margin is positive or less than 1 cm.