Risk Factors for Recurrence of Malignant Phyllodes Tumors of the Breast

Abstract

Background/Aim: In this study, the treatment outcome and risk factors for recurrence in patients undergoing surgery with or without adjuvant radiotherapy (RT) for malignant phyllodes tumors of the breast (MPTB) were analyzed. Patients and Methods: Forty-three patients (61.4%) underwent breast-conserving surgery (BCS) and 27 (38.6%) underwent mastectomy. Fifteen patients (21.4%) received adjuvant RT. Results: With a median follow-up of 76 months, the 7-year local control (LC), distant metastasis-free survival (DMFS), disease-free survival (DFS), and cause-specific survival (CSS) rates were 90.7%, 85.2%, 80.3%, and 87.1%, respectively. Either the extent of surgery or treatment with adjuvant RT did not affect the outcomes. On multivariate analysis, the presence of tumor necrosis was associated with inferior DFS (p=0.017), while infiltrative tumor border showed a marginal significance (p=0.078). When stratified using these two adverse pathological features, the 7-year DFS rates were 100%, 54.9%, and 55.6% in patients with 0, 1, and 2 risk factors, respectively (p=0.002). Conclusion: MPTB patients undergoing surgery with or without adjuvant RT had a favorable outcome. Although there was no local recurrence in patients treated with adjuvant RT, the effect of adjuvant RT failed to reach a statistical significance. Risk-grouping based on pathological features might help design a clinical trial for MPTB.