Background/Aim: Phyllodes tumors of the breast are rare fibroepithelial neoplasms with heterogeneous biological behavior. Reliable preoperative predictors of non-Benign (borderline and malignant) tumors remain incompletely defined. This study aimed to identify clinical predictors of non-Benign phyllodes tumors and to evaluate long-term outcomes. Patients and Methods: We retrospectively analyzed 106 patients who underwent surgical resection for breast phyllodes tumors at a single institution. Tumors were classified as benign, borderline, or malignant according to World Health Organization criteria. The presence of rapid tumor growth was determined based on clinical records. Univariate and multivariate logistic regression analyses were performed to identify predictors of non-Benign tumors. Local recurrence-free survival was assessed using long-term follow-up data. Results: Of the 106 tumors, 54 were benign, 46 borderline, and 6 malignant. The median follow-up period was 109 months. In univariate analysis, age and the presence of rapid tumor growth were significantly associated with non-Benign tumors. Multivariate analysis demonstrated that both age and the presence of rapid tumor growth were independent predictors of non-Benign phyllodes tumors. Tumor size and preoperative diagnosis were not independently associated with non-Benign tumors. Only one case (0.9%) of local recurrence was observed, and no distant metastases occurred during follow-up. Conclusion: Breast phyllodes tumors have an excellent long-term prognosis with a very low risk of recurrence. Age and the presence of rapid tumor growth are useful clinical indicators for predicting non-Benign phyllodes tumors and may aid in preoperative assessment and clinical decision-making.
Tsukiyama et al. (Mon,) studied this question.