Comparison of clinical characteristics between benign borderline and malignant phyllodes tumors of the breast.

BACKGROUND Phyllodes tumors of the breast are rare fibroepithelial lesions, so relatively little is known about this disease entity. The present study was designed to identify differences in clinical features between benign borderline and malignant phyllodes tumors. MATERIALS AND METHODS Data from 246 women with phyllodes tumors of the breast treated in Cancer Hospital Chinese Academy of Medical Sciences between 2002 and 2012 were collected and analyzed, including age at presentation, age at treatment, course, size of primary tumor, location, histological type, type of surgery and treatment, local recurrence, distant metastasis, fibroadenoma history, disease-free survival and number of mitosis per 10hpf. There are 125 (55%) benign, 55 (24%) borderline and 47 (21%) malignant tumors. RESULTS In univariate analysis, average age at presentation, average age at treatment, size of primary tumor, ulceration or not, type of primary surgery, distant metastasis and number of mitosis per 10 hpf turned out to be statistically different among the three PT types (p=0.014, 0.018, <0.000, 0.003, <0.000, 0.001 and <0.000, respectively), while recurrence and disease-free survival (DFS) demonstrated trends for statistical significance (P =0.055 and 0.060, respectively). Multivariate analysis revealed distant metastasis and excision were significantly different in benign, borderline and malignant phyllodes tumors of the breast (p=0.041 and 0.018, OR=0.061 and 0.051). At the same time, size of primary tumor with p=0.052 tended to be different between groups (OR=1.127). However, age at treatment, ulceration and DFS showed no statistically significant variation (p=0.400, 0.286 and 0.413, respectively). CONCLUSIONS Benign borderline and malignant phyllode tumors have different distant metastasis risk, different primary tumor size and different surgical procedures, and malignant PTs are more likely to be bigger and to metastasize.