Statistical analysis on the behavior and recurrence of breast phyllodes tumors.

e294 Background: Statistical analysis on the behavior, diagnosis accuracy, treatment, and recurrence of breast phyllodes tumors. Methods: Thousands of phyllodes tumor cases have been analyzed by mathematical statistics in order to assess the behavior, diagnosis, classification, treatment, recurrence, and five-year survival rates. Results: The age of breast phyllodes tumor patients generally ranges from ten years old to over eighty years old, and the disease most frequently occurs between ages of forty and fifty among various ethnicities. For clinic-pathological features, over 70% of the patients' tumors may be classified as benign, about 20% borderline, and less than 10% malignant. Patients who had ages over 40, larger tumor sizes, permeative borders, atypia, high stromal hypercellularity, and especially high mitotic activity were observed to develop borderline and malignant phyllodes tumor more frequently. Recurrences were noted in about 13% for all patients, but the ratio of recurrence rate of benign : borderline : malignant tumor is approximately 1: 1.5 : 3. A five-year survival rate was observed in almost 100% of patients with benign tumors, 98% with borderline, and about 88% with malignant. Accurate diagnosis at an early stage plays a vital role for effective treatment. Conclusions: Early stage accurate diagnosis, post-excision pathology analysis on the fibroepithelial tumor tissue for confirming the clinicopathological features, and wide excision (with negative margins) may reduce the risk of tumor recurrence and improve the respective survival rates of the breast phyllodes tumor patients.