Radiation therapy for malignant phyllodes tumors: An analysis of over 3,100 patients from 1998 to 2009.

183 Background: Malignant phyllodes tumors of the breast are uncommon. Currently, there are no standard treatment guidelines for adjuvant therapy. We hypothesized that there has been a trend towards increased use of radiation despite its uncertain effect on outcomes. Methods: Using the National Cancer Data Base, treatment trends and predictors of radiation utilization were examined for women with malignant phyllodes from 1998 to 2009. Kaplan-Meier and Cox regression were used to determine the effect of radiation on local recurrence (LR), disease-free survival (DFS), and overall survival (OS). Results: Of 3,153 patients, 57.4% underwent lumpectomy and 42.6% underwent mastectomy. Overall, 14.2% received radiation, with utilization doubling over the study period (9.2% in 1998 vs. 19.8% in 2009, p 10cm (OR 2.28, 95% CI ...