Phyllodes Tumors: Race-Related Differences

BACKGROUND: Phyllodes tumors (PT) are rare breast malignancies accounting for 0.5% to 1% of all breast tumors. PT have unpredictable behavior, with recurrence rates as high as 40%. A dearth of information exists about racial differences; elucidation of these differences is the objective of this study. STUDY DESIGN: A retrospective review of patients treated for PT at either Moffitt Cancer Center or University of Texas Health Science Center San Antonio from 1999 to 2010. RESULTS: Of the 124 patients, 71 (57%) were treated at Moffitt Cancer Center and 53 (42%) at University of Texas Health Science Center San Antonio. Mean age at diagnosis was 44 years (15 to 70 years). Thirty-three patients required mastectomy. Combining both cohorts, 42% of the patients were Caucasian, 43% were Hispanic, and 12% were black. Tumors were benign in 49% patients, borderline in 35%, and malignant in 16%, with a higher percentage of borderline and malignant tumors in Hispanic patients (p < 0.01). Hispanic patients tended to have larger tumors and higher mitotic rates (p = 0.01; p = 0.03). At a median follow-up time of 13 months, the local recurrence rate (6.4%) was associated with tumor size, tumor grade, mitotic rate, and close margin status (<2 mm) (p < 0.01; p < 0.01; p = 0.01; p = 0.04). However, these findings did not translate into a survival difference by race. CONCLUSIONS: In this multi-institutional review of PT we found substantial pathologic differences by race with higher-grade tumors present more often in Hispanic patients. These differences did not substantially affect outcomes at short-term follow-up. Further investigation into additional molecular, biologic factors, geographic impact, and socioeconomic factors is needed to more clearly delineate this finding. (J Am Coll Surg 2011;213:537-542. (C) 2011 by the American College of Surgeons)