Margin Management and Adjuvant Therapy for Phyllodes Tumors: Practice Patterns of the American Society of Breast Surgeons Members.

BACKGROUND: Phyllodes tumors (PTs) are rare breast neoplasms with variable clinical behavior by histologic type: benign, borderline, or malignant. Until recently, management guidelines recommended one approach for all subtypes.
METHODS: A 21-question survey was sent to American Society of Breast Surgeon members to evaluate management patterns by subtype. Surgeon demographics, decisions regarding management of margins, re-excision, surveillance, and synoptic reporting were collected. Chi-square or analysis of variance (ANOVA) were used as appropriate, with significance set at p < 0.05.
RESULTS: A total of 493 of 2969 surveys were completed for a response rate of 18.3%. Among the survey takers, 55% were fellowship trained, 72% were in practice > 10 years, and 82% performed > 100 breast cases per year. Although 25% of respondents enucleate a mass with clinical suspicion of a PT alone, this decreased to 18% if a preoperative core biopsy performed was suggestive of PT. For margin management, 47% do not re-excise positive margins for benign PTs, but 96% would for a borderline or malignant PTs (p < 0.001). Only 2% perform axillary staging for malignant PTs, and 90% refer borderline or malignant PTs for radiation. Two-year surveillance was performed by about half of respondents for benign PT. However, two-thirds of respondents would increase surveillance to 5 years for borderline or malignant PTs. Only 38% report a templated synoptic pathology report at their institution.
CONCLUSION: PT management patterns are evolving but still variable when looking at initial margin intent, decision for re-excision, radiation referral, pathologic reporting, and surveillance. This suggests the need for more specific management guidelines by subtype given differences in clinical behavior.