Local recurrence after breast-conserving therapy for phyllodes tumors: A 15-year retrospective review

There are few data on the long-term outcomes of patients with phyllodes tumors following breast-conserving surgery with or without radiation therapy (RT). We reviewed 69 patients diagnosed from 2000 to 2015 with surgical specimens available for central pathology assessment for outcome in relation to histopathologic subtype, margin width, and utilization of RT. Median follow-up was 63 months (interquartile range, 35-131 months). Forty-eight patients had benign, 13 borderline, and eight malignant phyllodes tumors, with local recurrence rates of 4%, 0%, and 38%, respectively (P ≤ .04 comparing malignant lesions to both benign and borderline lesions). None of the eight patients who received RT suffered a local recurrence. Two of the 26 (8%) patients with benign phyllodes tumors who did not receive RT with margins that were positive or <1 mm had local recurrence, compared to none of 18 patients with margins 1 mm or wider who did not receive RT. The one patient with a malignant phyllodes tumor who did not receive RT with margins that were positive or <1 mm did not locally recur, while both patients with margins 10 mm or wider who did not receive RT had local recurrence. One patient with a malignant phyllodes tumor developed distant recurrence following local recurrence. Phyllodes histologic type and margin width were both associated with the risk of local recurrence following breast-conserving surgery without RT, though the number of events and patients was too small to show these trends were statistically significant.