Phyllodes tumors of the breast: a retrospective analysis of 57 cases.

INTRODUCTION: Current guidelines for the treatment of phyllodes tumors recommend wide local excision for all histopathological subtypes. However, it is unknown which subtypes have tendency to recur after marginal or incomplete excision. This may lead to over-treatment by re-excision surgery for tumors with little or no potential to recur. MATERIALS AND METHODS: All patients with benign, borderline or malignant phyllode tumors presenting at our institution between 2000 and 2016 were retrospectively analyzed. RESULTS: A total of 57 patients could be included, of which 39 tumors were benign (60%), three were borderline (5%), and seven were malignant phyllodes tumors (12%). There were also eight phyllodes-like fibroadenomas (14%). Fifty-two patients (91%) underwent local excision as primary treatment, resulting in tumor-positive or close-resection margins in 32 patients (61.5%) of whom five patients (15.6%) had re-excision surgery. During a median follow-up of 5 years, local recurrence occurred in four patients (7.0%) with a median time-to-recurrence of 12 months. Borderline and malignant subtypes were associated with a significantly higher recurrence rate compared to other subtypes (p = 0.039). CONCLUSION: Although an adequate tumor-negative resection margin should be obtained for borderline and malignant phyllodes tumors, this study confirms that wide local excision is the appropriate primary treatment for all histopathological subtypes. However, if tumor-negative margins were not obtained at first excision, a wait-and-see approach is justified for benign phyllodes tumors.