Phyllodes Tumors of the Breast: Recurrence and the Importance of Clinical Follow-up

AIM: Phyllodes tumors, including benign and borderline types, have a substantial potential for recurrence. The objective of this study was to evaluate histologic features that can help predict recurrences, and to emphasize the importance of close follow-up in this regard. MATERIAL AND METHOD: The demographic, clinicopathological characteristics, treatment approaches, and follow-up data of the 64 patients who were treated between 2006 and 2018 at the Istanbul University, Institute of Oncology with the diagnosis of phyllodes tumors were evaluated retrospectively by examining the patient files and pathology records. RESULTS: The median age was 38.8±12.2. The median tumor size was 53.1 mm (range, 11 mm to 210 mm). The phyllodes tumors were classified as follows: benign (n= 36, 56.3%), borderline (n= 11, 17.2%), and malign (n= 17, 26.6%). High mitotic number, cellular pleomorphism, stromal overgrowth, tumoral heterogeneity, and tumor margin irregularity were found to be independent prognostic factors in the development of local recurrence. The common feature of tumor recurrence in the process of benign and borderline phyllodes tumors was tumor margin irregularity. The mean period of recurrence of phyllodes tumors was determined as 29.7 months (range, 10 to 64). In the study, 7 out of 10 recurrences were observed when excision was performed with an insufficient surgical margin of closer than 1 cm, and in three cases when a clear surgical margin was obtained far than 1 cm (p= 0.045). CONCLUSION: Phyllodes tumors were classified as benign, borderline, and malignant. A negative surgical margin of ≥1cm plays a major role in the management of phyllodes tumors. The study may emphasize the importance of close follow-up, given that the recurrence period is short, especially if tumor margin irregularity is detected on definitive pathological examination, even if it is benign or borderline type. Keywords: Phyllodes tumor, breast surgery, margin status