LAUSR

BACKGROUND Phyllodes tumor (PT) is a relatively rare breast tumor, accounting for <1% of all breast tumors. MAIN BODY Adjuvant therapy with chemotherapy or radiation therapy, other than surgical excision, has not been established yet. PT, similar to other breast tumors, is classified as benign, borderline, and malignant according to the World Health Organization classification system, depending on stromal cellularity, stromal atypia, mitotic activity, stromal overgrowth, and tumor border. However, this histological grading system cannot effectively or fully reflect the clinical prognosis of PT. Several studies have investigated prognostic factors for PT as some PTs recur or metastasize to distant sites, and thus, prediction of prognosis is clinically imperative. CONCLUSION This review discusses clinicopathological factors, immunohistochemical markers, and molecular factors that have been investigated in previous studies to have an impact on the clinical prognosis of PT.