Malignant phyllodes tumor of the breast: treatment and prognosis.

Surgery remains the mainstay of the treatment in patients with malignant phyllodes tumor of the breast (MPTB); however, the extent of surgery (breast conserving surgery [BCS] versus mastectomy) and the role of adjuvant radiotherapy have been controversial. We report a single institution's experience with MPTB. We discuss controversial therapeutic aspects of this rare tumor. Seventy patients with MPTB treated primarily with surgery were evaluated. The mean age was 50 years (21-76), and the mean size of the tumor was 6 cm. Thirty-four (48.6%) patients were treated with total mastectomy, and 36 (51.4%) were treated with BCS (lumpectomy or wide local excision). Microscopic surgical margins were free of tumor in all cases. In 64 (91.4%) patients, margins were ≥1 cm. Remaining 6 (8.6%) patients treated with BCS margins were <1 cm and subsequently radiotherapy was performed. Among 70 patients, 58 (82.9%) had no evidence of disease (NED) after 5 years. The extent of surgery was not significantly related to the 5-year NED survival rates (82.4% in patients who underwent mastectomy and 83.3% in patients who underwent BCS only or BCS with adjuvant irradiation). The 5-year NED survival rates in BCS (tumor-free margin ≥1 cm) and BCS with irradiation (tumor-free margin <1 cm) groups were identical (83.3%). Our data support the potential use of BCS in patients with MPTB. Mastectomy is indicated only if tumor-free margins cannot be obtained by BCS. Adjuvant radiotherapy may be considered if tumor-free margins are <1 cm.