Adjuvant radiotherapy for phyllodes tumor of breast.

Our purpose was to examine the role of radiotherapy in the management of phyllodes tumor of the breast. Eight patients were treated with adjuvant radiotherapy for nonmetastatic phyllodes tumor of the breast at the M.D. Anderson Cancer Center between December 1988-August 1993. Tumors were classified as benign (n=2), borderline (indeterminate; n=1), or malignant (n=5). Median follow-up was 36.5 months. Primary surgery consisted of either lumpectomy in 2 patients or mastectomy in 6 patients. Seven patients received adjuvant radiation therapy to the breast or chest wall to a dose of 60 Gy. One patient received 50 Gy to the breast, followed by an interstitial boost of 20 Gy for a total of 70 Gy. Radiotherapy was administered for a combination of reasons, including bulky tumor volume, positive margins, recurrence, and/or malignant histology. There were no local or distant failures. This retrospective review suggests that adjuvant radiotherapy may be underutilized in the treatment of phyllodes tumor of the breast, particularly in patients with adverse features. Although treatment to the breast or chest wall (not the lymphatics) to a dose of 60 Gy appears effective, a dose-response has not been established, and lower doses (50-60 Gy) may be equally effective.