2001 CTOS Annual Meeting Posters— Radiation Oncology

RADIATION INDUCED LEIOMYOSARCOMA: A REPORT OF 3 CASES
Bruce E Brockstein¹,  Arno Mundt²,  Daniel J Haraf²,  Anthony Montag^2
1Evanston Hospital, Northwestern University,  ²University of Chicago

METHODS: Presentation of a series of three cases.

RESULTS: A variety of solid tumors have been reported to occur within the radiation fields of radiation administered for both benign and malignant conditions. A variety of bone and soft-tissue sarcomas have been reported to occur in this setting. Leiomyosarcoma, however, has rarely been reported as a secondary malignancy following radiotherapy. We report on three such cases. CASE #1: A 71 year old man was treated 10 years before presentation with a low anterior resection for rectal cancer, followed by 5-FU chemotherapy and radiation. Pulmonary metastases of unknown primary site were histologically identified as a high grade leiomyosarcoma. Subsequently, the primary site was identified as a perirectal mass extending into his left buttock. The patient was treated palliatively. CASE #2 A 60 year old man was treated over a 30 year period for relapsing midline destructive disease with surgery, antibiotics, and chemotherapy. In addition, he was treated with radiation to the mid-face 27 and 14 years prior to the current presentation. A small mass appeared beneath the left eye and prompted a CT scan of the face and sinuses, demonstrating a large left facial mass with involvement of the maxillary sinus and orbit. A biopsy revealed a high grade leiomyosarcoma. The patient was treated with three cycles of adriamycin and ifosfamide chemotherapy. Resection of residual tissue revealed only microscopic foci of leiomyosarcoma. He received 2 more cycles of adriamycin and ifosfamide, and remains well after a year. CASE #3- A 76 year old woman was treated 12 years prior for a T2N0M0 squamous carcinoma of the epiglottis with lasar excision, and 10 years prior with chemoradiation after recurrence of her cancer. The patient remained well, but was found to have a large, obstructive tracheal mass when she presented with stridor. Biopsy revealed a high grade leiomyosarcoma. The patient received one course of palliative chemotherapy before succumbing to her disease.

CONCLUSION: These 3 cases demonstrate that leiomyosarcoma may occur as a consequence of prior radiotherapy. Concomitant chemotherapy was given in all 3 patients reported here, and may play a role in the pathogenesis. Typical onset occurs after 10 years, and the clinical course may be variable.