Radiation-Induced Leiomyosarcoma: Does Antimetabolite Chemotherapy Contribute? A Report of Three Cases

PURPOSE Radiation therapy in low and high doses is known to be associated with the occurrence of late secondary sarcomas. The addition of chemotherapy has not been clearly demonstrated as a contributing factor. We describe three patients with radiation-associated leiomyosarcoma who had also received antimetabolite chemotherapy. METHODS Three cases of leiomyosarcoma occurring 9-27 years after radiation and antimetabolite chemotherapy are presented, along with histopathological details. A Medline search was used to assess prior reports of leiomyosarcoma after radiation. RESULTS These three cases appear to be the first reported in which leiomyosarcoma followed therapy with radiation and antimetabolites. DISCUSSION With the increasing use of antimetabolite therapy combined with radiation, there is the potential for more occurrences of leiomyosarcoma or other post-treatment sarcomas.