Successful treatment of metastatic alveolar rhabdomyosarcoma with MGMT gene promoter methylation by temozolomide-based combination chemotherapy.

A 3-year-old male presented with a large retroperitoneal mass and multiple metastases. Biopsy results suggested alveolar rhabdomyosarcoma bearing a methylated O6-methylguanine-DNA methyltransferase (MGMT) gene promoter. Serum microRNA-206 levels were elevated and remained high after three cycles of vincristine, dactinomycin, and cyclophosphamide (VAC). Replacement of vincristine, irinotecan, and temozolomide (VIT) for VAC induced a marked tumor reduction and normalization of the miR-206 levels. The patient completed 14 cycles of VIT with local radiotherapy and has been in remission for 31 months. Temozolomide could be effective for tumors with a methylated MGMT gene promoter. Individualized therapy is warranted for such patients.