Carboplatin/etoposide induces remission of metastasised malignant peripheral nerve tumours (malignant schwannoma) refractory to first-line therapy

Abstract

Malignant peripheral nerve tumours (MPNT), e.g. malignant schwannoma, represent a relatively rare tumour entity which is usually regarded as a member of the group of soft-tissue sarcomas and treated accordingly. For chemotherapeutic approaches in metastasised disease, ifosfamide and doxorubicin have been identified as the most efficient agents, with overall response rates distinctly less than 50%. In case of non-response, recommendations for effective second-line regimens are lacking. We present the case histories of two patients with pulmonary metastasised MPNT that was primarily refractory to ifosfamide/doxorubicin. Both patients developed a partial remission with tumour reduction exceeding 50% after treatment with carboplatin in combination with etoposide (CE), 150 mg/m2 each, days 1-4 in 4-week intervals. Complete resectability of lung metastases could be achieved, with histologic evidence for advanced tumour regression at the time of resection. Patients remain in stable complete remission 20 and 28 months after surgery, respectively. Major CE-associated toxicity was cumulative myelosuppression, especially thrombocytopenia, reaching WHO grade 4. To our knowledge, this is the first report showing that CE is a possibly successful chemotherapeutic regimen in advanced MPNT, although further studies are necessary to evaluate its efficacy.