First-line chemotherapy for malignant peripheral nerve sheath tumor (MPNST) versus other histological soft tissue sarcoma subtypes and as a prognostic factor for MPNST: an EORTC Soft Tissue and Bone Sarcoma Group study

Background: The role of chemotherapy in advanced malignant peripheral nerve sheath tumor (MPNST) is unclear. Patients and methods: Chemotherapy-naive soft tissue sarcomas (STS) patients treated on 12 pooled nonrandomized and randomized European Organization for Research and Treatment of Cancer Soft Tissue and Bone Sarcoma Group trials were retrospectively analyzed. Clinical outcomes, overall survival, progression-free survival (PFS) and response were determined for MPNST and other STS histotypes and compared. Additionally, prognostic factors within the MPNST population were defined. Studied cofactors were demographics, sarcoma history, disease extent and chemotherapy regimen. Results: After a median follow-up of 4.1 years, 175 MPNST out of 2675 eligible STS patients were analyzed. Outcome was similar for MPNST versus other STS histotypes, with a response rate, median PFS and overall survival of 21% versus 22%, 17 versus 16 weeks and 48 versus 51 weeks, respectively. Performance status was an independent prognostic factor for overall survival. Chemotherapy regimen was an independent prognostic factor for response (P < 0.0001) and PFS (P = 0.009). Compared with standard first-line doxorubicin, the doxorubicin-ifosfamide regimen had the best response, whereas ifosfamide had the worst prognosis. Conclusion: This series indicates the role of chemotherapy in treatment of advanced MPNST. This first comparison showed similar outcomes for MPNST and other STS histotypes. The apparent superiority of the doxorubicin-ifosfamide regimen justifies further investigations of this combination in randomized trials.