Treatment and outcome of patients with localized intrathoracic and chest wall rhabdomyosarcoma: a report of the Cooperative Weichteilsarkom Studiengruppe (CWS)

Purpose Rhabdomyosarcoma (RMS) is the most common pediatric soft tissue sarcoma. In 7% of the cases it is localized at the chest wall or intrathoracically. The aim of this study was to analyze the multimodal treatment concepts and outcomes of children suffering from intrathoracic and chest wall RMS treated within three different Cooperative Soft Tissue Sarcoma (CWS) trials and one registry (Soft Tissue Sarcoma Registry, SoTiSaR). Methods Data of 51 patients with thoracic RMS enrolled in three different CWS trials (CWS-86, -91, -2002P) and one registry (SoTiSaR) were analyzed retrospectively. Surgery and its influence on outcome were assessed. Median follow-up was 37.5 months (0.9-152.5). Results Median age of the patients was 8.8 years (range 0-19 years). The 5-year overall survival rate (OS) was 57% (95%-CI 49-65) and the 5-year event-free survival rate (EFS) was 45% (38-52). Thirty-five patients had tumors located at the chest wall (EFS: 51%, 43-59), and 16 patients had intrathoracic tumors (EFS: 26%, 13-39). Seventeen patients with tumors <= 5 cm had a better outcome (EFS: 64%, 52-76) compared to patients with tumors larger than 5 cm (EFS: 36%, 27-45). Radiotherapy (RT) significantly improved the survival of patients with alveolar RMS compared to patients with embryonal histology (EFS: 66%, 52-80 vs. 32%, 21-43 p = 0.02). Complete tumor excision during delayed surgery was the main prognostic factor for survival (p = 0.045). Conclusion Thoracic RMS is a rare tumor entity. Completeness of tumor resection significantly improved survival of the patients.