Vanderbilt University Medical Center Nashville, TN
L. Luo1, W. Xue2, A. Qumsera2, J. Vasquez3, R. Venkatramani4, S. L. Wolden5, and D. L. Casey5; 1Massachusetts General Hospital, Boston, MA, 2University of Florida, Gainesville, FL, 3Yale School of Medicine, New Haven, CT, 4Baylor College of Medicine, Texas Children’s Hospital, Houston, TX, 5Memorial Sloan Kettering Cancer Center, New York, NY
Purpose/Objective(s): Rhabdomyosarcoma patients with metastatic disease have a poor prognosis despite therapy intensification. The aim of this study was to investigate the efficacy of whole lung irradiation (WLI) in patients with rhabdomyosarcoma and lung metastases. Materials/
Methods: Rhabdomyosarcoma patients with lung metastases enrolled on four Children’s Oncology Group protocols (D9802, D9803, ARST08P1, ARST0431) were retrospectively reviewed. Event-free (EFS) and overall survival (OS) were compared between patients who received and did not receive WLI. Results: In 143 analyzable rhabdomyosarcoma patients with lung metastases, 65 patients (45.5%) received WLI, 78 patients (54.5%) did not receive WLI despite protocol requirements. 5-year EFS was 38.3% (95% CI 24.8%-51.8%) in patients who received WLI and 25.2% (95% CI 13.8%-36.6%) in patients who did not receive WLI, (p=0.0496). 5-year OS was 45.5% (95% CI 31.8-59.3%) in patients who received WLI and 32.4% (95% CI 20.4%-44.4%) in patients who did not receive WLI (p=0.08). In exploratory subgroup analyses, the benefit of WLI on EFS and OS was significant in patients 10 years and older. Other clinical factors associated with EFS on univariate analysis included age, histology FOXO1 fusion status, number of metastatic sites, location of metastatic sites, and Oberlin Score. Conclusion: Rhabdomyosarcoma patients with lung metastases who received WLI had improved EFS compared to patients who did not receive WLI. These results support the use of WLI and highlight the need for more stringent protocol compliance for administering WLI.
