Real World Outcomes of Metastatic Rhabdomyosarcoma in Children Treated With a Multimodal Protocol: A Single Center Experience
Kruti Shah, Badira Cheriyalinkal Parambil, Venkata R.M. Gollamudi, Maya Prasad, Siddhartha Laskar, Nehal Khanna, Jifmi J. Manjali, Sajid Qureshi, Mukta Ramadwar, Poonam Panjwani, Vasundhara Patil, Akshay Baheti, Sneha Shah, Myvizhi Kannan, Girish ChinnaswamyBackground and Aims:
Metastatic rhabdomyosarcoma (RMS) at diagnosis has poor outcomes. We audited these outcomes in children at a tertiary sarcoma unit.
Methods:
Children aged 15 years or younger with RMS at first diagnosis staged by FDG-PET CECT scan between January 2013 and December 2024 were retrospectively analyzed. Pulmonary, lymph node, and oligometastatic bone disease were treated with curative intent on a multimodal protocol comprising chemotherapy and local therapy to the primary and metastatic sites.
Results:
Of 126 patients, 19% had isolated pulmonary, 81% had extrapulmonary metastases, with bone marrow involvement in 3.1%. After neoadjuvant chemotherapy in 73 patients (treated with curative intent), 74% had complete response (CR), 19% partial response (PR), 4% stable disease, and 3% progression. Local therapy to the primary was given to 68 patients (radiotherapy: 70.5%, surgery+radiotherapy: 22.1%, surgery: 7.3%), and metastatic sites were treated in 61.8%. At a median follow-up of 11 months (IQR: 3.31, 20.8), 2-year EFS and OS probabilities were 30.2% (95% CI: 19.8-41.2) and 44.4% (95% CI: 32.5-55.6), respectively; survival did not differ by metastasis site. Complete response at primary (HR: 0.09, 95% CI: 0.30-0.29,
Conclusions:
Despite multimodal therapy, metastatic rhabdomyosarcoma continues to have poor outcomes. Tumor size ≥3.3 cm in oligometastatic disease and bone marrow involvement predicted poor prognosis, while complete primary site response after neoadjuvant chemotherapy was associated with improved survival.