Rhabdomyosarcoma

Abstract

Rhabdomyosarcoma is a malignant soft tissue tumor of childhood, which resembles striated muscle. It can arise in a wide variety of locations, even those devoid of skeletal muscle, With the most common origin the head and neck, genitourinary tract, and extremities. Prognosis depends on patient age, tumor site and size, histology, completeness of resection, and biological factors, particularly the presence of the characteristic PAX-FOXO1 gene rearrangement. In the past 50 years, management has transitioned towards a multimodal approach with more conservative surgery while maintaining disease-free survival rates. Through serial clinical trials utilizing this approach, survival has increased to greater than 70%. Treatment assignment is based on a risk stratification depending on the pretreatment clinical stage, postresection surgico-pathologic group, and the histologic type. The role of the surgeon is crucial in pretreatment staging for risk allocation, as well as local control of the primary tumor. The goal of surgery is complete resection or achieve microscopic clearance of disease while preserving form and function. If initially unresectable, tumors are biopsied and treated with neoadjuvant chemotherapy. Primary re-excisions, delayed primary excisions, and second-look surgeries are employed for subsequent local control. Radiotherapy is used for local control of residual disease, and treatment of involved regional lymph nodes and selected distant metastases. Management and subsequent prognosis vary significantly with different anatomic sites, with excellent survival outcomes in genitourinary and orbital sites. Future developments involve the use of novel biologically targeted chemotherapeutic agents, particularly for advanced stage disease, and analysis of biological factors for better prognostication of outcomes (Yohe et al. Pediatr Blood Cancer. (2019) 66(10):e27869).