Comparing Clinicopathologic Features and Outcomes Between Young Children, Adolescents, and Adults with Rhabdomyosarcoma at a Single Institution

BackgroundThere are limited data comparing clinical and pathologic features and outcomes of rhabdomyosarcoma (RMS) between young children, adolescent/young adults (AYAs), and adults. Design/MethodsWe performed a retrospective chart review of patients with RMS treated at our institution between 2000 and 2017. We compared clinical and pathologic features, treatment modalities, and outcomes among three different age groups (young children: <15 years of age, AYA: 15-39 years of age, and older adults: >39 years of age). ResultsAmong 65 patients, 33 (50.8%) were young children, 14 (21.5%) were AYAs, and 18 (27.7%) were older adults. Head and neck was the most common tumor site among young children, AYAs tumor sites were variable, while extremities were the most frequent location for adults. AYAs were more likely to have stage 4 disease at presentation (64.3% vs. 21.2% in children, p=0.01, and vs. 27.8% in adults, p=0.08). Similarly, clinical group and risk classifications were higher among AYAs as compared to the other two age groups. Tumors in children were alveolar and embryonal histology, while AYAs primarily developed alveolar RMS. Older adults had tumors with diverse histologies, including pleiomorphic and spindle cell. Children and AYAs received multimodal therapy, but a subset of adults did not. Five-year overall survival (OS) varied by age at diagnosis (p=0.001), with highest OS among young children (81.8%) following by adults (50.0%), with the lowest OS among AYAs (14.29%). ConclusionThis study highlights the need for ongoing collaboration between pediatric and adult multidisciplinary teams to improve outcomes for patients with RMS across the age spectrum.