Abstract
e23539 Background: Spindle cell rhabdomyosarcoma (SC-RMS) is a rare malignancy characterized by elongated spindle cells displaying eosinophilic and fibrillar cytoplasm, resembling smooth muscle fibers. SC-RMS is primarily diagnosed in children with particular involvement of the nasopharynx, parotid gland, nasal cavity, and paratesticular regions. Though surgical resection and chemotherapy are the current recommendations, definitive treatment guidelines remain unestablished. Because SC-RMS is a novel cancer type, evaluating the diagnostic trend of the disease has the potential to provide valuable insights into its epidemiology. An analysis of the National Cancer Database (NCDB) was conducted to identify the demographic factors associated with patients who have been diagnosed with SC-RMS. Methods: A retrospective cohort analysis of the 2004–2020 NCDB, using ICD-O-3 code 8912/3, included patients with a histologically-confirmed diagnosis of SC-RMS (N = 132). Demographic factors (age, sex, race, Hispanic status, educational attainment, insurance status, facility type, distance from facility, and Charles/Deyo score) were analyzed by descriptive statistics and incidence trends were interpreted in regression analysis. Results: A total of 132 patients with a confirmed diagnosis of SC-RMS were identified, with a declining incidence of diagnoses per year (R² = 0.4507). The average age of diagnosis was 33.9 years (SD = 27.2, Range = 1-90). SC-RMS was more commonly observed among males (63%), with a majority of patients being non-Hispanic (87%) and White (74.2%). The top primary site was the testis (20%). Most patients (83%) had a Charlson/Deyo comorbidity score of 0. The majority (69%) of patients received surgery as their primary treatment. Most patients were privately insured (49%) and resided in metropolitan areas with a population greater than 1 million (48%). More (29%) patients were in the highest quartile of income earners of $74,063 or greater. Patients were treated most often at an academic/research program (19%) or comprehensive community care program (12%). Patients lived an average of 68.2 miles (SD = 267.9, Range = 0.6 - 2403.1) from the treatment facility. Conclusions: To the best of our knowledge, this is the first NCDB analysis on SC-RMS. Our analysis revealed that the majority of SC-RMS patients were young males with primary involvement of the testis, supporting previous studies. Analysis of the socioeconomic factors of SC-RMS patients revealed that more patients were privately insured, resided in densely populated metropolitan areas, and were part of the top quartile of income earners. Further research is supported to better understand the impact of socioeconomic factors on diagnosis, treatment options, and overall mortality rates associated with SC-RMS.