Analysis of demographic and socioeconomic factors in biphasic synovial sarcoma using data from the National Cancer Database.
Authors: Bitar Gabriel Anthony , Loken Delaney , Reddy Nisha , Grover Jasika , Silberstein Peter T. , Heise Craig , Hsia Beau 
Published: June 2024

e23524 Background: Synovial sarcoma, a rare type of soft tissue sarcoma, can be classified into two subtypes - biphasic and spindle cell. Of the two, biphasic synovial sarcoma (BSS) has a better 5-year survivorship; however, 35% of patients diagnosed with BSS die within 5 years. Despite past controversy, adjuvant chemotherapy has been found to improve overall survival for patients with stage III BSS. The National Cancer Database (NCDB) was examined to discover the demographics of individuals diagnosed with BSS. Methods: The 2004-2020 NCDB was analyzed to conduct a retrospective cohort analysis. Patients with a histologically confirmed diagnosis of BSS (ICD-O-3 code 9043) were included (N = 92). Demographic factors like age, sex, race, Hispanic origin, insurance status, educational attainment, distance from facility, facility type, and Charles/Deyo score were evaluated using descriptive statistics and incidence trends were interpreted with regression analysis. Results: Ninety-two biphasic synovial sarcoma cases sampled between 2004 and 2020 revealed an average age at diagnosis of 47.3 years (SD = 19.9, range = 5–87), with males being more likely to be diagnosed (58%). The patients reside at an average of 42 miles from treatment facilities (SD = 108.56, range = 0.3–800.6). Primary disease sites varied, including the lower lobe of the bronchus or lung (12%), upper lobe (11%), and long bones (11%). Diagnosis frequency (2004–2020) showed minimal variation (R^2 = 0.007). Palliative care was not received in 95% of cases, and 41% of patients did not undergo a surgical procedure at the primary site. In patients who received surgery, residual tumor absence post-resection was noted in 56% of patients. Primary treatments included chemotherapy (48%) and radiation therapy (42%), with an average tumor size of 65.2 mm (SD = 42.8, range = 9–195 mm). Notably, 74% survived beyond 90 days post-surgery, with a thirty-day mortality rate of 2%. Patients survived an average of 8.5 years post-diagnosis. Facility-wise, 37% were in academic/research programs. Privately insured patients constituted 60%, with 51% of all patients residing in metropolitan areas of 1 million or more. Conclusions: This analysis addresses a critical knowledge gap, offering insights into the demographics and socioeconomic factors affecting the diagnosis and treatment of Biphasic Synovial Sarcoma (BSS). The average age of BSS diagnosis is 47.3 years with males being predominantly affected, consistent with earlier case reports. BSS patients showed diverse geographic distribution. Survival beyond 90 days post-surgery was high. Chemotherapy and radiation therapy were common treatments. Unique findings include a majority residing in metropolitan areas, and non-academic program treatments. This study underscores the necessity for further research to grasp the impact of these factors on BSS diagnosis, treatment, and overall survival.