Analyzing factors associated with the receipt of surgery in clear cell sarcoma.

Abstract

447 Background: Clear cell sarcoma (CCS) is a ultrarare soft tissue sarcoma, which is highly aggressive and associated with a poor prognosis. CCS is histologically characterized by clear cells, representative of intracellular glycogen accumulation. Primary tumors commonly arise from tendinous sheaths or aponeuroses in the upper and lower extremities—the most common site being around the ankles. Average age at diagnosis is 25 years old. 5-year survival is between 40 and 60%. CCS is the result of fusion gene EWSR1/ATF1. Multimodal therapy, including wide surgical excision with radiotherapy, is often used to treat CCS. Chemotherapy may be used if patients are not eligible for surgery. No significant study has analyzed the factors which predict the utilization of wide surgical excision. This study aims to describe the factors involved in the receipt of this surgery. Methods: The National Cancer Database (NCDB) was used to identify patients diagnosed with CCS from 2004 to 2020 using histology codes 9044 as assigned by the Commission on Cancer Accreditation program. Kaplan-Meier, ANOVA Chi-Square, and Logistic Regression tests were performed, and data were analyzed using SPSS version 27. Statistical significance was set at α = 0.05. Results: 669 patients with CCS formed the initial sample. Of these patients, 466 patients (69.7%) received a surgical procedure of the primary site. Additionally, 14 patients (2.09%) received radiation and 69 patients (10.31%) received adjuvant chemotherapy. The receipt of surgery was associated with a marked increase in median survival ( 91.5 months vs. 8.525 months; p<0.05). Surgical resection with clear margins was achieved in 409 patients (61.14%), of whom experienced improved survival compared to patients with residual tumor burden. Each additional year of age in a patient conferred a 2.4% decrease in likelihood of the patient receiving surgery. Lower stage disease was significantly more likely to be treated surgically (OR 11.4; p<0.001), while stage IV disease and abdominal primary site tumors were associated with lower rates of surgery. Facility type (academic vs. nonacademic), insurance, or distance travelled for care had no effect on rates of surgery. Conclusions: As a significant portion of CCS patients receive surgical treatment, this study confirms that tumor resection is associated with increased overall survival of patients with CCS. Improved survival with surgery correlates with clear surgical margins and full tumor resection. It appears that patients are more likely to be treated surgically if their disease is of lower stage. Patients with abdominal primary site tumors or stage IV disease are less likely to receive surgery. This research serves as the beginning of developing standardized treatment plans for CCS patients. Further studies are needed to better understand the factors involved in receiving surgery and other treatment modalities as part of CCS treatment.