(P 143) EXPLORING HOSPITAL VOLUME THRESHOLDS FOR IMPROVED SARCOMA TREATMENT ACROSS DIFFERENT AGE CATEGORIES IN THE UNITED STATES

Objective: Management of sarcomas is inherently complex due to their diverse nature, necessitating multidisciplinary care, challenging surgeries, a range of systemic therapies, radiation therapy, and long-term monitoring. Prior research has demonstrated that receiving treatment at high-volume hospitals is associated with improved outcomes, including better postoperative results and overall survival rates. Building upon these findings, our study aims to further characterize what hospital volume thresholds in management of sarcoma are necessary for improved outcomes across age groups.

Methods: Patients with Ewing sarcoma, osteosarcoma, rhabdomyosarcoma and non-rhabdomyosarcoma soft tissue sarcoma (NRSTS) who were treated at a single institution were queried from the National Cancer Database (NCDB) from 2004-2019. Patients were further divided into three age groups: children (0-17 years old [y.o.]), young adults (18-39 y.o.) and adults (≥40 y.o.). Multivariate models with restricted cubic splines were used to identify a hospital volume threshold by plotting the number of cases per year against the adjusted hazard ratio. Kaplan-Meyer survival curves and multivariate cox proportional regression accounting for age, sex, cancer type, cancer size and metastasis at diagnosis were then used to test the validity of the extrapolated threshold.

Results: A total of 71,463 patients were included in our study. Among them, 7,829 (10.94%) were children, 12,901 (18.07%) were young adults, and 50,733 (70.99%) were adults. Additionally, 31,569 (44.16%) were female. 4,093 (5.73%) patients had Ewing sarcoma, 55,668 (77.86%) had NRSTS, 8,342 (11.66%) had osteosarcoma, and 3,360 (4.70%) had rhabdomyosarcoma. Median follow up time was 49.5 months. The identified volume thresholds for high-volume hospitals (HVH) were 30 cases per year for patients of all ages, 5 for children and young adults, and 24 for adults. For all ages, 22 out of 1289 hospitals were identified as HVH, treating 25.03% of all patients. For children, 40 out of 443 were HVH, treating 43.73% of the patients. For young adults, 16 out of 970 were HVH, treating 18.18% of patients. For adults, 30 out of 1283 were HVH treating 19.18% of patients. When comparing 5-year overall survival rates, we found that HVH had higher rates of survival compared to non-HVH for all ages (64% vs. 60%), children (72% vs. 71%), and adults (63% vs. 57%). No difference was seen in 5-year OS by hospital volume in young adults (66% vs. 66%) . On multivariate cox proportional regression, being treated at these HVH was associated with increased survival in all groups (for all ages: Adjusted Hazard Ratio (aHR) 0.85, 95% CI 0.83-0.88, p< 0.001; for children: aHR 0.91, 95% CI 0.83-0.98, p=0.032; for young adults: aHR 0.94, 95% CI 0.88-0.99, p=0.048; and for adults: aHR 0.81, 95% CI 0.78-0.85, p< 0.001).

Conclusion: Treatment of sarcoma at HVH is associated with improved outcomes compared to non-HVH in children, young adults, and adults. Our study revealed distinct volume thresholds for hospitals caring for children, young adults, and adults with sarcoma, providing valuable guidance for healthcare professionals for enhancing the referral process and ultimately improving treatment outcomes.. By channeling patients to high-volume hospitals, we can maximize the chances of favorable outcomes.