(P 351) THE ROLE OF SOCIOECONOMIC DISPARITIES ON SURVIVAL OUTCOMES IN MALIGNANT PERIPHERAL NERVE SHEATH TUMORS

Objective: Malignant Peripheral Nerve Sheath Tumors (MPNST) are rare and aggressive sarcomas with poor prognosis. Factors influencing survival include status of neurofibromatosis type 1 (NF1), tumor size, and adequacy of resection margins. Emerging evidence indicates socioeconomic factors may also impact survival rates. This study aims to compare outcomes of MPNST patients (pts) treated at a tertiary center with national data, focusing on social determinants of health.

Methods: We conducted a retrospective study of pts with NF1-associated MPNST treated at MD Anderson Cancer Center (MDA) between 1980-2020. We collected data and assessed socioeconomic status using Center for Disease Control and Prevention's (CDC) Social Vulnerability Index (SVI), defining high vulnerability as SVI ≥0.5. We compared our results to the Surveillance, Epidemiology, and End Results (SEER) program. Survival analysis was performed using Cox regression and Kaplan-Meier methods.

Results: Of ~900 pts with NF1, 174 developed MPNST. At presentation, 72% had localized disease and 28% had metastases, compared to 54% localized and 34% metastatic in the SEER population. There was no difference in overall survival (OS) when comparing MDA localized NF1-MPNST to SEER cases. The median SVI was 0.80 (interquartile range [IQR], 0.57-0.92) for MDA pts with NF1-MPNST, with 141 pts categorized as having a high SVI (≥0.5-1.0) and 33 pts categorized as low SVI ( < 0.5). A lower educational level was independently associated with poorer OS (hazard ratio 4.2, P=0.008). Additionally, the MDA NF1-MPNST cohort included a higher proportion of African American (19.5% vs. 10.6%) and Hispanic (23.6% vs. 17.8%) pts compared to the SEER population (P=0.001). Finally, we compared the actual OS (aOS) of the NF1-MPNST cohort to the predicted OS (pOS) from the Sarculator and MONACO nomogram models. The aOS was found to be 35.8% (95% confidence interval 28.3% - 43.4%), significantly lower than the pOS of 69% (Sarculator) and 51% (MONACO).

Conclusion: High SVI and low education were linked to worse OS, suggesting that socioeconomic barriers affect access to care. Actual survival was markedly lower than predicted, underscoring the need to address social determinants to improve outcomes and highlighting the need to incorporate social risk factors into the research and care of rare cancers.