Patterns in advanced radiation technique use and survival for pancreatic ductal adenocarcinoma and neuroendocrine tumors: Insights from the NCDB (2004-2022).

Abstract

671 Background: Pancreatic ductal adenocarcinoma (PDAC) and pancreatic neuroendocrine tumor (pNET) encompass the predominant types of pancreatic cancer. PDAC hallmarks include chemoresistance and rapid progression. In contrast, pNET ranges from more indolent to very aggressive. While surgical resection remains standard of care, chemotherapy and radiation may supplement or be primary options if unresectable. Past studies have revealed disparities in which Black and Asian populations with PDAC are less likely to obtain care per guidelines and often present later with more advanced disease leading to worse survival rates. Similarly, in pNET, uninsured status, lower income and education attainment, and identifying as Black had worse associations with survival. Disparities have not been examined with focal consideration of conventional and advanced radiation modalities such as stereotactic body radiation therapy (SBRT) or proton therapy (PT). This study evaluates clinical practice patterns and survival outcomes of SBRT, PT, and conventional radiation treatment (CRT) in the National Cancer Database (NCDB) for PDAC and pNET. Methods: Patients diagnosed from 2004 – 2022 in the NCDB were selected using histology codes 8140, 8500, and 8150, 8240, 8246, and 8249, respectively. Demographic variables underwent descriptive analysis for patterns of care. Kaplan-Meier curves with log-rank tests were conducted for radiation treatment analysis. Data was analyzed using R version 4.4.2 with α = 0.05. Results: 73974 patients with PDAC or pNET were identified (CRT = 66302, SBRT = 7174, PT = 498). More comorbid conditions resulted in fewer patients receiving CRT (0 = 89.7% vs. 3+ = 84.4%), while use of SBRT increased (0 = 9.6% vs. 3+ = 15.1%). Utilization of SBRT and PT was increased if treated at an academic facility (6.8% to 13.3% and 0.4% to 1%). Moreover, those living rurally less often were treated with advanced options (3.2% vs. 5.3%). More Black patients were prescribed CRT (90.8%) compared to Caucasian patients (89.6%), while 0.7% in both subgroups for PT. Separately, more Asian patients (12.9%) were given SBRT than any other race. A significant difference in median survival existed between SBRT, PT, and CRT (17.8 vs. 18.7 vs. 15.4 months, p < 0.001). Further log-rank tests revealed significant differences for both SBRT and PT compared to CRT (p < 0.001). Conclusions: This study suggests SBRT and PT may offer extended survival over CRT in the most common pancreatic cancers. However, important demographic factors appear to signal distinct patient subsets more frequently and possibly disproportionately are prescribed advanced radiation treatment options. Future analysis should consider confounders and expand to tumor variables and assess for disparities with radiation. In this effort, the most important predictors of patient survival may be elucidated.