Disparities in late-stage pancreatic cancer: Retrospective analysis of genomic testing and outcomes between Hispanics and non-Hispanics.

Abstract

663 Background: Late-Stage Pancreatic Cancer (LS-PC) represents the 7th leading cause of cancer-related deaths worldwide. Hispanic (H) ethnicity is underrepresented in genomic studies and disparities have been demonstrated in overall treatment and outcomes. Germline, somatic tissue, and somatic liquid testing are effective tools that aid in identifying targeted genetic alterations. We comprehensively evaluated the differences in genomic testing among H and Non-Hispanic (NH) patients with LS-PC. Methods: This is a retrospective analysis of LS-PC with ductal adenocarcinoma from the University of Arizona Cancer Center from 2013 to 2021. Data collected included: patient demographics, clinical characteristics, treatment regimens, germline, somatic tissue, and somatic liquid genetic testing, and outcomes. LS was defined as unresectable and/or metastatic de novo or recurrence. Univariate comparisons used parametric and nonparametric tests as appropriate to evaluate for differences between H and NH groups. Fisher's exact tests were performed to evaluate the difference in frequency. Kaplan Meier and Cox regression analysis assessed progression-free and overall survival. Results: The analysis included 198 patients who had LS-PC with 20.7% H. 64.1%, 48.9%, and 48.9% of the patients had germline, somatic tissue, and somatic liquid testing, respectively. No significant differences were noted in baseline characteristics, treatments, and outcomes [PFS (HR 1.1, 95% CI 0.7-1.6, p=0.70) / OS (HR 1.2, 95% CI 0.7-1.9, p= 0.54)]. There was no statistically significant difference in common mutations or variants among groups. Conclusions: To our knowledge, this is the first and largest study to report LS-PC genomic and therapeutic implications in H patients. H were significantly less likely to receive germline screening and more likely to have potentially actionable pathogenic variants via somatic tissue and liquid biopsy testing. This highlights the importance of genetic testing to reveal mutations that can be targeted by clinical trials for LS-PC on minorities. Although our review revealed increased germline, somatic tissue, and somatic liquid biopsy genetic testing over time, there remains a critical need towards advancing genomic sequencing efforts to improve outcomes for LS-PC in the underrepresented H population.[Table: see text]