A. Greenbaum1, E. Alkhalili1, R. Rodriguez1, J. O’Neill1, O. Estrada Munoz1, F. Qeadan2, O. Myers3, I. Nir1, K. Morris1 1University Of New Mexico HSC,Surgery,Albuquerque, NM, USA 3University Of New Mexico HSC,Internal Medicine,Albuquerque, NM, USA 2University Of New Mexico HSC,Pathology,Albuquerque, NM, USA
Introduction: Native Americans (NA) have a higher incidence of and mortality from biliary tract cancers, though demonstrate lower pancreatic cancer incidence than non-Hispanic Whites (NHW). In this study, we examined the treatment and outcomes of pancreatic adenocarcinoma in Southwest NA. We hypothesized there would be no differences when comparing NA to NHW and Hispanics (H), which compromise the three main ethnic groups in our state.
Methods: A retrospective chart review was performed of all patients diagnosed with pancreatic adenocarcinoma and treated at a university National Cancer Institute (NCI) Comprehensive Cancer Center between January 2002 and July 2016. Data extracted included patient demographics, AJCC 7th edition staging at presentation, tumor resectability, treatment modalities offered and received, clinical outcomes and survival data. We employed multivariable logistic regression to determine the odds ratios (OR) and 95% confidence intervals (CI). Student’s t-Test and ANOVA tests were used to compare means of continuous values. Chi-square tests were used to assess associations among nominal variables. Overall survival (OS) was examined using Kaplan-Meier analyses. P-values less 0.05 were considered significant.
Results: A total of 457 patients met inclusion criteria. Our final cohort included 240 (52.5%) NHW, 186 (40.7%) H and 31 (6.8%) NA patients. After adjusting for age and sex there were no significant differences between ethnic groups in overall stage at presentation, presence of unresectable disease or distant metastases. All groups were offered surgery and received radiation therapy at similar rates. NHW (OR 2.41, 1.11 – 5.25. p 0.026) and H (OR 2.37, 1.08-5.24, p=0.032) were more likely to receive chemotherapy than NA at any stage of their treatment and for unresectable disease (OR 2.80, 1.13-6.88; p=0.025 and OR 2.48, 1.00-6.18; p=0.05). Kaplan-Meier models revealed no significant difference in OS between the three ethnic groups (median OS 12, 13 and 6 months in NHW, H and NA respectively; p=0.224). However, a significantly larger percentage of NA died within 1 month of diagnosis (25%) compared to 7.5% NHW (OR of being alive after 1 month 4.1, CI 1.56-10.90; p=0.004) and 9.1% H (OR 3.3, 1.24-8.88; p=0.017). There were no major differences in the number of comorbid conditions or Charlson Comorbidity Index scores between ethnic groups (mean scores 4.46 NHW, 4.58 H and 4.84 NA; p=0.63).
Conclusion:
Southwest NA diagnosed with pancreatic adenocarcinoma are less likely to receive chemotherapy and are significantly more likely to die within 30 days of diagnosis than NHW and H. The latter may be due to more biologically aggressive disease, though no differences in medical comorbidities, stage at presentation or overall survival were noted. Larger studies are needed to examine whether cultural factors and access to care due to financial or geographic constraints contribute to these findings.