Race, socioeconomic status, treatment, and survival time among pancreatic cancer cases in California

Abstract

Background: Poor survival in pancreatic adenocarcinoma is associated with African-American race and also with low socioeconomic status (SES). However, it is not known whether the observed poor survival of African-American pancreatic adenocarcinoma cases is due to SES itself and/or treatment disparities. We set out to determine this using the large, population-based California Cancer Registry (CCR) database as a model.

Methods: We conducted a case-only analysis of CCR data (1989-2003), including descriptive analysis of relevant clinical variables and SES. The SES variable used has been derived from principle component analysis of census block level CCR data linked to census data to address seven major indicators of SES. Overall survival univariate analyses were conducted using the Kaplan-Meier method. Multivariate survival analyses were done using Cox proportional hazards ratios (HR).

Results: Incident cases of pancreatic cancer (24,735) were analyzed. Among adenocarcinomas, after adjustment for age, year of diagnosis, and gender, African-Americans [HR, 1.14; 95% confidence interval (95% CI), 1.08-1.21] and Hispanics (HR, 1.06; 95% CI, 1.01-1.11) had an increased risk of death compared with Caucasians. These differences persisted after adjustment for stage. However, after further adjustment for SES, surgery, radiation, and chemotherapy, the risk of death for African-Americans (HR, 1.00; 95% CI, 0.94-1.06) and Hispanics (HR, 0.97; 95% CI, 0.93-1.02) was not statistically different from Caucasians.

Conclusions: Differences in treatment and SES likely account for the observed poor survival of African-Americans and Hispanics among pancreatic adenocarcinoma cases. These data highlight the importance of improving access to care for ethnic minority pancreatic cancer patients.