Differences in outcome for patients with cholangiocarcinoma: Racial/ethnic disparity or socioeconomic factors?

Background: Inequities in cancer survival are well documented. Whether disparities in overall survival (OS) result from inherent racial differences in underlying disease biology or socioeconomic factors (SEF) is not known. Our aim was to define the association of race/ethnicity and SEF with OS in pts with cholangiocarcinoma (CCA). Methods: Patients with CCA of all sites and stages in the National Cancer Data Base (2004-13) were included. Racial/ethnic groups were defined as non-Hispanic White (NH-W), non-Hispanic Black (NH-B), Asian, and Hispanic. Income and education were based on census data for patients' zip code. Income was defined as high (>$63,000) vs low (<$63,000). Primary outcome was OS. Results: 27,151 patients were included with a mean age of 68 yrs; 51% were male. 78% were NH-W, 8% NH-B, 8% Hispanic, and 6% Asian. 56% had Medicare, 33% private insurance, 7% Medicaid, and 4% were uninsured. 67% had low income. 19% lived in an area where >20% of adults did not finish high school. NH-B and Hispanic patients had more unfavorable SEF including uninsured status, low income, and less formal education than NH-W and Asian pts (all p < 0.001). They were also younger, more likely to be female and to have metastatic disease (all p < 0.001). Despite this, NH-B race and Hispanic ethnicity were not associated with decreased OS. Male sex, older age, non-private insurance, low income, lower education, non-academic facility, location outside the Northeast, higher Charlson-Deyo score, worse grade, larger tumor size, and higher stage were all associated with decreased OS (all p < 0.001). On MV analysis, along with adverse pathologic factors, type of insurance (p = 0.003), low income (p < 0.001), and facility type and location of treatment (p < 0.001) remained associated with decreased OS; non-white race/ethnicity was not. Conclusions: Disparities in survival exist in CCA, however they are not driven by race/ethnicity. Non-privately insured and low-income patients had decreased OS, as did patients treated at non-academic centers and outside the Northeast. This suggests that decreased ability to access and afford care results in worse outcomes, rather than biological differences amongst racial/ethnic groups.