Mediating Effects of Neighborhood-Level Socioeconomic Deprivation on the Association Between Race/Ethnicity and Advanced Hepatocellular Carcinoma

Abstract

Background: Racial/ethnic minorities are more likely than non-Hispanic whites (NHW) to be diagnosed with advanced stage hepatocellular carcinoma (HCC). We examined the role of neighborhood disadvantage as a mediator of the association between race/ethnicity and HCC stage at diagnosis. Methods: We used data from HCC cases diagnosed in Texas from 2007 to 2015. HCC cases were classified as local versus regional/advanced stage. A mediation model approach was used to estimate the average direct effect, average mediated (indirect) effect, total effect, and proportion mediated by the Area Deprivation Index (ADI), a composite measure of disadvantage. Results: 7,622 had local while 6303 had regional/advanced HCC. 46.1% of cases were NHW, 15.0% non-Hispanic Black (NHB), and 38.9% Hispanic. NHBs were less likely than NHWs to be diagnosed with local stage HCC [total effect RR, 0.921; 95% confidence interval (95% CI), 0.898–0.947]; however, only 2.26% of this effect was mediated through ADI. Conversely, Hispanics were more likely than NHWs to be diagnosed with local stage HCC (total effect RR, 1.019; 95% CI, 1.001–1.037) and ADI mediated 12.56% of the effect of race/ethnicity on HCC stage. ADI was not associated with HCC stage and therefore was not a mediator of the association with HCC stage when we compared Hispanics with NHBs. Conclusions: Neighborhood socioeconomic disadvantage may explain/mediate some of the association between race/ethnicity and HCC stage; however, the mediating effect was not uniform across populations. Impact: For NHBs, other individual and neighborhood level factors, not reflected in the ADI, contribute to their lower likelihood of being diagnosed with local HCC.