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

backgroundRacial/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.

methodsWe 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.

results7,622 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.

conclusionsNeighborhood 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. See related commentary by Lazo et al., p. 1254.