Racial disparities in the survival time of patients with hepatocellular carcinoma and intrahepatic cholangiocarcinoma between Chinese patients and patients of other racial groups: A population-based study from 2004 to 2013

Abstract

The aim of the present study was to investigate the racial disparities in the presentation, treatment and survival time of patients with hepatocellular carcinoma (HCC) or intrahepatic cholangiocarcinoma (ICC) between Chinese and other racial groups from the Surveillance, Epidemiology, and End Results (SEER) database between January 1st 2004, and December 31st 2013. Key covariates, including clinical presentation, treatment and survival time, were recorded and compared, demonstrating the racial differences. Kaplan-Meier analysis and Cox regression models were performed to identify these disparities in survival time. A total of 30,954 patients were identified in the SEER database. Among these, 27,767 (89.7%) had HCC and 3,187 (10.3%) had ICC. In the HCC cohort, Chinese patients had the highest survival time. Compared with the mortality risk of Chinese patients, the mortality risk of Other Asian, non-Hispanic white, Hispanic and African-American patients increased by 16.8, 35.1, 28.3 and 33.3%, respectively. Compared with other groups, Chinese patients were more likely to present with localized stage, and without vascular invasion, adjacent invasion and metastasis. In the ICC cohort, the Chinese group had improved survival time, compared with the other groups following univariate analysis, although no significant differences were observed between Chinese and Other Asian and Hispanic patients following adjusting for contributing factors. Furthermore, there was no significant differences in the presentation between the groups, which differed from the HCC analysis. In conclusion, race/ethnicity was a significant independent prognostic factor in the HCC cohort, whereas it was not significant in the ICC cohort. The synergistic effect of contributing factors, including demographic, socioeconomic, biological and treatment differences, caused the racial disparity observed in primary liver cancer survival time.

Keywords: SEER database; population; primary liver cancer; racial disparities; survival analysis.

Figure 1.

The OS and CSS of patients with primary liver cancer according to race/ethnicity. (A) The OS of the HCC cohort. (B) The CSS of the HCC cohort. (C) The OS of the ICC cohort. (D) The CSS of the ICC cohort. OS, overall survival; CSS, cause-specific survival; NHW, non-Hispanic white; HCC, hepatocellular carcinoma; ICC, intrahepatic cholangiocarcinoma.

Figure 2.

Forest plot displaying the estimated HR and 95% CI of ethnicity for the CSS of hepatocellular carcinoma from the multivariate Cox models of all groups. The Chinese group was set as the reference. The first HR in the bottom is the crude effect of race/ethnicity followed by HRs following adjusting for contributing variables in a forward stepwise method, in order to determine their impact on CSS. Chinese patients had significantly improved survival time, which was demonstrated with univariate and multivariate analysis in each group. HRs of (A) NHW, (B) African-American, (C) Other Asian and (D) Hispanic patients. *P<0.05. HR, hazard ratio; CI, confidence interval; CSS, cause-specific survival time; NHW, non-Hispanic white; AFP, α fetoprotein.

Figure 3.

Forest plot displaying the estimated HR and 95% CI of ethnicity for the CSS of intrahepatic cholangiocarcinoma from the multivariate Cox models of all groups. The Chinese group was set as the reference. The first HR in the bottom is the crude effect of race/ethnicity followed by HRs following adjusting for contributing variables in a forward stepwise method, in order to determine their impact on CSS. (A) HR of NHW patients, where treatment was the only key factor. (B) HR of African-American patients, where Chinese patients had significantly improved survival time, which was demonstrated with univariate and multivariate analysis. (C) HR of Other Asian patients, where marital status, tumor biological and clinical variables were the key factors. (D) HR of Hispanic patients, where treatment was the only key factor. *P<0.05. HR, hazard ratio; CI, confidence interval; CSS, cause-specific survival time; NHW, non-Hispanic white; AFP, α fetoprotein.

Figure 4.

Univariate and multivariate analysis of CSS for patients with HCC and ICC following surgery. The results of the univariate and multivariate analysis are presented as a Kaplan-Meier curve and forest plotting, respectively. Forest plotting depicted the HR and 95% CI of each racial group, compared with the Chinese group, as a reference. (A) The Kaplan-Meier curve for patients with HCC. (B) Forest plotting of CSS for patients with HCC. (C) The Kaplan-Meier curve for patients with ICC. (D) Forest plotting of CSS for patients with ICC. *P<0.05. CSS, cause-specific survival time; NHW, non-Hispanic white; HR, hazard ratio; CI, confidence interval; ICC, intrahepatic cholangiocarcinoma; HCC, hepatocellular carcinoma.

Figure 5.

Comparison of the mean survival time for patients with HCC and ICC in Asian and other racial groups. ICC, intrahepatic cholangiocarcinoma; HCC, hepatocellular carcinoma; NHW, non-Hispanic white.

Figure 6.

Univariate and multivariate analysis of CSS for patients from Asian subgroups with HCC and ICC. The results of the univariate and multivariate analysis were presented as a Kaplan-Meier curve and forest plots, respectively. The forest plots depicted the HR and 95% CI of each racial group, compared with the Chinese group. (A) The Kaplan-Meier curve for patients with HCC. (B) Forest plotting of CSS for patients with HCC. (C) The Kaplan-Meier curve for patients with ICC. (D) Forest plotting of CSS for patients with ICC. *P<0.05. CSS, cause-specific survival; HR, hazard ratio; CI, confidence interval; ICC, intrahepatic cholangiocarcinoma; HCC, hepatocellular carcinoma.