The most significant conclusion from this study is that Asian-Americans with HCC in our cohort presented with earlier stage liver disease compared to non-Asian-Americans. Though not statistically significant, fewer Asian-Americans had cirrhosis. However, the Asian-Americans who did have cirrhosis had statistically significant earlier stage cirrhosis by Child-Pugh and MELD score. Furthermore, being Asian-American was independently associated with lower Okuda score on multivariate analysis. There may be several explanations for these findings.
One main reason is the higher incidence of HBV in the Asian-American patients with HCC compared to non-Asian HCC patients, which has been shown in this study as it has in many previous studies. There is a higher incidence of HCC in pre-cirrhotic individuals with HBV, and chronic HBV infection can promote hepatocarcinogenesis in the absence of cirrhosis [24
]. When HBV patients with HCC and HCV patients with HCC were directly compared in our study, those with HBV did have significantly lower Child Pugh scores than those with HCV. However, the mean MELD score and Okuda score were not significantly different in both groups.
Two other possible explanations for earlier stage liver disease in Asian-Americans with HCC are the lower incidence of alcohol use in Asian-Americans and the lower percentage of Asian-American patients with BMI ≥ 30. Previous studies have linked excessive alcohol use to the development of HCC [25
], and concomitant alcohol use in the setting of other underlying liver disease may accelerate the progression of liver disease. The same line of reasoning may be used for patients with a BMI ≥30 as these patients are at increased risk of developing non-alcoholic steatohepatitis and fibrosis [27
One other possible explanation for the earlier stage liver disease in our cohort of Asian-Americans with HCC is implementation of HCC screening. It has been reported that healthcare providers with Asian language abilities and greater knowledge of HBV risk factors and screening guidelines were more likely to screen for HBV [28
]. Given the high number of Southeast Asians who live in Southern California, it cannot be discounted that healthcare providers taking care of our cohort of patients may been more aware of specific issues related to Asian-Americans, such as higher incidence of HBV and the need to screen for HCC. However, further studies will be needed to determine whether appropriately screened patients actually resulted in an earlier diagnosis of HCC in these patients.
Our study emphasizes another important point that is often overlooked. Although HBV is very prevalent in the Asian community as a cause of HCC, HCV is also important and accounted for 37% the HCC in Asian patients in this study. This is consistent with the reported prevalence of HCV in Asian populations at 3–8% in Southeast Asia [30
]. Though HCV-cirrhosis is more often associated with HCC [31
], a significant incidence of HCC was found in patients with pre-cirrhotic fibrosis in the prospective HALT C trial [35
]. It is clear that besides HBV, HCV is also a major cause of HCC in the Asian population. These patients should be identified and screened regularly along with those patients with hepatitis B.
The presence of cirrhosis and hepatic decompensation may impact the management and outcome of HCC. Decompensated liver disease may contraindicate surgical resection [37
], or other ablation therapies, such as radiofrequency ablation [39
]. Wong et al. reported that Asian and Pacific-Islander American patients with HCC presented with earlier stage cirrhosis compared to non-Asian American patients [13
]. However, as treatment data and survival data were not collected, this present study was not able determine whether a lower frequency of decompensated cirrhosis, together with earlier stage of HCC, would imply a better outcome of HCC in Asian-American patients, which has been reported previously [14
In summary, in our single center cohort study of HCC patients, being Asian-American was an independent risk factor predicting earlier Okuda stage on multivariate analysis, and Asian-Americans presented with earlier stage cirrhosis. Obviously, there were severe limitations to our study, including the retrospective nature of the study, referral bias, and the study being solely at a single tertiary care center. Additionally, the present study was not able to compare HCC presentation among subgroups of Asian Americans. Thus, the results should be interpreted with caution. Nevertheless, our study underscores the need for further prospective studies to identify specific factors placing patients at higher risk for HCC and to appropriately screen these patients in hopes of an earlier diagnosis and, therefore, better options for managing HCC.