HCC in SG: NASH aetiology on the rise, curative therapy more accessible

Hepatocellular carcinoma (HCC) in Singapore has changed markedly throughout the last decade, with patients being diagnosed at an increasingly older age and cryptogenic cirrhosis/nonalcoholic steatohepatitis (NASH) becoming a more important aetiology, according to a recent study.

Although the impact of chronic hepatitis B (CHB) infection has waned over time, it still remains a predominant risk factor for HCC.

The current study “is the largest single study of HCC patients in Singapore,” the researchers said. “The study population spanned over nearly four decades from all three tertiary hospitals in Singapore. Hence, it is an accurate representation of the epidemiology of HCC in the country. This is also the only study to date that describes the treatment landscape of HCC in Singapore.”

A total of 3,017 HCC patients from the Singapore General Hospital, Tan Tock Seng Hospital, and National University Hospital were enrolled into the current study. Participants were divided into two groups according to the date of HCC diagnosis: cohort A (diagnosed before 2008; n=1,334) and cohort B (diagnosed from 2008 onwards; n=1,679). Cohorts were compared in terms of patient demographics, disease aetiology, and treatment.

Patients in cohort B were diagnosed with HCC at a slightly but significantly older age than cohort A comparators (mean, 68.6±11.2 vs 61.2±12.6 years; p<0.001). There was also a significantly higher percentage of foreigners diagnosed with HCC from 2008 onward (6.7 percent vs 4.3 percent; p=0.007). [JGH Open 2021;5:1015-1018]

Overall, CHB emerged as the dominant aetiology of HCC, explaining 52.1 percent of all cases. This was followed distantly by cryptogenic cirrhosis/NASH (22.7 percent) and alcohol consumption (15.4 percent).

However, analysis by decade showed that the proportion of HCC diagnoses due to CHB was declining, dropping from 57.2 percent in cohort A to 46.6 percent in cohort B (p<0.0001). In contrast, cryptogenic cirrhosis/NASH showed increasing importance as an HCC aetiology (18.6 percent vs 27.1 percent; p<0.0001). There was no significant change over time in the proportion of HCC diagnoses due to alcohol use.

Aside from aetiology and demography, treatment patterns for HCC also showed significant changes over the years. There was a significant increase in the percentage of patients who were able to receive curative treatment (27.1 percent to 43.7 percent; p<0.0001), but a decline in best supportive care (44.7 percent to 26.8 percent; p<0.0001). The rate of palliative therapy remained consistent.

Though the present study confirms that CHB is still the most predominant risk factor for HCC in Singapore, “there is already an increasing importance of NASH/cryptogenic cirrhosis and undoubtedly its prevalence will grow in the near future,” the researchers said.

“Patients were increasingly amenable to curative therapy,” they added. However, there remain a substantial number of patients without any active treatment option, and this is a strong impetus for a more robust HCC surveillance programme in our at-risk population to enable diagnosis of HCC at an earlier treatable stage. Likewise, there should also be more vigilance in identifying and managing patients at risk for NASH.”