Hepatocellular carcinoma (HCC) is the second cause of cancer mortalities in Hong Kong and China. As such, the population would stand to benefit from a strong screening programme.

A recent study published earlier this year sought to compare the survival rates between a nearly 3000-strong cohort study of patients with liver cancer from both Japan and China. Philip Johnson from the University of Liverpool and several other researchers found that over 75% of cases in Japan are detected by their comprehensive surveillance programme, while less than 20% of Hong Kong patients are detected before the appearance of symptoms.

Stage of diagnosis of HCC was the most important factor in determining survival

When comparing the Japanese and Hong Kong cohorts, the median survival in Japan was 52 months in comparison to the 17.8 months in Hong Kong. The Hong Kong statistics, on the other hand, were 31.7% and 44.1%, respectively. Analysis of Japanese patients before and after the implementation of their nationwide screening programme revealed that patients who underwent screening had a much earlier disease stage.

Most of the Japanese patients had a diagnosis of hepatitis C, while the Hong Kong patients were more likely to have a hepatitis B infection. Despite the difference in aetiology, the Japanese patients had longer survival rates. Interestingly, the likelihood of there being ‘better treatments’ in Japan was negated by the fact that Hong Kong patients who were diagnosed early had better survival rates than their Japanese counterparts.

These findings underscore the importance of an effective screening system.

Liver cancer made up 11% of all cancer deaths in Hong Kong in 2015

There is a striking imbalance in the incidence of HCC with Asian countries facing a greater number of cases compared to the rest of the world. Southeast Asian countries (Thailand, Singapore, Malaysia) and East Asian countries (Taiwan, Korea, Hong Kong) have rates of 10 to 20 per 100,000 population versus Western countries, South America and Australia, which have rates of one to three individuals per 100,000 population.

No population wide screening programme exists in Hong Kong due to concerns on its cost-effectiveness. Current practice involves a combination of transabdominal ultrasound and alpha-fetoprotein (AFP) levels every six months in high-risk groups (those with liver cirrhosis, chronic hepatitis B/C carriers). Although the age-standardised death rate for HCC has been declining between 1981 and 2015 – HCC remains an important community health concern.

Surveillance programmes need tumour biomarkers and surveillance intervals

Studies show that nearly 40% of patients still die from liver cancer within five years despite regular surveillance in Hong Kong. This reveals a gap in the efficiency of the screening programme.

One factor could be that AFP has been noted to be neither sensitive nor specific enough for screening. In Japan, a total of five blood markers are used – bilirubin, albumin, lens culinaris agglutinin-reactive alpha-fetoprotein (AFP-L3), AFP and des-gamma-carboxy prothrombin (DCP) every three months. However, the regular utilisation of these sophisticated markers in the everyday practice may be unfeasible.

Despite the presence of a randomised control trial, the data from the study provides great support on the surveillance of HCC mortality. MIMS

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