A study conducted by the Centre for Cancer Research of The University of Hong Kong Li Ka Shing Faculty of Medicine discovered that regular screening of liver cancer can achieve a higher rate of curative treatment and improve survival for liver cancer patients. Furthermore, survival results of patients with liver cancer detected by screening continued to improve over the past 15 years, whereas no significant improvement was observed in patients with symptomatic liver cancer. In view of the importance of early diagnosis and treatment in the fight against liver cancer, the Centre initiated the first community-wide liver cancer screening programme in Hong Kong in collaboration with private practitioners to encourage high-risk people to undergo regular screening.

Liver Cancer �V The Second Most Common Cause of Cancer Death

Liver cancer is a major cause of cancer mortality in Hong Kong, with around 1,600 new cases per year. It is the third most common cancer in males and the seventh most common cancer in females, and overall it is the second most common cause of cancer death.

Hepatitis B and C viruses are the main causes of primary liver cancer. In Hong Kong, it has been estimated that 10% of the population are hepatitis B virus carriers. Hepatitis B virus carriers have 100 to 200 times risk of developing primary liver cancer compared with non-carriers. Other risk factors, including alcoholism and genetic factors, have also been implicated as causes of primary liver cancer.

Screening Improves Treatment Results and Survival

Screening for liver cancer among high-risk persons by regular ultrasound examination and a serum tumor marker called alpha-fetoprotein allow detection of early cancers that are amenable to curative treatments. Unfortunately, the majority of liver cancer patients present with late-stage symptomatic tumors.

A study conducted by the Centre of Cancer Research of The University of Hong Kong Li Ka Shing Faculty of Medicine on 1,366 primary liver cancer patients with known chronic hepatitis B or C viral infection who were managed at Department of Surgery, Queen Mary Hospital between 1991 and 2004 discovered that:

(1) only 440 (32%) of the patients had their cancer detected by screening, while the others did not undergo regular screening despite that they are known high-risk persons;

(2) the mean tumor size at the time of diagnosis was much smaller in the group detected by screening compared with the patients with symptomatic presentation (3 cm versus 7 cm);

(3) the rate of curative treatments was higher in the former group (48% versus 34%);
(4) the 5-year survival rate was 51% versus 21%.

Furthermore, the survival results of patients with liver cancer detected by screening have improved significantly in recent years as a result of new curative treatments such as liver transplantation and radiofrequency ablation, whereas the survival of symptomatic patients has remained poor.

Community-wide Screening Programme for Liver Cancer

The study clearly shows that screening for liver cancer among high-risk persons improves the chance of cure and long-term survival. Unfortunately, there is no population-wide public screening programme for liver cancer in Hong Kong because of the tremendous cost involved.

High-risk persons for development of liver cancer, including hepatitis B or C virus carriers, first-degree family members of liver cancer patients, and patients with known cirrhosis, are recommended to undergo regular screening for liver cancer half yearly. To encourage high-risk persons to undergo regular screening, the Centre for Cancer Research has started a community-wide screening programme in collaboration with private practitioners in the whole territory of Hong Kong. Apart from promoting screening for liver cancer, the programme allows research on the genetic predisposition to liver cancer, which is important as familial primary liver cancer is not uncommon. Furthermore, serial blood samples of participants of the programme will be collected for research to identify new serum tumor markers which, together with identification of genetic factors for liver cancer, can lead to development of better screening strategy in the future.

Conclusion

Hepatitis B virus infection is a major public health problem in Hong Kong affecting 10% of its population, and primary liver cancer is the most serious complication that requires early detection to reduce the mortality rate. The Centre for Cancer Research of The University of Hong Kong Li Ka Shing Faculty of Medicine takes the first initiative to start a screening programme in collaboration with private practitioners. A population-wide screening programme is feasible only through such kind of collaboration between public and private medical sectors. The public media can play an important role in promoting this programme to the tens of thousands of high-risk people who currently are not undergoing screening because of the lack of knowledge of its importance or inadequate attention to their own health.