MOST hepatitis B infections and liver cancer cases could be eliminated if the Government spent $300 per person on vaccinations, a doctor has said. Dr Ignatius Yu Tak-sun, lecturer at the Chinese University Department of Community and Family Medicine, said many of the 1,000 deaths from liver cancer each year in Hongkong could be prevented. He said the lack of action was an example of the low priority prevention and health promotion had in Hongkong. Liver cancer is the second most common malignant tumour in Hongkong, comprising 12.7 per cent of all cancer cases. Speaking after a seminar on Families at Risk, organised by the Hongkong University, Dr Yu said hepatitis B was believed to be the major contributory factor in liver cancer in the territory. In other countries the tumour was linked to alcohol abuse. Doctors estimated that about 10 per cent of the population - almost 600,000 people - were carriers of the deadly virus. Studies had shown that one in four hepatitis B carriers eventually developed liver cancer. ''We all know now that we can prevent hepatitis B by vaccination,'' Dr Yu said. ''If we can prevent the hepatitis B infection, it will result in much lower liver cancer rates.'' The Government vaccinates all newborn babies against the virus and is also vaccinating primary schoolchildren. Dr Yu said the Government should vaccinate all those at risk of infection - estimated at 50 per cent of the population after accounting for carriers and those already with antibodies. The vaccination would cost only $300 per person, he said. That might seem like a lot of money overall but it had to be compared to the huge cost of treating liver cancer patients and the emotional price paid by their families, he said. ''It is difficult to understand why we can commit ourselves to spending millions of dollars each year on treating liver cancer patients but still not choose to spend $300 per person to eliminate this highly endemic and deadly infection,'' he said.