The number of liver cancer cases in Canada has tripled in men and doubled in women since the 1970s, health officials say. That development comes as the death rate for all cancers combined has been in decline for males in most age groups and for females in all age groups except over 70. In releasing its annual cancer statistics report Wednesday, the Canadian Cancer Society said that the incidence of liver cancer has risen every year by 3.6 per cent in men and 1.7 per cent in women. The greatest risk factors for liver cancer are chronic hepatitis B and hepatitis C infections, but the viruses aren\'t well recognized as health threats, the society said. One of the problems with the disease is that it does not develop symptoms or patients aren\'t aware that they have the problem until the disease is very advanced, at a very large and untreatable stage. To lower rates, the society said, it\'s important to find and treat people with hepatitis B or C, encouraging primary health-care providers to offer hep B vaccinations or testing for those at risk. Other risk factors for liver cancer include heavy alcohol use, obesity, diabetes and smoking. The report said that about 2,000 new cases of liver cancer are expected this year with about 1,000 deaths from the disease.