EPIDEMIOLOGIC RESEARCH during the past decade has helped identify major risk factors for primary liver cancer in China. Public health efforts are now under way to help reduce several of these risk factors, says Shen-Long Ye, MD, PhD, professor and vice chair of Shanghai Medical University's Liver Cancer Institute.Ye says more than 137000 cases of primary liver cancer—more than 43% of all cases in the world—are diagnosed in China each year. Despite advances in diagnosis and treatment, the 5-year mortality rate for hepatocellular carcinoma, which makes up the vast majority of primary liver cancers, remains more than 95%. During the 1990s, liver cancer passed gastric cancer as the leading cause of cancer mortality in rural areas of China, with an annual death rate of 24 per 100000. In China's cities, it is second only to lung cancer, with an annual death rate of 20 per 100000.