Liver cancer will strike an estimated 14,500 Americans in 1999, according to the American Cancer Society. Most will get hepatocellular carcinoma. Only 5 percent of people with hepatocellular carcinoma are alive five years after diagnosis, because the tumors usually are found only after the cancer has spread. The cancer is often caused by chronic hepatitis B and hepatitis C, viral diseases that lead to liver scarring, known as cirrhosis, which in turn can lead to liver cancer. Hepatitis also can cause other changes in liver cells that make them cancerous.
Alcoholism is another leading cause of cirrhosis and liver cancer.
But alcoholism is declining and hepatitis B infections are slowing because of a vaccine and effective treatments. So researchers believe most of the increase in liver cancer is due to hepatitis C, a disease discovered a decade ago. Many Americans with hepatitis C got it from transfusions before the blood supply was cleaned up by 1992. The virus can also be spread between drug users sharing needles, and in rare cases, through sex. In half of all cases, doctors do not know how patients got it.