A total of 306 individuals from South Vietnam were studied: 61 had a diagnosis of primary liver cancer (38 had a tissue diagnosis, and 23 had a clinical diagnosis and a positive alpha-fetoprotein); 9 had viral hepatitis; 101 were hospitalized patients (60 with various other forms of liver disease and 41 without liver disease); 94 were blood donors; 29 were drug users, and 12 were medical students. Alpha-fetoprotein was present in 45 of 61 (74%) of those with a diagnois of primary liver cancer (PLC) and in none of the other patients. Using immunoelectroosmophoresis, hepatitis BS antigen (HBSAg) was found no more frequently in those with PLC than in the other groups studied. In contrast, using a radioimmunoassay technique HBSAg was present 3 to 8 times as frequently in the PLC patients as in other subjects without viral hepatitis. There was a close relationship between the presence of alpha-fetoprotein and HBSAg in the patients with PLC. Malaria seropositivity rates were no different in the PLC groups than the other groups. It appears that in South Vietnam PLC is associated with an increased frequency of HBSAg.
