Hepatitis B virus, aflatoxins, and hepatocellular carcinoma in southern Guangxi, China.

We examined the roles of the hepatitis B virus and aflatoxin B1 in the development of primary hepatocellular carcinoma (PHC) in a cohort of 7917 men aged 25 to 64 yr old in southern Guangxi, China, where the incidence of PHC is among the highest in the world. After accumulating 30,188 man-yr of observation, 149 deaths were observed, 76 (51%) of which were due to PHC. Ninety-one% (69 of 76) of PHC deaths were hepatitis B surface antigen (HBsAg) positive at enrollment into the study in contrast to 23% of all members of the cohort (RR = 38.6). Three of the four patients who died of liver cirrhosis also were HBsAg positive at enrollment. There was no association between HBsAg positivity state and other causes of death. Within the cohort, there was a 3.5-fold difference in PHC mortality by place of residence. When estimated aflatoxin B1 levels in the subpopulations were plotted against the corresponding mortality rates of PHC, a positive and almost perfectly linear relationship was observed. On the other hand, no significant association was observed when the prevalence of HBsAg positivity in the subpopulations was compared with their corresponding rates of PHC mortality.

Preserved foods and nasopharyngeal carcinoma: a case-control study in Guangxi, China.

One hundred twenty-eight mothers of nasopharyngeal carcinoma (NPC) cases under age 45 in Yulin Prefecture, China and 174 mothers of population controls were interviewed as part of an epidemiological study to examine childhood exposures in relation to the development of NPC. Exposure before age 2 years to a number of fermented foods was a risk factor for NPC. During weaning, intake of salted fish [relative risk (RR) = 2.6, one-sided P (P) = 0.01], salted duck eggs (RR = 5.0, P = 0.03), salted mustard green (RR = 5.4, P = 0.03), and chung choi (RR = 2.0), P = 0.003), a kind of salted root, was significantly related to an increased risk of NPC. Between ages 1 and 2 years, intake frequency of dried fish [P for linear trend test (linear trend P) = 0.002], fermented black bean paste (linear trend P = 0.0009), and fermented soy bean paste (linear trend P = 0.007) was also positively associated with NPC. A multivariate analysis of these different foods showed all except fermented black bean paste to be independently related to NPC.

Risk factors for hepatocellular carcinoma in Guangxi, People's Republic of China.

Fusui County in the Guangxi Autonomous Region of China is a high-risk area for hepatocellular carcinoma (HCC). In 1971-73, the average annual standardized (world population) mortality rate of HCC in Fusui was 20.09 and 111.75/100,000 person-years for females and males, respectively. Epidemiologic and pathologic studies of HCC have been conducted in Fusui since 1959. This paper describes some of the studies relating to the hepatitis B virus infection and aflatoxin contamination of foodstuffs.

A serological case-control study of primary hepatocellular carcinoma in Guangxi, China.

Guangxi is a very high-risk area for primary hepatocellular carcinoma (PHC); the age-standardized (world population) rates for males and females in that Chinese Autonomous Region were 32.5 and 8.5, respectively. Blood specimens from 50 PHC patients and 50 age- and sex-matched controls in Guangxi were analyzed for hepatitis B surface antigen, antibody to hepatitis B surface antigen, and antibody to hepatitis B core antigen. Eighty-six % of cases were hepatitis B surface antigen positive, compared to 22% of controls (relative risk, 17.0). We estimate from the data that persistent hepatitis B virus infection can account for at least 80% of all PHC cases occurring in Guangxi. The consistency of our findings with those from Hong Kong and Taiwan strongly suggests that hepatitis B virus infection is also an important risk factor for PHC in other parts of southern China.