Longitudinal study of aflatoxin exposure in the development of primary liver cancer in patients with chronic hepatitis

Abstract

To study the relationship between aflatoxin exposure and the development of primary liver cancer (PLC) in patients with chronic hepatitis. A 21-year longitudinal study was carried out in a large cohort of 515 PLC high-risk individuals with HBV infection in PLC high prevalence region. (1) The PLC year-incidence of cohort was 1437.25/100,000. And it was significantly higher than that of the same natural peoples (184. 53/100,000, P = 0.000, RR = 7.79). There was no significant difference in the incidence of other tumors between these two groups (P = 0.576). (2) The PLC patients in the cohort were diagnosed at an average age 1.4 year younger than those in the same natural peoples and had an average survival of 6.42 months longer than the latter. (3) The PLC year-incidence of those with the exposure to aflatoxin was significantly higher than that of unexposed people (2784. 96/100,000 vs. 1251.02/100,000, P = 0.008, RR = 2.23). There was no relationship between the incidence rate of other tumors and the aflatoxin exposure. (4) The PLC year-incidence of aflatoxin-exposing people increased with the rising urine excretion of AFM1. When the urine excretion of AFM1 was more than 100 ng during 24 hours, the PLC year-incidence was high as 4717.82/100,000. The urine excretion of AFM1 was also obviously related with the abnormal liver function (P = 0.035). There was no relationship with the positive rate of HBeAg (P = 0.812). (5) The PLC year-incidence of those with the exposure to aflatoxin were infected with HBV (2 784. 96/100 000) significantly higher than that of cohort people (P = 0.001) and the same natural peoples (P = 0.000, RR = 15.09). (6) It took an average time of 14.65 years (median 13.68) from hepatitis occurrence to PLC diagnosis and 7.38 years (median 6.40) from liver cirrhosis to PLC diagnosis. HBV infection is a main etiological factor of PLC and the aflatoxin exposure has obvious synergistic effect in the carcinogenesis of PLC. Regular observation in a PLC high-risk cohort is effective for an early diagnosis and treatment. Hepatitis control and aflatoxin de-pollution is effective to inhibit the occurrence of PLC.