Insulin-like growth factor-related components and the risk of liver cancer in a nested case-control study

Insulin-like growth factor-1 (IGF1) is a potent mitogen. IGF-binding protein-3 (IGFBP3) binds and inhibits IGF1. High circulating IGF1 levels and low IGFBP3 levels are associated with increased risk of several cancers. We examined relationships between serum levels of these factors and hepatoma risk in a case-control study nested in a prospective cohort study (the Japan Collaborative Cohort Study (JACC Study)). A baseline survey was conducted from 1988 to 1990, and 39,242 subjects donated blood samples. Participants diagnosed with hepatoma by 1997 were considered cases for nested case-control studies. Ninety-one cases and 263 sex- and age-matched controls were analyzed. A conditional logistic model was used to estimate odds ratios (ORs) for the incidence of hepatoma associated with serum IGF1 and IGFBP3 levels. Neither IGF1 nor the molar ratio of IGF1/IGFBP3 was correlated with hepatoma risk. After adjustment for hepatitis viral infection, body mass index, smoking, and alcohol intake, a higher molar difference of (IGFBP3 - IGF1) was associated with a decreased hepatoma risk more than IGFBP3 alone (p for trend <0.001 and = 0.003, respectively). People in the highest quartile had a lower risk (OR = 0.098; 95 % confidence interval = 0.026-0.368). In subgroup analyses of males and females, the molar difference was associated with a decreased hepatoma risk (p for trend <0.05). In non-elderly individuals, the difference was inversely correlated with the incidence of hepatoma (p for trend <0.01). The molar difference of (IGFBP3 - IGF1) may be inversely associated with the incidence of hepatoma.