Association between dietary tomato intake and the risk of hepatocellular carcinoma: The Singapore Chinese Health Study

Background: Intake of tomato and/or lycopene has been associated with reduced risk of several cancers, but there is no report on the association with risk of hepatocellular carcinoma (HCC). Methods: The associations of tomato and lycopene consumption with risk of HCC were examined in the Singapore Chinese Health Study, a prospective cohort of 63,257 Chinese ages 45 to 74 years at enrollment. Diet was assessed using a validated semiquantitative food frequency questionnaire. Cox proportional hazard regression models were used to estimate HR and its 95% confidence interval (CI) of HCC with the consumption of tomato and lycopene among all cohort participants, and unconditional logistic regression was used to assess the association by hepatitis B surface antigen (HBsAg) positivity in a nested case–control study. Results: After a mean follow-up of 17.6 years, 561 incident HCC cases were identified. Higher tomato intake was associated with lower risk of HCC after adjustment for potential confounders (P_trend < 0.001). Compared with the lowest quartile, HRs (95% CIs) of HCC for the second, third, and fourth quartile of tomato intake were 0.70 (0.56–0.88), 0.73 (0.58–0.92), and 0.63 (0.49–0.81). Among HBsAg-negative individuals, the inverse association remained (P_trend ¼ 0.03). There was no association between lycopene intake and HCC risk (P_trend ¼ 0.54). Conclusions: Tomato intake may offer protection against the development of HCC, particularly among individuals without chronic infection with hepatitis B virus. Impact: Tomato intake is a low-cost preventative measure against HCC that may help reduce risk due to increasing rates of nonalcoholic fatty liver disease.