Levels of vitamin A and cellular retinol binding protein in human hepatocellular carcinoma and adjacent normal tissue

The levels of vitamin A (retinol) and vitamin E were measured in the blood, in tissues of human hepatocellular carcinoma (HCC), and in adjacent liver parenchyma. The median values of vitamin A were 11.5 micrograms/g (ranging 0-82.5 micrograms/g) in HCC and 52.1 micrograms/g (ranging 0.4-895.2 micrograms/g) in normal liver tissues; the difference was statistically significant (p less than 0.05). By contrast, there was no significant difference in vitamin E levels between the two tissues. Although the levels of vitamin A were significantly lower in HCC in 10 patients, no significant difference was noted in the cellular retinol binding protein levels in the normal and malignant tissues. These results suggest that the decreased levels of vitamin A in HCC are not due to altered cellular retinol binding protein levels in tumors and the different vitamin A blood supply system. We conclude that either the decreased uptake of vitamin A, but not vitamin E, by HCC cells or the lack of vitamin A-storing cells in tumors might be responsible for the low levels of vitamin A in HCC.