Address of Corresponding Author

Intervirology 2005;48:39-45 (DOI: 10.1159/000082093)

  Key Words

• Lectin-reactive alpha-fetoprotein
• Chemoprevention
• Clonal deletion
• Protein induced by vitamin K absence or antagonist-II
• Retinoid

  Abstract

Oral administration with acyclic retinoid, a synthetic vitamin A analog, for a limited period of 12 months (48 weeks) prevented the development of second primary hepatocellular carcinoma (HCC) and also improved the survival of patients who underwent curative treatments of the initial tumor. Following that randomized controlled study reported in 1996 and 1999, we have continued to follow up the patients by medical imaging and blood chemical analyses, and found that the preventive effect of acyclic retinoid lasted up to 199 weeks after randomization (or 151 weeks after completion of retinoid administration). The retinoid's effect was not mediated by reduction in hepatic necro-inflammation since no significant decrease in serum aminotransferase activity was seen in the retinoid group. Such observation seems quite distinct from the cancer-preventive mechanism of interferon, a potent immunopreventive agent for HCC. We have also shown here the reduction by the retinoid in serum levels of lectin-reactive -fetoprotein (AFP-L3) and protein induced by vitamin K absence or antagonist-II (PIVKA-II), both of which indicate the presence of latent HCC cells. These results suggest that acyclic retinoid may delete such malignant clones before they expand to clinically detectable tumors and thereby inhibited second primary HCC. Once such latent clones are eradicated, it may well take at least several years for the next cancer clone to arise clinically. This may possibly explain a reason for the long-term effect of the retinoid even after the limited period of administration.

Copyright © 2005 S. Karger AG, Basel

  Author Contacts

Hisataka Moriwaki, MD
Department of Gastroenterology
Gifu University School of Medicine
Gifu 501-1194 (Japan)
Tel./Fax +81 58 230 6313, E-Mail hmori@cc.gifu-u.ac.jp

  Article Information

Number of Print Pages : 7
Number of Figures : 4, Number of Tables : 2, Number of References : 21