Background: By analyzing a tumor growth of hepatocellular carcinoma (HCC) detected in sustained responders (SR) to interferon (IFN) therapy for chronic hepatitis C, we sought to determine the duration of follow up in SR that would be sufficient to detect HCC. In addition, we sought to elucidate the presence of HCC, which truly developed after the eradication of hepatitis C virus (de novo HCC development).
Methods: Tumor volume doubling time (DT) was calculated in a total of 46 cases of HCC detected in SR after IFN therapy. Based on DT, the annual growth rate was estimated for each tumor. Survival was compared between patients with HCC < or = 30 mm and patients with HCC > 30 mm in diameter.
Results: Doubling time in SR was similar to the previously reported DT of HCC irrespective of IFN therapy. However, extensive DT was observed in three HCCs despite relatively poor differentiation, which may represent de novo HCC development. In the analysis of tumor growth, all HCCs grew to exceed 20 mm in estimated diameter between 6 months and 7 years after the end of IFN therapy. Better survival was observed in patients with HCC < or = 30 mm in diameter compared with patients with HCC > 30 mm (P = 0.0107). In surviving patients, recurrences of HCC were very infrequent.
Conclusions: We may be able to detect most HCC in SR between 6 months and 7 years after IFN therapy. However, we cannot neglect the presence of de novo HCC development after the eradication of HCV, which makes it difficult to determine completely sufficient follow-up duration after IFN therapy in this population.