Histological aspects of post-TACE hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common type of cancer in men and the seventh in women and is the third most common cause of death from cancer worldwide [http://globocan.iarc.fr]. The overall incidence of HCC remains high in developing countries and is steadily rising in most industrialized countries [Shariff MI et al., 2009]. A variety of therapeutic modalities is available for treating hepatocellular carcinoma, but orthotopic liver transplantation (OLT) represents a curative option. Due to the shortage of donor organs and the increasing need for liver transplantation in the last decade, local ablation therapy (LAT) has been increasingly used in many centers as a bridge to transplant [Majno PE et al., 1997; Decaens T et al., 2005; Herber S et al., 2005; Bharat A et al., 2006; Obed A et al., 2007; Otto G et al., 2007]. We retrieved from the archive in the Histopathology Laboratory, Institute of Liver Studies, King's College Hospital, London, UK, 28 cases of HCC, which underwent treatment with TACE (Doxorubicin 40 mg/m²) as a bridge to transplantation, between 2008 and 2010. We also analyzed 14 additional post-TACE tumors, classified according to the architectural patterns published by Morisco F et al. (2008), for quantification of necrosis. Extensive tumor necrosis was observed in 12 (42.85%) of the patients. Viable hepatocellular carcinoma showed a wide range of differentiation, from well to poorly differentiated. The phenotype of the tumors was mostly hepatocelluar, but 14% showed a mixed phenotype, including glandular/pseudoglandular formation and cholangiocellular components. The percentage of necrosis ranged between 0% and 100%, with an average of 50.6%. There was no statistical correlation between the total size of the nodules and the surface of necrosis in our series (p=0.125). In conclusion, the systematic pathological assessment of post-TACE resected HCC can help in investigating the biology of treated tumors but needs to incorporate sampling protocols, digital image analysis, phenotypic classification by immunohistochemistry and enzymatic function.