Dr Brunt: Several new findings have led to a consideration of reclassification from the 2010 WHO classification of primary liver carcinomas, specifically related to the combined hepatocellular-cholangiocarcinoma. The 2010 combined hepatocellular-cholangiocarcinoma classification included the classical type, and then the second type was of three types with stem cells. The newer thinking is that, rather than emphasize the stem cells (because stem cell phenotypes can be found in almost all types of combined hepatocellular carcinoma), we should emphasize less the stem cell phenotype in favor of morphological features. So there is a current proposal to classify combined hepatocellular carcinoma: intrahepatic carcinoma as one type, a second type as cholangiolocarcinoma, and a third type as intermediate cell carcinoma.
Dr Brunt: As I mentioned, we have the classic combined hepatocellular and intrahepatic cholangiocarcinoma. That is one type. The second type is cholangiolocellular or cholangiolocarcinoma. And the third type is intermediate cell carcinoma. There are specific criteria for each of those and those are very detailed.
Dr Brunt: We won’t know the impact yet because this new classification has only just been proposed. Until we actually start studying the tumors using the new classification system and seeing how that unfolds will we start to understand how it impacts diagnosis and treatment and outcomes for patients. From what we can tell though, it is a much cleaner way to subgroup patients than the 2010 WHO classification, in which several studies (which I outlined in my presentation here today) showed so much overlap between the subtypes with stem cells that people were not finding them very useful in terms of subdividing patients.