Dr Singal: The talk I have given here at ILCA was on precision screening for hepatocellular carcinoma in patients with cirrhosis. The idea of the talk was that, right now, ultrasound and AFP are standard of care for HCC screening in patients with cirrhosis, however, we see that there is variation in HCC risk as well as the performance of these screening tests across patients. The question was whether we could do a better job of finding tests that would find cancer at an early stage in these patients.
Dr Singal: Right now, the current surveillance strategy for HCC is ultrasound with or without alpha-fetoprotein (AFP). There are five phases of biomarker development and AFP is currently the only biomarker that has gone through all of these phases of biomarker development and validation. When you take a look at the level of evidence, then I think that that is the best biomarker we have. We have several promising biomarkers - AFP-L3, DCP - but these are not necessarily as well validated as AFP.
Dr Singal: It is an interesting question. In terms of risk prediction and risk stratification, I think that is one of the key things in precision screening. There is a tissue-based gene signature that actually allows us to risk stratify patients. That has been shown in the hepatitis C population, the hepatitis B population, as well as non-viral etiologies, but the limitation of this approach is that it has historically been tissue-based. Work is currently going on to make this blood-based, and if that were to happen and we were then able to risk stratify patients, it would allow us to have precision screening in at-risk patients.
Dr Singal: Once again this relates to the GALAD score I mentioned, which combines three biomarkers (AFP, AFP-L3 and DCP). We know HCC is a heterogeneous tumor so it is likely that a single biomarker will not be sufficient. Biomarker panels and algorithms are the direction we should be heading in for the future. However, these biomarker algorithms are relatively new and require validation in large cohorts of patients. These studies are currently underway, and I am hoping over the next couple of years, they are really pushed forward in terms of data collection and become standard.