The potential of spectroscopy in the diagnosis of hepatocellular carcinoma – a pilot study

Summary: None of the bio­markers studied so far in the HCC area has yielded higher sensitivity and specificity in the early-stage dia­gnosis than the liver ultrasonography examination. There is an urgent clinical need for establishing a laboratory marker for HCC that meets the requirements for high sensitivity and specificity for the screening and early dia­gnosis of at-risk patients. As a variety of pathological processes, including carcinogenesis, may cause changes in both the concentration and the structure and spatial arrangement of body bio­molecules, the spectroscopic analysis of blood-based derivatives appears to be an appropriate tool for the early detection thereof. In our research, the focus is on the identification of novel bio­markers in blood plasma, which would exhibit sufficient sensitivity and specificity to detect early and potentially curable HCC stages, and which would be potentially useful for routine screening of this disease in well-defined at-risk groups. For this purpose, we utilised a unique combination of two chiroptical methods – electronic circular dichroism (ECD) and Raman optical activity (ROA) – supplemented by non-polarised variants – infrared (IR) absorption and Raman spectroscopy. Methods: Blood plasma of 18 selected patients with liver cirrhosis, 8 of which also suffered from HCC, was analysed by a combination of ECD, ROA, IR and Raman spectroscopy. Results: The obtained spectral data were processed by a multivariate statistical evaluation using principal component analysis (PCA) and linear discriminant analysis (LDA). The visualisation of the LDA results showed the separation of the two monitored groups with only a slight overlap. Based on the spectral analysis within this preliminary study, sensitivity and specificity for the discrimination between cirrhotic individuals with and without HCC reached 88% and 90% after leave-one-out cross validation, respectively. The area under the ROC curve of 0.975 proved high reliability of the established model. Conclusion: Based on our findings, the combination of advanced spectroscopic methods for the analysis of blood plasma might be a promising tool in HCC dia­gnosis and potentially in the screening thereof. Key words: hepatocellular carcinoma – blood plasma – spectroscopy – cirrhosis