J Hepatol: Single-region sample evaluates the reliability of tumor immune microenvironments in hepatocellular carcinoma

Heterogeneity in tumors in patients with hepatocellular carcinoma (HCC) is often reportedTherefore, the reliability of a single-region tumor sample to assess the tumor immune microenvironment is also debatableWe conducted a prospective study to analyze the similarity of tumor immune microenvironments between different regions of single-region tumorsmulti-region sampling of newly removed tumorsTumor immunotromystasis is evaluated by immune group staining of PD-L1, CD4, CD8, CD8, CD20, FoxP3, DC-LAMP (or LAMP3), CD68, MPO, and tertiary lymphatic tissue (TLSs)The expression of PD-L1 is manually quantified based on the percentage of tumor or matrix cells stained by PD-L1The density of immune cells (quantity/mm2) and the number of TLSs per sample are determined by the full slice countRNA sequencing was applied in selected samplesThe similarity of the tumor immune microenvironment within each tumor was evaluated by the multivariable Mahalanobis distance analysis13 tumor samples were collected from 12 patientsThe median diameter of the tumor is 9 cm (range 3-16 cm)The median number of each tumor is 6 samples (range 3-12)Nine (69.2%) tumors showed uniform expression of PD-L1 in all areas of the tumorOf the 13 tumors analyzed for immunohistomydology, 8 (61.5%) showed a narrower Mahalanobis distance in all areas of the tumor, while 8 (66.7%) of the 12 tumors analyzed by RNA were at a narrower Mahalans distanceImmune hetology and RNA-sequencing had a higher rate of fitness for immunohislification and RNA-sequencing when assessing the similarity of the immune microenvironment of tumors in tumors (83.3 per cent; 10 out of 12 tumors), the results suggest that tumor samples in a single region may be reliable in evaluating tumor immune microenvironments in about 60-70% of HCC patients