Abstract 210P
Background
Gastric-type hepatocellular carcinoma (HCC) was recently described as histological variant of HCC that is histologically characterized by double positivity for V-set and immunoglobulin domain containing 1 (VSIG1) and TTF1 and a better prognosis, compared with classic HCC. The aim of the paper is to examine the PDL-1 expression in HCC, using two clones, and to see its possible particularities in gastric-type HCC.
Methods
In 50 HCC samples, the expression of PDL-1 was checked using immunohistochemistry (IHC) methods and two clones (22C3 and 28-8, from Agilent). The obtained data were correlated with the clinico-pathological parameters.
Results
Of 50 examined cases, 26 were negative for both clones. When the clone 22C3 was used, of the 24 remaining cases, 13 expressed positivity over 1% in tumor cells and 11 were negative. When clone 28-8 was used, 16 positive cases showed positivity in tumor cells (they included the 13 cases with positivity for 22C3) and lymphocytes were marked in 8 cases. All gastric-type carcinomas (n=16), characterized by double positivity for TTF1 and VSIG1, expressed PDL-1 clone 28.8. In only 7 of them PDL-1 positivity for 22C3 was also found.
Conclusions
In HCC, clone 28-8 seems to be more sensitive to identify gastric-type HCC. These carcinomas might be candidates for immunotherapy.
Legal entity responsible for the study
George Emil Palade University of Medicine, Pharmacy, Science, and Technology of Targu Mures, Romania.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.