The prognostic value of immune checkpoints and lymphocyte infiltration in hepatocellular carcinoma: analysis of intratumoral and peritumoral distribution

Ateş V., Öztürk Ç., Okcu O.

38th European Congress of Pathology, Stockholm, İsveç, 12 - 16 Eylül 2026, cilt.489, ss.553-554, (Özet Bildiri)

  • Yayın Türü: Bildiri / Özet Bildiri
  • Cilt numarası: 489
  • Basıldığı Şehir: Stockholm
  • Basıldığı Ülke: İsveç
  • Sayfa Sayıları: ss.553-554
  • Recep Tayyip Erdoğan Üniversitesi Adresli: Evet

Özet

Background & Objectives: Hepatocellular carcinoma (HCC) is an aggressive tumour that can be resistant to treatment due to the heterogeneity of the immune microenvironment. This study aimed to determine the intratumoral (IT) and peritumoral (PT) distribution of PD-1, PD-L1, CD4 and CD8 expression in HCC, and to investigate the association of these parameters with survival and clinicopathological characteristics. Methods: The study included 45 patients with HCC. The expression levels of PD-L1 (tumour proportion and combined score), PD-1 (IT/PT), CD4 (IT/PT), and CD8 (IT/ PT) in tumour samples were evaluated by immunohistochemistry. Data were grouped by median values, and overall survival (OS) times and their correlations with clinical parameters (age, AFP, tumour size, cirrhosis/hepatitis status) were statistically analysed. Results: The mean patient age was 69.7 ± 11.4 years, and 86.7% were male. Most cases showed low PD-1 expression (median IT: 1%). PD-1 density in the peritumoral area (9.84%) was about twice that in the intratumoral area (4.82%). There was a strong positive correlation between IT-CD8 and PT-CD8 densities (r = 0.51, p < 0.001). Median overall survival was 17.4 months in the high PD-L1 combined score (CPS) group and 10.8 months in the low-CPS group. High peritumoral CD8 levels also showed a survival advantage. Aggressive tumours with high AFP levels had increased IT-CD4 infiltration (r = 0.41). As tumour size increased, peritumoral immune activity (PD-1 and CD8) decreased. Conclusion: Our study suggests that HCC predominantly exhibits an immune-excluded pattern, with immune cells clustering more closely at the tumour edge. Low PD-1 expression was considered a characteristic finding for this tumour type, and further research is needed to determine its role in the development of this condition. PD-L1 (CPS) and peritumoral CD8 density are potential prognostic biomarkers for HCC patients.