W164 - PD-L1 Is Fascinating but IDO Needs Attention in Non-HCV and Non-HBV-Associated Hepatocellular Carcinoma Patients

Shaarif Bashir – Shaukat Khanum Memorial Cancer Hospital & Research Centre (SKMCH&RC); Iftikhar Ali Ali Rana – Shaukat Khanum Memorial Cancer Hospital & Research Centre (SKMCH&RC); Muhammad Abu Bakar – Shaukat Khanum Memorial Cancer Hospital & Research Centre (SKMCH&RC); Asim Farooq – Shaukat Khanum Memorial Cancer Hospital & Research Centre (SKMCH&RC); Muhammad Hassan – Shaukat Khanum Memorial Cancer Hospital & Research Centre (SKMCH&RC); Zukhruf Asif – Shaukat Khanum Memorial Cancer Hospital & Research Centre (SKMCH&RC); Mahnoor Afzal – Shaukat Khanum Memorial Cancer Hospital & Research Centre (SKMCH&RC); Iqra Masood – Shaukat Khanum Memorial Cancer Hospital & Research Centre (SKMCH&RC); Muhammad Ishaq – Shaukat Khanum Memorial Cancer Hospital & Research Centre (SKMCH&RC); Muhammad Tahseen – Shaukat Khanum Memorial Cancer Hospital & Research Centre (SKMCH&RC); Sundus Bilal – Shaukat Khanum Memorial Cancer Hospital & Research Centre (SKMCH&RC); Shafqat Mehmood – Shaukat Khanum Memorial Cancer Hospital & Research Centre (SKMCH&RC); Nosheen Kanwal – Shaukat Khanum Memorial Cancer Hospital & Research Centre (SKMCH&RC); Islah Ud Din – Shaukat Khanum Memorial Cancer Hospital & Research Centre (SKMCH&RC); Asif Loya – Shaukat Khanum Memorial Cancer Hospital & Research Centre (SKMCH&RC)

Abstract Text: Background/

Aim: Hepatocellular carcinoma is one of the most common forms of liver cancer that is modulated by the immune system. Programmed cell death ligand-1 (PD-L1) has emerged as a novel therapeutic target in cancers. Indoleamine 2,3-dioxygenase (IDO) is an immunosuppressive enzyme that is associated with poor prognoses in cancers. Our aim was to investigate the PD-L1 expression, and clinicopathological features of non-HCV and non-HBV-associated HCC patients, including IDO expression.

Methods: Immunohistochemical analysis was performed to analyze the expression of PD-L1 and IDO. FFPE tumor tissues (n=50) were obtained from the pathology department, at Shaukat Khanum Memorial Cancer Hospital and Research Centre, Lahore, Pakistan between 2005 and 2022. Furthermore, it was a rare group of patients with no previous history of any viral hepatitis. For statistical analysis, chi-square or Fisher exact test and Mann–Whitney U-test was performed.

Results: Of 50 tissue specimens, PD-L1+ was observed in 21 [high: 12 (24%), low: 9 (18%)] and PD-L1- was observed in 29 HCC patients. IDO+ was observed in all 50 specimens [high: 42 (84%), low: 8 (16%)]. Additionally, both PD-L1 and IDO had high expression in 11 (22%) patients. While both PD-L1 and IDO had low expression in 2 (4%) patients. Furthermore, in IDO+/PD-L1- group, 20 (69%) out of 29 patients died while in the IDO+/PD-L1+ group, 9 (43%) out of 21 patients died.

Conclusion: Evaluation of IDO and PD-L1 expression may add therapeutic advantage in non-HCV and non-HBV-associated HCC patients that overexpress IDO. Further validation in a larger cohort is warranted.