Chronic inflammation in the gallbladder leading to persistent epithelium damage promotes invasive cancer. The study aimed to assess the prognostic value of PDL1 and CA19-9 markers in cancer/inflammatory lesions of the gallbladder. A total of 29 cases (19 cancer and 10 inflammatory) were included. The PDL1 protein concentration level and mRNA expression were assessed in the tissues' lysates by ELISA and real-time PCR, respectively. PDL1 and CA19-9 concentration levels were compared and statistically related with clinico-pathological variables. The PDL1 protein level and its relative mRNA expression were correlated. Kaplan-Meir survival and Cox regression analyses were conducted for predicting prognosis. This study investigated the PDL1 and CA19-9 marker expression in both cancer and inflammatory cases of the gallbladder (p = 0.48 and p = 0.17 respectively). PDL1 protein expression was significantly associated with the hormonal profile of the cases (p = 0.04) at an optimum cut-off value of 13 pg/mL, while the CA19-9 marker expression was correlated with the status of liver metastasis (p = 0.0043) and size of the tumor (p = 0.004). A low PDL1 concentration was found when compared to the CA19-9 level among cancer cases (p = 0.12) and proportional in the inflammatory lesions (p = 0.63). A significant positive correlation was found between the PDL1 protein and its relative mRNA expressions in the inflammatory lesions (p = 0.029) when compared to cancer cases (p = 0.069). Our results showed that a protein-based assay for PDL1 expression would be more sensitive compared to RNA based assays for GBC risk stratifications. Overall survival was predicted with CA19-9 and PDL1 levels (p = 0.0074, p = 0.23, respectively). PDL1 and CA19-9 may act as a probable predictor of a poor prognosis in gallbladder cancer (GBC) cases.
Keywords: enzyme-linked immunosorbent assay (ELISA); gallbladder cancer (GBC); immunotherapy; inflammatory lesion; programmed cell death-1 ligands (PDL1); real time-PCR.