Diagnostic Value of Biomarkers in the Diagnosis of Cholangiocarcinoma and Its Benign Mimickers.

Background & objective: Cholangiocarcinoma (CCA) is a malignancy that accounts for approximately 3% gastrointestinal cancer. The aim of this study was to evaluate and compare the diagnostic value of CD56, SMAD4, CEA, and p53 biomarkers in diagnosing cholangiocarcinoma and its benign mimickers.

Methods: This retrospective cross-sectional study was conducted on 54 CCA specimens and 27 non-cancerous pancreatobiliary tissue samples diagnosed between 2018 and 2022. All specimens were evaluated using immunohistochemistry (IHC) staining for CD56, SMAD4, CEA, and p53 expression. The cut-off value of each marker was obtained from the respective kit instructions and previous studies. The results were analyzed using SPSS version 26. A significance level of less than 0.05 was considered statistically significant.

Results: Of the 81 specimens, the mean age in the case and control groups was 57.33 ± 11.99 and 44.7 ± 16.69 years, respectively, and 51 (63%) samples were obtained from male patients. We found that 39.5% had grade III p53 expression, 13.5% had grade II p53 expression, 41.9% had grade III CEA expression, and 9.8% had grade II CEA expression. Additionally, 17.3% were positive for CD56 expression, and 7.4% showed SMAD4 loss. There were significant associations between the expression of CEA (79.6%) and p53 (74%) in the CCA group (p-value < 0.05). However, SMAD4 loss and CD56 expression were not statistically significant.

Conclusion: Expression of CEA and p53 based on IHC staining is associated with the occurrence of CCA. However, SMAD4 and CD56 were not significantly associated with CCA. Further survival analysis and sensitivity and specificity assessments are needed to obtain more comprehensive results.