Comparative study between Immunohistochemistry and Molecular method in detection of BRAF V600E mutation in papillary thyroid carcinoma

Background Papillary thyroid carcinoma is the most common endocrine and thyroid malignancy. The (BRAF V600E) mutation is the most common mutation in papillary thyroid cancer (PTC). The mutation is detected in about (60%) of the cases. Patients with BRAF mutation have been linked to aggressive clinical behavior, high recurrence rate, metastasis, and failure of treatment Aim of the study This study aims to find whether Immunohistochemisrty can substitute molecular analysis in detection of BRAF V600E mutation in papillary thyroid carcinoma. This will safely time, cost, and effort. Patients and method This was a retrospective study, carried out in Basrah province, wax blocks were collected from histopathology labs during period from October through September 2023. Tissue sections were obtained from the paraffin blocks and submitted to routine hematoxylin and eosin stain. Then Immunohistochemical staining using primary monoclonal antibody for detection of BRAF mutation in papillary thyroid carcinoma. After examination of H &E slides, the area of papillary thyroid carcinoma was determined and Then piece of tumor tissue with thickness of 5~10 um and a surface Darweesh, S., Al-Diab, J., Al-Harron, S., Hasson, H. Comparative study between Immunohistochemistry and Molecular method in detection of BRAF V600E mutation in papillary thyroid carcinoma. Basrah Journal of Surgery, 2023; 29(2): 76-87. doi: 10.33762/bsurg.2023.144308.1062 77 area between 0.5~1 cm². was taken from the wax block for DNA extraction and detection of BRAF mutation using Real-time PCR. Results Thirty cases of papillary thyroid carcinoma were included in this study. Twenty-five case (83%) were female and five cases (16.66%) were male with mean age of 41.33+16.1 (range 16-81 years). Using real-time PCR, twelve cases (40%) were positive for BRAF mutation and eighteen cases (60%) were negative for BRAF mutation. Using immunohistochemistry, thirteen cases (43.3%) were positive for BARF mutation & seventeen cases (56.7%) were negative for the mutation. The sensitivity of Immunohistochemistry in detecting BRAF mutation in papillary thyroid carcinoma is (66.7%) with specificity (72.2%). The positive predictive value is (61.5%) and the negative predictive value is (76.5%). Conclusion The findings from this study reveal a discrepancy between Immunohistochemistry and real-time PCR in identifying the BRAF V600E mutation. It is important to note that Immunohistochemistry should not serve as a substitute for molecular methods in detecting this mutation. In fact, relying solely on Immunohistochemistry may not be reliable due to its lower sensitivity. This could potentially lead to increased time, cost, and effort in the diagnostic process