Assessing the diagnostic value of CAIX and ProEx-C in cervical squamous intraepithelial lesions

Cervical squamous intraepithelial lesions (SILs) may present a diagnostic challenge due to their morphological similarity to benign conditions and variability in interpretation, necessitating the exploration of objective biomarkers to aid in their identification and grading. This study evaluates the immunohistochemical markers Carbonic Anhydrase IX (CAIX) and ProEx-C to assess their diagnostic potential in cervical SILs. We retrospectively identified 56 SIL cases, including 20 low-grade SILs (LSIL) and 36 high-grade SILs (HSIL), alongside a control group of nine chronic cervicitis cases. Immunohistochemical staining was performed on formalin-fixed, paraffin-embedded tissue blocks, and the sensitivity and specificity of CAIX and ProEx-C were evaluated for detecting and grading SILs. CAIX exhibited a sensitivity of 64.3 % and a specificity of 100 % for detecting SILs. ProEx-C staining displayed a sensitivity of 66.1 % and a specificity of 100 % for detecting SILs. The combination of CAIX and ProEx-C staining increased the sensitivity for detecting SILs to 80.4 % without compromising the specificity. These markers alone or in combination were not found to be significant in distinguishing LSIL from HSIL. Both markers showed positivity in benign endocervical and squamous epithelium in high rates. In conclusion, CAIX and ProEx-C are valuable immunohistochemical markers for detecting SILs in cervical specimens, with high sensitivity and specificity. Further research is needed to elucidate their roles in cervical carcinogenesis and their relationship with HPV infection.