Carbonic anhydrase IX (CA-IX) and high-risk human papillomavirus (H-HPV) as diagnostic biomarkers of cervical dysplasia/neoplasia in Japanese women with a cytologic diagnosis of atypical glandular cells (AGC): a Gynecologic Oncology Group (GOG) Study

BACKGROUND: High-risk human papillomavirus (H-HPV) infection is linked to cervical neoplasia but its role in detecting cervical glandular lesions (GLs) is unclear. Carbonic anhydrase IX (CA-IX) is a hypoxic biomarker that is highly expressed in neoplastic cervical GLs. The diagnostic utility of these biomarkers was evaluated by the Gynecologic Oncology Group in Japanese women with a cytological diagnosis of atypical glandular cells. METHODS: Immunostaining was used to detect CA-IX in a conventional Pap smear. Immunoreactivity of CA-IX was interpreted by a panel of pathologists blinded to the histological diagnosis. Polymerase chain reaction was used to detect H-HPV in a liquid-based cytology specimen. RESULTS: Significant cervical lesions (SCLs), defined as cervical intraepithelial neoplasia (CIN2, CIN3), adenocarcinoma in situ or invasive carcinoma, were observed in 37/88 (42%) of women. CA-IX testing alone (n=88) had a sensitivity of 89, 100 or 73% for SCLs, GLs or significant squamous lesions (SLs), respectively, with a false negative rate (FNR) of 14%. Testing for H-HPV (n=84) had a sensitivity of 65, 53 or 80% for SCLs, GLs or SLs, respectively, with a FNR of 22%. The combination of CA-IX and H-HPV testing had a sensitivity of 97, 100 or 93% for SCLs, GLs or SLs, respectively, with a FNR of 5%. Among eight H-HPV-negative GLs, six (75%) had a diagnosis of lobular endocervical glandular hyperplasia (LEGH). CONCLUSION: The combination of CA-IX and HPV testing improved the diagnostic accuracy. The low rate of H-HPV positivity in the GLs was associated with coexisting LEGH independent of H-HPV.