New Screening Strategy Combining Anal Papanicolaou and Human Papillomavirus Tests for Human Papillomavirus-Related Anal Cancer: A Prospective, Single-Center Study.

ABSTRACT

BACKGROUND: The objective of this study was to evaluate the performance of a combined approach of liquid-based anal cytology and human papillomavirus (HPV) testing in predicting patients who should undergo high-resolution anoscopy for the early detection of anal cancer and anal intraepithelial neoplasia (AIN)-2+. METHODS: We conducted a prospective single-center quality improvement study. We consecutively enrolled men who had sex with men (MSM) attending our sexually transmitted disease clinic to undergo anal Papanicolaou (Pap) and HPV tests. All patients with an abnormal anal Pap test result and/or positive HPV test result underwent high-resolution anoscopy. RESULTS: We enrolled 217 MSM, 80 HIV-positive patients, and 137 HIV-negative patients. Cytology showed a sensitivity of 100%, a specificity of 64.1%, an accuracy of 66.7%, a positive predictive value (PPV) of 15.7%, and a negative predictive value (NPV) of 100% for the detection of AIN-2+. The high-risk (HR)-HPV test showed sensitivity, specificity, accuracy, PPV, and NPV of 100%, 36.4%, 40%, 9.4%, and 100%, respectively. The combination of abnormal cytology with identification of infection by at least 1 HR-HPV strain on the HPV test had a sensitivity of 100%, a specificity of 73%, an accuracy of 74.6%, a PPV of 19.1%, and an NPV of 100%. CONCLUSION: Anal HR-HPV testing, complementary to cytology, improves the diagnostic accuracy of screening for anal cancer.