Do cytology, genotyping, and high resolution anoscopy allow to establish a protocol for early detection of squamous cell carcinoma of the anal canal in risk population?

Abstract

Introduction: The incidence of anal cancer has increased in recent years. It is mediated by HPV and preceded by precancerous changes, raising the possibility of directing preventive efforts towards high-risk groups. The indication of screening remains controversial and which methods would be the ideal ones. Objective: To validate the screening tests established actually, comparing it with the biopsy considered as the “gold standard”.

Materials and Methods: A cross-sectional study was performed, with prospective data collection in a cohort of VIH+ patients, who have male homosexual anal relations, belonging to Gregorio Marañón and Infanta Leonor Hospitals in a period of 2 years.

Results: A total of 179 patients were selected with 286 visits to the screening Outpatient Clinic in which 3 parallel screening tests were performed (anal cytology, HPV genotyping and high resolution anoscopy (AAR) with a biopsy directed on a suspicious or random area). The sensitivity and specificity for the detection of high-grade dysplasia and cancer and their degree of agreement with the biopsy was as follows: cytology 3.23%/94.43% (k: 0.03), high HPV genotyping. risk 90.32%/27.45% (k: 0.05), AAR 32.26%/87.45 (k: 0, 17), the diagnostic accuracy of the three tests being very low.

Conclusion: Cytology shows a very low diagnostic accuracy compared to the genotype that represents the highest one. In light of our results, clinical protocols as they are currently being developed should be abandoned.