UCSF

Background

Women living with HIV (WLWH) experience high rates of anal cancer. Screening using anal cytology, high-resolution anoscopy (HRA) with biopsies, can histologically diagnose anal cancer precursors called high-grade squamous intraepithelial lesions (HSIL). The low specificity of screening using anal cytology results in HRA referral for many WLWH without HSIL. Screening using high-risk human papillomavirus (HR-HPV) may improve specificity.

Methods

Two hundred seven WLWH (63% non-Hispanic black) were screened for anal histologic HSIL (hHSIL) using cytology, HRA-guided biopsies, and Xpert HPV. Xpert performance for predicting anal hHSIL was compared with that of cytology. Usng Xpert 5 HPV genotypic results and accompanying cycle thresholds, receiver operator characteristic curve and recursive partitioning analyses were used to create predictive models for hHSIL.

Results

The performance of Xpert to predict hHSIL was not different from that of cytology with a sensitivity (Sn) of 89% and specificity (Sp) of 49%. Interpretation of Xpert was modified using genotypic results and receiver operator characteristic curve analysis, which produced a screen with an Sn and Sp of 75% and 84% for hHSIL, respectively. Another reinterpretation of Xpert was created using recursive partitioning and cycle thresholds, which predicted hHSIL with an Sn and Sp of 75% and 86%, respectively. The detection of HPV-16 was highly predictive of hHSIL in all analyses. These modified screening tests would reduce HRA referral in this population by almost half compared with anal cytology.

Conclusions

Xpert HPV is an alternative to anal cytology to screen for anal HSIL and can be optimized to reduce the number of unnecessary HRAs performed in WLWH.