Anal cancer screening in men who have sex with men living with HIV: The pilot of anal screening study (PASS).

BACKGROUND

People living with HIV are at the highest risk of anal cancer. Screening people living with HIV and treatment of identified anal high-grade squamous intraepithelial lesions (HSIL) are now recommended to reduce cancer incidence. We investigated the implementation of such a programme in a large HIV clinic in Sydney, Australia.

METHODS

Men who have sex with men (MSM) living with HIV aged 35+ were invited to participate in an anal screening programme. Following informed consent, participants underwent digital anorectal examination (DARE) and anal swabs (self- and clinician-collected) for HPV genotyping and cytological testing. Swab collection order was randomized. Positive results for HPV16, atypical squamous cells-cannot exclude HSIL (ASC-H), HSIL or abnormal DARE suspicious of anal cancer led to immediate referral for high-resolution anoscopy (HRA). The rest returned in 6 months for repeat tests. Screening logs captured reasons for declining screening.

RESULTS

Of the 225 people invited to participate, 23.1% declined, 49.8% did not respond to repeated contact and 27.1% consented (median age 57.5 years). Of those who consented, 66.1% had high-risk HPV and 78.7% had cytological abnormalities of which 48.6% were HSIL or ASC-H. No differences in swab positivity were found between self- and clinician-collected specimens. Thirty-eight participants were referred for HRA with 100% attendance. Of these, 42.1% had histological HSIL. One had anal cancer.

CONCLUSIONS

Uptake of the screening programme was poor, with only a quarter agreeing to participate. Those who underwent screening had excellent adherence (100% HRA attendance) with substantial quantities of HSIL found. Further research is required to understand and address barriers to initial screening programme uptake.