Question

What is the risk of AIN3 progressing to anal cancer in people living with HIV?

12 August 2024. Related: All topics, Opportunistic infections, Support.

Answer

Answer: Simon Collins

Hi there

Thanks – this is a good but difficult question.

Data on progression rates for cancers are complicated because they report average results from people with very wide ranges of different risk factors and these could be different for someone who wants to understand the risk for themselves or another individual.

Many different studies have reported results but the first two below refer to progression without treatment and the third one shows that treatment reduces this risk. The full text of these studies are online to look at the full details.

Even though these are in different populations and at different times, with likely different access to care, all studies report that progression rates are unfortunately higher for people living with HIV.

A Danish study from 2019  (Arens Y and others)  included almost 600 people living with HIV. More than 95% of were men and average age was just under 50. People were enrolled based on an AINIII diagnosis recorded from 200-2011 and they were followed for an average of six years.

The incidence of anal cancer (33 people progressed) was 1.2% and 5.7% at 1 and 5 years, respectively.

A second Danish study (Faber and others) reported that the risk of anal cancer risk increased with increasing severity of lesions, reaching 4% 5 years after diagnosis of AIN3. The study also reported that the absolute 5-year risk of anal cancer following AIN3 was considerably higher among HIV-positive (14.1%) than HIV-negative (3.2%) individuals.

Treatment can be very effective though and this study from New York in 2014 (Goldstone SE and others) reported that treating AIN£ significantly reduced the risk of progression to about 2% at 3 years in over 700 gay men (about 450 were HIV positive).

If this is about your own care, perhaps use these studies as references when discussing your individual risk with the doctors involved in your cancer. This team should include an expert in HIV-related cancers from one of the larger HIV clinics.

Reference links

Arens Y et al. Risk of Invasive Anal Cancer in HIV-Infected Patients With High-Grade Anal Dysplasia: A Population-Based Cohort Study. Dis Colon Rectum. 2019 Aug;62(8):934-940. doi: 10.1097/DCR.0000000000001384.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6613994/