By Dr. Harold Dion
He has worked at the Clinique médicale l’Actuel in Montreal for the past 25 years.
He is also co-editor-in-chief of “e-Relais VIH”, a Canadian bilingual online publication for patients living with HIV.
Over the past 10 years, Dr. Dion has published several articles on various health issues, for both general public (Coup de pouce, 7 Jours, Reader’s Digest) and healthcare professionals (L’actualité médicale, Le Clinicien, l’Omnipraticien, MedActuel FMC, Le Médecin du Québec).
I attended the 20th International AIDS conference that was held from July 20-25, 2014 in Melbourne, Australia. In the next few columns, I will summarize some of the highlights of this conference.
Clearance of anal high-grade squamous intraepithelial lesions (HSIL) is high in HIV positive homosexual males
I have chosen to summarize for you, the paper on anal HSIL that was presented during the oral session on co-morbidities and co-infections. Anal cancer is common in HIV positive men and women in the current antiretroviral era, as HIV positive people now live much longer. Whether people with anal HSIL should be treated routinely or closely observed is controversial because treatment carries some risk, recurrence rate is high and HSIL does not always result in cancer.
To shed some light on this question, Andrew Grulich from the Kirby Institute at the University of New South Wales and other colleagues from Sydney, Australia designed the Study of the Prevention of Anal Cancer (SPANC), a prospective cohort study, to learn more about the natural history of anal human papillomavirus (HPV) infection and its precursors, including incidence, clearance and risk factors.
The investigators are aiming to recruit 600 men by July 2015. Participants are expected to attend five study visits over a 3-year period. At each visit, they receive anal swabs for HPV genotyping and cytology, as well as high-resolution anoscopy. Those with visually apparent abnormalities undergo a biopsy for histologic assessment.
The results of an interim analysis involving 450 men recruited through June 2014, was presented at this session. The median age was 49 years and 139 (31%) were HIV positive. At the baseline visit, HSIL prevalence was 46% in HIV+ men and 34% in HIV- men, a statistical significant difference (P = 0.014).
Among the 197 men without HSIL at baseline, there were 45 new cases of HSIL. The incidence rate was nearly twice as high for HIV positive men, although the difference did not reach statistical significance (p=0.061). Also, the HSIL incidence did not differ significantly by age.
In addition, results showed that HPV-16 carried the highest risk of anal cancer. Men positive for HPV-16 at baseline and their latest visit ran a 6-fold higher risk of HSIL than men negative for HPV-16 at both visits. HPV-18 positivity at baseline quadrupled the risk of developing HSIL.
Finally, among men who had HSIL at baseline, clearance rates were almost identical in HIV+ and HIV- men. Men with any high-risk genotype (HPV-16, HPV-18, etc.) had almost an 80% lower chance of clearing HSIL.
The researchers concluded that HSIL is highly prevalent and dynamic. Its high clearance rate implies that not all HSIL requires treatment. Thus, they suggested that repeat HPV testing has a role in the assessment of HSIL and that treatment could be targeted to people with persistent HSIL.
A US trial aiming to enroll 5,000 HIV positive men and women with HSIL, will randomize the participants either to topical or ablative treatment versus close monitoring, in order to determine whether treating HSIL lowers anal cancer incidence.
Grulich, et al. Incidence and clearance of anal high-grade squamous intraepithelial lesions (HSIL) in HIV positive and HIV negative homosexual men. AIDS 2014. 20th International AIDS Conference. July 20-25, 2014. Melbourne. Abstract WEAB0101.