Anal cancer rates are rising in men and women worldwide with anal intraepithelial neoplasia (IN) thought to be a precursor. Anal warts have been associated with high rates of IN especially in HIV infection, and anal cancer has been recognised as arising from anal warts. Cofactors other than HPV are likely to be associated with the development of anal cancer and its precursors. A surgical data base with epidemiological and histological data from patients surgically treated for anal warts was created at Royal Perth Hospital in 1996, and findings from this database have been previously reported.1,2
Patients who underwent surgical excision of anal and/or perianal condylomata acuminata or mapping biopsies from December 1995 to November 2016 were included in the analysis. Demographic data were collected including sex, sexual preference, lifetime sexual partners, history of gonorrhoea, or chlamydia and serological data for syphilis, herpes type 2 antibody (HSV2) and HIV 1 and 2 antibody at the time they were enrolled for surgery. Anal HPV testing byDigene Hybrid Capture II for high-risk strains (hrHPV) was included as a standard of care from June 2005 onwards.
463 patients were included in the analysis, the majority of whom were MSM (367) . Almost one third were HIV positive and had high-grade squamous intraepithelial neoplasia (HSIL). Overall 75% of the samples tested positive for hrHPV, with HIV positive men having 95% hrHPV. HSV-2 , gonorrhoea, and syphilis were associated with the risk of HGAIN:OR 14.3 (95%CI 6.20-33.1), OR 10.4 (95%CI 4.32-25.0) OR 9.83 (95%CI 4.20- 23.0) respectively.
The association of STI’s such as gonorrhoea, syphilis and genital herpes with the presence of HGAIN deserves further study. Given rates of gonorrhoea are increasing in the MSM community, patients should be counselled to avoid STI acquisition and use condoms to reduce their risk of anal cancer .Detection of HGAIN is problematic with high resolution anoscopy clinics being scarce. A history of gonorrhoea, syphilis or HSV-2 could be used to triage patients at risk of HGAIN to these clinics
[1] McCloskey J, Metcalf C, French M, Flexman J, Burke V, Beilin L. The frequency of high-grade intraepithelial neoplasia in anal/perianal warts is higher than previously recognised Int J STD & AIDS 2007; 18:538-42.
[2] McCloskey J, Phillips M, French M, Flexman J, McCallum D, Metcalf C. Update on the Royal Peth Hospital Anogenital Wart Database. In: Barros E, editor. HIV Infection- Impact Awareness and Social Implications of Living with HIV/AIDS: In Tech; 2011. p. 81-90.