Anal cancer precursor lesions in HIV-positive and HIV-negative patients seen at a tertiary health institution in Brazil

Ivan Tramujas Da Costa E Silva,Rosilene Viana De Andrade,Felicidad Santos Gimenez,Luiz Carlos De Lima Ferreira,Ticiane Costa Martins,Adriana Gonçalves Daumas Pinheiro Guimarães,Lucília Rocha Lopes,Celso Rômulo Barbosa Cabral,José De Ribamar Araújo

doi:10.1590/s0102-86502011000100012

Ivan Tramujas Da Costa E Silva, Rosilene Viana De Andrade + Show 7 more

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https://doi.org/10.1590/s0102-86502011000100012

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Abstract

To investigate the prevalence of anal squamous intraepithelial lesions (ASIL) or anal cancer in patients attended at the Tropical Medicine Foundation of Amazonas. 344 patients consecutively attended at the institution, in 2007/2008, were distributed in the following strata according to presence/abscense of at risk conditions for anal cancer: Group 1 - HIV-positive men-who-have-sex-with-men (101); Group 2 - HIV-positive females (49); Group 3 - patients without any at risk condition for anal cancer (53); Group 4 - HIV-positive heterosexual men (38); Group 5 - HIV-negative patients, without anoreceptive sexual habits, but with other at risk conditions for anal cancer (45); Group 6 - HIV-negative men-who-have-sex-with-men (26); and Group 7 - HIV-negative anoreceptive females (32). The histopathological results of biopsies guided by high-resolution anoscopy were analyzed by frequentist and bayesian statistics in order to calculate the point-prevalence of ASIL/cancer and observe any eventual preponderance of one group over the other. The point-prevalence of ASIL for all the patients studied was 93/344 (27%), the difference between HIV-positive and negative patients being statistically significant (38.3% versus 13.5%; p < 0.0001). The prevalence of ASIL for each one of the groups studied was: Group 1 = 49.5%, Group 2 = 28.6%, Group 3 = 3.8%, Group 4 = 21.1%, Group 5 = 11.1%, Group 6 = 30.8% and Group 7 = 18.8%. Standard residual analysis demonstrated that ASIL was significantly prevalent in patients of Group 1 and high-grade ASIL in patients of Group 2. The odds for ASIL of Group 1 was significantly higher in comparison to Groups 2, 3, 4, 5 and 7 (p < 0.03). The odds for ASIL of Groups 2, 4 and 6 were significantly higher in comparison to Group 3 (p < 0.03). In the patients studied, ASIL (low and/or high-grade) tended to be significantly more prevalent in HIV-positive patients. Nonetheless, HIV-negative anoreceptive patients also presented great probability to have anal cancer precursor lesions, mainly those of the male gender.

Highlights

Anal cancer, rare in the general population, has shown an increase in incidence in recent decades in some sections of the population considered at greater risk of developing the disease[1].The disease is associated with continued anal human papillomavirus (HPV) infection
About 75% of the sexually active population will develop HPV anogenital infection throughout life, most of the affected individuals will not present clinical signs of the illness[2]. These signs are similar to those found in association with cervical cancer, a malignancy with which anal cancer shares many characteristics[3]
In accordance with what is experienced with cervical intraepithelial neoplasia, to minimize considerable inter and intra-observer interpretative variability, the 2001 Bethesda Classification System of cellular atypia is used so that AIN 1 is defined as LSIL and AIN 2 and 3 are unified in a sole category, HSIL4

Summary

Introduction

Rare in the general population, has shown an increase in incidence in recent decades in some sections of the population considered at greater risk of developing the disease[1].The disease is associated with continued anal human papillomavirus (HPV) infection. About 75% of the sexually active population will develop HPV anogenital infection throughout life, most of the affected individuals will not present clinical signs of the illness[2]. When present, these signs (mainly anal intraepithelial neoplasia, or AIN) are similar to those found in association with cervical cancer, a malignancy with which anal cancer shares many characteristics[3]. Following the classification of cervical intraepithelial neoplasia, anal cancer precursor lesions, alike, have been conventionally defined as AIN 1, AIN 2 and AIN 3. In accordance with what is experienced with cervical intraepithelial neoplasia, to minimize considerable inter and intra-observer interpretative variability, the 2001 Bethesda Classification System of cellular atypia is used so that AIN 1 is defined as LSIL (low-grade squamous intraepithelial lesion) and AIN 2 and 3 are unified in a sole category, HSIL (high-grade squamous intraepithelial lesion)[4]

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Conclusion