The value of high-resolution anoscopy in the diagnosis of anal cancer precursor lesions in hiv-positive patients

Abstract

-Context -Anal cancer, although a still rare disease, is being observed in ascending rates among some population segments known to be at risk for the development of the disease. Human papillomavirus (HPV) infection, immunodepression and anal intercourse are some factors associated with the development of the malignancy. Its similarities to cervical cancer have led to many studies aiming to establish guidelines for detecting and treating precursor lesions of anal cancer, with the goal of prevention. Highresolution anoscopy is routinely used for the diagnosis of anal cancer precursor lesions in many centers but the medical literature is still deficient concerning the role of this diagnostic modality. Objectives -To evaluate diagnostic validation and precision measures of high-resolution anoscopy in comparison to histopathological results of anal biopsies performed in HIV-positive patients treated at the Tropical Medicine Foundation of Amazonas, AM, Brazil. To observe any possible association between some risk factors for the development of anal cancer and the presence of anal squamous intraepithelial lesions. Methods -A hundred and twenty-eight HIV-positive patients were submitted to anal canal cytological sampling for the detection of HPV infection by a PCR based method. High-resolution anoscopy was then performed after topical application of acetic acid 3% in the anal canal for 2 minutes. Eventual acetowhite lesions that were detected were recorded in respect to location, and classified by their tinctorial pattern, distribution aspect, relief, surface and vascular pattern. Biopsies of acetowhite lesions were performed under local anesthesia and the specimens sent to histopathological analysis. The patients were interviewed for the presence of anal cancer risk factors. Results -The prevalences of anal HPV infection and of anal squamous intraepithelial lesions in the studied population were, respectively, 79% and 39.1%. High-resolution anoscopy showed sensibility of 90%, specificity of 19.23%, positive predictive value of 41.67%, negative predictive value of 75%, and a kappa coefficient of 0.076. From the analyzed lesions, high-grade squamous intraepithelial lesions was more frequently observed in association to dense (68%), flat (61%), smooth (61%), non-papillary (83%) and normal vascular pattern (70%) acetowhite lesions, while low-grade squamous intraepithelial lesions tended to be associated to dense (66%), flat-raised or raised (68%), granular (59%), non-papillary (62%) and normal vascular pattern (53%) acetowhite lesions. No statistical significance was observed as to the association of epidemiological characteristics and of most of the investigated anal cancer risk factors and presence of acetowhite lesions or anal squamous intraepithelial lesions. However, anal receptive sex and anal HPV infection were significantly associated to anal squamous intraepithelial lesions (P = 0.0493 and P = 0.006, respectively). Conclusion -High-resolution anoscopy demonstrated to be a sensitive, but not specific test ...

HPV infection-associated anogenital cyto-colpo-histological findings and molecular typing in HIV-positive women

“…In several studies, HRA revealed a sensitivity varying from 56 to 100% and a specificity from 66 to 74%; as with cytology, there is performance improvement in populations with a higher prevalence of HIV (Gimenez et al, 2011). The usefulness of HRA as a diagnostic method depends on the ability of the healthcare professionals who utilize it, and the current obstacle for its implementation as a routine technique is the lack of technical expertise (Darragh and Winkler, 2011).…”

“…Initially, patients undergo screening using the Pap smear test; abnormal anal cytology, e.g., the presence of squamous intraepithelial lesions (SILs), is detected by high-resolution anoscopy (HRA), which permits biopsies and the identification of abnormal tissue (Dandapani et al, 2010;Gimenez et al, 2011), In some groups, particularly in younger age groups, almost all infections are transient and asymptomatic; the majority of infections spontaneously disappear. Thus, specific methods of HPV detection for severe dysplasia are required especially in risk groups .…”

HIV-Associated Anal Dysplasia and Anal Carcinoma

“…Optical magnification can be performed with a modern flexible chip camera endoscope and a spacer cap (anal chromoendoscopy, ACE) [44]. This approach showed a similar diagnostic performance as HRA [45]. Both methods combined with targeted biopsies of suspect lesions are superior compared to conventional proctoscopy and cytology [10].…”

“…Due to the low specificity of cytology and visual impression, biopsy collection from areas with pathological staining patterns is mandatory [44]. Taken together, the sensitivity of the 3 methods, cytology, HRA and ACE, was estimated at around 0.66-0.9, whereas the specificity showed the broad range of 0.29-0.9 [44][45][46]. The negative predictive value of HRA was 0.75 and the corresponding value for ACE was 0.87, underscoring their value as confirmatory examinations.…”

High-Risk HPV DNA Test for Screening Anal Lesions in HIV-Positive and Negative Patients

“…The screening procedures for anal dysplasia include anal Pap smears and high-resolution anoscopy [8]. High-risk HPV infection is confirmed by means of the HPV DNA test, using hybrid capture technology [9].…”