Objectives(1) To model the natural history of anal neoplasia in HIV-infected patients using a 3-state Markov model of anal cancer pathogenesis, adjusting for cytology misclassification; and (2) to estimate the effects of selected time-varying covariates on transition probabilities.DesignA retrospective cytology-based inception screening cohort of HIV-infected adults was analyzed using a 3-state Markov model of clinical pathogenesis of anal neoplasia.MethodsLongitudinally ascertained cytology categories were adjusted for misclassification using estimates of cytology accuracy derived from the study cohort. Time-varying covariate effects were estimated as hazard ratios.Results(1) There was a moderate to high probability of regression of the high grade squamous intraepithelial lesion (HSIL) state (27–62%) at 2 years after initial cytology screening; (2) the probability of developing invasive anal cancer (IAC) during the first 2 years after a baseline HSIL cytology is low (1.9–2.8%); (3) infrared coagulation (IRC) ablation of HSIL lesions is associated with a 2.2–4.2 fold increased probability of regression to
Objectives
The aim of the study was to estimate the cumulative incidence of, and rates of progression to, invasive anal cancer (IAC) according to baseline anal cytology screening category in an unselected HIV clinical care cohort in the antiretroviral era.
Methods
A retrospective cohort analysis of HIV-infected patients under care at the University of California at San Diego Owen Clinic was carried out. Patients were eligible for this analysis if they had at least two anal cytohistological results available for longitudinal analysis. Kaplan-Meier analysis was used to estimate the cumulative incidence of IAC over time according to baseline cytology category [less than high-grade intraepithelial lesion (HSIL) versus HSIL]. Cox regression analysis was used to adjust for the following covariates: antiretroviral use, level of HIV viraemia, smoking status and infrared photocoagulation (IRC) ablation therapy.
Results
Between 2000 and 2012, we followed 2804 HIV-infected patients for a median of 4 years under a clinic protocol requiring baseline anal cytology screening. Incident IAC was diagnosed in 23 patients. Patients with a baseline HSIL anal cytology had an estimated 5-year probability of progression to IAC of 1.7% and an estimated annual progression risk of 1 in 263. None of the examined covariates was significantly associated with IAC incidence when examined in separate unadjusted Cox models.
Conclusions
HIV-infected patients with a baseline HSIL anal cytology had a 5-year cumulative incidence of IAC of 1.65%, with an upper 95% confidence bound of 4.5%. This population-based study provides quantitative risk estimates that may be used for counselling patients regarding management options for abnormal cytology results.
BackgroundThe accuracy of screening for anal cancer precursors relative to screening for cervical cancer precursors has not been systematically examined. The aim of the current meta-analysis was to compare the relative accuracy of anal cytology to cervical cytology in discriminating between histopathologic high grade and lesser grades of dysplasia when the reference standard biopsy is obtained using colposcope magnification.Methods and FindingsThe outcome metric of discrimination was the receiver operating characteristic (ROC) curve area. Random effects meta-analysis of eligible studies was performed with examination of sources of heterogeneity that included QUADAS criteria and selected covariates, in meta-regression models. Thirty three cervical and eleven anal screening studies were found to be eligible. The primary meta-analytic comparison suggested that anal cytologic screening is somewhat less discriminating than cervical cytologic screening (ROC area [95% confidence interval (C.I.)]: 0.834 [0.809–0.859] vs. 0.700 [0.664–0.735] for cervical and anal screening, respectively). This finding was robust when examined in meta-regression models of covariates differentially distributed by screening setting (anal, cervical).ConclusionsAnal cytologic screening is somewhat less discriminating than cervical cytologic screening. Heterogeneity of estimates within each screening setting suggests that other factors influence estimates of screening accuracy. Among these are sampling and interpretation errors involving both cytology and biopsy as well as operator skill and experience.
BackgroundWe recently reported, using a receiver operating characteristic area metric, the first meta-analytic comparison of the relative accuracy of cervical and anal cytology in detecting moderate or severe histopathologic lesions by magnification directed punch biopsy. The aim of the present research was to meta-analytically examine cut-point specific operating characteristics (sensitivity, specificity) of cervical and anal cytology in detecting high grade squamous intraepithelial lesion (HSIL) histopathology by colposcope directed punch biopsy.Methodology/Principal FindingsThe primary eligibility requirement was availability of tabulated cytology (normal, atypical cells of unclear significance [ASCUS], low grade squamous intraepithelial lesion, HSIL or atypical squamous cells cannot rule out high grade [ASC-H]) and biopsy (
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.