Effects of Referral Bias on Estimates of Anal Intraepithelial Neoplasia Progression and Regression Rates in a 3-State Markov Model

Clinical Predictors and Outcomes of Invasive Anal Cancer for People With Human Immunodeficiency Virus in an Inception Cohort

BACKGROUND

Due to the heterogeneity of risk for invasive anal cancer (IAC) among people with human immunodeficiency virus (PWH), we investigated predictors of IAC and described outcomes among those with a cancer diagnosis.

METHODS

Using a longitudinal inception cohort of anal cancer screening, we evaluated risk factors and outcome probabilities for incident IAC in Cox models. Screening included anal cytology and digital anorectal examination, and, if results of either were abnormal, high-resolution anoscopy.

RESULTS

Between 30 November 2006 and 3 March 2021, a total of 8139 PWH received care at the University of California, San Diego, with 4105 individuals undergoing screening and subsequently followed up over a median of 5.5 years. Anal cancer developed in 33 of them. IAC was more likely to develop in patients with anal high-grade squamous intraepithelial lesions (aHSILs) on initial or subsequent follow-up cytology (hazard ratio, 4.54) and a nadir CD4 cell count ≤200/µL (2.99). The joint effect of aHSILs and nadir CD4 cell count ≤200/µL amplified the hazard of IAC by 9-fold compared with the absence of both. PWH with time-updated cytology aHSIL and CD4 cell counts ≤200/µL had 5- and 10-year probabilities of IAC of 3.40% and 4.27%, respectively. Twelve individuals with cancer died, 7 (21% of the total 33) due to cancer progression, and they had clinical stage IIIA or higher cancer at initial diagnosis.

CONCLUSIONS

PWH with both aHSIL and a nadir CD4 cell count ≤200/µL have the highest risk of IAC. PWH who died due to IAC progression had clinical stage IIIA cancer or higher at diagnosis, highlighting the importance of early diagnosis through high-resolution anoscopic screening.

Anal Cancer Screening and Prevention: Summary of Evidence Reviewed for the 2021 Centers for Disease Control and Prevention Sexually Transmitted Infection Guidelines

In June 2019 the Centers for Disease Control and Prevention (CDC) convened an advisory group to assist in development of the 2021 CDC sexually transmitted infections (STI) guidelines. The advisory group on anal cancer screening and prevention met to formulate key questions in this field. The group examined published literature and abstracts to assess evidence and give recommendations for development of the CDC guidelines. This article summarizes key questions, evidence, recommendations, and areas for further research for the screening, diagnosis, and prevention of anal cancer.

Risk of Anal Cancer Following Benign Anal Disease and Anal Cancer Precursor Lesions: A Danish Nationwide Cohort Study

BACKGROUND

Human papillomavirus (HPV) is associated with the majority of anal high-grade intraepithelial neoplasia (AIN) and anal cancers. Little is known about the risk of anal cancer following a diagnosis of benign anal disease and AIN.

METHODS

Using data from nationwide, population-based Danish registries, a cohort of 126,174 individuals with either non-neoplastic anal disease or AIN 1 to 3 during 1970 to 2016 was followed until first occasion of anal cancer. Information on HIV status was obtained from the Danish HIV Cohort Study. The absolute risk of anal cancer was estimated using the Aalen-Johansen estimator taking into account censoring at emigration and end of follow-up and competing risk at time of death. Standardized incidence ratios (SIR) for anal cancer among individuals with non-neoplastic anal disease, including inflammatory lesions, hemorrhoids, and polyps, were estimated in Poisson models. Sex-, age-, and calendar period-specific national population rates were estimated using the Danish National Pathology Registry.

RESULTS

Anal cancer risk increased with increasing severity of lesions, reaching 4% 5 years after diagnosis of AIN3. Even among those with non-neoplastic anal lesions, particularly inflammatory lesions, anal cancer risk was significantly higher than expected from Danish national anal cancer rates (SIR = 2.8; 95% confidence intervals, 2.3-3.2). The absolute 5-year risk of anal cancer following AIN3 was considerably higher among HIV-positive (14.1%) than HIV-negative (3.2%) individuals.

CONCLUSIONS

Anal cancer risk increases with increasing severity of lesions and is especially high among HIV-positive individuals.

IMPACT

Vaccination against HPV is important in the prevention of both high-grade AIN and anal cancer.

Expectant Management of High-Grade Anal Dysplasia in People with HIV: Long-term Data

BACKGROUND

Both ablation and expectant management of high-grade squamous intraepithelial lesions have been proposed. Expectant management would be reasonable if 1) the rate of high-grade squamous epithelial lesion progression to anal squamous cell carcinoma were low, and 2) anal squamous cell carcinoma arising under surveillance had a better prognosis than anal squamous cell carcinoma presenting without an identified precursor.

OBJECTIVE

This study aims to quantify aspects of high-grade squamous epithelial lesion/anal squamous cell carcinoma clinical evolution in a surgical practice.

DESIGN

This is a retrospective cohort study.

SETTINGS

This study was performed in 1 colorectal surgeon's practice over a 20-year period.

PATIENTS

Consecutive patients with high-grade squamous intraepithelial lesion and anal squamous cell carcinoma were included.

MAIN OUTCOME MEASURES

We looked at the rate and timing of progression to anal squamous cell carcinoma, and the stage, treatment, and outcome of anal squamous cell carcinoma. We reviewed a comparison group of HIV-positive patients presenting de novo with anal squamous cell carcinoma (no prior history of high-grade squamous intraepithelial lesion).

RESULTS

With consideration of only HIV-positive patients, 341 patients had a mean 5.6 years follow-up from high-grade squamous intraepithelial lesion diagnosis to the most recent documented anal examination. Twenty-four of these surveillance patients developed anal squamous cell carcinoma, yielding a progression rate of 1.3% per patient-year. Mean follow-up was 7.3 years from the initial cancer diagnosis to the most recent contact. Forty-seven patients who presented de novo with anal squamous cell carcinoma developed 74 lesions, with a mean follow-up of 5.7 years after initial diagnosis. This de novo group had higher anal squamous cell carcinoma-specific mortality (3% per patient-year vs 0.05%). Our study did not show a significantly higher rate of high stage (stage III or IV) at anal squamous cell carcinoma diagnosis in the de novo group in comparison with the surveillance group (25.5% vs 8.3% (p = 0.09)).

LIMITATIONS

This study was retrospective in nature and had a predominately male population.

CONCLUSIONS

The progression of untreated high-grade squamous intraepithelial lesion to anal squamous cell carcinoma approximates 1% per patient-year. Anal squamous cell carcinoma developing under surveillance tends to be of an earlier stage and to require fewer major interventions than anal squamous cell carcinoma presenting de novo. Cancer-specific mortality was lower for malignancies that developed under surveillance. We suggest that expectant management of patients with high-grade squamous intraepithelial lesion is a rational strategy for preventing anal cancer morbidity. See Video Abstract at http://links.lww.com/DCR/A699.

Disparities in the Clinical Evolution of Anal Neoplasia in an HIV-Infected Cohort

BACKGROUND

A recent meta-analysis suggested that anal intraepithelial neoplasia and invasive anal cancer are more prevalent among black men having sex with men (MSM).

METHODS

We conducted a retrospective cohort of HIV-infected adult patients under care between 2001 and 2012. Disparities in clinical evolution of anal intraepithelial neoplasia to high-grade squamous intraepithelial lesion (HSIL) and invasive anal cancer were evaluated in a three-state Markov model adjusted for cytology misclassification. We studied sociodemographic covariate effects for each state transition using multivariable models controlling for antiretroviral therapy and infrared coagulation treatment of HSIL.

RESULTS

Among 2804 patients with a median age of 40 years, 78% were MSM and 38% non-white. There were no disparities in HSIL prevalence (14%) by age, sex, race, or risk group. After 4.0 years of follow-up, 23 patients developed invasive anal cancer. Females and black patients had lower transition rates from <HSIL→HSIL (HR = 0.35 and HR = 0.55, respectively); those with age >40 had lower rates of both <HSIL→HSIL progression (HR = 0.64) and HSIL→<HSIL regression (HR = 0.56); and MSM had higher rates of progression from <HSIL→HSIL (HR = 3.30). Controlling for antiretroviral therapy and infrared coagulation (IRC) treatment as time-updated covariates, the univariable effects of sex, black race, and HIV risk factor remained significant.

CONCLUSIONS

Black race was not associated with prevalent anal intraepithelial neoplasia nor with post-baseline progression of anal intraepithelial neoplasia.