Squamous Cell Carcinoma of the Anus Incidence, Mortality, and Survival Among the General Population and Persons Living With HIV in Puerto Rico, 2000-2016

Anal carcinoma - exploring the epidemiology, risk factors, pathophysiology, diagnosis, and treatment

Anal carcinoma is a relatively rare tumor that accounts for approximately 2% of gastrointestinal malignancies and less than 7% of anorectal cancers. Most anal tumors originate between the anorectal junction and the anal verge. Risk factors for the disease include human papillomavirus infection, human immunodeficiency virus, tobacco use, immunosuppression, female sex, and older age. The pathogenesis of anal carcinoma is believed to be linked to human papillomavirus-related inflammation, leading to dysplasia and progression to cancer. Squamous cell carcinoma is the most common type of anal tumor, with an annual incidence of approximately 1 to 2 per 100000 persons. Treatment regarding anal cancer has emerged over time. However, chemoradiation therapy remains the mainstay approach for early localized disease. Patients with metastatic disease are treated with systemic therapy, and salvage surgery is reserved for disease recurrence following chemoradiation. This article aims to provide background information on the epidemiology, risk factors, pathology, diagnosis, and current trends in the management of anal cancer. Future directions are briefly discussed.

Association of body mass index with anal human papillomavirus infection and histologically confirmed high-grade squamous intraepithelial lesions in people who receive services at the Anal Neoplasia Clinic in Puerto Rico

Objective

This study aimed to assess the association of body mass index (BMI) with anal high-risk human papillomavirus (HR-HPV) and biopsy-confirmed histologic anal high-grade squamous intraepithelial lesions (HSIL) among a clinic-based sample of Hispanics in Puerto Rico.

Methods

This cross-sectional study evaluated medical records of adults who received services at the Anal Neoplasia Clinic of the University of Puerto Rico Comprehensive Cancer Center between October 2014 and December 2022. The study included 543 records with complete clinical information regarding anal HR-HPV and anal HSIL status. Chi-square and logistic regression analyses were performed.

Results

Mean age of participants was 44.10 ± 13.24 years, 65.2% were men, 71.7% were HIV-infected, 74.4% had anal HR-HPV infection, and 37.9% had biopsy-confirmed HSIL. Regarding BMI, 2.4% were underweight, 31.9% normal weight, and 39.0 % overweight; while 17.3 % had class I, 5.2% class II, and 4.2% class III obesity. No significant association was observed between BMI and anal HR-HPV infection in adjusted analyses. Lower odds of anal HSIL were observed among overweight individuals (OR: 0.63, 95% CI: 0.41 - 0.99) and those with class II/III obesity (OR: 0.48, 95% CI: 0.22 - 1.01) compared to adults with underweight/normal BMI, after adjusting for potential confounders. No significant association was observed for class I obesity.

Conclusion

BMI was not associated with anal HR-HPV infection. Overweight and obese individuals had lower odds of having anal HSIL than adults with underweight/normal BMI. This finding could suggest underdiagnosis of HSIL among overweight/obese individuals, or reduced risk in this group.

Recent and projected incidence trends and risk of anal cancer among people with HIV in North america

BACKGROUND

Anal cancer risk is elevated among people with HIV (PWH). Recent anal cancer incidence patterns among PWH in the United States (US) and Canada remain unclear. It is unknown how the incidence patterns may evolve in future years.

METHODS

Using data from the North American AIDS Cohort Collaboration on Research and Design, we investigated absolute anal cancer incidence and incidence trends in the US, Canada, and different US regions. We further estimated relative risk compared with persons without HIV, relative risk among various subgroups, and projected future anal cancer burden among US PWH.

RESULTS

During 2001-2016, in the US, age-standardized anal cancer incidence declined 2.2%/year (95%CI=-4.4% to -0.1%), particularly in the Western region (-3.8%/year [95%CI=-6.5% to -0.9%]. In Canada, incidence remained stable. Considerable geographic variation in risk was observed by US regions (eg, over four-fold risk in the Midwest and Southeast compared to the Northeast among men who have sex with men [MSM] with HIV). Anal cancer risk increased with a decrease in nadir CD4 count and was elevated among those with opportunistic illnesses. Anal cancer burden among US PWH is expected to decrease in future years (through 2035), but >70% of cases will continue to occur in MSM with HIV and people with AIDS.

CONCLUSION

Geographic variation in anal cancer risk and trends may reflect underlying differences in screening practices and HIV epidemic. MSM with HIV and PWH with AIDS will continue to bear most anal cancer burden, highlighting the importance of precision prevention.

Comparing the Diagnostic Performance of Quantitative PCR, Digital Droplet PCR, and Next-Generation Sequencing Liquid Biopsies for Human Papillomavirus-Associated Cancers

Human papillomavirus (HPV)-associated cancers, including oropharyngeal squamous cell carcinoma (HPV + OPSCC), cervical cancer, and squamous cell carcinoma of the anus (HPV + SCCA), release circulating tumor HPV DNA (ctHPVDNA) into the blood. The diagnostic performance of ctHPVDNA detection depends on the approaches used and the individual assay metrics. A comparison of these approaches has not been systematically performed to inform expected performance, which in turn affects clinical interpretation. A meta-analysis was performed using Ovid MEDLINE, Embase, and Web of Science Core Collection databases to assess the diagnostic accuracy of ctHPVDNA detection across cancer anatomic sites, detection platforms, and blood components. The population included patients with HPV + OPSCC, HPV-associated cervical cancer, and HPV + SCCA with pretreatment samples analyzed by quantitative PCR (qPCR), digital droplet PCR (ddPCR), or next-generation sequencing (NGS). Thirty-six studies involving 2986 patients met the inclusion criteria. The sensitivity, specificity, and quality of each study were assessed and pooled for each analysis. The sensitivity of ctHPVDNA detection was greatest with NGS, followed by ddPCR and then qPCR when pooling all studies, whereas specificity was similar (sensitivity: ddPCR > qPCR, P < 0.001; NGS > ddPCR, P = 0.014). ctHPVDNA from OPSCC was more easily detected compared with cervical cancer and SCCA, overall (P = 0.044). In conclusion, detection platform, anatomic site of the cancer, and blood component used affects ctHPVDNA detection and must be considered when interpreting results. Plasma NGS-based testing may be the most sensitive approach for ctHPVDNA overall.

Progress in the treatment of anal cancer: an overview of the latest investigational drugs

INTRODUCTION

Anal cancer, a rare malignancy accounting for 2.5-3.0% of gastrointestinal cancers, primarily manifests as squamous cell carcinoma associated with HPV. Recent years have witnessed significant advancements in managing squamous cell carcinoma of the anus (SCCA), particularly with the introduction of immune checkpoint inhibitors (ICIs) and randomized data on front-line chemotherapy.

AREAS COVERED

This review discusses the current standard treatments for both early and advanced SCCA, based on published data. The authors then describe the new approaches, focusing on ICI combinations, targeted agents, T-cell adoptive therapy, and HPV-therapeutic vaccines.

EXPERT OPINION

The current standard treatment for SCCA includes front-line carboplatin and paclitaxel, with pembrolizumab and nivolumab as later-line options. While modified DCF has shown promise in single-arm studies, its role as a front-line therapy requires confirmation through randomized data. We eagerly anticipate the results of phase 3 trials investigating the front-line chemo-immunotherapy for metastatic SCCA and ICI consolidation following chemoradiation for early-stage SCCA. Novel approaches like T-cell adoptive therapy, HPV-therapeutic vaccines, and bifunctional antibodies combined with HPV vaccines are in early-stage trials for HPV-mediated tumors, including HPV-positive SCCA. These approaches targeting HPV epitopes may eventually gain tumor-agnostic approval, although their role in SCCA may take time to establish.

Barriers and facilitators to anal cancer screening among people living with HIV in Puerto Rico

BACKGROUND

Anal cancer (AC) disproportionally affects people living with HIV (PLWH). Although there are no consensus-based AC screening guidelines, experts recommend anal pap as a primary screening tool in settings where high-resolution anoscopy (HRA) is available. We aimed to assess barriers and facilitators to anal cancer screening in a sample of Hispanic PLWH in Puerto Rico.

METHODS

To assess their knowledge and attitudes, we conducted a cross-sectional survey from 2020-2021 among PLWH in Puerto Rico (n = 212). Data was collected through a telephone interview that assessed information on sociodemographics, knowledge, and attitudes about AC, and the history of AC screening. The chi-square test, Fisher exact test, and logistic regression models were used to assess factors associated with screening uptake.

RESULTS

Anal Pap and HRA awareness were 60.4% and 30.7%, respectively. Anal Pap and HRA uptake was 51.5% and 19.3%, respectively. The most common barriers for anal Pap and HRA were lack of knowledge about the test and lack of physician recommendation. MSM were more likely to have heard of anal Pap (OR: 2.15, 95% CI:1.30-3.54) than MSW. MSM (OR: 3.04, 95% CI: 1.79-5.19) and women (OR: 3.00, 95% CI: 1.72-5.20) were also more likely to have undergone anal Pap. Similarly, individuals with a history of genital warts were more likely to have heard of anal Pap and HRA and have undergone anal Pap and HRA. Awareness of where to go for concerns about anal health was positively associated with having received anal Pap and HRA.

CONCLUSIONS

With emerging evidence on the effectiveness of screening and treatment for anal cancer, several organizations are steering toward generating consensus-based anal cancer screening recommendations. Our study provides foundational data on barriers and facilitators to anal cancer screening in Puerto Rico that will be critical to informing screening implementation in this US territory.

Evaluating the performance of anal cytology and high-risk HPV genotyping for detecting anal HSIL in a clinic-based sample of people living with and without HIV in Puerto Rico

BACKGROUND

Given the disproportionately elevated anal cancer risk in high-risk populations, it is important to assess the performance of commonly used anal cancer screening tools to improve the effectiveness of detection and treatment methods. This study evaluates 1) the concordance between anal cytology and histology results and 2) the performance of cytology and high-risk human papillomavirus (HR-HPV) genotyping as screening tools for detecting histologically confirmed anal high-grade squamous intraepithelial lesions (HSIL).

METHODS

Data from the Anal Neoplasia Clinic in Puerto Rico (2014-2021; n = 466) was used. The clinical performance of anal cytology and HR-HPV genotyping to detect HSIL was compared to the gold standard: high-resolution anoscopy-guided biopsy. Sensitivity, specificity, positive predictive value, negative predictive value, and κ coefficients were calculated.

RESULTS

A total of 66.95% of the patients were men, 74.0% were people living with HIV, 76.2% had anal HR-HPV infection, and 40.34% had histologically confirmed anal HSIL. The weighted κ statistic between the tests (cytology and histology) was 0.25 (p < .001). The sensitivity and specificity of cytology alone to detect anal HSIL were 84.3% (95% confidence interval [CI], 78.3%-89.1%) and 36.0% (95% CI, 30.3%-42.0%), respectively. Anal HR-HPV genotyping had higher sensitivity (92.2%; 95% CI, 87.4%-95.6%) and similar specificity (34.8%; 95% CI, 29.2%-40.7%) compared to cytology. The two tests combined (positive results following cytology or HR-HPV test) improved sensitivity to detect anal HSIL (97.9%; 95% CI, 94.8%-99.4%), but specificity was compromised (19.2%; 95% CI, 14.7%-24.4%).

CONCLUSION

Although HR-HPV genotyping improved the detection of anal HSIL, HR-HPV testing had lower specificity than anal cytology alone.

Survival outcomes used to generate version 9 American Joint Committee on Cancer staging system for anal cancer

The American Joint Committee on Cancer (AJCC) staging system for all cancer sites, including anal cancer, is the standard for cancer staging in the United States. The AJCC staging criteria are dynamic, and periodic updates are conducted to optimize AJCC staging definitions through a panel of experts charged with evaluating new evidence to implement changes. With greater availability of large data sets, the AJCC has since restructured and updated its processes, incorporating prospectively collected data to validate stage group revisions in the version 9 AJCC staging system, including anal cancer. Survival analysis using AJCC eighth edition staging guidelines revealed a lack of hierarchical order in which stage IIIA anal cancer was associated with a better prognosis than stage IIB disease, suggesting that, for anal cancer, tumor (T) category has a greater effect on survival than lymph node (N) category. Accordingly, version 9 stage groups have been appropriately adjusted to reflect contemporary long-term outcomes. This article highlights the changes to the now published AJCC staging system for anal cancer, which: (1) redefined stage IIB as T1-T2N1M0 disease, (2) redefined stage IIIA as T3N0-N1M0 disease, and (3) eliminated stage 0 disease from its guidelines altogether.

State Variation in Squamous Cell Carcinoma of the Anus Incidence and Mortality, and Association With HIV/AIDS and Smoking in the United States

PURPOSE

Squamous cell carcinoma of the anus (SCCA) incidence and mortality rates are rising in the United States. Understanding state-level incidence and mortality patterns and associations with smoking and AIDS prevalence (key risk factors) could help unravel disparities and provide etiologic clues.

METHODS

Using the US Cancer Statistics and the National Center for Health Statistics data sets, we estimated state-level SCCA incidence and mortality rates. Rate ratios (RRs) were calculated to compare incidence and mortality in 2014-2018 versus 2001-2005. The correlations between SCCA incidence with current smoking (from the Behavioral Risk Factor Surveillance System) and AIDS (from the HIV Surveillance system) prevalence were evaluated using Spearman's rank correlation coefficient.

RESULTS

Nationally, SCCA incidence and mortality rates (per 100,000) increased among men (incidence, 2.29-3.36, mortality, 0.46-0.74) and women (incidence, 3.88-6.30, mortality, 0.65-1.02) age ≥ 50 years, but decreased among men age < 50 years and were stable among similar-aged women. In state-level analysis, a marked increase in incidence (≥ 1.5-fold for men and ≥ two-fold for women) and mortality (≥ two-fold) for persons age ≥ 50 years was largely concentrated in the Midwestern and Southeastern states. State-level SCCA incidence rates in recent years (2014-2018) among men were correlated (r = 0.47, P < .001) with state-level AIDS prevalence patterns. For women, a correlation was observed between state-level SCCA incidence rates and smoking prevalence (r = 0.49, P < .001).

CONCLUSION

During 2001-2005 to 2014-2018, SCCA incidence and mortality nearly doubled among men and women age ≥ 50 years living in Midwest and Southeast. State variation in AIDS and smoking patterns may explain variation in SCCA incidence. Improved and targeted prevention is needed to combat the rise in SCCA incidence and mitigate magnifying geographic disparities.

Global burden of HPV-attributable squamous cell carcinoma of the anus in 2020, according to sex and HIV status: A worldwide analysis

Squamous cell carcinoma of the anus (SCCA) is caused by HPV, and is elevated in persons living with HIV (PLWHIV). We aimed to estimate sex- and HIV-stratified SCCA burden at a country, regional and global level. Using anal cancer incidence estimates from 185 countries available through GLOBOCAN 2020, and region/country-specific proportions of SCCA vs non-SCCA from the Cancer Incidence in Five Continents (CI5) Volume XI database, we estimated country- and sex-specific SCCA incidence. Proportions of SCCA diagnosed in PLWHIV, and attributable to HIV, were calculated using estimates of HIV prevalence (UNAIDS 2019) and relative risk applied to SCCA incidence. Of 30 416 SCCA estimated globally in 2020, two-thirds occurred in women (19 792) and one-third among men (10 624). Fifty-three percent of male SCCA and 65% of female SCCA occurred in countries with a very high Human Development Index (HDI). Twenty-one percent of the global male SCCA burden occurred in PLWHIV (n = 2203), largely concentrated in North America, Europe and Africa. While, only 3% of global female SCCA burden (n = 561) occurred in PLWHIV, mainly in Africa. The global age-standardized incidence rate of HIV-negative SCCA was higher in women (0.55 cases per 100 000) than men (0.28), whereas HIV-positive SCCA was higher in men (0.07) than women (0.02). HIV prevalence reached >40% in 22 countries for male SCCA and in 10 countries for female SCCA, mostly in Africa. Understanding global SCCA burden by HIV status can inform SCCA prevention programs (through HPV vaccination, screening and HIV control) and help raise awareness to combat the disease.

Development of a multivariable prediction model for anal high-grade squamous intraepithelial lesions in persons living with HIV in Puerto Rico: a cross-sectional study

Background

Persons living with HIV (PLWH) are at high risk of developing anal high-grade squamous intraepithelial lesions (HSIL). We aimed to develop a prediction model for anal HSIL based on individual characteristics of PLWH.

Methods

Cross-sectional study of PLWH aged ≥21 years who attended the Anal Neoplasia Clinic of the University of Puerto Rico Comprehensive Cancer Center from 2016 to 2022. The primary outcome was biopsy-confirmed anal HSIL. For each sex, relations between potential predictors and HSIL were examined using univariate (ULRM) and multivariable (MLRM) logistic regression models. Risk modelling was performed with MLRM and validated with bootstrapping techniques. The area under the ROC Curves (AUC) was estimated with 95% CI.

Findings

HSIL was detected among 45.11% of patients, 68.48% were males, and 59.42% were ≥45 aged. Multivariable analysis showed that, in women, the only significant predictor for HSIL was having a previous abnormal anal cytology (p = 0.01). In men, significant predictors for HSIL were having a previous abnormal anal cytology (p < 0.001) and a history of infection with any gonorrhoea (p = 0.002). Other suggestive predictors for HSIL among women were obesity and smoking. No association between smoking and HSIL among men was observed (p < 0.05). The AUC estimated among women (0.732, 95% CI: 0.651-0.811) was higher than in men (0.689, 95% CI: 0.629-0.748).

Interpretation

Our results support that the inclusion of individual characteristics into the prediction model will adequately predict the presence of HSIL in PLWH.

Funding

This work was supported by the NCI (Grants #U54CA096297, #R25CA240120), the NIGMS (Grant #U54GM133807), and the NIMHD (Grant #U54MD007587).

[Efforts towards the consolidation of public policies for the prevention of HPV-associated cancers in Puerto RicoEsforços realizados em Porto Rico para a consolidação de políticas públicas de prevenção de cânceres associados ao HPV]

The purpose of this special report is to describe chronologically the events that contributed to the development and approval of legislation and subsequent implementation of a school vaccination mandate in order to prevent HPV and HPV-associated cancers in Puerto Rico (PR). Starting in 2010, PR initiated public-policy approvals aimed at improving cancer registries and HPV vaccine coverage through health insurance for adolescents aged 11 to 18 years. In 2014, scientific and community efforts succeeded in documenting the magnitude of morbidity caused by HPV and jointly developing HPV vaccine prevention and promotion strategies. In August 2018, PR became one of the first four territories of the United States of America to implement the HPV vaccine school entry requirement to decrease the incidence of HPV-associated cancers on the island. In 2019, it was enshrined in law that every immunization provider must submit immunization data to the Puerto Rico Immunization Registry. The case of PR demonstrates that public policy-making alongside collaboration between academic, scientific, and community coalitions can achieve population change and measurable outcomes aimed at HPV prevention. Countries with a similar public health problem could adopt efforts similar to those presented herein and align them with the World Health Organization goal of eradicating cervical cancer by 2030.

Association of smoking with anal high-risk HPV infection and histologically confirmed anal high-grade squamous intraepithelial lesions among a clinic-based population in Puerto Rico

INTRODUCTION

Current smoking is a risk factor for anal cancer. Yet, its association with anal human papillomavirus infection (HPV) and anal high-grade squamous intraepithelial lesions (HSIL) remains unclear. We assessed the association of smoking with 1) anal high-risk HPV (HR-HPV) infection and 2) anal HSIL.

METHODS

Data from the baseline visit of patients from the Anal Neoplasia Clinic of the University of Puerto Rico Comprehensive Cancer Center (May 2015- June 2021) was analyzed. Patients were eligible if they had information on smoking status, complete high-resolution anoscopy (HRA) with biopsy, and HR-HPV testing (n =  427). Logistic regression models estimated the odds ratio (OR) with 95% confidence intervals (CIs) adjusting for covariates.

RESULTS

Mean age was 44 ± 13 years, 69% were men, 74% were HIV-infected, and 25% reported being current smokers. 74% had anal HR-HPV infection. HSIL was diagnosed in 40% of patients. Current smokers had significantly higher odds (OR: 1.71, 95% CI: 1.04-2.82) of having HSIL compared to non-smokers after adjusting for age, sexual risk group, lifetime number of sexual partners, HIV status, and HR-HPV infection. Smoking was not associated with HR-HPV infection (OR: 1.56, 95% CI: 0.83-2.95) after adjusting for age, sexual risk group, lifetime number of sexual partners, and HIV status.

CONCLUSIONS

Current smoking was associated with histologically confirmed HSIL but not with HR-HPV infection among this high-risk Hispanic population. Results highlight the need to explore targeted smoking cessation campaigns among populations at higher risk of developing HSIL, as an anal cancer prevention strategy.

Implementation of the human papillomavirus school-entry requirement in Puerto Rico: barriers and facilitators using the consolidated framework for implementation research

In 2018, Puerto Rico (PR) enacted a Human papillomavirus (HPV) vaccine school-entry requirement for students ages 11 to 12. Using the Consolidated Framework for Implementation Research (CFIR), we aimed to identify potential barriers and facilitators of this implementation. We conducted 38 qualitative interviews with stakeholders in PR from different organizations (Department of Health, Schools, Healthcare Providers, and Community organizations). We evaluated construct rating variability between the organizations to determine barriers and facilitators. The strongest facilitator determined was stakeholder's awareness of the parent's and student's needs to meet the HPV school-entry requirement. Other facilitators included initiatives for school-entry policies and the relative advantage of this requirement over different strategies. The strongest barriers included was the cost for private providers to administer the HPV vaccine, the negative influence of social media about the vaccine, which affected parents' acceptance, and the lack of school nurses as available staff resources for the school entry requirement. Findings from this study can be used to improve implementation (adaptations/modifications) and inform other states and countries in earlier stages of consideration of the adoption of similar immunization policies. Most barriers can be modifiable with the implementation of educational programs/training across schools, considering that they are the first line of response to parents of this school entry requirement.