Cost-effectiveness analysis of anal cancer screening in women with cervical neoplasia in British Columbia, Canada

Monitoring Patients With Inflammatory Bowel Disease at High Risk of Anal Cancer

Anal cancer is a rare but deadly disease that disproportionately affects patients with inflammatory bowel disease (IBD). Rates of adenocarcinoma and human papillomavirus-related squamous cell carcinoma have been consistently demonstrated to be higher in patients with ulcerative colitis and Crohn's disease. Despite this increased risk, uniform screening, diagnosis, and treatment algorithms are lacking. This review describes the most recent literature surrounding anal cancer in the IBD population as well as the unique challenges inherent in diagnosing and treating this population. We conclude by proposing a new screening motif based off literature review and multidisciplinary clinical experience that aims to increase early detection of anal cancers in the IBD population.

Anal Cancer in High-Risk Women: The Lost Tribe

In developed countries the incidence of anal squamous cell carcinoma (SCC) has been rising; especially in women over the age of 60 years who present with more advanced disease stage than men. Historically, anal SCC screening has focused on people living with Human Immunodeficiency Virus (HIV) (PLWH) who are considered to be at the highest risk of anal SCC, and its precancerous lesion, anal squamous intraepithelial lesion (SIL). Despite this, women with vulval high-grade squamous epithelial lesions (HSIL) and SCCs have been shown to be as affected by anal HSIL and SCC as some PLWH. Nevertheless, there are no guidelines for the management of anal HSIL in this patient group. The ANCHOR trial demonstrated that treating anal HSIL significantly reduces the risk of anal SCC in PLWH, there is therefore an unmet requirement to clarify whether the screening and treatment of HSIL in women with a prior genital HSIL is also beneficial. This review presents the current evidence supporting the screening, treatment, and surveillance of anal HSIL in high-risk women with a previous history of genital HSIL and/or SCC.

Anal cancer screening among women with HIV: provider experiences and system-level challenges

Women living with HIV (WLWH) are at increased risk of anal cancer compared to women without HIV, often due to persistent human papillomavirus (HPV) infections. This paper describes current practices and challenges conducting anal cancer screening for WLWH at an urban integrated safety-net system and a non-profit community-based HIV clinic. We conducted 25 semi-structured interviews with clinical and administrative stakeholders to assess knowledge, clinic practices and procedures, and experiences with anal cancer screening. Interview transcripts and fieldnotes were thematically analyzed using an iterative deductive and inductive coding scheme. Findings were organized by the Consolidated Framework for Implementation Research (CFIR) domains and constructs. Provider-level barriers to conducting anal cancer screening included limited knowledge of guidelines. System-level barriers included: structural characteristics such as lack of coordination between clinics to discern provider roles and responsibilities; and limitations in available resources such as configuration of electronic health records and infrastructure to manage referrals of abnormal anal Pap results. We conclude that anal cancer screening and follow-up for WLWH requires organization and coordination between multiple care teams, updated clinical information systems to facilitate communication and support anal Pap ordering and result documentation, and infrastructure that includes policies and protocols for management of abnormal results.Trial registration: ClinicalTrials.gov identifier: NCT02135419.

The Lifetime Cost Estimation of Human Papillomavirus-related Diseases in China: A Modeling Study

OBJECTIVES

To estimate the lifetime treatment costs of patients with human papillomavirus (HPV) infection-related diseases in China and to provide cost estimates for the economic evaluation of HPV intervention strategies.

METHODS

We extracted real-world hospital data from 2012 to 2019 and screened for subjects who met the criteria of clinical diagnosis of HPV-related diseases to obtain country-specific inputs into a Markov decision model. The model simulated lifetime treatment costs for HPV from the perspective of a national payer. A 5% discount rate was applied. Costs were converted and inflated to 2020 US dollars (USD).

RESULTS

Using 2021 as the base year, the lifetime costs per patient for carcinoma in situ, local metastasis, and distant metastasis cervical cancer are $24,208 (95%CI: 18,793-30,897), $19,562 (95%CI: 14,456-25,567), and $17,599 (95%CI: 10,604-25,807), respectively. For carcinoma in situ, local metastasis, and distant metastasis vaginal cancer, the lifetime costs are $17,593 (95%CI: 14,962-23,596), $17,120 (95%CI: 13,215-22,417), and $22,411 (95%CI: 12,172-22,249), respectively. The base-case lifetime cost per patient for different stages of vulvar cancer/penile cancer/anal cancer/oral cancer/oropharyngeal cancer/laryngeal cancer falls within $17,120-$58,236.

CONCLUSIONS

Using real-world data, we calculated lifetime treatment costs of HPV-related cancer in China and found that the lifetime cost for patients exceeded $17,000 for various stages of disease. The national burden of HPV-related disease could be significantly reduced by eliminating HPV infection.

Anal cancer screening and prevention: a review for dermatologists

The incidence of and mortality from anal cancer, predominantly squamous cell carcinoma (SCC), have been increasing since the 1980s, during an era when many common malignancies have seen decreases in mortality. Dermatologists may be more likely to see patients at an increased risk for anal SCC, such as those living with HIV, MSM and those presenting for management of anogenital warts, yet there is little guidance in the field on how to manage these patients. We underwent a project to review the evidence surrounding screening and prevention of anal SCC. HPV vaccination, the main preventative measure for anal SCC, is often underutilized and may not be effective for those most at risk. Screening methods currently include high-risk HPV and anal cytology testing, with high-resolution anoscopy (HRA) reserved for biopsy and confirmatory testing. High-risk HPV testing has been associated with high sensitivity for intraepithelial neoplasia, but low specificity in high-risk groups. Recent meta-analyses examining AIN detection using anal cytology estimate a similarly high sensitivity of 74-87%, with a relatively higher specificity (44-66%) for identifying high-grade AIN. HRA is the gold standard for diagnosis, but its accessibility and cost are deterrents from its use as a screening tool. Cervical cancer screening, initially adopted without significant evidence of its impact, has significantly decreased cervical cancer rates. The argument can be made that rates of anal SCC may also benefit from appropriate screening methods, particularly anal cytology. It is prudent for dermatologists to be aware of the methods available to them in the management of at-risk patients, the data supporting them, and the potential benefits of screening in order to counsel patients appropriately and address the increasing burden of disease.

Risk of HPV-related extra-cervical cancers in women treated for cervical intraepithelial neoplasia

Background

The aim was to estimate the risk of subsequent extra-cervical Human Papillomavirus (HPV) related cancer in patients surgically treated for high grade cervical intraepithelial neoplasia (CIN 2–3). This is the first study in Italy investigating the occurrence of extra-cervical tumors in this cohort of patients.

Methods

3184 patients surgically treated for CIN2–3 since 1992 at the Department of Surgical Sciences of University of Torino were considered. The risk of HPV-related cancer was calculated as Standardized Incidence Ratio (SIR), using as expected values tumour age specific incidence of resident population.

Results

173 second primary cancer (SCPs) were identified. SIR to develop cancer after treatment for CIN2–3 was 2.2 (CI 95% 1.89–2.50). Among these occurrences, 10 are in HPV related sites: 1 anus (SIR = 1.8; 0.04–10.0), 3 vagina (SIR = 12.4; 2.56–36.3), 1 vulva (SIR = 1.7; 0.04–9.59), 5 oropharynx (SIR = 8.5; 2.76–19.8).

Significant risk has been also recorded for pulmonary (SIR = 3.1; 0.70–5.27) and bladder (SIR = 4.05; 1.10–10.56), with smoking as possible cofactor. We also found increased risk for breast (SIR = 2.4; 2.07–2.84) and ovarian cancers (SIR = 2.1; 1.13–3.49), probably due to an higher adherence to spontaneous and programmed screening programs.

Conclusions

Our study supports the hypothesis of an increased risk of HPV-related tumours for CIN treated patients, mostly for CIN3. It is conceivable the need of early diagnosis for these cancers in this higher-risk populations.

Investigating epidemiologic trends and the geographic distribution of patients with anal squamous cell carcinoma throughout Canada

Background

Anal cancer is a rare disease, constituting 0.5% of new cancer cases in the United States. The most common subtype is squamous cell carcinoma (scc). Studies in several developed nations have reported on an increasing incidence of anal cancer in recent decades, and various risk factors pertaining to the pathogenesis of the disease have been identified, including infection with the human papillomavirus, tobacco use, and immunosuppression. The epidemiology and distribution of anal scc throughout Canada remain poorly understood, however.

Methods

Using 3 population-based cancer registries, a retrospective analysis of demographic data across Canada for 1992-2010 was performed. The incidence and mortality for anal scc was examined at the levels of provinces, cities, and the forward sortation area (FSA) component (first 3 characters) of postal codes.

Results

During 1992-2010, 3720 individuals were diagnosed with anal scc in Canada; 64% were women. The overall national incidence rate was 6.3 cases per million population per year, with an average age at diagnosis of 60.4 years. The incidence increased over time, with significantly higher incidence rates documented in British Columbia and Nova Scotia (9.3 cases per million population each). Closer examination revealed clustering of cases in various urban centres and self-identified lgbtq communities in Toronto, Montreal, and Vancouver.

Discussion

This study provides, for the first time, a comprehensive analysis of the burden of anal scc in Canada, identifying susceptible populations and shedding light onto novel avenues of research to lower the incidence of anal cancer throughout the country.

Anal cytology in women: Experience from a single tertiary center

INTRODUCTION

Anal cytology (AC) can be used as a screening tool for detection of anal HPV associated lesions, mainly in men who have sex with men and in immunosuppressed patients. Our aim is to review our experience with AC in women.

MATERIAL & METHODS

We have retrospectively reviewed all AC diagnosed between 2010-2017 in a single tertiary hospital (n = 644) and selected those performed in women (n = 158).

RESULTS

24.53% of AC were performed in women. 14.7% of all women were HIV positive and 56.7% referred anal intercourse. Squamous lesions were found in 27.2% of women, most of them ASCUS and LSIL (14% and 11.5%). HPV DNA was detected in 38.6% of patients, and 63.9% of them showed positivity for multiple high-risk types. Anal biopsy showed high grade lesions in 20% of biopsied patients. We observed a significant relationship between HPV status and receptive anal sex, and the association between HPV status and anal histological diagnosis tended to significance. Sensitivity, specificity, negative predictive value and positive predictive value for anal cytology were 57%; 83%; 28% and 94%, respectively. 70.9% of women had synchronous cervical cytology, and squamous cervical lesions were detected in 46.4% of the cases, most of them LSIL or ASCUS (21.4% and 15.2%). We did not confirm a significant association between cytological diagnosis of cervical and anal samples.

CONCLUSIONS

AC is less widely used in women than in homosexual men. However, women show important rates of anal lesions, regardless of their HIV status. More studies should be performed to assess the potential impact of screening protocols in this population.

Patients with newly diagnosed cervical cancer should be screened for anal human papilloma virus and anal dysplasia: Results of a pilot study using a STELLA computer simulation and economic model

BACKGROUND

Women with cervical cancer often have anal human papillomavirus (HPV) infection and anal dysplasia. However, effectiveness of anal HPV screening is unknown.

METHODS

A dynamic model was constructed using STELLA. Populations are represented as "stocks" that change according to model rates. Initial anal cytology in new cervical cancer patients, dysplasia progression and regression, cost of treating high-grade squamous intraepithelial lesions (HSIL), and lifetime costs for anal cancer care were extrapolated from the literature. Local costs of anal HPV testing and cytology were obtained. Outcomes included anal cancer rates, anal cancer deaths, screening costs and cancer care.

RESULTS

Benefits in the screened group included reduction in anal cancers after three years and anal cancer deaths after four years. After 10 years, predicted costs per anal cancer prevented and anal cancer deaths were $168,796 and $210,057 and were $98,631 and $210,057 at 20 years. Predicted costs per quality of life year saved at 10 and 20 years were $9785 and $1687. Sensitivity analysis demonstrated cost-effectiveness of screening for a variety of cure rates HSIL with electrocautery.

CONCLUSION

Screening for anal HPV and treatment of anal HSIL in patients with cervical cancer is cost-effective, prevents anal cancer and reduces anal cancer deaths.

Anal Cancer and Anal Cancer precursors in Women with a History of HPV-Related Dysplasia and Cancer

The epidemiology of anal cancer in the U.S. has changed over the past 3 decades. During this period the incidence of anal cancer has increased among both men and women. Of note, women with a history of anogenital HPV infection are at higher risk than the general population for anal cancer. The increased risk ranged from increased incidence rate ratios ranging from 1.82 to 6.3 in women with a history of cervical cancer, to 4.2-16.4 in women with a history of prior cervical intraepithelial neoplasia 3 (CIN 3). In addition, studies describing screening women with a previous history of anogential HPV infection (including CIN 3) for anal HPV and anal pre-cancers demonstrate that the prevalence of anal HPV is measureable in this population. The prevalence of anal high grade squamous intraepithelial lesions (HSIL) in this population was relatively low, which may have been related to the fact that many of these studies had insufficient samples, and the numbers of patients undergoing HRA remain low. Future studies evaluating anal cancer screening strategies in this high-risk group are needed.