The Utility of Digital Anal Rectal Examinations in a Public Health Screening Program for Anal Cancer

Epidemiology of HPV-associated cancers past, present and future: towards prevention and elimination

Cervical cancer is the first cancer deemed amenable to elimination through prevention, and thus lessons from the epidemiology and prevention of this cancer type can provide information on strategies to manage other cancers. Infection with the human papillomavirus (HPV) causes virtually all cervical cancers, and an important proportion of oropharyngeal, anal and genital cancers. Whereas 20th century prevention efforts were dominated by cytology-based screening, the present and future of HPV-associated cancer prevention relies mostly on HPV vaccination and molecular screening tests. In this Review, we provide an overview of the epidemiology of HPV-associated cancers, their disease burden, how past and contemporary preventive interventions have shaped their incidence and mortality, and the potential for elimination. We particularly focus on the cofactors that could have the greatest effect on prevention efforts, such as parity and human immunodeficiency virus infection, as well as on social determinants of health. Given that the incidence of and mortality from HPV-associated cancers remain strongly associated with the socioeconomic status of individuals and the human development index of countries, elimination efforts are unlikely to succeed unless prevention efforts focus on health equity, with a commitment to both primary and secondary prevention.

Men who have sex with men experience low anxiety and few barriers to performing anal self or companion examinations: a qualitative study of the Prevent Anal Cancer Palpation Study

While rare in the larger population, anal cancer incidence is significantly higher in groups such as sexual minority men and people living with HIV. This qualitative analysis examined participants' experiences and perceptions of barriers to anal self-examination and anal companion examination through interviews completed as a part of a larger clinical trial. Interviews were conducted online with participants (n = 131) within a week of their baseline appointment between January 2020 and October 2021. Content analysis denoted participants' thoughts and perceptions about anal self-examination and anal companion examinations. Of the 131 cisgender men interviewed (mean age 49.9 years, SD 12.7), 92.4% identified as gay, 54.9% identified as white, 22.1% identified as Black, 19.9% identified as Latino, and 44.3% of participants were living with HIV. Participants did not report feelings of excessive anxiety when an abnormality was detected. However, three salient themes emerged as to why participants may not perform an anal self-examination or anal companion examination: (1) physical limitation(s), (2) potential sexualisation of the examination, and (3) level of comfort discussing anal health. Future work must continue to explore methods that not only decrease stigma surrounding anal health but also bolster feelings of accessibility to perform self and couple examinations.

Global trends in anal cancer incidence and mortality

OBJECTIVE

Anal cancer is a rare disease, affecting more frequently women than men, mainly related to human papillomavirus infection (HPV). Rising incidence and mortality have been reported over the past four decades in different countries.

METHODS

To provide an up-to-date overview of recent trends in mortality from anal cancer, we analysed death certification data provided by the WHO in selected countries worldwide over the period from 1994 to 2020. We also analysed incidence derived from Cancer Incidence in Five Continents from 1990 to 2012 for all histologies as well as for anal squamous cell carcinoma (SCC).

RESULTS

The highest age-standardised mortality rates around 2020 were registered in Central and Eastern Europe, such as Slovakia (0.9/100 000 men and 0.40/100 000 women), in the UK (0.24/100 000 men and 0.35/100 000 women), and Denmark (0.33/100 000 for both sexes), while the lowest ones were in the Philippines, Mexico, and Japan, with rates below 0.10/100 000 in both sexes. Upwards trends in mortality were reported in most countries for both sexes. Similarly, incidence patterns were upward or stable in most countries considered for both sexes. In 2008-2012, Germany showed the highest incidence rates (1.65/100 000 men and 2.16/100 000 women).

CONCLUSION

Attention towards vaccination against HPV, increased awareness of risk factors, mainly related to sexual behaviours and advancements in early diagnosis and management are required to control anal cancer incidence and mortality.

A case of a rare type of cancer: Anal squamous cell carcinoma in a patient without significant risk factors

INTRODUCTION

Anal carcinoma is a relatively uncommon tumor that accounts for less than 2% of large bowel malignancies and approximately 1-6% of anorectal tumors. Most anal cancers originate in the mucosa between the anorectal junction and the anal verge. Risk factors for anal carcinoma include human papillomavirus (HPV), immunosuppression, older age, female gender, and smoking. Approximately 85% of anal cancers are squamous cell carcinoma, and the pathophysiology is believed to be linked to HPV-related inflammation, leading to dysplasia and progression to cancer.

CASE PRESENTATION

We present the case of a 65-year-old woman who sought medical attention at the emergency department (ED) due to rectal pain and concurrent rectal lesions persisting for the past three months. Before admission, she reported abdominal discomfort and constipation for 2-3 months, during which she took laxatives for relief. Laboratory findings in the ED were significant for anemia and leukocytosis, with all other values within normal limits. Blood tests, including antibodies for HPV and human immunodeficiency virus, were negative. A computed tomography scan of the abdomen and pelvis was largely unremarkable. On physical examination, perianal lesions with heaped-up edges were observed. A punch biopsy was subsequently performed, revealing squamous cell carcinoma (SCC). About three weeks following discharge, after one week of admission to the general medicine ward, the patient started chemoradiation therapy and reported some improvement in her symptoms. Seven weeks later, she was in remission.

DISCUSSION

Squamous cell carcinoma (SCC) of the anus, a rare disease entity, is often a slow and progressive malignancy. The length of time for patients to become symptomatic, in combination with its mimicking clinical presentation to common gastrointestinal tract diseases and its rarity, makes diagnosis challenging. Additionally, a patient lacking traditional risk factors for anal cancer, such as HPV and smoking, may further complicate diagnosis, treatment, and quality of life.

CONCLUSION

This case report emphasizes the pathogenesis and the similarities in clinical presentation of anal cancer to mild diseases, which may lead to a delay in diagnosis. Patients with anal carcinoma often delay seeking medical care, which is anecdotal in relation to the considerable overlap in symptoms of benign diseases such as hemorrhoids. Therefore, patients with "hemorrhoid" complaints, rectal bleeding, or rectal mass should warrant further physical examination and prompt referral to a gastroenterologist or a colorectal surgeon for additional evaluation.

Digital Anal Rectal Examination Usage Among Individuals at Increased Risk for Anal Cancer

OBJECTIVE

Multiple organizations recommend an annual digital anal rectal examination (DARE) for people at highest risk for anal cancer. The authors assessed DARE usage among sexual minority men and transgender women.

METHODS

Community-recruited and asymptomatic individuals from a mid-sized US city were enrolled into the Prevent Anal Cancer Self-Swab Study, a longitudinal clinical trial of anal cancer screening. Self-reported data from the baseline survey were used to assess usage of DARE in the last year and during the lifetime. Adjusted odds ratios (aORs) and CIs for factors associated with each outcome were determined using multivariable logistic regression.

RESULTS

Among 241 participants, median age was 46 years (interquartile range, 33-57 years), 27.0% were living with HIV, and 24.5% reported a previous diagnosis of anal warts. A total of 13.7% (95% CI = 9.4%-18.0%) of individuals reported a DARE in the previous year, whereas 53.9% (95% CI = 47.7%-60.2%) reported a DARE during the lifetime. The following were associated with a DARE in the previous year: increasing age (aOR = 1.04; 95% CI = 1.01-1.08 for each additional year), any previous anal cytology (aOR = 2.62; 95% CI = 1.19-5.80, compared with no previous test or no knowledge of a test), and preferred receptive position during anal sex (aOR = 4.93; 95% CI = 1.17-20.86 compared with insertive).

CONCLUSIONS

Despite guidelines recommending an annual DARE, it was uncommonly reported. There is an urgent need to understand barriers to conducting DARE among individuals most vulnerable to anal cancer and their health care providers.

Identification and Reporting of Anal Pathology during Routine Colonoscopies

The gold-standard procedure for anal canal examination is anoscopy. Nonetheless, patients are referred for a colonoscopy for many reasons, and a routine exam might provide an opportunity to diagnose anal pathologies, such as hemorrhoids, anal fissures, anal polyps, condylomas, and anal squamous cell carcinoma. It is important to know the main features of these conditions and relevant information to report in order to help guide patient treatment and follow-up.

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.

Comparison of anal pre-cancer screening strategies among men who have sex with men

PURPOSE

Comparison of anal pre-cancer screening strategies in men who have sex with men (MSM).

METHODS

MSM in the Multicenter AIDS Cohort Study underwent repeated anal cytology (aCyt), oncogenic human papillomavirus (oncHPV) testing. A subset received High-Resolution Anoscopy (HRA). We evaluated three screening strategies for their ability to predict anal histological High-Grade Squamous Intraepithelial lesion (HSIL): single aCyt, sequential aCyt, and oncHPV co-testing. Multivariable logistic regression models evaluated risk of HSIL among participants undergoing HRA within 5 years of screening. Sensitivity and specificity were estimated among participants with HRA, and results corrected for verification bias using weighted generalized estimating equations.

RESULTS

There were 1426 MSM with aCyt screening (48% people with HIV [PWH]) and 428 that underwent HRA. Median age was 57 years, 14% of PWH had CD4< 350 cells/mm3. HSIL probability was higher in MSM with one (39%, p < 0.01) or two abnormal aCyt results (46%, p < 0.01), versus those with normal aCyt (23-24%). Among men with abnormal aCyt, men with oncHPV+ had significantly higher risk than those who were oncHPV- (47% vs. 16%, p < 0.01). Specificity was modest with single aCyt+ (50%) but increased with sequential aCyt+ (79%) or oncHPV+ (67%). Sensitivity was high with single oncHPV+ (88%), moderate with single aCyt+ (66%) and oncHPV+ co-testing (61%), and low with sequential aCyt+ (39%). After correcting for potential verification bias, specificity increased and sensitivity decreased, but inferences were similar.

CONCLUSION

None of the screening strategies evaluated had both sufficient specificity and sensitivity to warrant routine widespread use.

Do we DARE? Improving digital ano-rectal examination in men who have sex with men living with HIV: a quality improvement initiative

Men who have sex with men (MSM) living with HIV are at increased risk of anal cancer and annual screening via digital ano-rectal examination (DARE) is recommended. Baseline audit (Cycle 1) was undertaken of the medical records of MSM living with HIV aged ≥50years (n =85) from 1 January 2017 to 31 December 2018, in line with guidelines at the time. Data collection included whether DARE was discussed and offered, and whether DARE was accepted or declined. We provided staff training and altered clinic proformas aiming to increase DARE. Audit Cycle 2 (Cycle 2) was undertaken of eligible MSM (n =86) who attended between 1 January 2019 to 31 December 2020. DARE frequency increased from 4.7% in Cycle 1 to 41.8% in Cycle 2 (P <0.001) and discussion and offer of DARE increased from 8% to 64% in Cycle 2 (P <0.001).

Prevalence of and factors associated with anal high-risk human papillomavirus in urban Tanzanian men who have sex with men, 2011-2012

Background: Anal cancer is primarily caused by high-risk human papillomavirus (hrHPV), is associated with HIV infection, and has a very high incidence among men who have sex with men (MSM). We assessed prevalence of hrHPV, and factors associated with hrHPV in anal canal specimens collected in Dar es Salaam, Tanzania from HIV-positive and HIV-negative MSM. Methods: MSM were recruited using respondent-driven sampling in this cross-sectional study. The primary outcome in this ancillary analysis of 116 MSM was prevalence of HPV-16 and other hrHPV types. Prevalence ratios (PR) estimated the association between hrHPV and HIV-negative participants' demographics, sexual behaviour and sexually transmitted infections. Results: Median age was 23 years and 33.6% of participants were HIV-positive. HrHPV and HPV-16 prevalence was 54.3% and 17.2%, respectively, with HPV-16 prevalence highest among HIV-positive MSM identifying as gay (36.1%) and lowest among HIV-negative MSM identifying as bisexual (2.9%). Having two or more receptive anal sex partners in the past month was associated with hrHPV (PR 3.20, 95%CI 1.69-6.07, vs. 0 partners) among HIV-negative MSM.Conclusions: HrHPV prevalence was high among MSM in Dar es Salaam and highest among HIV-positive MSM identifying as gay. These estimates may be used to support HPV vaccination and screening initiatives.

A cross-sectional survey on attitudes of men who have sex with men towards anal self-examination for detection of anal syphilis

Studies suggest men who have sex with men (MSM) practising receptive anal sex are more likely to present with secondary syphilis, implying primary anorectal lesions are likely to be missed. If men could detect anorectal lesions in the primary stage by regular anal self-examination (ASE), transmission could be reduced by early diagnosis and treatment. We aimed to explore the attitudes of MSM on performing ASE to detect primary anorectal syphilis. An online anonymous cross-sectional survey among MSM over 18 years of age living in Australia, was conducted between July and November 2020 and recruitment was from a sexual health clinic and social media. A total of 568 MSM completed the survey (median age: 34 [IQR 27–45]): 32% (183) had previously performed ASE. Among 66% (374) who had never performed ASE, 68% (250) would consider performing ASE in the future with a preferred median frequency of 2 times per 4 weeks (IQR 1–4), whilst men who were already performing ASE were performing it at median 1 per 4 weeks (IQR 0.2–3). Almost two-thirds of MSM who had never performed ASE were willing to adopt ASE practice in the future. Studies are required to determine the effectiveness of ASE for syphilis detection.

Provider Preferences for Anal Cancer Prevention Screening: Results of the International Anal Neoplasia Society Survey

Objective

This study explores provider preferences regarding anal cancer screening indications, initiation age, tools, and referral threshold to high resolution anoscopy (HRA).

Methods

International Anal Neoplasia Society affiliates were invited to complete an online survey. Options for initiation age and tools were delineated by sub-groups. HRA referral thresholds separately queried recommendations by patient immune status.

Results

One hundred forty respondents participated. Although consensus was lacking with regard to specific screening initiation age, more respondents recommended younger initiation ages for men who have sex with men (MSM) living with HIV (LWH) compared with MSM not LWH (p < 0.01). “No age threshold” ranged 44-55% among sub-groups with lower genital tract disease. Cytology and digital anorectal exam (DARE) were the most frequently selected tools for all sub-groups (ranges 77-90% and 74-86%, respectively). HRA was recommended significantly more frequently for MSM LWH (58%) and patients with vulvar cancer (52%) compared to others (p < 0.01). “Any [test] abnormality” was more often selected as indication for HRA for immunocompromised (56%) and immunocompetent (46%) patients than a specific cytology test result (29%, 36% respectively).

Conclusion

Cytology and DARE were preferred screening tools; screening initiation age and HRA referral threshold showed less consensus. Evidence-based guidelines are needed and may lead to more consistent screening practices.

Gaps and Opportunities to Improve Prevention of Human Papillomavirus-Related Cancers

Human papillomavirus (HPV) infections cause more than 35,900 cancers annually in the United States. Although cervical cancer is the most prevalent HPV-related malignancy in women, the virus is also responsible for a significant percentage of anal, vaginal, and vulvar cancers. A comprehensive approach to mitigating cervical cancer includes HPV vaccination (primary prevention), screening and treatment of precancerous lesions (secondary prevention), and diagnosis and treatment of invasive cancer (tertiary prevention). Although a successful strategy, there are opportunities to innovate and increase access that can also be adapted to address the unique clinical care gaps that exist with the other anogenital cancers. The Society for Women's Health Research held a series of interdisciplinary meetings and events, during which expert researchers, clinicians, patient advocates, and health care policy leaders evaluated the current landscape of HPV-related cancers and their effects on women's health. This report summarizes the discussions of this working group and areas it identified in which to address gaps in primary and secondary prevention approaches to improve access and health outcomes for women with HPV-related anogenital cancers.

Exploring the attitudes of men who have sex with men on anal self-examination for early detection of primary anorectal syphilis: a qualitative study

BACKGROUND

Studies show men who have sex with men (MSM) practising receptive anal sex are more likely to present with secondary syphilis, suggesting anorectal primary lesions are being missed. Regular anal self-examination might be able to detect anorectal syphilis lesions, hence potentially reducing transmission. This study aimed to explore the attitudes of MSM on performing anal self-examination to detect primary syphilis.

METHODS

In this qualitative study, 20 MSM over 18 years of age were purposively sampled from a sexual health clinic to participate in semi-structured interviews. Interviews were recorded, transcribed verbatim and data analysed thematically.

RESULTS

Four major themes and 12 sub-themes were generated from the study: (1) reasons for performing anal self-examination, (2) preferred educational resources for anal self-examination, (3) attitudes towards partner anal examination, and (4) acceptability of anal self-examination. Most participants had performed some form of anal self-examination in the past, and, just over half performed regularly for mostly health-related concerns. Most participants who infrequently or never performed anal self-examination were agreeable to perform regularly if it was recommended by health professionals with appropriate guidance. Participants preferred education on anal self-examination from health professionals and trusted online learning resources.

CONCLUSION

Our study showed MSM were agreeable to anal self-examination however would like to receive education and training to gain more confidence in conducting anal self-examination as a screening tool. Further studies are required to explore the adherence and acceptability of anal self-examination for syphilis prior to studies examining efficacy. The study provides foundation for any future policy aiming at utilising anal self-examination as a screening tool for syphilis among MSM.

Prevention and Screening of HPV Malignancies

It is estimated that 5% of the global cancer burden, or approximately 690,000 cancer cases annually, is attributable to human papillomavirus (HPV). Primary prevention through prophylactic vaccination is the best option for reducing the burden of HPV-related cancers. Most high-income countries (HICs) have introduced the HPV vaccine and are routinely vaccinating adolescent boys and girls. Unfortunately, although they suffer the greatest morbidity and mortality due to HPV-related cancers, many lower- and middle-income countries (LMICs) have been unable to initiate and sustain vaccination programs. Secondary prevention in the form of screening has led to substantial declines in cervical cancer incidence in areas with established screening programs, but LMICs with absent or inadequate screening programs have high incidence rates. Meanwhile, HICs have seen incidence rates of anal and oropharyngeal cancers rise owing to the limited availability of organized screening for anal cancer and no validated screening options for oropharyngeal cancer. The implementation of screening programs for individuals at high risk of these cancers has the potential to reduce the burden of cervical cancer in LMICs, of anal and oropharyngeal cancers in HICs, and of anal cancer for highly selected HIV+ populations in LMICs. This review will discuss primary prevention of HPV-related cancers through vaccination and secondary prevention through screening of cervical, anal, and oropharyngeal cancers. Areas of concern and highlights of successes already achieved are included.

Early Diagnosis of Occult Blood of Colorectal Cancer Based on Nano-Colloidal Gold Sandwich Immunochromatography

The development of science and technology has deepened people's understanding of cancer, changing the management of malignant tumors in the medical field. Given the common precancerous characteristics of colorectal cancer (CRC), researchers studied early CRC screening. The complexity of traditional diagnostics forced medical staff to speed up CRC innovation early screening methods. Here, we prepared nano-colloidal gold raw materials with different particle sizes (15 and 30 nm) and observed the morphological characteristics and properties of the materials. Simultaneously, the nanocolloidal gold double antibody sandwich kit was designed through the optimum pH value and protein content screening experiment. The results of clinical enteroscopy confirmed the important guiding significance of the equipment in early CRC screening.

Rationale and design of the Prevent Anal Cancer Self-Swab Study: a protocol for a randomised clinical trial of home-based self-collection of cells for anal cancer screening

INTRODUCTION

Squamous cell carcinoma of the anus is a common cancer among sexual minority men, especially HIV-positive sexual minority men; however, there is no evidenced-based national screening protocol for detection of anal precancers. Our objective is to determine compliance with annual anal canal self-sampling or clinician-sampling for human papillomavirus (HPV) DNA.

METHODS AND ANALYSIS

This is a prospective, randomised, two-arm clinical study to evaluate compliance with annual home-based versus clinic-based HPV DNA screening of anal canal exfoliated cells. The setting is primary care community-based clinics. Recruitment is ongoing for 400 HIV-positive and HIV-negative sexual minority men and transgender persons, aged >25 years, English or Spanish speaking, no current use of anticoagulants other than nonsteroidal anti-inflammatory drugs and no prior diagnosis of anal cancer. Participants are randomised to either receive a swab in the mail for home-based collection of an anal canal specimen at 0 and 12 months (arm 1) or attend a clinic for clinician collection of an anal canal specimen at 0 and 12 months (arm 2). Persons will receive clinic-based Digital Anal Rectal Examinations and high-resolution anoscopy-directed biopsy to assess precancerous lesions, stratified by study arm. Anal exfoliated cells collected in the study are assessed for high-risk HPV persistence and host/viral methylation. The primary analysis will use the intention-to-treat principle to compare the proportion of those who comply with 0-month and 12-month sampling in the home-based and clinic-based arms. The a priori hypothesis is that a majority of persons will comply with annual screening with increased compliance among persons in the home-based arm versus clinic-based arm.

ETHICS AND DISSEMINATION

The study has been approved by the Medical College of Wisconsin Human Protections Committee. Results will be disseminated to communities where recruitment occurred and through peer-reviewed literature and conferences.

TRIAL REGISTRATION NUMBER

NCT03489707.

Anal cancer and precancerous lesions: a call for improvement

Anal squamous cell carcinoma is the most common type of anal cancer and is largely associated with anal human papillomavirus infection. The incidence of anal squamous cell carcinoma is increasing, and although still uncommon in the general population, a high incidence has been noted in specific population groups (eg, patients with HIV, men who have sex with men [MSM], recipients of solid organ transplants, women with genital neoplasia, and patients with systemic lupus erythematosus or inflammatory bowel disease). The higher incidence among individuals who are HIV-positive makes anal squamous cell carcinoma one of the most common non-AIDS-defining cancers among HIV-positive individuals. Anal cancer screening in high-risk groups aims to detect high-grade squamous intraepithelial lesions, which are considered anal precancerous lesions, and for which identification can provide an opportunity for prevention. A blind anal cytology is normally the first screening method, and for patients with abnormal results, this approach can be followed by an examination of the anal canal and perianal area under magnification, along with staining-a technique known as high-resolution anoscopy. Digital anorectal examination can enable early anal cancer detection. Several societies are in favour of screening for HIV-positive MSM and recipients of transplants. There are no current recommendations for screening of anal precancerous lesions via endoscopy, but in high-risk groups, a careful observation of the squamocolumnar junction should be attempted. Several treatments can be used to treat high-grade squamous intraepithelial lesions, including argon plasma coagulation or radiofrequency ablation, which are largely limited by high recurrence rates. Gastroenterologists need to be aware of anal squamous cell carcinoma and anal precancerous lesions, given that patients at high risk are frequently encountered in the gastroenterology department. We summarise simple procedures that can help in early anal squamous cell carcinoma detection.

Screening Women for Anal Cancers: Guidance for Health Care Professionals

Anal cancer is rare in the general population but is steadily increasing in incidence over the past decade especially in women. Identification and screening of women with high risk facilitates detection of anal precancer and early-stage cancer, improves survival, and potentially uses less invasive therapies compared with the conventional chemoradiation treatments used for advanced cancers. No recently published guidelines currently describe details about screening women for anal squamous cell cancer (ASCC). The available evidence supports the existence of groups of women with higher prevalence of ASCC (e.g., women with human immunodeficiency virus, immune suppression, or previous lower-genital high-grade lesion or cancer) who would likely benefit from screening with some combination of anal cytology and human papillomavirus testing. Additional research is needed to establish the cost-effectiveness and the influence of screening on ASCC mortality rates.

State of the Science: Screening, Surveillance, and Epidemiology of HPV-Related Malignancies

Oropharyngeal, cervical, vulvar, and anal cancers share a common risk factor of HPV infection. HPV vaccination is currently recommended at age 11 or 12 to prevent new HPV infections for all genders with catch-up vaccination recommened up to age 26. Despite the known effectiveness of HPV vaccination to prevent HPV-related cancer, there is continued low uptake in the United States; only 40% of eligible persons were vaccinated in 2018, though rates are 70% among teenagers. Current American Cancer Society cancer screening guidelines recommend cervical cancer screening, but do not have specific recommendations for screening for other HPV-related cancers. Oropharyngeal cancer precursors have yet to be identified, and there are currently no routine screening tests for oropharyngeal cancer recommended by the U.S. Preventive Services Task Force. The U.S. Preventive Services Task Force and American Cancer Society recommend cervical cancer screening for women at average risk up to age 65, and screening guidelines do not currently differ by HPV vaccination status. Primary HPV DNA testing was first approved for cervical cancer screening in 2016 and was shown to be superior for cervical cancer prevention. Vulvar and anal cancer precursors have been identified, but optimal screening remains unclear. Examination of the anal canal and perianus is best performed by trained clinicians using high-resolution anoscopy, and effectiveness of using high-resolution anoscopy to detect and treat anal high-grade squamous intraepithelial lesions to prevent cancer is actively being researched. Current multistep approaches to control HPV-related malignancies include HPV vaccination coupled with cervical cancer screening or surveillance for oropharyngeal, vulvar, and anal cancers.

A meta-analysis of anal cancer incidence by risk group: Toward a unified anal cancer risk scale

Certain population groups are known to have higher than average anal cancer risk, namely persons living with HIV (PLHIV), men who have sex with men (MSM), women diagnosed with human papillomavirus (HPV)-related gynecological precancerous lesions or cancer, solid organ transplant recipients (SOTRs) and patients with autoimmune diseases. Our aim was to provide robust and comparable estimates of anal cancer burden across these groups. Summary incidence rates (IRs), as cases per 100 000 person-years (py), were calculated by fixed-effects meta-analysis. IRs were 85 (95% confidence interval [CI] = 82-89) for HIV-positive MSM (n = 7 studies; 2 229 234 py), 32 (95% CI = 30-35) for non-MSM male PLHIV (n = 5; 1626 448 py) and 22 (95% CI = 19-24) for female PLHIV (n = 6; 1 472 123 py), with strong variation by age (eg, from 16.8 < 30 years to 107.5 ≥ 60 years for HIV-positive MSM). IR was 19 (95% CI = 10-36) in HIV-negative MSM (n = 2; 48 135 py). Anal cancer IRs were much higher after diagnosis of vulvar (IR = 48 [95% CI = 38-61]; n = 4; 145 147 py) than cervical (9 [95% CI = 8-12]; n = 4; 779 098 py) or vaginal (IR = 10 [95% CI = 3-30]; n = 4; 32 671) cancer, with equivalent disparity after respective precancerous lesions. IR was 13 (95% CI = 12-15) in SOTRs (n = 5; 1 946 206 py), reaching 24.5 and 49.6 for males and females >10 years after transplant. Anal cancer IRs were 10 (95% CI = 5-19), 6 (95% CI = 3-11) and 3 (95% CI = 2-4) for systemic lupus erythematosus, ulcerative colitis and Crohn's disease, respectively. In conclusion, a unifying anal cancer risk scale, based upon comprehensive meta-analysis, can improve prioritization and standardization in anal cancer prevention/research initiatives, which are in their public health infancy.

The importance of anal cancer screening and high-resolution anoscopy to gastroenterology practice

PURPOSE OF REVIEW

Although human papillomavirus (HPV)-related anal squamous cell cancer (ASCC) is rare, its incidence has been rising and in high-risk populations exceeds the incidence of cancers for which screening programs are implemented. Therefore, targeted screening techniques are being evaluated with high-resolution anoscopy (HRA) as the current gold standard because of its ability to detect anal intraepithelial dysplasia (AIN) and premalignant high-grade squamous intraepithelial lesions (HSILs). However, a scarcity of trained providers presents a barrier to screening.

RECENT FINDINGS

ASCC incidence is rising especially in elderly women and young black men. Premalignant HSIL may not only progress to ASCC but also regress. Biomarkers such as HPV type, p16 immunostaining and DNA methylation markers may emerge as predictors of disease progression.HRA with acetic acid and Lugol's iodine staining can be used to detect HSIL and ASCC. Recent studies suggest that anal cancer screening may have an impact on the stage of ASCC at diagnosis and the incidence of anal cancer.The Anal Cancer HSIL Outcomes Research (ANCHOR) study is underway to determine whether treating HSIL effects ASCC incidence.

SUMMARY

Although there are no consensus screening guidelines for anal cancer, it is reasonable to screen high-risk populations with physical examination, anal cytology and HRA. Gastroenterologists can support anal cancer screening programmes through identifying patients at risk, performing noninvasive screening and considering to incorporate endoscopic techniques to examine the anal canal. VIDEO ABSTRACT: http://links.lww.com/COG/A32.