Hepatic Metastasectomy in Squamous Cell Carcinoma of the Anal Canal: A Case Series of a Curative Approach

BACKGROUND

Squamous cell carcinoma of the anal canal (SCCA) is rare. Most cases are diagnosed in a localized setting. Metastatic SCCA is rare, and investigation has been limited in the past for these patients. We believe that hepatic-only metastatic disease could have a unique treatment landscape compared to diseases with diffuse metastatic involvement. Here, we describe cases at our institution.

METHODS

We reviewed eight SCCA cases with hepatic-only metastatic disease (diagnosed February 2018-January 2022). The objectives were to determine the overall survival and disease-free survival with this approach.

RESULTS

The median age was 62 years old (yo). Patients had an ECOG of 0-1. All patients received definitive chemoradiation to their primary anal tumor. A median of three months of neoadjuvant systemic therapy was provided. All patients had a response on their first scan after systemic therapy. Sixty-two percent received carboplatin + paclitaxel. A complete pathologic response was seen in 62% of patients. At their last follow-up, all patients were alive. Three patients had recurrent disease. The estimated 1-year disease-free survival probability was 56.2%.

CONCLUSION

Our report shows the feasibility of a curative-intent approach for patients with hepatic-only metastatic SCCA following the neoadjuvant application of carboplatin + paclitaxel. This approach appears promising in these select patients and warrants further investigation.

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.

Home-based self-sampling vs clinician sampling for anal precancer screening: The Prevent Anal Cancer Self-Swab Study

Sexual minority men are at increased risk for anal squamous cell carcinoma. Our objective was to compare screening engagement among individuals randomized to self-collect an anal canal specimen at home or to attend a clinic appointment. Specimen adequacy was then assessed for human papillomavirus (HPV) DNA genotyping. A randomized trial recruited cisgendered sexual minority men and transgender people in the community and assigned them to use a home-based self-collection swabbing kit or attend a clinic-based swabbing. Swabs were sent for HPV genotyping. The proportions of participants completing screening in each study arm and the adequacy of their specimens for HPV genotyping were assessed. Relative risks were estimated for factors associated with screening. A total of 240 individuals were randomized. Age (median, 46 years) and HIV status (27.1% living with HIV) did not differ by study arm. A total of 89.2% and 74.2% of home-arm and clinic-arm individuals returned the swab, respectively (P = .003), difference between groups, 15.0% (95% CI 5.4%-24.6%). Among black individuals, 96.2% and 63.2% in the home and clinic arms screened (P = .006). Among individuals with HIV, 89.5% and 51.9% in the home and clinic arms screened (P < .001). Self-collected swabs and clinician-collected swabs were comparable in adequacy for HPV genotyping (96.3% and 93.3%, respectively). People at highest risk for anal cancer may be more likely to screen if they are able to self-collect swabs at home rather than attend a clinic.

Trends in utilization of first-line palliative treatments for anal squamous cell carcinoma

BACKGROUND

Anal squamous cell carcinoma patients often present with significant symptoms, including pain, bleeding, and obstructive symptoms. This requires palliation-directed therapy as a first-line treatment to alleviate symptoms. The proportion of patients receiving first-line palliative treatments is unknown. We aimed to study the factors associated with the use of first-line palliative treatments in stage II-IV anal squamous cell carcinoma patients.

METHODS

We used the National Cancer Database to identify adult patients diagnosed with stage II-IV anal squamous cell carcinoma between 2004 and 2016. We performed univariable and multivariable logistic regression analysis to determine the clinical and sociodemographic variables associated with the utilization of palliative treatment in the first-line setting, including palliative radiotherapy, chemotherapy, surgery, and pain management.

RESULTS

Among 16,944 patients diagnosed with stage II-IV anal squamous cell carcinoma, only a small proportion of 492 (2.9%) required first-line palliative treatments to control symptoms. The majority of these patients received palliative radiotherapy (32%), followed by palliative surgery (25%), palliative chemotherapy (19%), combination therapies (14%), and pain management (10%). On multivariable analysis, higher stage disease, lower income, Medicare and Medicaid insurance, and life expectancy <6 months were associated with higher odds of use of first-line palliative therapy.

CONCLUSIONS

First-line use of palliative treatments to control symptoms is needed in a small proportion of anal squamous cell cancer patients. It was utilized in all stages, but it was most frequently observed in patients with stage IV disease and patients with <6 months life expectancy. First-line palliative therapy was also more frequent in lower-income patients and patients with Medicare and Medicaid insurance which highlights the disparities in anal cancer management.

Biomarkers in Anal Cancer: Current Status in Diagnosis, Disease Progression and Therapeutic Strategies

Squamous cell carcinoma of the anal canal (SCCA) is a rare neoplasm, but with rising incidence rates in the past few decades; it is etiologically linked with the human papillomavirus (HPV) infection and is especially prevalent in immunocompromised patients, mainly those infected with HIV. Fluoropyrimidine-based chemoradiotherapy remains the cornerstone of the treatment of non-metastatic disease, but the locally advanced disease still presents high rates of disease recurrence and systemic therapy of SCCA is an unmet clinical need. Despite sharing common molecular aspects with other HPV-related malignancies, such as cervical and head and neck cancers, SCCA presents specific epigenomic, genomic, and transcriptomic abnormalities, which suggest that genome-guided personalized therapies should be specifically designed for this disease. Actionable mutations are rare in SCCA and immune checkpoint inhibition has not yet been proven useful in an unselected population of patients. Therefore, advances in systemic therapy of SCCA will only be possible with the identification of predictive biomarkers and the subsequent development of targeted therapies or immunotherapeutic approaches that consider the unique tumor microenvironment and the intra- and inter-tumoral heterogeneity. In the present review, we address the molecular characterization of SCCA and discuss potential diagnostic, predictive and prognostic biomarkers of this complex and challenging disease.

Anal Squamous Intraepithelial Lesions (SILs) in Human Immunodeficiency Virus-Positive Men Who Have Sex With Men: Incidence and Risk Factors of SIL and of Progression and Clearance of Low-Grade SILs

BACKGROUND

Human immunodeficiency virus (HIV)-positive men who have sex with men (MSM) are at risk of anal squamous cell carcinoma. Data are limited on the natural history of the precursor to this carcinoma, anal squamous intraepithelial lesions (SILs).

METHODS

HIV-positive MSM were screened for histopathological SILs by means of high-resolution anoscopy (HRA). For participants without SILs at baseline, we estimated the cumulative incidence and risk factors for SILs. For those with low-grade SILs (LSILs) at baseline, the risk of progression to high-grade SILs (HSILs) and the clearance rate were estimated at the lesion level.

RESULTS

Of 807 men without SILs at baseline, 107 underwent follow-up HRA between 1 to 4.5 years later. At the second visit 18 men (16.8%) showed LSIL, and 25 (23.4%) HSIL. Age was associated with incident LSILs (adjusted odds ratio [aOR], 2.10 per 10-year increase in age; P = .01). Of 393 men with LSILs at baseline, 114 underwent follow-up HRA 0.5 to 2.5 years later. Of the 177 LSILs found at baseline, 87 (49.2%) had cleared at the second visit, and 29 (16.4%) had progressed to HSILs.

CONCLUSION

Incident LSILs and HSILs were common during follow-up among HIV-positive MSM without dysplasia at baseline. Among men with LSILs at baseline, nearly half of these lesions cleared, and a small portion progressed.

Challenges of improving treatment outcomes for colorectal and anal cancers in Japan: the Colorectal Cancer Study Group (CCSG) of the Japan Clinical Oncology Group (JCOG)

Colorectal cancer is a major public health concern in Japan. While early-stage colorectal adenocarcinoma treatment entails radical resection of the primary tumor, the importance of perioperative treatment is growing as physicians seek to further improve treatment outcomes. For anal squamous cell carcinoma, definitive chemoradiotherapy is superior to radical surgery in terms of improved patient quality of life. The Colorectal Cancer Study Group of the Japanese Clinical Oncology Group was established in 2001 and has worked to provide answers to common clinical questions and improve treatment outcomes for colorectal and anal cancers through 15 large-scale prospective clinical trials. Here, we discuss the current state of perioperative treatment for early-stage colon, rectal and anal cancers in Japan and approaches taken by the Colorectal Cancer Study Group/the Japanese Clinical Oncology Group to improve treatment outcomes for these cancers.

A phase II study of axalimogene filolisbac for patients with previously treated, unresectable, persistent/recurrent loco-regional or metastatic anal cancer

Squamous cell carcinoma of the anorectal canal (SCCA) is a rare HPV-related malignancy that is steadily increasing in incidence. A high unmet need exists for patients with persistent loco-regional and metastatic disease. Axalimogene filolisbac (ADXS11-001) is an investigational immunotherapy that stimulates tumor-specific responses against HPV-associated cancers, and has demonstrated benefit in metastatic cervical cancer. We conducted this single-arm, multicenter, phase 2 trial in patients with persistent/recurrent, loco-regional or metastatic SCCA. Patients received ADXS11-001, 1 × 10⁹ colony-forming units intravenously every 3 weeks. A Simon 2-stage design was used to test primary co-endpoints of overall response rate (ORR) and 6-month progression-free survival (PFS) rate. Study would proceed to full enrollment if ORR ≥ 10% or 6-month PFS rate ≥ 20%. Thirty-six patients were treated; 29 patients were evaluable for response. One patient had a prolonged partial response (3.4% ORR). The 6-month PFS rate was 15.5%. Grade 3 adverse event were noted in 10 patients, with the majority being cytokine-release symptoms; one grade 4 adverse event was noted. No grade 5 adverse events occurred. ADXS11-001 was safe and well-tolerated in patients with SCCA. However, this study did not meet either primary endpoint. ADXS11-001 may be more beneficial when administered in combination with other cytotoxic or targeted agents.

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

OBJECTIVES

There are no uniform screening recommendations for anal cancer. Medical practice guidelines are now available on the use of Digital Anal Rectal Examinations (DARE) for the detection of anal cancer; however, because screening can result in more harm than benefit, our objective was to assess the evidence for use of DARE as a public health screening tool.

MATERIALS AND METHODS

We conducted a current critical appraisal of anal cancer literature using World Health Organization criteria for assessing the potential utility of a public health screening program.

RESULTS

Digital Anal Rectal Examination satisfies most, but not all, World Health Organization criteria for a public health program that seeks to detect early invasive anal cancer in populations at high risk for anal cancer, most notably HIV-positive men who have sex with men; however, DARE is not appropriate when facilities for treatment are nonexistent. In addition, there are insufficient data on DARE sensitivity and specificity.

CONCLUSIONS

The mildly invasive nature of DARE, limited likelihood of adverse procedure-related events, cost-effectiveness and patient acceptability, as well as wide availability of DARE support consideration of its integration into screening for populations at high risk of anal cancer, especially HIV-positive men who have sex with men.

Reaching 80% human papillomavirus vaccination prevalence by 2026: How many adolescents need to be vaccinated and what are their characteristics?

BACKGROUND

Human papillomavirus vaccination (HPVV) prevents several types of cancer. The American Cancer Society recently established a goal that by 2026, 80% of adolescents will be up to date (UTD) before their 13th birthday. However, the number in need of vaccination to reach this goal is unknown. This study estimated the number of additional adolescents (11-12 years old) who need HPVV for 80% prevalence to be reached by 2026.

METHODS

The study used de-identified and publicly available data and exempt from institutional review board approval and informed consent. The 2016 National Immunization Survey for Teens was used to estimate the baseline HPVV prevalence. Linear growth to 80% HPVV prevalence by 2026 was applied to set intermediate targets. US Census Bureau data were used for population projections. This study estimated the cumulative number of additional adolescents 11 to 12 years old who would need to become UTD (ie, receive 2 doses) by first subtracting the number who would need to be vaccinated to achieve an intermediate target prevalence from the estimated number currently compliant and then summing these numbers between 2018 and 2026.

RESULTS

Nationwide, an additional 7.62 million males (95% confidence interval [CI], 6.78 million to 8.40 million) and an additional 6.77 million females (95% CI, 5.95 million to 7.55 million), aged 11 to 12 years, would need to receive 2 doses of the vaccine between 2018 and 2026 for 80% prevalence to be achieved. Most adolescents not UTD (80%) also needed to initiate vaccination, and more than 90% recently visited a health care provider.

CONCLUSIONS

It is estimated that at least 14.39 million additional adolescents aged 11 to 12 years in the United States will need to receive 2 doses of HPVV for a UTD HPVV prevalence of 80% to be achieved by 2026. To reach this goal, improvements in facilitators of HPVV initiation, including physician recommendations and parental acceptability, are needed.

Development and Calibration of a Mathematical Model of Anal Carcinogenesis for High-Risk HIV-Infected Men

OBJECTIVES

Men who have sex with men who are living with HIV are at highest risk for anal cancer. Our objective was to use empirical data to develop a comprehensive disease simulation model that reflects the most current understanding of anal carcinogenesis, which is uniquely positioned to evaluate future anal cancer screening strategies and provide insight on the unobservable course of the disease.

SETTING

North America.

METHODS

The individual-based simulation model was calibrated leveraging primary data from empirical studies, such as a longitudinal HIV-positive men who have sex with men cohort study [Human Immunodeficiency and Papilloma Virus Research Group (HIPVIRG); n = 247] and the North American AIDS Cohort Collaboration on Research and Design [(NA-ACCORD); n = 13,146]. We used the model to infer unobservable progression probabilities from high-grade precancer to invasive anal cancer by CD4 nadir and human papillomavirus (HPV) genotype.

RESULTS

The calibrated model had good correspondence to data on genotype- and age-specific HPV prevalence; genotype frequency in precancer and cancer; and age- and nadir CD4-specific cancer incidence. The model-projected progression probabilities differed substantially by HPV genotype and nadir CD4 status. For example, among individuals with CD4 nadir <200, the median monthly progression probability from a high-grade lesion to invasive cancer was 0.054% (ie, 6.28% 10-year probability) and 0.004% (ie, 0.48% 10-year probability) for men with an HPV-16 infection versus without a detectable HPV infection, respectively.

CONCLUSIONS

We synthesized existing evidence into a state-of-the-art anal cancer disease simulation model that will be used to quantify the tradeoffs of harms and benefits of alternative strategies, understand critical uncertainties, and inform national anal cancer prevention policy.