Clinical presentation of minimally invasive and in situ squamous cell carcinoma of the anus in homosexual men

A phase II clinical study to assess the feasibility of self and partner anal examinations to detect anal canal abnormalities including anal cancer

OBJECTIVE

Anal cancer is a common cancer among men who have sex with men (MSM); however, there is no standard screening protocol for anal cancer. We conducted a phase II clinical trial to assess the feasibility of teaching MSM to recognise palpable masses in the anal canal which is a common sign of anal cancer in men.

METHODS

A clinician skilled in performing digital anorectal examinations (DARE) used a pelvic manikin to train 200 MSM, aged 27-78 years, how to do a self-anal examination (SAE) for singles or a partner anal examination (PAE) for couples. The clinician then performed a DARE without immediately disclosing results, after which the man or couple performed an SAE or PAE, respectively. Percentage agreement with the clinician DARE in addition to sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated for the SAE, PAE and overall.

RESULTS

Men had a median age of 52 years, 42.5% were African American and 60.5% were HIV positive. DARE detected abnormalities in 12 men while the men's SAE/PAEs detected 9 of these. A total of 93.0% of men classified the health of their anal canal correctly (95% CI 89.5 to 96.5). Overall percentage agreement, sensitivity and specificity were 93.0%, 75.0% and 94.2%, respectively, while PPV and NPV were 45.0% and 98.3%, respectively. The six men who detected the abnormality had nodules/masses ≥3 mm in size. More than half of men (60.5%) reported never checking their anus for an abnormality; however, after performing an SAE/PAE, 93.0% said they would repeat it in the future.

CONCLUSION

These results suggest that tumours of ≥3 mm may be detectable by self or partner palpation among MSM and encourage further investigation given literature suggesting a high cure rate for anal cancer tumours ≤10 mm.

Anal intraepithelial neoplasia and anal cancer in dermatological practice

Anal intraepithelial neoplasia is considered to be a precursor lesion of invasive anal cancer. It is now increasingly recognized in high-risk groups, such as men who have sex with men and HIV-infected patients. Human papillomaviruses are considered to be an important aetiological agent in both anal intraepithelial neoplasia and anal cancer. Dermatologists are likely to encounter these conditions among the differential diagnoses to be considered in high-risk patients presenting with perianal and anal lesions. Anal cancer rates are also increasing among the HIV-infected and HIV-non-infected population. The successful treatment of anal intraepithelial neoplasia may reduce the risk of subsequent development of anal cancer. However, current therapies for anal intraepithelial neoplasia may be associated with treatment-related morbidity and are not well validated. It is currently not proven that they reduce the likelihood of the development of anal cancer. Nevertheless, screening for anal intraepithelial neoplasia is being advocated for high-risk groups and may become standard dermatological care for these patients. In view of recent developments in the understanding of this condition, this article reviews the current understanding of anal intraepithelial neoplasia and its treatment from a dermatological perspective.

High prevalence of anal squamous intraepithelial lesions and squamous-cell carcinoma in men who have sex with men as seen in a surgical practice

INTRODUCTION

Anal high-grade squamous intraepithelial lesions are probable invasive anal squamous-cell cancer precursors, and although unproved, treatment of high-grade squamous intraepithelial lesions may prevent progression to anal squamous-cell cancer. Men who have sex with men are often treated for benign anorectal disorders without consideration given to the possibility of concurrent high-grade squamous intraepithelial lesions or anal squamous-cell cancer. We determined the prevalence of anal high-grade squamous intraepithelial lesions and anal squamous-cell cancer in an urban surgical practice of men who have sex with men referred for treatment of anal condyloma and other benign noncondylomatous anal disorders.

METHODS

One hundred thirty-one HIV-positive and 69 HIV-negative men who have sex with men referred for surgical treatment of presumed benign anorectal disease were evaluated by anal cytology, high-resolution anoscopy, and biopsy. Anal cytology and histology were reported with a modified Bethesda classification.

RESULTS

One hundred fifty-seven patients (79 percent) were referred for condyloma, 4 (2 percent) for anal squamous intraepithelial lesions (anal high-grade squamous intraepithelial lesions) diagnosed by primary care providers, and 39 (19 percent) for other benign anorectal disorders. One hundred forty-three patients (93 percent) had abnormal anal cytology, with 107 (54 percent) having high-grade squamous intraepithelial lesions on cytology. Biopsy results revealed 120 patients (60.0 percent) with high-grade squamous intraepithelial lesions and 5 patients (3 percent) with invasive squamous-cell carcinoma. Four of five men with anal squamous-cell cancer were HIV positive. Fourteen men (36 percent) who have sex with men referred for noncondylomatous benign anal disorders had high-grade squamous intraepithelial lesions, and three (8 percent) had anal squamous-cell cancer. High-grade squamous intraepithelial lesions and anal squamous-cell cancer were seen most often at the squamocolumnar junction.

CONCLUSIONS

Men who have sex with men referred for treatment of either condyloma or noncondylomatous benign anorectal disease had a high prevalence of anal high-grade squamous intraepithelial lesions and anal squamous-cell cancer. All men who have sex with men referred for treatment of benign anorectal disease should have high-resolution anoscopy and aggressive biopsy of all abnormal areas. Treatment of external lesions alone could miss high-grade squamous intraepithelial lesions or anal squamous-cell cancer.

Outcome analysis of HIV-positive patients with anal squamous cell carcinoma

PURPOSE

With improved antiretroviral therapy, HIV-positive patients are achieving a longer life expectancy. An increased incidence of anal squamous cell carcinomas has been noted in these patients. The purpose of this study was to determine the outcome of HIV-positive patients with anal squamous cell carcinomas.

METHODS

We conducted a review based on our tumor registry from 1980 through 1999. We identified 73 patients with anal squamous cell carcinoma treated at the University of Texas Southwestern Medical Center affiliated hospitals; 23 were HIV positive (18 had AIDS). In the HIV-positive group, 9 had in situ squamous carcinomas and 14 had invasive squamous cell carcinomas. Data collected included age, CD4 count, treatment, complications, and survival; these data were analyzed by Student's t-test.

RESULTS

All patients were male. Those with squamous cell cancer of the anus were offered radiation therapy and chemotherapy. Beginning in 1998, all patients received highly active antiretroviral therapy before treatment. Seven of 14 anal squamous cell carcinoma patients had their therapy adjusted owing to toxicity. Morbidity included proctocolitis and diarrhea (n = 2) requiring diversion (n = 1), hemorrhagic cystitis (n = 1), neutropenic fever (n = 3), bone marrow suppression (n = 1), and urethral stricture (n = 1). Mean age was 42 years for anal squamous cell carcinoma patients and 36 years for squamous cell carcinoma in situ patients (P = 0.05). Mean CD4 count was 222 cells/ml in patients with infiltrating carcinoma and 200 in the in situ patients (P = NS). One-year and five-year mortality rates, respectively, were 40 percent and 80 percent for infiltrating carcinoma patients and 17 percent and 50 percent for the in situ patients. Both of the in situ patients who died had CD4 counts <20 cells/ml at diagnosis, whereas the rest had CD4 counts >100 cells/ml and are currently without anal disease. Mean CD4 count at diagnosis for all patients who died was 133 cells/ml, whereas for those surviving, it was 261 cells/ml (P = 0.03). Eight (all with infiltrating carcinoma) of the 10 patients who died had persistent anal disease, but none had metastasis.

CONCLUSION

HIV-positive patients with in situ carcinomas present at an earlier age than those with infiltrating lesions. In situ patients with CD4 counts as low as 105 cells/ml do well with local excision. A low CD4 count at diagnosis without highly active antiretroviral therapy predicts a poor prognosis. Because these patients appear to succumb to their HIV status and not the anal disease, anal squamous cell carcinoma should be included with cervical squamous cell carcinoma as an AIDS-defining illness. HIV-positive patients, particularly AIDS patients, with invasive anal cancers and without effective antiretroviral therapy obtain little benefit and significant toxicity from current radiation therapy and chemotherapy. Initiation of highly active antiretroviral therapy in HIV-positive patients before radiation therapy and chemotherapy are begun may decrease toxicity and improve survival. Additional clinical trials are warranted to test this theory.

Anorectal manifestations of sexually transmitted infections

Sexually transmitted infections have a wide range of clinical presentations, including involvement of the anal verge, anal canal and rectum. This review focuses on anorectal sexually transmitted infections which may cause diagnostic difficulty when encountered by the coloproctologist. An approach to the diagnosis of a variety of sexually transmitted infections is set out, with a discussion of the role of biopsy and a summary of relevant histopathological findings. The value of early antibiotic treatment is discussed. Problems related to HIV/AIDS are highlighted, as clinical presentation may be atypical in immunosuppressed individuals. Sexually transmitted oncogenic viruses and their role in anal neoplasia are also briefly summarized.

Cost-effectiveness of screening for anal squamous intraepithelial lesions and anal cancer in human immunodeficiency virus-negative homosexual and bisexual men

PURPOSE

Homosexual and bisexual men are at an increased risk for human papillomavirus-induced squamous intraepithelial lesions and cancer of the anus. Our objective was to estimate the cost-effectiveness of screening for anal squamous intraepithelial lesions in these high-risk patients.

SUBJECTS AND METHODS

A Markov model was developed to evaluate alternative screening strategies using anal cytology in a hypothetical cohort of homosexual and bisexual men. Data were obtained from prospective cohort studies, national databases, Medicare reimbursement rates, and the published literature. Model outcomes included life expectancy, quality-adjusted life expectancy, total lifetime costs, and incremental cost-effectiveness ratios.

RESULTS

The undiscounted life expectancy gain associated with anal cytology screening every 3 years was 5.5 months. Compared with no screening, screening every 3 years increased the discounted quality-adjusted life expectancy by 1.8 months and cost $7,000 per quality-adjusted life year (QALY) gained. Screening every 2 years cost $15,100 per QALY gained compared with screening every 3 years. Annual screening provided incremental benefits of less than 0.5 quality-adjusted months and had an incremental cost of $34,800 per QALY gained. Screening every 6 months provided little additional benefit (i.e, 5 days) over that of annual screening and had an incremental cost of $143,500 per QALY gained.

CONCLUSION

In homosexual and bisexual men, screening every 2 or 3 years for anal squamous intraepithelial lesions with anal cytology would provide life-expectancy benefits comparable with other accepted preventive health measures, and would be cost-effective.