In response, clinical care is continually adapting to the dramatically altered natural history of disease.
Today, the cutting edge of clinical care overlaps with primary care. The clinical vanguard addresses the medical vulnerabilities of patients with HIV, seeking to eliminate preventable morbidity and premature death. Among this clinical vanguard is the screening for and prevention of anal cancer. With the increased longevity of people living with HIV and the nearly universal exposure to human papillomavirus (HPV), there is now potential for progression to mucosal cellular dysplasia and eventual malignancy.
We know that prevention is possible because of the example of cervical cancer, the etiology of which is exposure to oncogenic serotypes of HPV (16 and 18 are most common). Screenings for cervical cancer (regular clinical examinations and Pap smears) and treatments to eliminate high-grade dysplasia have decreased the incidence rate by over 50% since the 1970s. Vaccination against HPV has been available since 2006 and offers the prospect of preventing HPV-associated malignancies, including head and neck cancer, in future decades.
However, rates of anal cancer are increasing. The CDC estimates that about 4,700 new cases of HPV-associated anal cancers are diagnosed in women and about 2,300 are diagnosed in men each year in the United States. Anal cancer rates in individuals with HIV have increased in the era of effective antiretrovirals and greater longevity. The highest rates, at 95 per 100,000, are in HIV-positive men who have sex with men. Very similar rates were noted in a more recent study that found increased risk with advancing age and in those with an AIDS diagnosis.
All patients with HIV should be screened
The New York State AIDS Institute Clinical Guidelines Program recommends screening for anal dysplasia in all patients with HIV. A proactive approach similar to cervical cancer screening is appropriate and includes measures easily implemented by all clinicians.
- History: Assess for rectal symptoms, anal pain, discharge, and lumps.
- Physical exam: Assess for presence of perianal lesions; perform a thorough digital rectal exam.
- Anal Pap test for anal cytology: Insert a Dacron swab moistened with tap water about 3 inches into the anal canal, applying pressure to lateral anal walls and rotating the swab. Then remove and place the swab into liquid cytology solution, shake vigorously for a full 30 seconds, and assess for any dysplasia (high-grade squamous intraepithelial lesion, low-grade intraepithelial lesion, atypical squamous cells of undetermined significance), which would warrant further evaluation by high-resolution anoscopy (HRA).
High-resolution anoscopy
HRA for anal dysplasia corresponds to colposcopy for cervical dysplasia. The ability to treat and eliminate high-risk precursor lesions interrupts the progression to malignancy. The efficacy of this strategy is being evaluated in a National Institutes of Health prospective trial called the Anchor Study. The epidemiology of HPV; the clinical horror of witnessing the painful, preventable deaths of young patients with well-controlled HIV caused by anal cancer; and the example of controlling cervical cancer have motivated my practice to assure comprehensive care for our patients.
Unfortunately, establishing HRA in one’s practice is challenging. Barriers to practice include the expense of required equipment and the absence of consensus on specific products. In addition, hands-on precepting to ease newcomers to competence is not generally available. Considerable skill is required for complete visualization of the anal transformative zone in the folds of the anal canal, and recognizing high-risk lesions requires study and accumulated experience. The International Anal Neoplasia Society is a useful resource that also offers a training course. We are invited to train ourselves, and to rely on the eventual feedback of biopsy results and the forbearance of our early patients.
The expanding scope of our medical practices must shift to meet the evolving needs of the growing population of virologically suppressed patients who are living longer. HIV care involves curing life-threatening opportunistic infections, encouraging antiretroviral adherence, and providing comprehensive care – which now includes preventing anal cancer.
A version of this article first appeared on Medscape.com.