The practice of routine anal Pap screenings as part of HIV care is being considered after US researchers determined, as published in the latest edition of AIDS Patient Care and STDs, that the procedure is both appropriate and feasible for early detection of pre-cancerous cells.
HIV-infected people appear to be at a much higher risk of anal cancer, many cases of which result from infection with the human papillomavirus or HPV, but they are not routinely screened. It is hoped that by changing this rates will fall similar to how rates of cervical cancer fell after routine screening was introduced.
As in the case with all cancers, early detection of pre-cancerous cells can dramatically improve treatment and survival outlooks.
Abnormal anal cells were detected in 53% of patients. A low CD4 cell count was associated with abnormal cytology, but there was no relationship with anal intercourse.
“Our study is in concordance with other studies showing that anal precancerous lesions are commonly found in HIV-infected individuals,” comment the investigators.
Investigators from the Department of Veteran’s Affairs in Miami, Florida, wished to see if an anal Pap screening programme would be acceptable to their patients. They also wanted to establish the prevalence and risk factors for pre-cancerous cell changes.
The study was conducted between February and July 2006. A total of 160 patients were invited to participate in the research, and 131 (82%) agreed. All were men. These patients had a median age of 49 years, 52% were black and 60% denied any history of anal intercourse.
Over half (53%) of the patients with adequate samples had abnormal anal cytology, and 37% of these individuals had low-grade pre-cancerous cell changes, with a further 5% having high-grade changes.
After controlling for potential confounders, a low CD4 cell count was the only factor significantly associated with abnormal anal cytology (p = 0.026).
A total of 33 patients with abnormal cytology had further investigations including high-resolution anoscopy and biopsy. These examinations confirmed the presence of pre-cancerous lesions in all but two of the patients. Moreover, anal cancer was detected in two individuals.
The study showed a higher than expected rate of failed tests, a majority of which were put down to those administering the tests not doing so correctly, highlighting that, as with all new or relatively uncommon procedures, training will be paramount in ensuring viable test samples. Investigators also noted the problem of men self-reporting sexual activity.
Clinicians usually recommend that men who have sex with men, people who have HIV and those that have suffered from anal warts all get screened, however there exists no standard common practice for this, so introducing screenings as a part of regular HIV care practice would be a proactive step forward.
An anal Pap screening is usually carried out in much the same way as a cervical smear is undertaken but without need for the use of a speculum or anoscope. A small polyester Dacron swab is used to collect cell samples from the anal canal by swabbing the surfaces of the anus and rectum. Samples are then reviewed at a lab and a physician should be able to give the results of the screening within a few days. To find out more, please click here.