There are no guidelines currently set about anal cancer diagnosis. But many doctors are referring their patients to colon-rectal surgeons every two years or so to get high resolution anoscopies. Others just use anal pap smears as a first step to determine if an anoscopy is justified. These simple tests can detect precancerous tissue before they may become a problem. They are removed with infrared coagulation. Biopsies are usually taken prior to the removal of the suspect tissue to determine it is low grade or high grade dysplasia.
Wkipedia has a good explanation for dysplasia:
“Dysplasia is the earliest form of pre-cancerous lesion recognizable in a pap smear or in a biopsy by a pathologist. Dysplasia can be low grade or high grade (see “Carcinoma in situ,” below). The risk of low grade dysplasia transforming into high grade dysplasia, and eventually cancer, is low. Treatment is usually straightforward.
High grade dysplasia represents a more advanced progression towards malignant transformation.
Carcinoma in situ, meaning “cancer in place,” represents the transformation of a neoplastic lesion to one in which cells undergo essentially no maturation, and thus may be considered cancer-like. In this state, epithelial cells have lost their tissue identity and have reverted back to a primitive cell form that grows rapidly and without regulation. However, this form of cancer remains localized, and has not invaded past the basement membrane into tissues below the surface.
Invasive carcinoma is the final step in this sequence. It is a cancer which has invaded beyond the basement membrane and has potential to metastasize (spread to other parts of the body). Invasive carcinoma can usually be treated, but not always successfully. However, if it is left untreated, it is almost always fatal.”
The American Cancer Society says that a great deal of research is now under way to learn how HPV
might cause anal cancer. There is good evidence that HPV causes many anal squamous cell carcinomas. But the role of this virus in causing anal adenocarcinomas is less certain. More than 100 subtypes of HPV have been found. The subtype known as HPV-16 is often found in squamous cell carcinoma and is also found in some anal warts. Another type, HPV-18, is found less often. Most anal warts are caused by HPV-6 and HPV-11. Warts containing HPV-6 or HPV-11 are much less likely to become cancerous than those containing HPV-16.
The HPV tests on the market are only used to help screen for cervical cancer. There is no general test for men or women to check one’s overall “HPV status,” nor is there an HPV test to find HPV on the genitals or in the mouth or throat. But HPV usually goes away on its own, without causing health problems. So an HPV infection that is found today will most likely not be there a year or two from now.
I tell HIV+ long term survivors not to neglect their anal area ( tops or bottoms, women or men). Although anal cancer is a disease that progresses slowly, it is better to be proactive about it than waiting until it needs chemotherapy.
I posted a list of doctors in a previous answer on this subject. I live in Houston and used to travel to New York once a year for an anoscopy, but gladly there is now a physician trained in my city. If you live in a place where there is no colon rectal doctors who perform this procedure, have your doctor contact local physicians to see if any of them is interested in being trained at the University of California- San Francisco. They provide a two day training session. Their web site is http://www.ucsfhealth.org/adult/special/d/12748.html
Doctors that are trained on this issue will be better equipped to help people as they age with HIV, so it is a good thing to do right now while we wait for more data that will support future guidelines on this important cancer that is showing up as one of the highest incidence in HIV.