Should Your Doctor Be Screening You for Anal Cancer?
A new study is looking into whether new screening policies should be in place.
It's uncomfortable for some people to talk about their anus. And it can be embarrassing to ask your healthcare provider about anal symptoms such as pain, burning, itching, blood, or pus in the stool. Health care providers might feel awkward, too.
But a new study out of Toronto is looking into whether new screening policies should be in place for anal cancer to help with that.
It's estimated that roughly 70 percent of sexually active Canadians will get some variation of the human papilloma virus (HPV), which can infect the throat, vagina, penis and anus. There are over 100 types of HPV. At least 13 are cancer-causing, and certain strains do cause anal cancer.
Anal cancer is more common in women but very high rates are being found in HIV-positive men having sex with men (MSM). Despite high numbers, screening policies for anal HPV and cancer precursors haven't been established and high-risk individuals aren't being assessed.
""The rate of anal cancer now, in HIV-positive MSM, is higher than the rate of cervical cancer was before they started screening for cervical cancer," Dr. Irving Salit, director of the immunodeficiency clinic at Toronto General Hospital, told VICE.
Salit is doing the first study of its kind in Canada, which focuses on anal cell changes in HIV-positive MSM. Patients who agree to the study get an anal Pap smear. It's the same test as a cervical Pap except a swab is inserted in the anus. If this shows abnormal cells, the patient undergoes an exam where a tube is inserted through the anus to examine and take a sample of the anal canal tissue. If the biopsy shows abnormal cell changes, patients are randomized to receive treatment (electrocautery or burning the tissue) or active monitoring.
There's no standard treatment for anal cancer. One goal of the study is to see if treatments are necessary.
Men often think HPV is a female thing or a young person thing. Or they think they're getting tested for HPV with their routine swabs when they're not.
"Anal Pap tests are being done by some family doctors but mainly (the one's involved) in this study," Salit said. "Family doctors don't know about them or don't know to do them."
Experts say patients' embarrassment about their butts is something healthcare providers need to overcome.
"There's a lot of stigma around the anal canal…especially from patients," said Marie Sano, a registered nurse at the immunodeficiency clinic. "Certain symptoms aren't necessarily HPV but people aren't swabbing the anal canal and it's usually because of stigma. You may get a colonoscopy done when all that's needed is an anal swab. Colonoscopies are important but sometimes a simple test can get you the results."
The development of anal dysplasia (abnormal cells) or cancer can be due to a weakened immune system or an aggressive strain of HPV. Some people get rid of the virus but others don't. The reason for this is uncertain. Cervical or vaginal HPV might migrate to the anal canal. "We don't really know why," said Sano. "It may be from wiping the area as HPV likes that mucosa. It doesn't need to be penetration. It's just skin to skin." Anal sex increases your chance of anal HPV but it isn't required.
"HPV is the most common viral infection in humans," Dr. Colin Kovacs, who has one of the biggest HIV practices in Canada and is an HIV primary care specialist/researcher involved in the study, told VICE. "There's a tsunami of patients who have this virus and the question is: who has cancer and who will go on to develop cancer. If you can prevent cancer it's a tremendous thing."
Dysplasia leading to cancer is not unique to HIV-positive people. "I've opened my practice to MSMs, straight men, females, and HIV negative," said Kovacs. "In HIV-negative MSM there are high grade changes [in anal cells]."
But experts point out that anal cancer remains quite rare.
According to 2013 Cancer Care Ontario (CCO) statistics, 219 Ontarians were diagnosed with anal cancer: 72 males and 147 females. In comparison, there were 405 newly diagnosed cases of larynx cancer in 2012 and about 630 women are diagnosed with cervical cancer each year. Rates of anal cancer started decreasing in 2005, likely due to increased HPV prevention and treatment. CCO doesn't provide screening recommendations.
"I don't think we have the evidence yet to say we should have routine screening, even among high risk individuals," Dr. Jill Tinmouth, lead scientist at CCO, told VICE. "I think the right screening is through research protocols."
When asked if Tinmouth thinks anal cancer is on the rise in men and women she responded, "I believe it to be true. With the use of (HPV) vaccination, I think we'll see the rates of anal cancer dropping. But we won't see those results for a long time."
The incubation for anal cancer can be long, evolving over 10 to 15 years. It develops faster in HIV patients who don't have the immunology to suppress HPV.
"Community members need to bring it (anal cancer) forward to their physicians and ask for the test," said Kovacs. "My hope is that we get it into the mainstream. It will take a while but I think we'll get there."
Tiffany Bateman is a public health nurse specializing in infectious diseases.