Anal cancer is a condition about which individuals from numerous demographics should be concerned. According to the Centers for Disease Control and Prevention ( CDC ), there are about 3,400 new cases of human papilloma virus ( HPV )-associated anal cancers diagnosed every year in women, and about 1,800 new cases in men.
Being HIV-positive significantly increases the risk, said Gary Bucher, MD, of Anal Dysplasia Clinic-Midwest, 2551 N. Clark St. The current rate of anal cancer is about 140 per 100,000 HIV-positive men who have sex with men ( MSM ), and 35 per 100,000 HIV-negative MSM. HIV-positive women and HIV-positive men who have sex with women have similar rates of anal cancer to HIV-negative MSM.
"Definitely you can see that the biggest group is the HIV-positive MSM," Bucher noted, adding that such high rates are compelling health providers and advocates to get the message out that people need to be screened.
At the root of the condition is HPV, which is the most commonly-transmitted STD since it is largely transmitted via skin-to-skin contact. "You can get HPV just by rubbing the penis or the anal area, or through oral sex," he explained.
Most people who are infected with HPV will clear it from their system within two years. Bucher added, "But for people with HIV, for some reason, even though the immune system looks good T-cell-wise, you can still have some some kind of issue where the HPV continues to 'hang out' and cause problems."
About 95 percent of HIV-positive MSM"will always have HPV in their bottoms," he continued. "About 60 percent of gay men who are negative will also always have it in their bottoms. That is why it persists, and why those two groups are most at risk."
Cellular changes from the HPV can eventually lead to the precancerous condition anal dysplasia.
"In HIV-positive MSM, about 50-60 percent of that group will have those precancerous areas, and about one in 10 of those people will develop anal cancer over their lifetime, so it's pretty common," Bucher said.
While some primary care providers have been offering patients anal Pap smears more frequently, a rectal examination is additionally necessary, he said. "If there's a cancer there, the physician can actually feel it, and determine if it's gotten large enough that the patient actually has to go for treatment."
One stumbling block is largely a matter of comfort-levels: Most patients are uncomfortable asking for the rectal exam—or simply don't know they should—while many physicians are uncomfortable asking if they want one.
"But the problem is that, with most Paps, the swabs have to get in all the folds of the anal canal, and there are a lot of folds," Bucher said. "So you can have a lot of Paps that come back normal when there are actually precancerous areas there."
He added that, no matter whether a patient is HIV-positive or -negative, "If we catch a cancer early, and it's small, we can surgically remove it, and they can avoid chemo and radiation. But typically when people come in, the tumor is too large to remove surgically, so it's chemo and radiation for them. If we catch it early and it hasn't metastasized to other body locations, the five-year survival rate is greater than 60 percent, which is really great for cancers that have been treated."
Patients can only have the chemo or radiation treatments once. If the cancer reoccurs, they must have their anus surgically removed.
"So it's important to find these cancers early in high-risk groups," Bucher said. Those groups who should be screened include HIV-positive men and women; HIV-negative MSM who are 45 and older; women with a history of cervical, vaginal or vulval cancer or high-grade disease; transplant patients; and persons with certain diseases of the gastrointestinal tract.
Bucher suggested concerned persons say to their primary-care physicians, '"I've been reading, and I know that I'm in a high-risk group for anal cancer. I know that, in screening for that, I should probably have a rectal exam every year, and a Pap smear if possible.' … It's an education piece for the provider as well, where the patient needs to take charge also, especially if they're in one of those high-risk groups."
Bucher's clinic is a study-site of the national Anal Cancer HSIL Outcomes Research ( ANCHOR ) Study, an 8-year study examining the overall effectiveness of Pap smears and cell-removal surgeries in detecting and preventing anal cancer. He said volunteers are still being sought.
"We need to enroll over 5,000 people nationally," Bucher noted, adding that HIV-positive men, women and transgender persons were especially needed. "They get a free screening, which is high-resolution oscopy, and if they qualify, we'll be following them every six months. … It's a really important trial and we need people to come in, get screened and help answer these questions."
For more information, see AnchorStudy.org .
