When you tell someone you have cancer, the first question you often hear is, "What kind?" Unfortunately, if it's anal cancer, the response may be "colorectal cancer," mumbled ambiguous words, or some other dodge. Discussion -- even mere mention -- of the anus is still considered taboo in many cultures, and this silence can be life-threatening, especially for people with HIV. But anal cancer is affecting more people every year. While the rate in the U.S. is not has high as other cancers, it is increasing at a rate of about 2% a year, and the National Cancer Institute expects 5,820 cases -- 3,680 women and 2,140 men -- to be diagnosed in 2011.
Certain groups are more likely to encounter anal HPV infection, which can lead to anal cancer. Though more women than men are diagnosed with anal cancer each year, some groups, such as HIV-positive men who have sex with men (MSM), have a significantly elevated risk of anal cancer. The social stigma that anal cancer carries with it prevents the open discussion and awareness needed to battle the disease, and stagnates funding to support research and care.
Human papillomavirus (HPV) is the most common sexually transmitted infection (STI) in the U.S. Over half the population will get it at some point in their lives. Each year 6 million people in the U.S. become newly infected with HPV, and 20 million people currently have the virus. While most HPV infections are resolved by the body's defenses, they cause half a million cases of cancer each year around the world.
A big misconception about HPV is that someone must be sexually promiscuous or have "casual sex" to contract the virus. Since HPV is a virus that is easily transferred, all it takes is one sexual partner to become infected. HPV is transmitted through skin-to-skin contact, including sexual intercourse. However, it can be transmitted by activity that does not include vaginal, oral, or anal intercourse. This includes deep kissing, genital skin-to-skin touching, and use of sex toys. Genital warts, which generally do not cause cancer but are caused by certain types of HPV, are transmitted in the same manner. In 90% of cases, the body clears the virus within two years without any treatment. But some patients, especially but not only those with weakened immune systems (such as people with HIV or organ transplant recipients) have difficulty clearing the virus on their own. If the HPV infection is persistent and caused by a high-risk (cancer-causing) strain of HPV, it can lead to cell abnormalities (also called dysplasia). Severe cases of dysplasia can lead to cancer over time.
While more women than men develop HPV-related cancers, HPV can cause anal, penile, and head and neck cancers in men. It can also cause cervical, vulvar, and vaginal cancer in women. According to the CDC, more than 20,000 HPV-related cancers occur in women and over 11,000 occur in men each year in the U.S. Worldwide, the World Health Organization documented 500,000 cases of cervical cancer alone and 260,000 related deaths in 2005.
There are about 150 types of HPV, with around 40 types transmitted through sex. Approximately 15 sexually transmitted HPV strains have the potential to cause cancer, and a person can be infected with multiple strains. Two strains, 16 and 18, cause around 70% of cervical and 85% of anal cancers. Most oral cancers are caused by type 16. Types 16 and 18 are also highly common in vaginal and penile cancer.
There are currently two FDA-approved vaccines: Gardasil and Cervarix. Both protect against the two most common cancercausing strains, HPV-16 and HPV-18. Gardasil also protects against HPV-6 and HPV-11, which are linked to 90% of genital warts. Both use virus-like particles to enable the body to develop immunity to these strains of the virus. If a person is infected by HPV but has not been exposed to all four strains covered by the vaccine, it can still protect against the other strains.
The HPV vaccine is not mandatory in the U.S., but the CDC recommends that both men and women, and the parents of boys and girls, discuss the vaccine with their medical providers. In November 2011, the CDC amended its policies to recommend that both boys and girls be routinely vaccinated against HPV. Vaccination allows both sexes to take a proactive step toward protecting themselves and their partners from the virus and its potential consequences. Since HPV is easily transmitted, vaccinating against the virus before a person becomes sexually active offers the most protection. Even after sexual activity has started, however, a person may still get protection from the vaccine.
The FDA has approved Gardasil to prevent vulvar, vaginal, and cervical cancer in women, and anal cancer and genital warts in men and women. It is approved for use in males and females ages 9-26. It is routinely recommended for girls and boys, with a target age of 11-12. "Catch-up" vaccination is routinely recommended for women in the 13-26 year age range and in men aged 13 to 21 years. The vaccine is also recommended for men aged 22 to 26 years, but the recommendation in this group is "permissive" and not "routine", meaning that men may not have it covered by their insurance. The FDA has also approved Cervarix to prevent cervical cancer. It is approved for girls ages 9-25. Recent studies suggest it may also protect against anal HPV infection, which can lead to anal cancer.
To date, HPV vaccination rates in the U.S. have been very low: a 2010 CDC report showed that only 32% of females aged 13 to 17 received the full three-shot course of the vaccine. By comparison, countries such as Australia and the United Kingdom have rates that are double or more than the U.S. (partially due to school vaccination programs). While all countries with access to the vaccine will see a decrease in HPV-related cancers, those with more people vaccinated will see a sharper reduction in these cancer rates. Mistaken concerns that vaccinating adolescents against a common STI will encourage early sexual activity may be partly to blame for the slow ramp-up of vaccinations in the U.S. Others have cited concerns about possible side effects as a reason to delay vaccination, but the FDA and the CDC continuously evaluate the vaccines' safety and have determined that both vaccines are safe.
Vaccination is by far the best way to prevent HPV infection. But further steps should be taken to prevent HPV-related diseases, even in vaccinated persons. Some people may already be infected with HPV before getting vaccinated, while others may contract an HPV type not covered by the vaccine.
While having just one sexual partner can expose you to HPV, fewer partners can reduce your risk of being infected with the virus. Of course, one can still contract the virus with just one partner. Although condoms can reduce the risk of HPV infection, they are not entirely effective because HPV can be transmitted through skin surfaces not covered by the condom or during sexual activity that occurs before the condom is used.
HPV-Associated Cancer in the U.S. (2011)
|Type of Cancer||New Cases||Deaths||% From HPV|
It's important to talk to your doctor about your risk factors for HPV and ask about testing options. Anal cancer does not affect all groups equally. In general, more women than men are diagnosed with anal cancer.
HIV-negative MSM are seventeen times more likely to develop anal cancer than non-MSM, and HIV-positive MSM are twice as likely as HIV-negative MSM to develop it. Rates of anal cancer are especially on the rise in older MSM with HIV. While HIV treatment has been successful at prolonging the lives of people with HIV, a weakened immune system over a long period of time can allow for an infection like HPV to develop into cancer. Sexual experiences that occurred years or even decades earlier may have resulted in an HPV infection that can lead to a malignancy years later.
A woman who has persistently tested positive on a cervical HPV test may be at higher risk for having an HPV infection in the anus that can lead to anal cancer. Women with a history of cervical cancer or vulvar cancer may also be at higher risk. Anal sex is not a requirement for anal HPV infection or anal cancer in women (or men), as studies have shown HPV infection to be present in the anal canal of heterosexual men and women without a history of anal sex, including adolescent females. This is why women should request anorectal exams as part of a routine check-up, and women with persistent high-risk HPV cervical infection should speak with their doctor about annual anal Pap smears. Current New York State recommendations are that all men and women with HIV should get an annual anal Pap smear.
A study published in 2010 concluded that anal cancer rates are rising among people with HIV and that HIV treatment does not appear to reduce the risk of developing it. However, there has been speculation by scientists that since HIV treatment improves immune function, it may prevent the progression of HPV to anal cancer. Still, it is clear that people with HIV have a significantly higher risk for anal cancer than those who are HIV negative. On its HPV information website, the CDC states "some experts recommend yearly anal Pap tests to screen for anal cancer in gay and bisexual men and in HIV-positive persons. This is because anal cancer is more common in those populations."
Certain other factors such as smoking and a higher number of sexual partners may also be linked to an increased risk of anal cancer.
In order to monitor potential HPV disease, everyone should have regular checkups after the onset of sexual activity. The cervical Pap smear and regular gynecological check ups have dramatically reduced the numbers of cases of cervical cancer in the U.S. in the last 40 years. But neither gender is regularly screened for HPV risk in other parts of the body, such as the anus or the mouth.
Women are routinely screened for cervical cancer when they receive their annual Pap smear at the gynecologist. But men often fall through the cracks when it comes to routine screening because anal HPV tests and anal Pap smears are not commonly offered to them by physicians. There are currently no routine anal cancer screening protocols. Certain anal specialists suggest the best way to check for anal cancer is through a digital anorectal exam. The name may be confusing, since there is no digital equipment used in the examination -- in this case the "digit" is simply a finger. In fact, it is a simple procedure in which the physician checks the anus for any abnormalities using a lubricated, gloved finger, much like a prostate exam.
Another simple test to check for abnormalities is an anal Pap smear, which is similar to a cervical Pap smear. An anal Pap smear merely involves placing a small swab in the anus and sending if off to the lab. But some general practitioners insist on referring patients to a specialist for this simple procedure, creating a barrier that often leads to it not being performed.
If precancerous anal lesions are found, a high-resolution anoscopy is recommended. This is often performed after an abnormal anal Pap smear and involves a magnification of the anal canal using a device called a colposcope. Vinegar is applied to the lining of the anus to show areas of abnormalities and identify dysplasia. If a problem area is spotted, a biopsy may be taken. Precancerous lesions can be treated with topical therapies, frozen with liquid nitrogen, or burned off with heat or laser therapy. Since the anus makes up only about the last inch of the anal canal, these precancerous lesions can often be dealt with in an outpatient procedure.
There is a common protocol for the treatment of early stage anal cancer. It usually involves 30 days of radiation therapy, along with two cycles of chemotherapy. If caught early, cure rates are high, although this regimen can come with significant side effects, some of which may be long lasting. Radiation can lead to long-term gastrointestinal and sexual health dysfunction, including narrowing of the anus or vagina due to scar tissue formation, often making sexual activity painful. For men, it could mean erectile dysfunction.
Unfortunately, anal cancer is often misdiagnosed and its treatment delayed, leading to metastasized cancer in other parts of the body. If you are diagnosed with what is believed to be a hemorrhoid and it has not resolved for several weeks, despite all recommended treatments, discuss it with your physician and have it formally re-evaluated. MSM in particular should be very aware of changes in the anus. Any abnormal bleeding or new bumps should lead to an immediate examination -- by a specialist, if needed.
Unfortunately, when diagnosed in late stage, anal cancer can have devastating effects. One of the authors of this article lost her mother to anal cancer in 2010. Farrah Fawcett, the actress and model, lost her life to it the year before.
Regular check ups and testing have been credited with reducing cervical cancer rates in the U.S. over the last half century. With increased awareness, vaccination programs, improved screening practices, and proactive questions from patients, the HPV cancer burden for anal cancer and other HPV-associated diseases can be reduced in the U.S. in the coming years.
The HPV and Anal Cancer Foundation is a 501(c)(3) not-for-profit organization established in 2010. The mission is to provide support for patients and families, improve preventive care measures and fund therapeutic research.
Justine, Tristan, and Camille Almada started the nonprofit after their mother died from anal cancer. The organization aims to spread awareness and knowledge about the disease, breaking the stigma of a cancer that is often misdiagnosed and misunderstood. The organization also seeks to empower people living with anal cancer to feel unashamed about having HPV or anal cancer.
We encourage you to reach out to us with any questions, concerns, or to share your story with us at www.analcancerfoundation.org.
Camille Almada and Nicoletta Bumbac are members of the Board of Directors of the HPV and Anal Cancer Foundation.