What You Should Know About Anal Cancer
- You do NOT have to participate in anal sex to develop anal cancer, but it is true that receptive anal sex increases the risk of anal cancer in both men and women.
- Even still, HPV (human papillomavirus) infection is the most important risk factor for anal cancer, and nearly every sexually-active person will get the HPV infection at some point in their lives.
- HPV vaccination is so important because it can decrease your risk for so many different cancers including cancers of the vagina, penis, anus and throat as well as cervical cancer.
First things first, SurvivorNet would like to dispel a prevalent myth within the world of anal cancer: You do NOT have to participate in anal sex to develop anal cancer.Read More
Understanding Anal CancerAnal cancer is a type of cancer that begins in the anus the opening at the lower end of the intestines. It's less common than colon and rectum cancers, and the American Cancer Society (ACS) considers the disease to be “fairly rare.”
The ACS estimates that in 2022 there will be approximately 9,440 new cases of anal cancer diagnosed. This disease affects women more than men with an estimated 6,070 in women to be diagnosed this year, and 3,020 men.
Assessing Your Risk
There are multiple types of anal cancer, but nearly 9 out of 10 anal cancer cases in the United States are squamous cell carcinomas. This is important to note because most squamous cell anal cancers are linked to infection with the human papillomavirus (HPV) making HPV infections the most important risk factor for anal cancer.
Other risk factors include the following:
- Anal warts. People who are infected with HPV subtypes that cause anal and genital warts are also more likely to be infected with HPV subtypes that cause anal cancer.
- Having previously had other cancers of the cervix, vagina, or vulva. This risk factor is likely due to the fact that these cancers are also linked to HPV.
- HIV infection.
- Sexual activity. Having multiple sex partners increases the risk of infection with HIV and HPV as well as the risk of anal cancer. As noted previously, receptive anal sex does increase the risk of anal cancer in both men and women. Because of this, men who have sex with men have a high risk of this cancer.
- Lowered immunity from things like AIDS, an organ transplant or medicines that suppress the immune system.
- Gender and race/ethnicity. Anal cancer is more common in white women and black men.
But in order to consider your risk assessment for anal cancer more fully, it’s crucial to understand what it means for anal cancer to be strongly linked to HPV. Some people have the misconception that you can only contract HPV-linked anal cancer through anal sex when you can, in fact, get it other ways including via vaginal sex.
"They've done studies of women who have never had anal sex that have had HPV in their anal canal, probably just from friction and moisture,” Dr. Stephen Abbott said. “Exchange of fluid during any type of rigorous sex can lead to HPV getting in the anal canal."
Anal cancer survivor Lillian Kreppel is determined to challenge the misconception that anal sex is the only way you can get anal cancer.
"You don't need to have anal sex to get anal cancer," she previously told SurvivorNet. "HPV travels, so you need to be on the lookout. You need to find a doctor who can do an anal Pap."
Anal cancer is not common in the United States, so general screening for anal cancer is not widely recommended. But some people may benefit from screening techniques like an anal pap which checks a sample of cells from the anus for any indicators of anal cancer.
Some people that may benefit from an anal pap, according to the ACS, includes men who have sex with men (regardless of HIV status), women who have had cervical cancer, vaginal cancer or vulvar cancer, anyone who is HIV-positive and anyone who is immunocompromised (such as people who have received an organ transplant or are on long-term steroids). Some experts also recommend screening for anyone with a history of anal warts and women older than 45 years old who are HPV 16 positive.
There is no widespread agreement on which groups of people could benefit from screening, so if you have any questions or are concerned about your risk for anal cancer, you should speak with your doctor.
Symptoms of Anal Cancer
Some anal cancers may not cause symptoms until they reach an advanced stage, but when they do it’s important to investigate these symptoms promptly with a doctor. Symptoms of anal cancer include:
- Bleeding from the rectum.
- Itching in or around the rectum.
- A lump or mass at the anal opening.
- Pain or a feeling of fullness in the anal area.
- Narrowing of stool or other changes in bowel movements.
- Abnormal discharge from the anus.
- Incontinence of stool (loss of bowel control).
- Swollen lymph nodes in the anal or groin areas.
It should be noted that these symptoms are much more likely to be caused by something benign (noncancerous) like hemorrhoids, anal fissures or anal warts. Even still, you should always investigate these symptoms with a doctor so that the true cause can be discovered and treated whatever that may be.
Understanding the Leading Risk Factor for Anal Cancer: HPV
Vaccinating eligible people against HPV is arguably the most important and easiest way to decrease your risk of getting anal cancer. So, let’s take a deeper look at HPV and the HPV vaccine.
Nearly every sexually-active person will get HPV at some point in their lives, but most people with the infection do not know they have it and never develop symptoms or health problems from it. The virus is spread via sexual activity and can manifest as warts on your genitals or mouth.
When people talk about HPV and cancer risk, they tend to focus on cervical cancer. And while it's true that nearly all cases of cervical cancer are caused by HPV, people should also be aware that HPV puts both men and women at risk of developing several other cancers as well including cancers of the vagina, penis, anus and throat.
Oral and throat cancers, for example, are both on the rise in young, non-smoking adults, and Dr. Ho says HPV is the cause.
"The fastest-growing segment of the people developing oral cancers are young non-smokers," Dr. Ho told SurvivorNet in a previous interview. "HPV, a very common virus, one responsible for the vast majority of cervical cancers, is now identified as a cause of this rapid rise of oral cancers."
Which HPV Vaccines Are Available?
Thankfully, there are three types of HPV vaccines Gardasil 9, Gardasil and Cervarix. All three went through years of extensive safety testing before being approved by the U.S. Food and Drug Administration (FDA), and the CDC reports that HPV vaccination has the potential to prevent more than 90 percent of HPV-attributable cancers.
The HPV vaccines, like other immunizations that guard against viral infection, stimulate the body to produce antibodies that attack if they encounter the HPV infection by binding to the virus and preventing it from infecting cells. HPV vaccines do not prevent other sexually transmitted diseases or treat existing HPV infections/HPV-caused disease, but their implementation can reduce the rates of certain cancers.
And while Dr. Susan Vadaparampil, the associate center director of community outreach, engagement and equity at Moffitt Cancer Center, previously told SurvivorNet there are few medical strategies that totally prevent against getting cancer in the first place, she emphasized that data from countries with high rates of vaccine coverage show decreases in HPV-related pre-cancer and cancer particularly so in the case of cervical cancer.
"We have a safe and effective vaccine to prevent HPV-related cancer," Dr. Vadaparampil told SurvivorNet. "It is widely available, and costs are typically covered by private or public insurance."
Eileen Duffey-Lind, a pediatric nurse practitioner at Dana-Farber Cancer Institute/Boston Children's Hospital, echoed Dr. Vadaparampil's sentiment.
"No one should die of a preventable cancer like those tied to HPV, especially since we have a highly effective and safe vaccine available," Duffey-Lind previously told SurvivorNet.
Who Should Get the HPV Vaccine?
According to the CDC, the HPV vaccine is recommended for all preteens (both girls and boys) 11 to 12 years old in two doses administered between six and 12 months apart. The series of shots can also be started as early as 9 years old.
That being said, the CDC also says that teens and young adults through age 26 who didn't start or finish the HPV vaccine series also need the vaccine. And people with weakened immune systems or teens and young adults who start the series between the ages of 15 and 26 should get three doses instead of two.
Additionally, the HPV vaccine is sometimes administered in adults up to 45 years old, but it is not recommended for everyone older than 26. Still, a person older than 26 might decide to get vaccinated after talking to their doctor about possible benefits even though it is less effective in this age range since more people have already been exposed to HPV by this time.
What Are The Possible Side Effects?
With more than 120 million doses of HPV vaccines distributed in the United States, there is plenty of data showing the safety of HPV vaccines. But, like any vaccine, there are possible side effects.
According to the CDC, the most common side effects are pain, redness or swelling in the arm where the vaccine was given, dizziness, fainting (which is more common among adolescents after receiving any vaccine), nausea and headache. With the exception of fainting, there have been no confirmed adverse HPV vaccination side effects occurring at higher than expected rates.
Anaphylaxis, a serious allergic reaction, occurs very rarely after any vaccine including HPV vaccines. The CDC says that anaphylaxis following vaccination in the U.S. has a reported rate of three cases per one million doses administered.
HPV Vaccine Hesitancy
Doctors say the benefit of having your child get the HPV vaccine outweighs any possible concerns, but timing is important. Duffey-Lind says the immune response is "significantly stronger" in those vaccinated before age 15.
"The greatest benefits for HPV vaccination occur when adolescents are vaccinated at younger ages," Dr. Vadaparampil previously told SurvivorNet. "Their immune response is better, and they are less likely to have been exposed to the virus. Also, two doses are required if the vaccine series is started at age 14 or before, compared to three doses required after that age. Thus, waiting for a child to be older, may lead to missed opportunity to be maximally protected."
So why are people hesitant to protect themselves and their children? One reason may be that there is a myth that that the HPV vaccine can cause autism.
"The HPV vaccines do not cause autism, there's always a risk of some vaccine-related side effects â€¦ local site injection pain, some redness, some swelling," says Dr. Jessica Geiger, a medical oncologist at Cleveland Clinic Cancer Center. "There are no syndromes such as autism or other neurologic symptoms that have been linked to the HPV vaccines."
Dr. Geiger also wants people to remember that, although you might not want to think about it, your children will likely participate in sexual activities at some point in their lives. Refusing to vaccinate your children denies them available protection from HPV-linked diseases, and that should be more important than not wanting to think about your kids ever having sex.
"The fact is that the majority of us are going to participate in sexual activity at some point in our lives," Dr. Geiger said. "It's unreasonable to think that just because your child isn't engaging in sexual activity now that they won't later in life."