14 common anal cancer questions

Anal cancer can be hard to talk about. And, even when it is talked about, anal cancer is often mistaken for — or lumped together with — colorectal cancer, instead of being recognized as the distinct type of cancer that it is.

But talking about anal cancer is important, both for educational purposes and to allow those affected by the disease to feel less alone — especially with rates of HPV-related anal cancer climbing. The topic may be a bit uncomfortable, but it isn’t without hope. Most early-stage anal cancers can be cured with chemoradiation alone. 

Here are some common anal cancer questions I hear. 

What is anal cancer, and how does it differ from colorectal cancer?

Anal cancer is a completely different disease with a different biology. It’s also treated differently. 

Colorectal cancers tend to be adenocarcinomas, which arise from the glands in the gastrointestinal tract. Anal cancers, on the other hand, tend to be squamous cell carcinomas, which develop on the surfaces lining the body.  

Anal cancer is also primarily caused by HPV infection; colorectal cancer is not.  

The two cancers are also treated differently. The standard treatment for anal cancer is chemoradiation alone if the cancer hasn’t spread. But colorectal cancer may be treated with some combination of chemotherapy, radiation and surgery, depending on its location. 

Who is most at risk for developing anal cancer? 

In the United States, women are twice as likely as men to develop anal cancer. People who are immunocompromised — whether it’s due to cancer treatment, diseases like HIV, immunosuppressive drugs for autoimmune diseases or a prior organ transplant — are also at higher risk. 

Still, it’s important to note that anal cancer is not very common. Only about 9,000 people are diagnosed with it a year in the United States. 

Can anal cancer be prevented?  

The majority of anal cancer cases are caused by exposure to the human papillomavirus (HPV). HPV is the most common sexually transmitted disease.  A lot of people never even realize they’ve been exposed to HPV, because the body usually clears it naturally. Only a very small fraction will develop HPV-related cancers like anal cancer. 

That’s why we highly recommend getting vaccinated against HPV, ideally at around age 11 or 12, or before the onset of sexual activity. That’s when you’ll derive the most benefit from it as a cancer-preventing vaccine. As early as age 9 is reasonable, though, and everyone up to age 26 should get the HPV vaccine. If you’re age 27-45 and have been sexually active, there may still be some benefit to getting the HPV vaccine. Talk to your doctor to see if it’s right for you. 

The vaccine has proven to be safe and effective at preventing infection from the nine known strains of HPV that are linked to cancer and genital warts. In addition to preventing most anal cancers, the vaccine also prevents most cervical, penile, vaginal and vulvar cancers, plus HPV-related throat cancers.  

How is anal cancer typically diagnosed? Are anal cancer symptoms ever mistaken for other things?

Anal cancer is often detected initially after patients experience certain symptoms, such as: 

• pain during a bowel movement
• a little bleeding during or after a bowel movement 
• a change in bowel habits 

That’s normally when people consult their doctors: when their symptoms persist, increase or get worse.

Can hemorrhoids cause anal cancer?  

No. Sometimes, people have what they think is a hemorrhoid that won’t go away, and it turns out to be anal cancer. But hemorrhoids and anal cancer are two separate things. And neither one causes the other. 

Is bowel leakage ever a sign of anal cancer?   

No. Not usually. But anal bleeding and discharge can be.  

What does anal cancer look like? Is it ever a lump you can see?

Occasionally, someone will be able to feel a lump or a mass through the skin. But anal cancer is not typically visible from outside the body. It tends to form internally, so the more common ways to see it usually are through an endoscope or on a scan.

How fast does anal cancer grow?  

Anal cancer is a fairly slow-growing disease. It probably takes several years to develop. 

What can patients expect during their first appointment for anal cancer?

At MD Anderson, you’ll meet with a team of specialists, including a medical oncologist, a radiation oncologist, and a surgical oncologist. All of them will specialize in treating anal cancer.  

You’ll go over your medical history. At some point, you’ll likely have a proctoscopy, a type of internal examination conducted with a scope. It’s similar to a colonoscopy but doesn’t require anesthesia or the same type of preparation. It can usually be performed in a doctor’s office.   

You’ll also have some imaging studies done to fully assess the extent of the cancer, and blood tests to help determine the most appropriate chemotherapy dosages.

What treatments are available for anal cancer? 

Most patients with anal cancer that hasn’t spread can be cured with chemoradiation alone. That’s when chemotherapy is given in tandem with radiation therapy to make the radiation more effective.   

If the cancer comes back, we’ll do surgery. We do everything we can to prevent that, though, because it often requires a permanent ostomy. We’ll use immunotherapy and other systemic therapies if other organs are involved.  

One thing we do differently here at MD Anderson involves the selection of chemotherapy agents and their dosages. We may dose patients differently than your local doctor normally would. What that means is that if you come to MD Anderson, your likelihood of survival will be about the same, but your treatment can be much less toxic. And that means you’ll likely have fewer side effects and a better quality of life.

Can anal cancer be cured?   

We cure over 80% of our patients with stage I or stage II anal cancer, and about 60% of our patients with stage III anal cancer.

Stage IV anal cancer usually cannot be cured, but it can be treated. 

What lifestyle changes can anal cancer patients expect after treatment?

Patients typically experience side effects for up to six months after treatment ends. But it takes some patients up to a year before they start feeling more like their old selves. 

Tender, sensitive skin is one of the most common short-term side effects of radiation therapy. For that, we normally recommend moisturizing creams and topical ointments. 

Long-term side effects may include differences in sexual, bowel or bladder function. We educate patients about how to manage those.

What are the latest research advances for anal cancer?

We’ve developed an in-house circulating DNA blood test to detect the presence of HPV and identify patients at high risk for recurrence.  

We’re also developing an immunotherapy clinical trial for these patients, which would be the first in the world to use circulating HPV-positive tumor DNA as a prerequisite for study entry.

What advice would you give to newly diagnosed anal cancer patients?

Where you go first for anal cancer treatment matters. You want to make sure you’re going someplace with a lot of experience in treating anal cancer. 

MD Anderson is one of the leading institutions in the United States for treating patients with anal cancer. Our focus is not only on curing the cancer but on personalizing the treatment so it’s less toxic than the standard therapy you might otherwise get from your local oncologist.  

We want our patients’ quality of life to remain as high and functional as possible, even after treatment. So, we go out of our way to create treatment plans that will cause fewer long-term disruptions to patients and their families.

Request an appointment at MD Anderson online or call 1-877-632-6789.