Anal Cancer

Anal cancer develops in the tissues lining your anal canal or in the skin near its opening (anus). Your anal canal is the lower part of your digestive system. Your anus is where stool (poop) leaves your body. Most anal cancers are squamous cell carcinomas.

Only about 11,000 people in the U.S. receive this diagnosis each year. It’s usually curable, especially when it’s caught early. This is why it’s important to schedule a visit with a provider if you have signs or symptoms of anal cancer.

Symptoms of anal cancer

Symptoms are sometimes similar to those in common conditions, like hemorrhoids. This is why it’s important to get checked out. Signs of anal cancer include:

• Rectal bleeding or bloody stools (most common)
• Pain or fullness in the area that feels like constantly needing to poop
• Changes in how often you poop or what your stools look like (like having thinner stools)
• A lump or mass at your anal opening
• An itchy anus

Having one or more of these symptoms doesn’t mean you have anal cancer. So, there’s no need to panic. But you should talk to a healthcare provider if things get worse or don’t improve within a few days.

Anal cancer causes

Experts don’t know what causes anal cancer for everyone. But most are linked to certain types of human papillomavirus (HPV) infection. The same strains of HPV that can lead to cervical cancer can also lead to anal cancer. HPV infection is very common and doesn’t usually cause symptoms. So, most people who have it are completely unaware.

It’s important to know that most people with HPV don’t get anal cancer. And not everyone with anal cancer has HPV.

Risk factors

In addition to HPV infection, other factors may increase your chance of developing this condition, including:

• Engaging in unprotected anal sex as the receiving partner: This is true for everyone, regardless of your sex. Having many sexual partners increases your risk for HPV and anal cancer.
• Not being vaccinated against HPV: The vaccine protects against the HPV strains linked to cancer.
• Having HIV: HIV weakens your immune system, so it’s not as good at fighting off viruses like HPV. Some people with anal cancer have both HPV and HIV infections.
• Being immunocompromised: Several conditions, not just HIV, can weaken your immune system and increase your risk. Medicines that weaken your immune response can also play a role.
• Having cancers that affect your genitals: This is especially the case if you have vulvar, vaginal or cervical cancer.
• Smoking: People who smoke are more likely to develop cancer of all kinds.

How to lower your risk

There’s no guaranteed way to prevent anal cancer. But you can reduce your chances by taking the following steps:

• Don’t start smoking and quit if you do.
• Use condoms when you have anal sex.
• Get the HPV vaccine if you’re eligible for it. (This vaccine not only prevents anal cancer, but also cancers of the mouth and throat, cervical cancer and penile cancer.)
• Ask a healthcare provider if you’d benefit from cancer screenings.

Healthcare providers don’t typically screen for anal cancer. But if you have a lot of risk factors, screenings like an anal pap test or an anal HPV test may be a good idea. This is especially the case as anal cancer doesn’t always cause symptoms in the early stages. These tests check a sample of tissue for abnormal cells or the HPV virus.

A provider can advise you on whether screenings may be helpful.

How doctors diagnose this condition

A healthcare provider will ask about your symptoms and review your medical history. They may ask about your sexual activity or if you’ve had the HPV vaccine.

You may need tests like:

• A physical exam: Your provider will likely do a digital rectal exam to feel for lumps. You may also need a pelvic exam if you’re female.
• Endoscopy tests: These tests use scopes with a light, lens and video camera to look inside your anus and rectum. Examples include an anoscopy and proctoscopy.
• Imaging tests: These tests allow providers to check for tumors or signs of cancer spread inside your body. You may need a CT scan, MRI or PET scan.
• Biopsy: Providers often take tissue samples from tumors during an endoscopy test. They may also take small pieces of nearby lymph nodes. Later, a lab specialist will test the tissue for cancer cells.

Anal cancer staging

Healthcare providers use cancer staging systems to plan treatment and determine your prognosis. A prognosis is what you can expect to happen after treatment. It includes how likely it is that your cancer can be cured or go into remission and how long your life expectancy is. There are four stages of anal cancer:

• Stage I (1): You have a tumor that’s 2 centimeters (cm) or less. That’s about the size of a peanut M&M®.
• Stage II (2): The tumor may be bigger than 2 cm with no cancer in your lymph nodes. Or it may be 5 cm or less (about the size of a lime) with cancer that has spread to nearby lymph nodes.
• Stage III (3): The tumor may be bigger than 5 cm or it may have spread to nearby organs. With more advanced stage III cancers, the tumor has spread to nearby lymph nodes.
• Stage IV (4): The cancer has spread to far away organs, like your liver or lungs.

Providers diagnose most anal cancers before they’ve spread. This means they’re easier to treat.

How is anal cancer treated?

Anal cancer treatment depends on the type and cancer stage. There are several options.

Chemoradiation

Most people get a combination of chemotherapy and radiation therapy. Chemotherapy uses drugs to kill cancer cells. Radiation uses a machine that blasts tumors with powerful X-rays. The combined treatments often get rid of anal cancer, so you don’t need surgery.

Surgery

Less often, providers remove small tumors with surgery. They’ll take care to preserve your sphincter. This muscle helps you control bowel movements. You may need radiation therapy and/or chemotherapy afterward to kill any remaining cancer cells.

Laparoscopic abdominoperineal resection is surgery that removes your anus, rectum and colon. It treats anal cancer that comes back or doesn’t respond to chemoradiation. If you have this surgery, your surgeon will also do a permanent colostomy. This procedure brings a part of your colon through an opening in your skin. It allows you to eliminate poop into a bag or pouch attached to your body.

Chemotherapy and Immunotherapy

For people with advanced anal cancer that can’t be treated with chemoradiation or surgically removed, the best treatment is a combination of chemotherapy and immunotherapy. Chemotherapy uses drugs to kill cancer cells. Immunotherapy helps your immune system find cancer cells and fight them. For most people, these treatments aren’t cures. But they can help you live longer and with a better quality of life.

Palliative care

Palliative care helps provide symptom relief. If the goal of your treatment is to cure the cancer, palliative care can still help manage cancer symptoms and treatment side effects. If your cancer is incurable, palliative care can be given along with cancer treatments to help maintain your quality of life.

When should I see my healthcare provider?

Schedule a visit with a provider if you have unexplained bleeding from your anus or other symptoms that worsen or persist. Lots of conditions can cause symptoms like anal cancer, so it’s important not to worry. But if it is cancer, getting treated sooner rather than later improves your chances of a cure.

What are anal cancer survival rates?

Most anal cancers are curable with chemoradiation. But the biggest factor when it comes to your life expectancy is the cancer stage. Medical experts monitor people closely for at least five years after they complete treatment. Most people who are cancer-free at the five-year mark stay cancer-free.

According to the U.S. National Cancer Institute, more than 7 out of 10 people (70%) with anal cancer are alive five years later. Survival rates by location and degree of spread are:

• Localized (the tumor hasn’t spread): 85%
• Regional (spread to nearby lymph nodes): 70%
• Spread to distant organs: 36%

It’s important to remember that survival rates are based on the experiences of large groups of people who may have different health issues. What’s true for them may not be true for you. Ask your provider to explain what you can expect.

Is there anything I can do to feel better?

Talk to your healthcare provider about treatment side effects. Both chemotherapy and radiation can cause changes in your body that your provider can help you manage. If you received a colostomy, your healthcare team will help you adjust.

In the meantime, be sure to attend follow-up appointments according to your care plan. It may take several months for the tumor to go away after chemoradiation. It’s important that your provider monitors you during this period and for some time after.

What’s the difference between anal cancer and anal dysplasia?

The difference is that anal dysplasia isn’t cancer. But it may pave the way for anal cancer. In anal dysplasia, cells in your anus become abnormal. Over time, these abnormal cells could form cancerous tumors.

How is anal cancer different from rectal cancer and colon cancer?

Your anus, rectum and colon are all parts of your digestive system. But the cells that make up each are different. This means that healthcare providers treat these cancers in different ways.