Anal cancer happens when abnormal cells grow and multiply in your anal area or anal canal. The anal canal connects your anus (the opening) to your rectum (the lower portion of your gastrointestinal tract). This passage is about 1 to 2 inches long. It’s the part of the body that excretes solid waste (poop). Anal cancer is also called carcinoma of the anal canal.
The most common type of anal cancer is something called squamous cell carcinoma. Under the microscope, this looks similar to a common type of skin cancer, but anal cancer is different. Other types of anal cancer include adenocarcinoma.
It’s important to note that anal cancer is different from rectal cancer and colon cancer. These are three separate diseases and they’re all treated differently.
Dysplasia refers to any kind of abnormal changes in your body’s cells. Anal dysplasia is a term used to describe conditions that develop before the onset of anal squamous cell cancer (SCC). Symptoms of anal dysplasia may include:
If you develop anal dysplasia, your healthcare provider may perform a procedure called chromoendoscopy to find and destroy any abnormal tissue. During this procedure, your healthcare provider uses an endoscope (a thin, flexible tube that lets them see inside of your gastrointestinal tract) and stains or dyes that make it easier to see when tissue is abnormal.
The risk of anal cancer is higher in women than in men. The overall risk of getting anal cancer is about 1 in 500 to 600 people.
The American Cancer Society predicts that there will be about 9,440 new cases of anal cancer in 2022. Women will account for about 6,290 of these cases. The organization estimates deaths at 1,670, with women representing 930 of the total. The number of cases of anal cancer has been on the rise in the past several years.
About a quarter of the people who have anal cancer don’t notice any symptoms. When present, anal cancer symptoms may include:
The exact cause of anal cancer is unknown. However, there are certain risk factors associated with the disease. For example, most anal cancer cases are linked to human papilloma virus (HPV). But, it’s important to note that the majority of people with HPV don’t get anal cancer.
In addition to HPV, there are other risk factors that could increase your chance of developing anal cancer, including:
In most cases, anal cancer spreads to nearby tissues through your lymphatic system. Very rarely, it can metastasize (spread) to your liver or lungs.
Your healthcare provider will perform an examination, ask about your symptoms and review your medical history in detail. They may use several tests to diagnose anal cancer, including:
Anal cancer treatment depends on what type of cancer it is and how far it’s spread. The most common treatments include surgery to remove early-stage anal cancer; a combination of chemotherapy and radiation therapy (chemoradiation) for most stage two or stage three anal cancers; abdominoperineal resection (a surgical procedure performed when cancer hasn’t responded to other treatments) or chemotherapy and/or immunotherapy for those with stage four anal cancer.
Early-stage cancer that hasn’t entered your anal wall can be treated by removing the affected skin entirely. Even some smaller tumors (under one-half inch in size) that have grown into the anal wall can be removed surgically. These smaller tumors usually don’t require further treatment with radiation or chemotherapy. This surgery is called local excision.
Chemotherapy uses drugs to kill cancer cells. Some chemotherapy can be taken by mouth, while other drugs must be given through your vein or as a shot into your muscle.
Radiation therapy uses equipment that focuses high-energy X-rays or particle streams at cancer cells in your body.
Chemotherapy and radiation therapy work together for optimal effectiveness. (This approach is called chemoradiation.) Your healthcare provider will tailor your treatment plan according to your specific needs.
There’s a surgical treatment called abdominoperineal resection (APR). APR removes cancer cells in your anus, rectum and large intestine by cutting into your abdomen. APR might also remove lymph nodes that have become cancerous. APR is used when the cancer doesn’t respond to other methods or if the cancer comes back. If you have APR, you’ll need to have a permanent colostomy. In this case, part of your colon is taken out and the remaining part opens into the stoma on your abdomen. The stoma is covered by a pouch so stool (poop) can exit your body.
Your healthcare provider may recommend immunotherapy with or without chemotherapy to ease symptoms in those with stage four anal cancer. Immunotherapy uses medications to boost your own immune system so it can fight cancer cells more effectively.
All treatments may have side effects. If you have any issues with side effects of any treatment, please be sure to talk to your healthcare provider. They’ll be able to help you find different ways of coping.
Length of anal cancer treatment depends on several factors, including how advanced the disease is, the treatment you receive and your overall health. Be sure to talk to your healthcare provider about what to expect in your situation.
There isn’t a completely effective way to make sure you don’t get anal cancer, but you can help protect yourself by reducing some risk factors. For example:
Up to 90% of anal cancer cases are treated with chemoradiation. Your healthcare provider may recommend follow-up visits every three to six months for 24 months after chemoradiation is completed. They may continue to monitor your progress even after the first two years.
Anal cancer is curable, especially when it’s detected and treated early on. The overall five-year anal cancer survival rate is 69%. When the cancer is diagnosed early, the five-year survival rate jumps to 82%. That means that 82% of people diagnosed with anal cancer are still alive five years later.
Keep in mind that survival rates are just estimates. They can’t tell you how you’ll respond to treatment or how long you’ll live. To learn more about anal cancer survival rates, talk to your healthcare provider.
You should contact your healthcare provider any time you notice changes in your bowel habits. For example, if your stools (poop) have blood in them, or if you go to the bathroom more frequently, schedule an appointment right away.
If you’re treated for anal cancer, you should follow the appointment schedule set up by your healthcare provider and contact them as directed. For instance, your healthcare provider might tell you to call if you have pain or a fever.
A note from Cleveland Clinic
An anal cancer diagnosis can be frightening. It’s important to learn everything you can about your condition so you can make informed decisions about your long-term health. Talk to your healthcare provider about the many resources available. You can find information from organizations like the Anal Cancer Foundation, Cancer Hope Network and CANCERcare. Additionally, you may want to join a support group, so you can talk with others who are going through the same thing.