Anal cancer is often curable if it’s diagnosed and treated before it spreads to distant organs. Doctors consider your cancer cured if it stays in remission for at least 5 years.

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Anal cancer is a rare type of cancer that develops on the outer part of your anus or your anal canal. It primarily affects older adults and is very rare in people under 35.

The lifetime chance of developing anal cancer is about 1 in 500. It occurs about 40 times more often in people with HIV compared with people in the general population. About 91% of cases are linked to human papillomavirus (HPV) infection.

Anal cancer is often curable if it hasn’t spread to distant tissues when it’s diagnosed. Treatment is usually palliative if the cancer has spread to other locations like your lungs or liver. “Palliative” means your treatment focuses on managing symptoms and improving your quality of life instead of curing the cancer.

Read on to learn more about how anal cancer is treated and when it’s usually curable.

When doctors say your cancer is cured, they usually mean that your cancer has gone away and isn’t expected to return.

If your treatment is working, a doctor may tell you that you’re in remission. “Remission” means the signs and symptoms of your cancer are reduced. If they go away completely, doctors say that you’re in complete remission.

Doctors often consider your cancer cured if you’re in complete remission for at least 5 years. Most cancers that return come back within this period.

Doctors will likely want to continue testing you beyond this period since there’s still a small chance that the cancer could come back.

Anal cancer can spread to surrounding tissues or distant parts of your body.

Doctors divide your cancer into stages depending on how far your cancer has spread. Doctors most often use the American Joint Committee on Cancer (AJCC) TNM system. This system divides cancer into stages ranging from stage 0 to stage 4.

StageDescription
0Stage 0 is considered precancerous. Cells are only found in the inner layer of your anus.
1The tumor is smaller than about 2 centimeters (cm), or 0.8 inches (in), and hasn’t spread to nearby lymph nodes or distant areas.
2In stage 2A, the cancer is no more than 5 cm (2 in) but hasn’t spread to nearby lymph nodes or distant sites.
In stage 2B, the cancer is larger than 5 cm (2 in) but still hasn’t spread to lymph nodes or distant sites.
3In stage 3A, the cancer is between 2 cm (0.8 in) and 5 cm (2 in) and has spread to nearby lymph nodes but not distant sites.
In stage 3B, the cancer is any size and is spreading into nearby organs but hasn’t spread to nearby lymph nodes or distant sites.
In stage 3C, the cancer is larger than 5 cm (2 in) and has spread to nearby lymph nodes but not distant sites.
4The cancer can be any size and has spread to distant organs such as your lungs and liver. It may also have spread to nearby lymph nodes and nearby organs.

Treatment for stage 0 to 3 anal cancer usually aims at curing the cancer. Stage 4 cancer is very difficult to cure, and treatment usually revolves around trying to manage your signs and symptoms.

Learn more about anal cancer stages.

The outlook for people with anal cancer is generally good when the cancer hasn’t spread to distant tissues. The stage of your cancer is one of the most important factors for determining your chances of survival.

The American Cancer Society doesn’t use the AJCC system for reporting 5-year survival rates. They use a simpler 3-stage system. The 5-year relative survival rate is a measure of how many people with the cancer are alive 5 years later compared with people without the cancer.

They report the following survival rates from 2011 to 2017 in the United States:

StageApproximate AJCC equivalent5-year relative survival rate
LocalizedStage 1 or 282%
RegionalStage 366%
DistantStage 435%
All stagesAll stages combined69%

Other factors linked to a better outlook for people with anal cancer include:

  • younger age and better overall health
  • being assigned female at birth
  • having a lower HPV load
  • having higher white blood cell or red blood cell counts before treatment

At what stage is anal cancer not curable?

Treatment is unlikely to cure stage 4 anal cancer. The goal of treatment is usually to keep your symptoms under control and to improve your quality of life.

How often does anal cancer return?

In a 2020 study, researchers examined the rate of reoccurrence in people with anal cancer treated with radiation therapy. They found that 20% of people experienced a reoccurrence in a distant part of their body and 14.1% had a reoccurrence in their anal area or nearby region.

Where does anal cancer typically spread to?

Anal cancer may spread to distant body parts such as your:

  • liver
  • lungs
  • distant lymph nodes
  • kidney
  • peritoneum, the tissue that lines your abdominal wall and pelvic cavity

Is anal cancer slow- or fast-growing?

The rate of growth of anal cancer is hard to predict. It may grow quickly in some people and slowly in others. Some rare types of anal cancer such as melanoma can be very aggressive with a 5-year survival rate of around 20%.

Anal cancer is often curable if it’s diagnosed and treated before it spreads to your distant organs. Treatment for early stage anal cancer usually focuses on trying to cure the cancer.

Cancer that has spread to distant areas is called stage 4 anal cancer. Treatment for stage 4 anal cancer usually focuses on minimizing your symptoms and improving your quality of life as opposed to curing the cancer.