Stages and types of anal cancer
The tests you have tell your doctor how big the cancer is and if it has spread. This is called the stage of a cancer. Knowing this helps your doctor decide the best treatment for you.
There are different ways to describe the stage of an anal cancer. This page is about the TNM staging system. Doctors may also use the number staging system.
Read more about the number staging system for anal cancer
Tumour describes the size of the cancer. There are 5 T stages for anal cancer.
Tis means some of the within the lining of the anus have abnormal changes. Doctors call this anal intraepithelial neoplasia (AIN) 2-3. Or a high-grade squamous intraepithelial lesion (HSIL). You might also hear it called carcinoma in situ.
This is not cancer but the cells might develop into cancer in the future.
Read more about anal intraepithelial neoplasia (AIN)
T1 means the cancer is 2cm or smaller.
If the cancer hasn't spread to the nearby or other parts of the body, T1 anal cancer is the same as number stage 1.
T2 means the cancer is larger than 2cm, but no bigger than 5cm.
If the cancer hasn't spread to the nearby lymph nodes or other parts of the body, T2 anal cancer is the same as number stage 2a.
T3 means the cancer is larger than 5cm.
If the cancer hasn't spread to the nearby lymph nodes or other parts of the body, T3 anal cancer is the same as number stage 2b.
T4 means the cancer is any size, but it is growing into the surrounding organs. This might include the , or the .
If the cancer hasn't spread to the nearby lymph nodes or other parts of the body, T4 anal cancer is the same as number stage 3b.
Node describes whether the cancer has spread to the lymph nodes near the cancer. These are the lymph nodes near the rectum, in the area between your hips (pelvis) or in your groin.
There are 2 main N stages for anal cancer:
N0 means there are no cancer cells in the nearby lymph nodes
N1 means there are cancer cells in the nearby lymph nodes
N1 can be further divided into a, b or c, depending on which lymph nodes the cancer cells have spread to.
Read more about the lymph nodes and cancer
Metastasis describes whether the cancer has spread elsewhere in the body, such as the liver and lungs.
There are 2 M stages for anal cancer:
M0 means the cancer hasn't spread to another part of the body
M1 means the cancer has spread to another part of the body
Where a cancer has spread to is called a secondary cancer. Secondary cancers are also called metastases. Unfortunately, if the cancer has spread elsewhere in the body, it means the cancer is advanced.
Find out more about secondary cancer
The stage of your cancer helps your doctor to decide which treatment you need. Treatment also depends on:
your type of cancer (the type of cells the cancer started in)
where the cancer is
other health conditions that you have
The stage of the cancer and these other factors can also give an idea of your outlook (prognosis).
Squamous cell cancer is the most common type of anal cancer. Treatment might include:
chemoradiotherapy – a combination of and
surgery
chemotherapy
radiotherapy
You may also have treatment as part of a clinical trial.
Read more about treatment for anal cancer
Anal cancer stages can be difficult to understand. You might feel frightened or overwhelmed after being told you have cancer. So you might not be able to take in everything your doctor tells you.
It might help to have a relative or friend with you when you see your doctor. They can:
support you
ask questions
take notes for you
You might also want to talk with your specialist nurse about the cancer stage. But you may want to wait until you’ve had a chance to take in what your doctor has said. Your specialist nurse can also arrange for you to see your doctor again if necessary.
Find out about coping with anal cancer
Last reviewed: 01 May 2025
Next review due: 01 May 2028
Anal cancer is when abnormal cells in the anus divide in an uncontrolled way. It can start in different parts of the anus and different types of cell.
If you have symptoms of anal cancer you should see your GP. They might ask you to have some tests and may refer you to a specialist.
The cancer's size and how far it has spread are described as a number between 1 and 4. Anal intraepithelial neoplasia (AIN) may be called stage 0.
Treatments include radiotherapy with chemotherapy (chemoradiotherapy) and surgery. For advanced cancer you might have chemotherapy or radiotherapy on their own.
Survival for anal cancer depends on different factors. Because this cancer is rare, survival is harder to estimate than for more common cancers.
Anal cancer is cancer that starts in the anus. The anus is also called the anal canal.
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