Anal Cancer

When malignant cancer cells form in the tissues around the anus (the end of the large intestine where stool leaves the body) this becomes known as anal cancer. The risk of developing anal cancer is often increased after being infected with the human papillomavirus (HPV).

Diagnosis of Anal Cancer

Once anal cancer has been diagnosed, tests will be carried out to determine whether the cancer cells have spread to other areas of the body. This process is known as staging, and will determine the stage of the disease – helping in the planning of treatment.

Methods used to determine the stage of anal cancer:

- CAT scans make detailed pictures of the inside of the body.
- Chest x-rays show the organs and bones within the chest.
- Endo-anal ultrasound. A probe is inserted into the anus and makes echoes of internal tissues and organs.

The Stages of Anal Cancer

When anal cancer is Stage 0, the cancer is only found in the innermost lining of the anus.

- Stage I means that the tumor is 2 centimetres or smaller.
- Stage II means that the tumor is bigger than 2 centimetres.
- Stage IIIa means that the tumor is any size but has spread to either the lymph nodes nearby the anus, or nearby - organs (vagina, bladder or urethra).
- Stage IIIb means that the tumor is any size and has spread to lymph nodes nearby the anus, the lymph nodes on one side of the pelvis as well as nearby organs, both sets of lymph nodes and on both sides of the pelvis.
- Stage IV means the tumor is any size and may have spread to nearby organs and lymph nodes as well as distant areas of the body.

Treatment for Anal Cancer

The treatment will depend on the stage the anal cancer has reached. In general radiation therapy is used (with high-energy x-rays killing cancer cells); or chemotherapy (using drugs to stop the growth of the cancer cells), and surgery (where the tumor is removed).

If the patient has HIV (human immunodeficiency virus) then treatment will be affected due to the fact the immune system is already weakened. This will mean lower dosages of the anti-cancer drugs.