Sometimes doctors discover anal cancer during a routine physical exam or minor procedure. Some kinds of anal cancer may not cause symptoms until they're at an advanced stage. Your doctor may recommend the following tests to help diagnose anal cancer:
Physical exam and medical history – The doctor will check for general signs of health or disease. He or she will ask about your health habits and past illnesses.
Digital rectal exam – This is an exam of the anus and rectum. The doctor inserts a gloved, lubricated finger into the anus to feel for lumps or anything else that seems unusual.
Endoscopy – For this test, the doctor uses a short lighted tube with an attached lens or video camera attached examine the anus, rectum, and part of the large intestine.
Biopsy – This is surgery to remove a tissue sample that will be examined under a microscope to check for cancer. Sometimes the surgeon removes the entire tumor during the biopsy. A biopsy may also be used to detect whether cancer has spread to the lymph nodes.
If the tests show cancer, the next step is to see whether it has spread within the anus or to other parts of the body. This process is called staging. It is important for determining your treatment options.
Imaging tests may be done as part of the staging process. These may include:
Computed tomography (CT ) scan of the pelvis and abdomen
X-ray of the chest
Ultrasound of the anus or rectum
Tumors of the anal canal are grouped into a set of stages. Stage 0 is the earliest stage, while stage IV is the most advanced. Sometimes anal cancer comes back after treatment. This is called recurrent anal cancer.