How is anal cancer diagnosed?

The first person to see will probably be a GP (general practitioner, primary care physician). The GP will ask the patient about his/her symptoms and carry out an examination. The doctor will also need to know about the patient's medical history. Then the patient will be referred to a colorectal surgeon - this is a doctor who specializes in bowel conditions. Colorectal surgeons are sometimes called proctologists. The specialist may carry out the following tests:

• A rectal examination - this may be a bit uncomfortable, but is not painful. A proctoscope or sigmoidoscope may be used - an instrument that allows the doctor to examine the area in more detail. In some countries this device is called an anoscope, and the procedure 'anoscopy'. The examination will determine whether the patient needs a biopsy.


• A biopsy - a small sample of tissue is taken from the anal area and sent to the lab for testing. Tissue will be examined under a microscope.

If cancerous tissue is detected after the biopsy the patient will need further tests to find out how advanced (big) the cancer is and whether or not it has spread. The following tests may be done:

• CT (computerized tomography) scan - X-rays are used to create a 3-dimensional picture of the target area.


• MRI (magnetic resonance imaging) scan - magnets and radio waves produce 2-dimensional and 3-dimensional pictures of the target area.


• Ultrasound scan - sound waves are used to create an image of the target area. This could be done internally with a rectal ultrasound - the instrument is inserted into the anus before the scanning begins.