Anal Cancer: Diagnosis

How is anal cancer diagnosed?

If your healthcare provider thinks you might have anal cancer, you will need certain exams and tests to be sure. Diagnosing anal cancer starts with your healthcare provider asking you questions. He or she will ask you about your health history, your symptoms, risk factors, and family history of disease.

He or she will also do a physical exam. This includes a digital rectal exam (DRE). During a DRE, your healthcare provider puts a gloved, lubricated finger into your rectum. He or she checks for hard or lumpy areas.

What tests might I need?

Pathologist examining tissue under a microscope.

During a biopsy, your healthcare provider takes a small sample of tissue from your anus. The tissue is sent to a laboratory and looked at under a microscope.

If your healthcare provider feels anything unusual or if you have symptoms, he or she may also do tests to check if you have anal cancer. You may need more than 1 of these tests:

  • Anoscopy. For this test, your healthcare provider puts a small lighted tube (anoscope) into your anus to look at the lining. The tube is about 3 to 4 inches long. Your healthcare provider will lubricate it before inserting it.

  • Proctoscopy. For this test, your healthcare provider uses a longer lighted instrument (proctoscope) to look at the inside of your anus and rectum. It’s about 10 inches long. Again, the tube is lubricated before it is inserted.

  • Biopsy. If your healthcare provider sees anything suspicious, you may need a biopsy. During a biopsy, he or she takes a small sample of tissue from your anus. The tissue is sent to a laboratory. Then it’s looked at under a microscope by a doctor who specializes in diagnosing diseases by looking at body tissues and fluids (pathologist). A biopsy is the only way to know for sure whether a change seen in the anus is cancerous (malignant) or noncancerous  (benign).

Getting your test results

When your healthcare provider has the results of your biopsy, he or she will contact you with the results. Your provider will talk with you about other tests you may need if anal cancer is found. Make sure you understand the results and what follow-up you need.