In addition to a review of your medical history and a physical exam, doctors may use tests like anoscopies, endoscopies, and biopsies to diagnose anal cancer.

Anal cancer is an uncommon type of cancer that causes symptoms, such as a lump near the anus, anal bleeding, and a change in bowel habits. The symptoms of anal cancer can be caused by many other, less serious, conditions, and you’ll need tests for a diagnosis.

Typically, testing will start with a physical exam. Your doctor will then order tests to look at the inside of your anus and rectum. These tests allow doctors to see tumors and other growths. Biopsies are often done at the same time. The results of these tests can confirm an anal cancer diagnosis.

This article reviews all the tests doctors may use for diagnosing anal cancer.

The first step in the process of getting an anal cancer diagnosis is a medical appointment. During your appointment, a doctor will review your symptoms and your medical history. They’ll likely ask about any family medical history of cancer.

You’ll also have a physical exam. If anal cancer is suspected, this will include a test called a digital rectal exam (DRE). During this test, a doctor will carefully feel the inside of your anus and rectum to check for lumps and abnormalities. In some cases, a pelvic exam and pap smear might also be done.

An anoscopy is a test done with a short and thin tube with a light on the end that’s called an anoscope.

During the procedure, the tube is coated in gel and gently inserted through the anus and into the rectum. The light attached to the tube gives the doctor a clear view of the inside of the anus and rectum.

Sometimes, tissue samples for a biopsy are taken during this procedure. This test is normally performed as an outpatient procedure, so you’ll go home after it’s finished.

An endoscopy is similar to an anoscopy.

A thin tube with a light will be inserted gently through the anus and into the rectum. However, an endoscopy uses a tube called an endoscope that also has a tiny video camera attached to it. The camera is connected to a computer screen doctors can see as the tube moves through the rectum. This gives them a detailed look at the inside of your anus and rectum.

Tissue samples for biopsies are sometimes collected during endoscopies.

A biopsy is a procedure that removes a piece of tissue so that it can be tested for cancer cells. It’s often done as part of an anoscopy or endoscopy. Sometimes, very small tumors are taken out completely during a biopsy. Biopsies can be done as an outpatient procedure, but the area is often numbed.

If a doctor suspects cancer has spread to nearby lymph nodes, they might also choose to take a biopsy of the lymph nodes. This is often done with a long needle that’s inserted through the skin and into the node. The needle removes tissue from the lymph node, and the tissue is tested for cancer in a lab.

Blood tests aren’t typically part of anal cancer testing. However, if you have risk factors for human immunodeficiency virus (HIV) your doctor might order a blood test to check for it.

HIV lowers your body’s immune response and can interfere with anal cancer treatment. You’ll need to be treated for both anal cancer and HIV together to achieve the best outcome.

There are several imaging tests that a doctor might order to help confirm an anal cancer diagnosis. Imaging tests help doctors get clear and detailed pictures of tumors and other abnormalities inside the body.

Common imaging tests for anal cancer include:

  • Ultrasounds: Ultrasounds can help see the size of the tumor, and see if it has grown into tissues around the anus
  • CT scans: CT scans can help see if cancer has spread to nearby lymph nodes.
  • MRIs: MRIs can help doctors see if lymph nodes or organs are swollen as a result of cancer spreading.
  • Chest X-rays and PET scans: Chest X-rays and positron emission tomography (PET) scan can help detect if cancer has spread to the lungs and other areas.

There are several known risk factors for anal cancer. Some risk factors are things you can’t control, such as being over the age of 50 and having a history of cancer. However, there are other risk factors, such as practicing sex without a condom or other barrier method and smoking, that you can avoid to lower your risk of anal cancer.

Risk factors for anal cancer include:

There are steps you can take to reduce your risk of anal cancer. For instance, an HPV vaccine can prevent HPV, thus lowering your risk of anal cancer.

You can also protect yourself by quitting smoking, always having sex with a condom or other barrier method, and getting regularly tested for sexually transmitted infections (STIs). Making these lifestyle adjustments doesn’t guarantee you’ll never develop anal cancer, but it does bring down your risk.

There are several tests that can help diagnose anal cancer. Typically, the process starts with a review of your medical history and a physical exam.

From there, your doctor will likely order a test called an anoscopy that allows them to get a better look at the inside of the anus and rectum.

Tissue might be taken for a biopsy at this time. Additional imaging tests may also be used to help confirm a diagnosis.