Advanced Colorectal Cancer


Doctors use a variety of tests to detect, diagnose, stage and monitor advanced colorectal cancer. Talk to your health care team about which tests you may need and what to expect from each.

Physical exam

If you show signs or symptoms of colorectal cancer, your doctor will obtain your complete medical history and perform a thorough physical examination. During the physical exam, the doctor may touch your abdomen to reveal the possible presence of a mass or an organ enlargement. You will also be given a performance status ranking based on how well you are physically functioning to help determine whether you are fit for a possible surgery.

Blood tests

Your doctor may order a blood test to check for carcinoembryonic antigen (CEA) and other substances in the blood. CEA is a tumor marker that is often elevated in people who have colorectal cancer, and testing for it serves a variety of purposes. First, the test can help doctors determine how widespread the cancer is in the body. It can also provide information about how well treatment is working by measuring CEA levels before, during and after treatment. And lastly, it can check to see if the cancer returns after treatment.

Fecal occult blood tests (FOBT) or fecal immunochemical tests (FIT) are sometimes used as well. Both tests check for hidden blood in fecal material (stool). Stool samples from one to three bowel movements are collected for these tests. Because the passage of feces can easily damage the blood vessels at the surface of large polyps or tumors, a small amount of blood (invisible to the naked eye) can be released into the stool.


During a sigmoidoscopy, the doctor inserts a lighted instrument called a sigmoidoscope through the rectum to examine the rectum and lower colon for precancerous and cancerous growths. Images from the scope are seen on a display monitor. Any growths found can then be either removed or biopsied.


Similar to a sigmoidoscopy, doctors insert a lighted instrument called a colonoscope (a longer version of a sigmoidoscope) through the rectum to check for abnormalities in the rectum and colon. The colonoscope is equipped with a video camera attached to a display monitor, which allows the doctor to closely examine the inside of the colon and rectum. With this procedure, the doctor can examine the entire colon, rather than just the lower portion (as with a sigmoidoscopy). Most patients receive some form of sedation before undergoing a colonoscopy.


A biopsy is the surgical removal of cells or tissue for microscopic examination by a pathologist (a doctor who specializes in diagnosing diseases using organs, tissue and body fluids). If any of the previously mentioned tests reveal a suspicious polyp or other abnormality, the doctor may order a biopsy to check for cancer cells.

Imaging tests

Imaging tests are primarily used to help define the size, shape and location of the tumor. They are also useful in assessing other parts of the body to see if the cancer has metastasized (spread) beyond the colon or rectum, which aids in defining the stage of the disease. You may not need every diagnostic imaging study listed here. Your doctors will consider the results of your physical examination and your general health status in deciding which tests will provide the most useful information.

Computerized tomography (CT)

CT produces three-dimensional, cross-sectional X-ray images, so it can provide more precise details than a standard X-ray. In cases of advanced colorectal cancer, CT scans can provide information about the size of the primary tumor in the colon or rectum and whether the cancer has metastasized to the liver, lungs or other organs. Therefore, CT scans of the chest, abdomen and pelvis are often recommended in patients with advanced disease.

CT colonography, also called virtual colonoscopy, is an advanced type of CT scan of the colon and rectum. To perform the test, the doctor inserts a small, flexible tube into your rectum. Air is then pumped through the tube into your colon to expand it to provide better images. CT colonography is less invasive than standard colonoscopy, so sedation is not necessary.

Endorectal ultrasound

Ultrasound uses sound waves and echoes to produce images. With this test, the doctor inserts a probe into your rectum. The probe produces sound waves that bounce off your rectum and nearby tissues, and a display monitor then creates images that can show doctors how large the primary tumor is and whether the cancer has spread to lymph nodes or other nearby tissues.

Magnetic resonance imaging (MRI)

Abdominal/pelvic MRIs are sometimes used in cases of colorectal cancer. MRI scans produced using radio waves and a powerful magnet can help doctors determine how deep the tumor has penetrated into the colon or rectum and whether the cancer has spread to any local lymph nodes.


X-rays produce images of the structures inside the body, particularly the bones. In cases of advanced colorectal cancer, X-rays of the chest may show whether the cancer has spread to the lungs. X-rays are also used in double contrast barium enemas. After the patient is given an enema with barium solution and has had air pumped into the colon, a series of X-rays of the colon and rectum are taken. The barium and air help outline the colon and rectum on the X-ray images and allow doctors to see any large polyps.


Common symptoms of advanced colorectal cancer

  • Constipation or diarrhea
  • Blood in the stool
  • Narrow stool
  • Chronic gas pains or cramps
  • Frequently feeling bloated or full
  • Incomplete bowel movements
  • Inexplicably losing weight
  • Nausea and/or vomiting
  • Chronic fatigue


Additional Resources


Previous Next


Register Now! Sign Up For Our Free E-Newletter!

Read Inspiring Cancer Survivor Stories

Order Your Guides Here