Colorectal Cancer Tests, Diagnosis and Stages

Every Banner MD Anderson Cancer Center colorectal cancer patient receives personalized testing, treatment and support from our team of experts. If you’re experiencing colorectal cancer symptoms or are at high risk, contact us to schedule an appointment.

What’s the Difference Between Cancer Screening and Diagnostic Tests?

Cancer screenings are medical tests performed when a person has no symptoms. If you have symptoms, doctors use diagnostic tests to find out the cause.

What Are the Screening Guidelines for Colorectal Cancer?

Patients with positive colorectal cancer screening tests (FOBT, FIT, flexible sigmoidoscopy, barium enema) should always follow up with a colonoscopy.

To benefit from early detection, men and women at average risk colorectal cancer should get a screening colonoscopy every 10 years beginning at age 50. African American men and women should begin regular screening colonoscopies at age 45.

Age 50 or Older:

Follow ONE of the screening options below:

  • Colonoscopy – Every 10 years. During a colonoscopy, a long, flexible tube with a camera is inserted into the rectum to look for abnormalities in the large intestine (colon).
  • Virtual colonoscopy (Computed Tomographic Colonography) – Every five years. A full colonoscopy will be performed if polyps are found during a virtual colonoscopy. If you choose a virtual colonoscopy, check with your health insurance provider to be sure it’s covered.
  • Fecal Occult Blood Test (FOBT) – Every year. Used to find blood in your stool.

Age 75 or Older:

Your doctor can help you decide if you need screening after age 75. Banner MD Anderson doesn’t recommend screening after age 85.

Adults at Increased or High Risk:

Patients at moderate to high risk for colon cancer should talk with their doctor about increased testing. You’re at increased or high risk if you have:

  • Personal history of precancerous colon polyps (adenomas)
  • Family history of colorectal cancer or precancerous polyps (adenomas)
  • Personal history of Familial Adenomatous Polyposis or suspected Familial Adenomatous Polyposis, but haven’t had genetic testing
  • Personal history of Hereditary Nonpolyposis Colorectal Cancer or family history of Hereditary Nonpolyposis Colorectal Cancer
  • Inflammatory bowel disease (chronic ulcerative colitis or Crohn’s disease)

If screening results suggest cancer, your doctor will recommend diagnostic tests of the colon or rectum. And, you will need more frequent exams if polyps (precancerous lesions) are found.

How Is Colorectal Cancer Diagnosed?

Doctors can use many tests to diagnose and measure the spread of colorectal cancer:

  • Colonoscopy: Your doctor inserts a thin, flexible tube called a colonoscope to examine the colon and rectum, performs a biopsy and removes polyps. It’s usually an outpatient procedure at a hospital, clinic or doctor’s office.
  • Biopsy: Your doctor removes a small tissue sample for examination.
  • Molecular or gene testing: Laboratory testing is done on a tumor to look for specific gene changes and determine treatment options.
  • Blood tests: A blood test can count red blood cells to determine if there’s bleeding in the intestine, a common symptom of colorectal cancer. It also can measure levels of the protein carcinoembryonic antigen (CEA). Higher levels can mean cancer has spread to other parts of the body.
  • Image testing: Through image testing, your doctor can look at suspicious areas and learn if and how far cancer has spread. It can include:
    • Computed tomography (CT or CAT) scan
    • Magnetic resonance imaging (MRI)
    • Ultrasound
    • Chest x-ray
    • Positron emission tomography (PET) or PET-CT scan

What Are the Stages and Prognosis of Colorectal Cancer?

When found early, colorectal cancer often can be cured. In recent years better treatment and increased screening have led to improved outcomes.

After being diagnosed with colorectal cancer, your doctor looks to see if or how much it has spread – this is called staging.

Stages of Colorectal Cancer

  • Stage 0 (in situ): Cancer is on the wall, or mucosa, of the colon. Treatment usually involves a colonoscopy to remove polyps.
  • Stage I (1): Cancer is in the wall and underlining, submuscosa, of the colon. Treatment involves surgery to remove the affected area.
  • Stage II (2): Cancer has spread past the colon wall and possibly to nearby organs. Treatment involves surgery to remove the affected areas and chemotherapy.
  • Stage III (3): Cancer has spread to the lymph nodes. Treatment involves surgery to remove the affected areas, chemotherapy and radiation treatment.
  • Stage IV (4): Cancer has spread to other organs in the body. Patients may undergo surgery to remove small areas of the affected organs and chemotherapy to shrink tumors or prolong life. Patients may find it helpful to seek out more than one opinion and clinical trials.

Colorectal Cancer Diagnosis by Stage and Survival Rate1

Diagnosis / SEER* Stage  Total % of Patients   5-Year Relative Survival Rate
 Early/Localized  39%  90%
 Moderate/Regional  35%  70%
 High/Distant  21%  14%

*SEER = Surveillance, Epidemiology, and End Results

Banner MD Anderson’s team of colorectal cancer experts is here to help you with your diagnosis. We take time to understand your needs and focus on providing you with effective, personalized treatment.