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Risk Factors
Imaging and scopes play an important role in determining how extensive the cancer is. During imaging, and scopes the following are studied
- Exact location of the primary tumor (primary site and subsite)
- Tumor size
- Whether the tumor has extended through the bowel wall
- Spread to adjacent tissues or organs
- Regional lymph node involvement
- Sites of distant metastases (including distant lymph nodes)
| Modality | Utility |
|---|---|
| Chest x-ray | Scanning for possible lung mets |
| Colonoscopy | Examination of the inside of the colon using a colonoscope, inserted into the rectum. A colonoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove tissue to be checked under a microscope for signs of disease. |
| Sigmoidoscopy | A procedure to look inside the rectum and sigmoid (lower) colon for polyps (small pieces of bulging tissue), abnormal areas, or cancer. A sigmoidoscope is inserted through the rectum into the sigmoid colon. A sigmoidoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove polyps or tissue samples, which are checked under a microscope for signs of cancer. |
| Virtual colonoscopy | A procedure that uses a series of x-rays called computed tomography to make a series of pictures of the colon. A computer puts the pictures together to create detailed images that may show polyps and anything else that seems unusual on the inside surface of the colon. This test is also called colonography or CT colonography |
| Abdominal & Pelvic Ultrasound | Diagnostic evaluation tool |
| Abdominal & Pelvic Computed Tomography (CT) | Diagnostic evaluation tool |
| Magnetic Resonance Imaging (MRI) | Evaluation of malignancy extending into adjacent structures |
| Positron Emission Tomography (PET)/CT | Colorectal staging Monitoring disease progression Looking for other possible areas of metastatic disease (bone, brain, liver, spleen) |
| Bone scan | Not common for colon cancers unless bone metastases are suspected |
See Diagnostic Tests | SEER Training website for more information on imaging.
Document imaging details in NAACCR # 2530: Text-Dx Proc-X-ray scan
Document results of Scopes in NAACCR Item # 2540: Text-Dx Proc-Scopes
Updated: June 24, 2025