Colon cancer staging is an estimate of the amount of penetration of a particular cancer.
It is performed for diagnostic and research purposes, and to determine the best method of treatment. The systems for staging colorectal cancers depend on the extent of local invasion, the degree of lymph node involvement, and whether there is distant metastasis.

Definitive staging can only be done after surgery has been performed and pathology reports reviewed. An exception to this principle would be after a colonoscopic polypectomy of a malignant pedunculated polyp with minimal invasion. Preoperative staging of rectal cancers may be done with endoscopic ultrasound. Adjunct staging of metastasis include abdominal ultrasound, MRI, CT, PET Scanning, and other imaging studies.

Common staging systems
- TNM (for tumors/nodes/metastases)
- Dukes classification
1. Astler-Coller classification
2. Full Dukes´classification

See reference for details.

Adapted from Wikipedia, the free encyclopedia. Internet. Accessed on January 18, 2016.