Colorectal cancer progresses through 4 stages.
In stage 1 and 2, the cancer is limited to the intestine only.
In stage 3, the cancer spreads to the lymph nodes.
In stage 4, the cancer spreads to other organs like liver, lung, brain or peritoneum.
Staging for Colorectal cancer is done on basis of a Colonoscopy with tumor biopsy, CT or PET CT scan, and after analysis of the tumor that is removed during surgery.