The colon is the latter portion of the large intestine, which is part of the digestive system. The National Cancer Institute reports that colon cancer is diagnosed in 106,100 people each year. When combined with rectal cancer (collectively called colorectal cancer), these two types of cancer are fatal in approximately 33 percent of people. The stage of colon cancer is ascertained by a health professional and determines how far advanced the cancer is and helps in deciding the course of treatment, according to the American Cancer Society.
Stage 0
Stage 0 is the earliest stage of colon cancer. The American Cancer Society reports that in stage 0 colon cancer, the cancerous cells have not grown beyond the mucosa, which is the innermost layer of the colon. Other names for this stage are carcinoma in situ or intramucosal carcinoma. The prognosis for people with this stage of colon cancer is quite good: according to Merck Manuals online medical library, over 95 percent of people with stage 0 colon cancer survive at least five years after diagnosis.
Stage 1
The American Cancer Society reports that, in stage 1 cancer, the cancerous cells have either grown through the mucosal layer of the colon and into the submucosa or through the mucosal and submucosal layers and into the thick muscle layer that surrounds the submucosa. According to Merck Manuals, more than 90 percent of people diagnosed with this stage of colon cancer live longer than five years after diagnosis.
Stage 2
In stage 2 colon cancer, the cancer has either grown into or through the outermost layers of the colon and may have attached to nearby organs or tissues, according to the American Cancer Society. However, in stage 2 colon cancer, the cancerous cells have not spread to nearby lymph nodes or other sites in the body. Merck Manuals estimates the five-year survival rate at 55 to 85 percent.
Stage 3
In Stage 3 colon cancer, the cancerous cells have spread through the colon wall and have spread to nearby lymph nodes, according to Merck Manuals. Colon cancer in this stage has a five-year survival rate of 20 to 55 percent.
Stage 4
Stage 4 colon cancer is characterized by cancer that has grown through the colon wall and has spread to lymph nodes and other organs, such as the liver, ovaries or lungs. The prognosis for people with stage 4 colon cancer is very poor, with a five-year survival rate of less than 1 percent.
