Colon cancer is often referred to as "colorectal" cancer, as it can occur in the colon, or large intestine, and/or the rectum, which is the end of the colon. The American Cancer Society states that as of 2009, colon cancer is the second leading cause of death for men and women in the United States. Colon cancer often has no symptoms, which is why it is not often detected early enough. Symptoms that do occur are changes in bowel movements, blood in the stools, pressure in the bowels, and fatigue. Once diagnosed with colon cancer, the cancer is categorized into a "stage," which represents how far the cancer has spread in the body. This staging enables the physician to get an accurate picture of the cancer, and the best method of treatment, and each stage has its own set of symptoms to deal with.
Stage 0
Stage 0 is the earliest stage of colon cancer, where abnormal cells have been found in the lining of the colon. These cells develop into cancer and can spread throughout local tissue. There are often no symptoms in stage 0 colon cancer: It usually is detected in a standard colonoscopy exam.
Stage I
Stage I colon cancer is diagnosed when the cancerous cells have spread beyond the initial layer of tissue and into deeper tissue layers of the colon. According to the National Cancer Institute, stage I is sometimes referred to as "Dukes A" colon cancer, after C.E. Dukes, who originally published staging for colon cancer in 1932.
Stage II
Stage II colon cancer actually has sub-stages of A and B. Colon cancer is classified as stage IIA when it has spread past the deeper tissue layers of the colon and into tissues surrounding the colon. Stage IIB cancer is diagnosed when the cancer has spread past the walls of the colon and into organs nearby. This is often referred to as Dukes B.
Stage III
Stage III colon cancer also has sub-stages of A, B and C. The American Cancer Society reports that stage IIIA is diagnosed when the cancer has spread beyond the colon and into at least three lymph nodes but not to other organs. In stage IIIB, the cancer has spread to the nearby organs and tissues in addition to up to three lymph nodes. In stage IIIC, in addition to spreading to nearby tissues and organs, the cancer is now into at least four lymph nodes. The Duke's staging system often refers to this stage as Dukes C.
Stage IV
Also referred to as Dukes D, stage IV colon cancer is in its most aggressive and deadly stage. The cancer has progressed past neighboring tissues, into lymph nodes, and is now found in other organs, such as the lungs or liver. According to Cancer Research, UK, this stage is often simply referred to as "advanced" colon, or bowel, cancer.
