Colon cancer can develop from any of the cell types within the colon or rectum. The National Cancer Institute reports that colon and rectal cancers caused over 50,000 deaths, and accounted for more than 100,000 new cancer cases diagnosed in the United States in 2009. Upon diagnosis, colon cancer is staged according to the size, invasiveness and aggressiveness of the tumor. Early-stage colon cancer is relatively localized within the colon or rectum, but if left untreated, can spread and develop into end-stage colon cancer.
Stage IIIC
Stage IIIC colon cancer is characterized by the spread of colon cancer cells towards neighboring tissues. Patients with stage IIIC colon cancer have already developed extensive cancer growth within the colon or rectum, and the cancer cells have begun to grow away from the original tumor growth toward other nearby tissues. Cancer cells in stage IIIC colon cancer actively kill healthy cells to allow more room for cancer cell growth, and the cell begin to grow through the wall of the colon or rectum, although it may not have reached neighboring organs. The American Cancer Society indicates that stage IIIC cancer cells have also invaded lymph nodes around the colon, components of the lymphatic system that help circulate lymph fluid throughout the body. If left untreated, the cancer will become more invasive and severe.
Stage IVA
Stage IVA colon cancer is considered metastatic cancer--tumor cells have migrated away from the original tumor site and begun to growth within a distant organs. The American Cancer Society indicates that patients with stage IVA colon cancer have developed metastases in one distant organ, typically the lungs or liver, and that cancer cells have also invaded several lymph nodes around the colon.
Colon cancer patients with liver or lung metastases develop symptoms as a result of organ damage from tumor growth. Cancerous growths in the liver lead to the development of liver scarring, or cirrhosis, which can impede liver functioning, causing pain and liver failure. Cancerous growths in the lungs decrease lung capacity and may lead to difficulty breathing.
Stage IVB
The final stage of colon cancer is stage IVB, which involves the development of cancer metastases in more than one distant organ throughout the body. Colon cancer cells have the ability to enter the bloodstream or the lymphatic system and circulate throughout the body, developing colonies in distant organs such as the lungs or liver. The cancer cells may also migrate throughout the abdominal cavity and develop growths within organs, or grow on the peritoneum, which lines the abdominal cavity.
Patients with stage IVB metastatic colon cancer may receive systemic cancer therapies, such as chemotherapy, which can target and kill colon cancer cells throughout the whole body, reports the National Comprehensive Cancer Network. Stage IVB colon cancer treatment may also include palliative therapy, designed to increase a patient's quality of life as their cancer progresses by relieving pain and discomfort.
