Colon cancer is the abnormal proliferation or growth of cancer cells in the large intestines, also known as the colon. A tumor in the colon usually starts in the lining of the large intestines. When colon cancer spreads to adjacent tissues and invade other organs in the body, it is called a metastatic colon cancer. Metastatic colon cancer is also a stage IV colon cancer.
A metastatic colon cancer usually occurs when cancer cells break off from their original site in the colon. Cancer cells then travel through the lymph nodes or the bloodstream and reach other parts of the body where they frequently form new cancerous growths. When metastasis or spread affects the vital organs such as the liver or the lungs, the chances for a complete cure is generally poor.
Some symptoms of colon cancer are unexplained loss of weight, abdominal pain, and the passing of pencil-like stools, which are sometimes stained with blood. Most symptoms of metastatic colon cancer often depend on the part of the body to which the cancer spreads. Those sites can include the liver, bones, and lungs.
In addition to the colon cancer symptoms, metastatic colon cancer in the liver also causes jaundice or yellowing of the skin and eyes. Edema or swelling of the feet as well as ascitis, which is the accumulation of fluid in the abdomen, are also often present. Cancer spreading to the lungs frequently manifests with breathing difficulty and chest pain. Bone pains, as well as weakness, are often the signs of bone involvement.
Metastatic colon cancer can be diagnosed with the use of blood tests and other diagnostic examinations. A liver function test is usually performed to assess the state of the liver. An abdominal computed tomography (CT) scan and ultrasound are also often helpful in evaluating the area for the possible spread of colon cancer.
A variety of treatment options are usually available to the patient. Metastatic colon cancer spreading to the liver may be treated by removing the involved portion through surgery, by ablation or burning of the tumor and by cryotherapy, which is done by freezing the tumor. Chemotherapy with radiation may also be used.
Management of metastatic colon cancer is usually done by a team of medical practitioners. These include the gastroenterologists, doctors who specialize in gastrointestinal tract diseases; surgeons; and oncologists, doctors who treat cancer patients. When the cancer has reach the lungs, a pulmonologist or doctor with specialization in the respiratory tract, is also often called.