The colon (large intestine) and the rectum are responsible for the absorption of some nutrients and the compaction of fecal material. When the lining of the rectum and colon develops genetic abnormalities, it can lead to colorectal cancer. Colorectal cancer can cause either local symptoms or can spread to other tissues, a process that is known as metastasis.
Polyps
According to MedlinePlus, colorectal cancer typically begins as small clusters of cells called polyps. These polyps often represent precancerous growths. Polyp removal can help prevent colorectal cancer from spreading or from occurring in the first place.
Symptoms
The Mayo Clinic notes that many of the symptoms of colorectal cancer involve the large intestine. These include changes in the frequency of bowel movements (either more or less frequent) as well as blood being present in feces. Patients may also feel fatigued, perspire at night (night sweats), and have chronic abdominal pain or discomfort. Patients may also feel like their bowels are not emptying all the way or have sudden unexplained weight loss.
Heredity
In some cases there are inherited genetic mutations that predispose a patient to developing colon cancer. These genetic disorders include familial adenomatous polyposis, or FAP, and hereditary nonpolyposis colorectal cancer, or HNPCC. Either genetic problem causes patients to have a much higher risk of developing colon cancer.
Testing
There are a variety of tests that can be used to diagnose colon cancer. Blood tests can be used to rule out other potential causes of intestinal problems. Doctors may also perform a colonoscopy, which uses a small flexible tube with a camera (a colonoscope) to visualize the inside of the large intestine. Barium enemas can also be used to allow doctors to use X-rays to see the inside of the colon and identify any unusual growths or tumors.
Treatment
The most common method of treating colorectal cancer is surgical removal of the cancerous tissue. In most cases the remaining healthy colon can be left in the patient, but if the cancer has spread, the entire colon may be removed. Chemotherapy and radiation treatment can also be used as an alternative or in addition to surgical approaches.
