Gastro-Intestinal (GI) cancer is a term for the group of cancers that affect the digestive system. This includes cancers of the esophagus, gallbladder, liver, pancreas, stomach, small intestine, bowel (large intestine or colon and rectum), and anus.
The symptoms for GI cancer relate to the organ affected and can include obstruction (blockage) leading to difficulty swallowing or defecating, abnormal bleeding, or other associated problems. The diagnosis often requires endoscopy, by placing a scope to examine the digestive tract, followed by biopsy of any suspicious tissue. The treatment depends on the location of the tumor, as well as the type of cancer cell and whether it has invaded other tissues or spread elsewhere. These factors also determine the prognosis.
One of the most common GI cancers is colorectal cancer. Colorectal cancer includes cancers of the colon or rectum. Most colorectal cancers are adenocarcinomas (cancers that begin in cells that make and release mucus and other fluids). Most colon cancers develop first as polyps, which are abnormal growths inside the colon or rectum that may later become cancerous.
Since colorectal cancer often begins as polyps, it is important to find and remove them in order to help prevent colorectal cancer. That is where screening comes in. Expert medical groups, including the U.S. Preventive Services Task Force, strongly recommend screening for colorectal cancer. Although minor details of the recommendations may vary, these groups generally recommend that people at average risk of colorectal cancer get screened at regular intervals with high-sensitivity fecal occult blood tests (FOBT), sigmoidoscopy, or a colonoscopy beginning at age 50. People at increased risk because of a family history of colorectal cancer, polyps, or because they have inflammatory bowel disease, may be advised to start screening before age 50 or have more frequent screening.
At Pacific Cancer Insitute, we treat colorectal cancer painlessly and noninvasively with external beam radiation therapy (EBRT). EBRT is an effective treatment for colorectal cancer, working within cancer cells to limit their ability to multiply. During treatment, high-energy X-rays are delivered to the cancer with a linear accelerator (LINAC). The treatment process is painless, safe and treatments take about 10 to 15 minutes. Side effects are usually minimal, and most patients return to routine activities immediately after each treatment.