Colorectal cancer, the third most common cancer in the world, results in 52 thousand deaths each year in the United States, as reported in 2007 by the Merck Manuals Online Medical Library. Around 95 percent of colon cancers are adenocarcinomas, slow-growing cancers that first develop in polyps. Adenocarcinomas of the colon can cause blood in the stool or a change in bowel habits, but may have no early symptoms. Survival rates after treatment of early-stage adenocarcinomas are 70 to 90 percent, notes the College of American Pathologists.
Surgery
Around 90 percent of adenocarcinomas of the bowel can be surgically removed, according to the College of American Pathologists. The tumor and nearby lymph nodes are removed and the healthy ends of the bowel are sewn together, or anastamosed. Creation of a stoma, an artificial opening on the abdominal wall to temporarily divert stool from the colon, allows the bowel to heal. A permanent colostomy is created in about 15 percent of patients because not enough bowel is left to reconnect to the rectum. Having less than 5 cm, or around 2 inches, of bowel left between the cancer and the opening of the anus remaining after surgery requires the creation of a permanent colostomy, states the Merck Manuals Online Medical Library.
Chemotherapy
Chemotherapy may be given to destroy cancer cells if it's suspected or known that the adenocarcinoma has spread beyond the colon. Chemotherapy done prior to surgery may also help shrink the tumor before removal. Chemotherapy can improve survival by 10 to 30 percent in people who have between one and four lymph nodes positive for cancer, according to the Merck Manuals Online Medical Library. Commonly used types of chemotherapy include leucovorin and 5-fluororacil.
Radiation
Radiation therapy, high-energy X rays aimed at cancer cells, can shrink tumors or kill leftover cancer cells after surgery, reports the College of American Pathologists. Radiation may also be used to decrease symptoms and improve quality of life in advanced colon cancer.
Monoclonal Antibodies
Drugs such as bevacizumab or cetuximab attach to cancer cells and block growth signals, according to MayoClinic.com. Using monoclonal antibodies may relieve symptoms and slow cancer growth in some patients with metastatic cancer, cancer that's already spread beyond the colon, according to the Merck Manuals Online Medical Library.
