What is Colorectal Cancer?

Colorectal cancer (CRC) is cancer that develops in the colon or the rectum-parts of the digestive system also called the gastrointestinal or GI tract. The digestive system processes food for energy and rids the body of solid waste. Colorectal cancer usually develops slowly over a period of many years. Before a true cancer develops, it usually begins as a non-cancerous polyp, a growth of tissue that develops on the lining of the colon or rectum. Certain kinds of polyps, called adenomas, are most likely to become cancerous.

The extent to which a colorectal cancer has spread is described as its stage. Physicians perform exams and tests to determine the stage of the cancer and to see whether the disease has spread from the original site to other parts of the body. It is important to know the stage of the disease in order to plan the best treatment.

Symptoms of colorectal cancer
The following symptoms might indicate colorectal cancer:

• Change in bowel habits
• Diarrhea, constipation, vomiting
• Narrower than normal stools
• Unexplained weight loss
• Constant tiredness
• Blood in the stool
• Feeling that the bowel does not empty completely
• Abdominal discomfort-gas, bloating, fullness, cramps
• Unexplained anemia

If you experience any of these symptoms for more than a few days, talk with a gastroenterologist about them. Colorectal cancer can be present in people without symptoms, known family history, or predisposing conditions, such as inflammatory bowel disease. Regular screening will help identify precancerous polyps and colorectal cancers earlier. Using our Find a Doctor feature, you can locate a qualified gastroenterologist in your area.

Diagnosis
If there is any reason to suspect colon or rectal cancer, your gastroenterologist will ask you questions about your symptoms and risk factors and do a physical exam. Then you will need to have further tests to find out if the disease is really present and if so, to see how far it has spread.

CRC Key Statistics:

• Excluding skin cancers, colorectal cancer is the third most common cancer diagnosed in men and in women in the United States. Colorectal cancer is the second leading cause of cancer-related deaths in the United States and is expected to cause about 56,290 deaths (28,540 men and 27,750 women) during 2005.
• The death rate from colorectal cancer has been dropping for the past 15 years. One reason for this is probably because polyps are being found by screening before they can develop into cancers. Also, colorectal cancer is being found earlier when it is easier to cure, and treatments have improved. There are approximately 1 million survivors of colorectal cancer in the United States, and this number continues to grow.
• The five-year relative survival rate for people whose colorectal cancer is treated in an early stage is greater than 90 percent. But only 39 percent of colorectal cancers are found at that early stage. Once the cancer has spread to nearby organs or lymph nodes, the five-year relative survival rate goes down.