What Is Colon Cancer?
Colon cancer forms in the tissues of the colon, which is part of the large intestine.
The colon is part of the body's digestive system, which is made up of the esophagus, stomach, and the small and large intestines. The first six feet of the large intestine are called the colon. The remaining several inches of the large intestine form the rectum.
Different types of cancer can develop in the colon. Most colon cancers are adenocarcinomas, which are cancers from glandular tissue. Other cancer types that can occur in the colon include carcinoid tumors, small cell carcinomas, and gastrointestinal stromal tumors (GIST).
The focus of this information is on colon cancers that are adenocarcinomas.
Colon and rectal cancers are the fourth most common cancers diagnosed in the United States. Survival after diagnosis has been gradually increasing in the past decade. There are several reasons for this. First, screening programs can catch the disease in its pre-cancerous or early stages, which are more curable. Second, there are better treatments, both surgical techniques and chemotherapies, including targeted therapies.
Our team has been a leader in clinical trials for various treatments for colon cancer to improve outcomes for patients and survivors.
When detected early, colon cancer is a very treatable form of cancer. The earlier it is found, the more likely it is that the cancer will be cured. As the cancer becomes more advanced, the cure rate declines, but it may still be treatable for long periods of time.
Most colon cancers start as polyps, or growths in the colon. Over time, some, but not all polyps change into cancers. Polyps that have a higher risk becoming cancer are known as adenomas.
- The reason screening is so important is that finding polyps before they become cancer reduces the risk of developing colon cancer by at least 90 percent.
- Finding ways to prevent polyps from forming is an important area of ongoing research at Dana-Farber Brigham Cancer Center.