Colon cancer forms inside the large intestine, which is approximately five and a half feet long. The first five feet of the large intestine is called the colon. The rectum makes up the last six inches. Read more about rectal cancer.
Colon cancer often develops slowly over several years. It typically starts as a small, abnormal growth on the surface of the colon called a polyp. Some polyps can eventually turn into cancer. A small percentage of colon cancers may look different due to a hereditary form of the disease.
Colon cancer is often contained within the colon. But when it becomes advanced, the cancer can metastasize (spread) to other organs, most often the liver and lungs.
The colon cancer experts at Memorial Sloan Kettering use several methods to confirm your diagnosis and determine the stage of your disease. These include physical examination and imaging tests such as CT scans.
Your treatment will depend on the stage of your cancer. You may have surgery, chemotherapy, radiation therapy, or some combination of these. Your treatment will also vary based on how advanced your disease is.
You may also be eligible for a clinical trial exploring a new therapy.
Colon cancer is declining overall because more people are being screened and treatment is advancing. However, there has recently been a troubling rise in colon cancer rates among younger adults, as early as their 20s and 30s. Many of these cancers aren’t discovered until they are advanced. This makes treatment more challenging.
MSK experts are pioneering research to find out what’s behind this trend. They are looking closely at known risk factors for colon cancer. These include obesity and diets high in processed foods and animal fat. Young adults should learn more about screening and should not ignore persistent colon cancer symptoms, such as a change in bowel habits that lasts more than a few days.