What Is Colorectal Cancer?

Colorectal cancer is indicated by malignant cells in the colon or rectum. The colon and the rectum are parts of the large intestine, which is part of the digestive system. Cancer that begins in the colon is called colon cancer, and cancer that begins in the rectum is called rectal cancer. Because colon cancer and rectal cancers have many features in common, they are sometimes referred to together as colorectal cancer. Cancerous tumors found in the colon or rectum also may spread to other parts of the body.

A type of cancer called adenocarcinoma accounts for more than 95% of cancers in the colon and rectum and is usually what is meant by the term "colorectal cancer." There are other types of cancer that can be found in the colon and rectum, but they are rare.

Clinical Trials

Clinical trials are research studies that evaluate a new medical approach, device, drug, or other treatment. As a Stanford Health Care patient, you may have access to the latest, advanced clinical trials.

Open trials refer to studies currently accepting participants. Closed trials are not currently enrolling, but may open in the future.

Before beginning treatment, ask your doctor about any clinical trials you should consider. Learn more about clinical trials for cancer patients.

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