This page was reviewed under our medical and editorial policy by
Maurie Markman, MD, President, Medicine & Science
This page was updated on May 20, 2022.
Intestinal cancer, also called small bowel cancer or small intestine cancer, is rare, representing fewer than 1 percent of all cancers diagnosed each year. Doctors use a variety of diagnostic tests to evaluate intestinal cancer and develop an individualized treatment plan for each patient.
After being diagnosed with intestinal cancer, the patient's care team reviews the pathology to confirm the diagnosis and staging information and develops a personalized treatment plan. If a recurrence occurs, the care team performs comprehensive testing and identifies a cancer treatment approach tailored to the patient's needs.
Adenocarcinoma, the most common type of intestinal cancer, may develop nearly anywhere in the body because it starts in glands lining the inside of the organs.
Adenocarcinomas are typically staged using the American Joint Committee on Cancer's TNM system. Some types of cancers like carcinoid tumors do not have a standard staging system. In this case, the spread of the cancer is simply defined as localized, regional or distant. The intestinal cancer stages described here are for the more common adenocarcinomas and are defined using the TNM system.
The combined categories, T, N and M, create the stages 0 through 4, as listed below.
T (tumor): This describes the size of the original tumor.
N (node): This indicates whether the cancer is present in the lymph nodes.
M (metastasis): This refers to whether cancer has spread to other parts of the body.
Cancer cells are present in the upper part of the small intestine's inner lining (the mucosa), but the cancer has not grown beyond the mucosa.
In this stage, the disease has grown beyond the mucosa, but has not spread beyond the small intestine to other sites or lymph nodes.
The cancer has grown into or through the intestinal wall. At this stage, it may or may not have reached nearby organs. There is no evidence of spread of disease to lymph nodes or distant sites.
In stage 3 of intestinal cancer, the disease has metastasized to nearby lymph nodes. The tumor may be any size (T1 through T4). The cancer may or may not have reached nearby organs. Distant sites like the lung or liver remain unaffected.
The cancer may be any size and has spread throughout the body to distant sites like the liver, lung or lining of the abdominal cavity.
Identifying the stage of cancer not only helps the care team determine a treatment plan, it also helps predict a potential prognosis. This is achieved by calculating the percentage of people with intestinal cancer who survive at least five years after diagnosis compared to people who don’t have that type of cancer. It’s important to remember that this is only a statistic based on all people with intestinal cancer several years in the past, so individual patient experiences may vary.
According to the American Cancer Society (ACS), the survival rate for intestinal adenocarcinoma is based on where the cancer started and how far the cancer has spread, as indicated below.
Localized: The cancer hasn’t spread beyond the small intestine wall. The five-year relative survival rate for localized intestinal cancer is about 84 percent.
Regional: The cancer has spread to nearby tissues or lymph nodes. The five-year relative survival rate for regional intestinal cancer is about 78 percent.
Distant: The cancer has spread to farther reaches of the body. The five-year relative survival rate for distant intestinal cancer is about 42 percent.
The overall five-year relative survival rate for intestinal cancer is 69 percent, according to the ACS.
Keep in mind that the survival rate for intestinal cancer depends on a variety of factors, including the patient’s age, overall health and the extent of the disease, so always talk to the care team about the patient’s individual prognosis.
Next topic: How is intestinal cancer diagnosed?