Intestinal Cancer Stages / Staging

Stages of Intestinal Cancer

Most adenocarcinomas of the small intestine develop in the duodenum, the first section of the small intestine. The duodenum connects to the stomach. The location of the cancer is an important piece of information for diagnosing and staging intestinal cancer. Once small intestine cancer is identified and the diagnosis is confirmed, the size and spread of the cancer is evaluated in a standardized process called staging.

Small intestine cancer staging begins by evaluating three key components of the cancer: size, location and spread. In the earliest stages of intestinal adenocarcinomas (stage 0), the cancer has not spread and tumors are localized to the inner layer (mucosa) of the small intestine. Later stages are characterized by the growth and spread of cancerous tissues into the layers of the intestinal wall. In stage IV, which is the most advanced stage of intestinal cancer, the disease has typically grown through the intestinal wall and spread into nearby tissues.

Understanding the TNM System

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 IV:

• Tumor (T) – The tumors are rated on a scale of 0 through 4, where T0 indicates no evidence of the primary tumor expanding into local tissue, and the increasing numbers (T1 through T4) describe the extent and spread of tumor into and through the intestinal wall. Carcinoma in situ tis describes an early cancer that has not gone beyond to the mucosa.
• Node (N) – If cancer is found in the lymph nodes, the quantity of cancer cells found is rated using N1 or N2. Conditions where the cancer has not spread to the lymph nodes is indicated by N0.
• Metastasized (M) – Cancer that has spread (metastasized) is indicated by M1. Otherwise, M0 is used if there are no signs of metastasis.

Each category (T, N and M) is assessed and rated. An X is used to denote insufficient information (the condition of the particular factor cannot be adequately assessed).

Intestinal Cancer Stage Grouping

The combined categories T, N and M create the stages 0 through IV:

• Stage 0 Small Intestine Cancer – The cancer has not grown beyond the mucosa. (Example: Tis, N0, M0)
• Stage I Small Intestine Cancer – In this stage, the disease has grown beyond the mucosa, but has not spread beyond the small intestine to other sites or lymph nodes. (Example: T1, N0, M0 or T2, N0, M0)
• Stage II Small Intestine Cancer – 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. (Example: T3, N0, M0)
• Stage III Small Intestine Cancer – In stage III 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. (Example: T1, N1, M0)
• Stage IV Small Intestine Cancer – 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. (Example: Any T, Any N, M1)

Next Topic: Intestinal Cancer Treatments