Stages of Stomach Cancer

Click to Enlarge: How in situ carcinoma spreads to other places.

Doctors need to know the stage of stomach cancer you have in order to decide what treatment to recommend. The stage is based on the size and extent of the tumor, the number of lymph nodes involved, and how far the cancer has spread. Your doctor gets this information from your biopsies, imaging tests, examination of the contents removed during surgery, and any other exams done. Staging studies for stomach cancer may include a CT scan, an endoscopic ultrasound, and laparoscopy (with or without ultrasound).

Staging for stomach cancer may not be complete until after surgery. The surgeon takes out nearby lymph nodes and may take samples of tissue from other areas in your abdomen. To check for cancer cells, a pathologist examines all contents removed during surgery. Pathologists are specially trained doctors who interpret the changes caused by disease in tissues. Decisions about treatment after surgery depend on these findings.

The most common way doctors describe the stage of stomach cancer is with the TNM system.

The TNM System

When you receive a diagnosis of stomach cancer, the doctor needs to know what stage the cancer is in. The International Union Against Cancer and the American Joint Committee on Cancer have developed a standard system of describing the extent of a cancer’s growth, which is the stage. This system is known as the TNM System. The TNM System is the most common one used to stage stomach cancer.

Here is what the letters stand for in the TNM System.

• T refers to the size of the tumor in the stomach.

• N refers to whether the lymph nodes in the area of the stomach have become cancerous.

• M refers to whether the cancer has spread—metastasized —to other, distant organs in the body, such as your liver or lungs.

Stage Groupings of Stomach Cancer

Once the doctor determines your T, N, and M stages, stage grouping is created. Stage grouping is used to determine your overall disease stage. It is expressed most often in Roman numerals from 0 (the least advanced) to IV (the most advanced stage). The following stage groupings are used for stomach cancer.

Stage 0. Also known as carcinoma in situ, the cancer is found only in the innermost layer of the stomach wall, called the mucosa, and has not spread anywhere else.

Stage I. The cancer is in the first or second layers of the stomach wall, called the mucosa and submucosa, respectively. The cancer has grown in one of these ways.

• It has not spread to lymph nodes.

• It is in the first layer of the stomach wall (mucosa) and has spread only to lymph nodes very close to the tumor.

Stage II. The cancer has grown in one of these ways.

• It is in the first layer of the stomach wall (mucosa) and has spread to lymph nodes further away from the tumor.

• It is only in the second layer of the stomach (submucosa) and has spread to lymph nodes very close to the tumor.

• It is in the third layer of the stomach wall (muscalaris) but has not spread to lymph nodes or other organs.

Stage III. The cancer has grown in one of these ways.

• It is in the second layer of the stomach wall (submucosa) and has spread to lymph nodes further away from the tumor.

• It is in all 3 layers of the stomach wall (mucosa, submucosa and muscalaris) and has spread to lymph nodes either very close to the tumor or further away from the tumor.

• It is in all five layers of the stomach wall (including the outer layers called the subserosa and the serosa) and has spread to nearby tissues. The cancer may or may not have spread to lymph nodes very close to the tumor.

Stage IV. The cancer has spread to nearby tissues and to lymph nodes further away from the tumor, or it has spread to other parts of the body.

Recurrent disease. Recurrent disease means that the cancer has come back (recurred) after it has been treated. It may come back in the stomach or in another part of the body, such as the liver or lymph nodes.