The stage of the cancer determines the treatment strategy for the patient. The stages of stomach cancer indicate the disease status and prognosis of the patient’s survival. The earlier the stage, the more effective the treatment, the better the prognosis and vice versa.
What is the stage of stomach cancer?
Stomach cancer staging is a way of describing how far a malignant cell has spread in the body. Once the histopathological diagnosis is made, the stage assessment determines the extent of invasion and metastasis of the disease to help doctors choose the treatment regimen and predict the patient’s survival.
After being diagnosed with stomach cancer, the patient will have many tests and imaging tests to determine the stage of the cancer. The purpose of cancer staging is to:
- Treatment planning
- Survival prognosis and recovery prediction
- Look for new treatment opportunities, join new trials
Decoding TNM classification in gastric cancer staging
The American Joint Committee on Cancer (AJCC) established the TNM system for staging different types of cancer. Doctors also rely on this TNM system to stage stomach cancer.
This system is used to classify all stomach cancers (carcinoma) except those that start at the gastroesophageal junction (where the stomach and esophagus meet) or those that start at the gastroesophageal junction (where the stomach and esophagus meet). The letter begins in the center (first part of the stomach) and is growing into the gastroesophageal junction. These cancers are staged and are often treated in the same way as esophageal cancers. Other types of cancer that can start in the stomach, such as gastrointestinal stromal tumor (GIST) and lymphoma, also have different stages.
The TNM system for gastric cancer is based on 3 main pieces of information:
Describe the extent of the primary (primary) tumor, including how far it has grown into the layers of the stomach wall and if it has reached nearby structures or organs.
The 5 layers of the stomach wall include:
- Mucosal: The innermost layer of the stomach consists of 3 epithelial cells, a layer of connective tissue (stromal layer) and a thin layer of muscle (muscle mucosa). Nearly all stomach cancers start in the lining of the stomach.
- Submucosa: A supportive layer under the mucosa.
- Muscularis propria: A layer of thick muscle that moves and mixes contents in the stomach
- Subserosa: The layer below the serosa.
- Serosa: The outer covering of the stomach.
Describe any cancer that has spread to nearby lymph nodes.
Describe any spread (metastasis) to distant parts of the body, such as the liver or lungs.
The numbers or letters after T, N, and M provide more detailed information about each of these elements. A higher number means the cancer is more advanced.
Stomach cancer stages
Once a person’s T, N, and M categories have been determined, this information is combined in a process known as stage grouping to assign an overall stage. The earliest stage of stomach cancer is called stage 0 (carcinoma in situ), then ranges from stages I (1) – IV (4). Accordingly, the lower the stage number, the less the cancer has metastasized.