There are five different, distinct stomach cancer stages. Each stage is defined by how far the cancer has spread. Stage zero means that it has not spread at all, and remains within the innermost layer of the stomach wall. The fifth stage, on the other hand, means that the cancer has spread from the stomach to other areas of the body. The stages of stomach cancer are very important to determine, because it gives the doctor a reference point to begin treatment.
Stage zero is the first stage of stomach cancer. Patients who are diagnosed with stage zero stomach cancer are fortunate to have such an early diagnosis. Cancer at this stage is found just in the mucosal layer, which is the inner layer of the lining of the stomach.
The second stage of stomach cancer is called stage one, and is only a bit more advanced than stage zero. There are two possible scenarios that make up this stage, depending on how deeply the cancer has moved into the stomach wall and the lymph nodes. In the first, the cancer is confined to the stomach wall's second layer, but has moved into the lymph nodes near the affected area. In the other scenario of this stage, there is no lymph node involvement, but the cancer is located in the second and/or third layers of the stomach's lining.
The criteria for stage two stomach cancer contains three possibilities, and is more advanced than the previous stomach cancer stages. Cancer at this stage may have penetrated all four layers of the stomach wall, but has not moved to the lymph nodes. It is also possible for the cancer to have moved into the closer lymph nodes, but only moved into the muscle, or third stomach wall layer. The third possibility is that the cancer has spread to the lymph nodes some distance from the tumor, but has only progressed into the stomach wall's second layer.
In the fourth of the stomach cancer stages, called stage three, there are three possible scenarios. The mildest classification of stage three stomach cancer is when it has reached lymph nodes far from the tumor and spread to the muscle layer of stomach lining. When the cancer has reached either the close or far lymph nodes and spread to all four of the stomach lining's layers, it is also considered stage three. The worse definition of stage three stomach cancer is when it is found not only in all layers of the lining of the stomach, but also in the tissues in the surrounding area.
The final stage of the stomach cancer stages is stage four. This means that the stomach cancer has reached metastasis. At this stage, the cancer can be found in all four layers of the stomach wall and in nearby tissue. It may have also spread to other areas throughout the body, including various lymph nodes.