Doctors will take many diagnostic tests to establish the correct diagnosis and the stage of the cancer. It is important to know the stage of the cancerous change. So, the doctors would know how to treat it and predict the recovery.
Adenocarcinoma is the most common of all stomach cancers. Doctors use TNM system to describe the cancer stage. They evaluate the tumor (T), lymph nodes around the tumor (N) and the metastasis of the cancer (M, the spread of the cancer to other parts of the body). There are 5 stages of the adenocarcinoma, from 0 to IV, according to the TNM changes in the body.
Tumor is usually described by the letter T and the numbers from 0 to 4. This marking explains the extent of the tumor growth into the stomach. There are also some sub-stages that explain the tumor in more details.
TX – the tumor can’t be evaluated.
T0 – there is no primary tumor in the stomach.
Tis - the cancer has been found on the surface of epithelial cells and didn’t spread to other parts of the stomach.
T1 – tumor invaded other layers of the stomach, such as lamina propria or muscularis mucosae (T1a), or submucosa of the stomach (T1b).
T2 – the cancer reached the muscle layers of the stomach.
T3 – the tumor passes through the muscles of the stomach into the connective tissue
T4 – the cancer passed through serosa (T4a) or invaded the organs near the stomach (T4b)
N of the TNM system stands for the (lymph) nodes in the abdominal cavity. The prognosis is better if less lymph nodes are affected with cancerous changes.
NX – lymph nodes in the abdomen can’t be evaluated.
N0 – lymph nodes are not affected with the cancer.
N1 – the cancer spread to one or two lymph nodes.
N2 – the cancer spread to 3 to 6 lymph nodes.
N3 - the cancer spread to 7 or more lymph nodes. N3a – up to 15 lymph nodes, and N3b – cancer affected more than 16 lymph nodes in the abdomen.
M in the TNM stands for metastasis of the tumor, indicating the spread of the tumor to other parts of the body.
MX – metastasis can’t be evaluated.
M0 – the tumor doesn’t have metastasis.
M1 – there are metastasis of the tumor in the body.
Stage 0 is carcinoma in situ, when the cancer is located only on the epithelial cells of the stomach (Tis, N0, M0).
Stage IA – T1, N0, M0
Stage IB – is the cancer characterized by T1, N1, M0 or T2, N0, M0.
Stage IIA - T1, N2, M0; T3, N0, M0 or T2, N1, M0.
Stage IIB - T1, N3, M0; T4a, N0, M0; T3, N1, M0 or T2, N2, M0
Stage IIIA – are the TNM profiles T4a, N1, M0; T3, N2, M0 or T2, N3, M0.
Stage IIIB – includes the TNM changes: T3, N3, M0; T4a, N2, M0 and T4b, N0 or N1, M0
Stage IV is the cancer that metastases to distant parts of the body.
There is also recurrent cancer, which may appear on the same place where it was or be a metastasis and appear on any other part of the body.