TNM Classification for Gastric Cancer
The American Joint Committee on Cancer (AJCC) tumor/node/metastasis (TNM) classification and staging systems for gastric cancer are provided below. [1] Post-neoadjuvant treatment staging classifications and overall survival data are also provided. [2]
Table 1. TNM classification for gastric cancer (Open Table in a new window)
Primary tumor (T) |
|
TX |
Primary tumor cannot be assessed |
T0 |
No evidence of primary tumor |
Tis |
Carcinoma in situ: intraepithelial tumor without invasion of the lamina propria |
T1 |
Tumor invades lamina propria, muscularis mucosae, or submucosa |
T1a |
Tumor invades lamina propria or muscularis mucosae |
T1b |
Tumor invades submucosa |
T2 |
Tumor invades muscularis propria |
T3 |
Tumor penetrates subserosal connective tissue without invasion of visceral peritoneum or adjacent structures |
T4 |
Tumor invades serosa (visceral peritoneum) or adjacent structures |
T4a |
Tumor invades serosa (visceral peritoneum) |
T4b |
Tumor invades adjacent structures |
Regional lymph nodes (N) |
|
NX |
Regional lymph node(s) cannot be assessed |
N0 |
No regional lymph node metastasis |
N1 |
Metastasis in 1-2 regional lymph nodes |
N2 |
Metastasis in 3-6 regional lymph nodes |
N3 |
Metastasis in seven or more regional lymph nodes |
N3a |
Metastasis in 7-15 regional lymph nodes |
N3b |
Metastasis in 16 or more regional lymph nodes |
Distant metastasis (M) |
|
M0 |
No distant metastasis |
M1 |
Distant metastasis |
Table 2. Clinical stage/prognostic groups (cTNM) (Open Table in a new window)
Stage |
T |
N |
M |
0 |
Tis |
N0 |
M0 |
I |
T1 |
N0 |
M0 |
T2 | N0 | M0 | |
IIA | T1 | N1, N2, N3 | M0 |
T2 | N1, N2, N3 | ||
IIB |
T3 |
N0 | M0 |
T4a |
N0 |
M0 |
|
III | T3 | N1, N2, N3 | M0 |
T4a | N1, N2, N3 | M0 | |
IVA |
Any T |
Any N |
M0 |
IVB | Any T | Any N | M1 |
Table 3. Pathological stage (pTNM) (Open Table in a new window)
Stage | T | N | M |
---|---|---|---|
0 | Tis | N0 | M0 |
IA | T1 | N0 | M0 |
IB | T1 | N1 | M0 |
T2 | N0 | M0 | |
II A | T1 | N2 | M0 |
T2 | N1 | M0 | |
T3 | N0 | M0 | |
II B | T1 | N3 | M0 |
T2 | N2 | M0 | |
T3 | N1 | M0 | |
T4a | N0 | ||
M0 | |||
III A | T2 | N3a | M0 |
T3 | N2, N1 | M0 | |
T4a | N2 | M0 | |
T4b | N0 | M0 | |
III B | T1, T2 | N3b | M0 |
T3 | N3a | M0 | |
T4b | N1, N2 | M0 | |
III C | T3, T4a | N3b | M0 |
T4b | N3a, N3b | M0 | |
IV | Any T | Any N | M1
|
A Japanese group reported improved pretreatment discrimination of stage III/IV gastric cancer from stage I/II gastric cancer using a Clinical Stage Prediction score (CSP). [3] See Table 4, below.
Table 4. Pretreatment gastric cancer Clinical Stage Prediction score (Open Table in a new window)
Clinical factor |
Points |
Carcinoembryonic antigen (CEA) elevation (≥ 5.1 ng/mL) |
2 |
Tumor diameter ≥ 60 mm |
8 |
Circumferential gastric involvement |
2 |
Esophageal infiltration |
2 |
Mucinous adenocarcinoma |
1 |
Macroscopic type Type 0 Type 2 Type 3 Type 4 |
-7 10 16 10 |
Using a score cutoff of < 17 points for stage I/II gastric cancer and of ≥ 17 points for stage III/IV gastric cancer, the CSP had a sensitivity of 78.7%, specificity of 92.1%, positive predictive value of 86.0%, and negative predictive value of 87.5%.
Table 5. Post-neoadjuvant therapy staging and overall survival (ypTNM) (Open Table in a new window)
Stage | T | N | M | 3-year survival (%) |
5-year survival (%) |
---|---|---|---|---|---|
I | T1, T2 | N0 | M0 | 81.4 | 76.5 |
T1 | N1 | M0 | |||
II | T1 | N2, N3 | M0 | 54.8 | 46.3 |
T2 | N1, N2 | M0 | |||
T3 | N0, N1 | M0 | |||
T4a | N0 | M0 | |||
III | T2 | N3 | M0 | 28.8 | 18.3 |
T3 | N2, N3 | M0 | |||
T4a | N1, N2, N3 | M0 | |||
T4b | N0,N1,N2,N3 | M0 | |||
IV | Any T | Any N | M1 | 10.2 | 5.7
|
Zhong et al developed and validated a modified ypTNM staging classification for gastric cancer, shown in Table 6, below (all stages are M0). [4]
Table 6. Modified post-neoadjuvant therapy staging and overall survival (ypTNM) (Open Table in a new window)
Stage |
T |
N |
5-year survival (%) |
IA |
T1 |
N0 |
79.1 |
IB |
T2-3 |
N0 |
61.6 |
II |
T1-3 |
N1 |
49.7 |
T4a |
N0-1 |
||
IIIA |
T1-2 |
N2-3 |
37.8 |
T3-4a |
N2 |
||
T4b |
N0-2 |
||
IIIB |
T3-4b |
N3 |
16.1 |