Gastric Cancer Đánh giá ban đầu

Clinical Presentation

Signs and Symptoms

Gastric Cancer_Initial Assesment

Screening

STAGING OF GASTRIC CANCER  

To ensure that the patients are appropriately selected for treatment interventions, a careful cancer tumor staging is essential. The most common sites of distant spread of gastric cancer are the liver, the peritoneum, and distal lymph nodes. The less common sites are the lungs and brain. A minimum of 15 examined lymph nodes is recommended for adequate staging.  Tumor size, perineural or lymphovascular invasion, and the nodal status have been shown to be stronger predictors of survival.  

There are 2 major classifications being used: The American Joint Commission on Cancer (AJCC) and the Union for International Cancer Control (UICC), and the Japanese classification which is more elaborate and is based on anatomic involvement, particularly the lymph node stations.  

Tumor, Nodes and Metastases (TNM) System (8th Edition of AJCC/UICC Guidelines)  

Primary tumor

Gastric Cancer_Initial Assesment 2

Tx - Tumor size cannot be assessed
T0 - No evidence of primary tumor
Tis - Carcinoma in situ; intraepithelial tumor has no lamina propria invasion
T1a - Tumor invades lamina propria or muscularis mucosa
T1b - Tumor invades submucosa
T2 - Tumor invades muscularis propria
T3 - Tumor penetrates subserosal connective tissue without invasion of visceral peritoneum or adjacent structures. This also includes tumors that are extending into the gastrocolic or gastrohepatic ligaments, or into the greater or lesser omentum, without perforation of the visceral peritoneum covering these structures.
T4a - Tumor invades serosa (visceral peritoneum)
T4b - Tumor invades adjacent structures (that include the spleen, transverse colon, liver, diaphragm, pancreas, abdominal wall, adrenal gland, kidney, small intestine and retroperitoneum)

Regional Lymph Node (LN) Evaluation

Nx - Regional lymph node cannot be assessed
N0 - No regional lymph node metastasis
N1 - Metastases in one to two regional lymph nodes
N2 - Metastases in three to six regional lymph nodes
N3 - Metastases in seven or more regional lymph nodes
N3a - Metastases in seven to fifteen regional lymph nodes
N3b - Metastases in sixteen or more regional lymph nodes

Distant Metastasis

M0 - No distant metastasis
M1 - Distant metastasis present

Histologic Grade (G)

GX - Grade cannot be assessed
G1 - Well differentiated
G2 - Moderately differentiated
G3 - Poorly differentiated, undifferentiated

Clinical Staging

Stage 0

• Tis N0 M0

Stage I

• T1 N0 M0
• T2 N0 M0

Stage IIA

• T1 N1, N2, N3 M0
• T2 N1, N2, N3 M0

Stage IIB

• T3 N0 M0
• T4a N0 M0

Stage III

• T3 N1, N2, N3 M0
• T4a N1, N2, N3 M0

Stage IVA

• T4b Any N M0

Stage IVB

• Any T Any N M1

Pathological Staging

Stage 0

• Tis N0 M0

Stage IA

• T1 N0 M0

Stage IB

• T1 N1 M0
• T2 N0 M0

Stage IIA

• T1 N2 M0
• T2 N1 M0
• T3 N0 M0

Stage IIB

• T1 N3a M0
• T2 N2 M0
• T3 N1 M0
• T4a N0 M0
• T4a N0 M0

Stage IIIA

• T2 N3a M0
• T3 N2 M0
• T4a N1 or N2 M0
• T4b N0 M0

Stage IIIB

• T1 N3b M0
• T2 N3b M0
• T3 N3a M0
• T4a N3a M0
• T4b N1 or N2 M0

Stage IIIC

• T3 N3b M0
• T4a N3b M0
• T4b N3a or N3b M0

Stage IV

• Any T Any N M1

Japanese Classification of Gastric Carcinoma (Japanese Gastric Cancer Association)  

Clinical Classification  

The clinical classification is used after pretreatment assessment in order to decide if surgery is an appropriate treatment option. This is essential in the selection of treatment and evaluation of therapeutic options. This is derived from physical examination, imaging studies, endoscopic, laparoscopic, and surgical findings, biopsy, cytology, and biochemical and biological investigations.  

Pathological Classification  

The pathological classification provides prognostic information. This helps in deciding if additional therapy is needed. This is derived from histological examination of surgically or endoscopically resected specimens or peritoneal lavage cytology.  

Histological Classification of Gastric Tumors  

The histological tumor findings are recorded in the following order: Tumor location, macroscopic type, size, histological type, depth of invasion, cancer-stroma relationship, pattern of infiltration, lymphatic invasion, venous invasion, lymph node metastasis, and resection margins.  

Size and Number of Lesions  

Two greatest dimensions should be recorded for each lesion. If there are multiple lesions, the most advanced T category (or the largest lesion where the T stage is identical) is classified.  

Tumor Location  

There are three portions of the stomach: U - upper third; M - middle third; L - lower third; E – esophagus; D – duodenum; and the EGJ - border between the esophageal and gastric muscles. Clinically, tumor location is often expressed as cardia, fundus, body, incisura and antrum.  

Macroscopic Types of Gastric Tumors  

The gross tumor morphology is categorized as either superficial or advanced type. The superficial type is typical of T1 tumors while T2-4 tumors usually manifest advanced types.

• Type 0 - Typical of T1 tumors (superficial)
  • Type 0-I - Polypoid tumors (protruding)
  • Type 0-II - Tumors with or without minimal elevation or depression relative to the surrounding mucosa (superficial)
    • Type 0-IIa - Slightly elevated tumors (superficial elevated)
    • Type 0-IIb - Tumors without elevation or depression (superficial flat)
    • Type 0-IIc - Slightly depressed tumors (superficial depressed)
  • Type 0-III - Tumors with deep depression (excavated)
• Type 1 - Polypoid tumors sharply demarcated from the surrounding mucosa (mass)
• Type 2 - Ulcerated tumors with raised margins surrounded by a thickened gastric wall with clear margins (ulcerative)
• Type 3 - Ulcerated tumors with raised margins surrounded by thickened gastric wall without clear margins (infiltrative ulcerative)
• Type 4 - Tumors without marked ulceration or raised margins, the gastric wall is thickened and indurated and the margin is unclear (diffuse infiltrative)
• Type 5 - Tumors that cannot be classified into any of the above types (unclassifiable)

Histological Types of Gastric Tumors

Benign Epithelial Tumor

• Adenoma

Malignant Epithelial Tumor (Common Type)

• Papillary adenocarcinoma (pap)
• Tubular adenocarcinoma (tub)
  • Well-differentiated (tub1)
  • Moderately differentiated (tub2)
• Poorly differentiated adenocarcinoma (por)
  • Solid type (por1)
  • Non-solid type (por2)
• Signet-ring cell carcinoma (sig)
• Mucinous adenocarcinoma (muc)

Mucinous adenocarcinoma (muc)

• Carcinoid tumor
• Endocrine carcinoma
• Carcinoma with lymphoid stroma
• Hepatoid adenocarcinoma
• Adenosquamous carcinoma
• Squamous cell carcinoma
• Undifferentiated carcinoma
• Miscellaneous carcinoma

Non-epithelial Tumor

• Gastrointestinal stromal tumor (GIST)
• Smooth muscle tumor
• Neurogenic tumor
• Miscellaneous non-epithelial tumors

Lymphoma (B-cell Lymphoma)

• MALT (mucosa-associated lymphoid tissue) lymphoma
• Follicular lymphoma
• Mantle cell lymphoma
• Diffuse large B-cell lymphoma
• Other B-cell lymphomas

Lymphoma (T-cell Lymphoma)

Lymphoma (Other Lymphomas)

Metastatic Tumor

Tumor-like Lesion

• Hyperplastic polyp
• Fundic gland polyp
• Heterotopic submucosal gland
• Heterotopic pancreas
• Inflammatory fibroid polyp (IFP)

Gastrointestinal Polyposis

• Familial polyposis coli, Peutz-Jeghers syndrome, juvenile polyposis, Cowden’s disease

The Cancer Genome Atlas (TCGA) Prognostic Subtypes

• EBV-positive subtype
• Microsatellite instability-high (MSI-H) subtype
• Genomically stable (GS) subtype
• Tumors with chromosomal instability (CIN): Enriched for copy number changes in key receptor tyrosine kinase oncogenes such as HER2, epidermal growth factor receptor (EGFR), fibroblast growth factor receptor 2 (FGFR2) and MET

Depth of Tumor Invasion

• TX - Unknown depth of tumor
• T0 - No evidence of primary tumor
• T1 - Tumor confined to the mucosa (M) or submucosa (SM)
  • T1a - Tumor confined to the M
  • T1b - Tumor confined to the SM
• T2 - Tumor invades the muscularis propria (MP)

Cancer Stromal Volume (to be recorded for T1b or deeper tumors)

• Medullary type (med) - scanty stroma
• Scirrhous type (sci) - abundant stroma
• Intermediate type (int) - the quantity of stroma is intermediate between the two above types

Tumor Infiltrative Pattern into the Surrounding Tissues (to be recorded in T1b or deeper tumors)

• INFa - Tumor displays expanding growth with a distinct border from the surrounding tissue
• INFb - Tumor shows an intermediate pattern between INFa and INFc
• INFc - Tumor displays infiltrative growth with no distinct border with the surrounding tissue 

Capillary Invasion

Lymphatic

• ly0 - No lymphatic invasion
• ly1 - Minimal lymphatic invasion
• ly2 - Moderate lymphatic invasion
• ly3 - Marked lymphatic invasion

Venous

• v0 - No venous invasion
• v1 - Minimal venous invasion
• v2 - Moderate venous invasion
• v3 - Marked venous invasion

Anatomical Definitions of Lymph Node Stations (LNs) and Lymph Node Regions

Lymph node stations 1-12 and 14v are defined as regional gastric lymph nodes. Metastasis to any other nodes is classified as M1. In tumors invading the esophagus, lymph node numbers 19, 20, 110, and 111 are included as regional lymph nodes. For carcinomas arising in the remnant stomach with a gastrojejunostomy, jejunal lymph nodes adjacent to the anastomosis are included as regional lymph nodes.

1 - Right paracardial lymph nodes, including those along the first branch of the ascending limb of the left gastric artery
2 - Left paracardial lymph nodes, including those along the esophagocardiac branch of the left subphrenic artery
3a - Lesser curvature lymph nodes along the branches of the left gastric artery
3b - Lesser curvature lymph nodes along the second branch and distal part of the right gastric artery
4sa - Left greater curvature lymph nodes along the short gastric arteries (perigastric area)
4sb - Left greater curvature lymph nodes along the left gastroepiploic artery (perigastric area)
4d - Right greater curvature lymph nodes along the second branch and distal part of the right gastroepiploic artery
5 - Suprapyloric lymph nodes along the first branch and proximal part of the right gastric artery
6 - Infrapyloric lymph nodes along the first branch and proximal part of the right gastroepiploic artery down to the confluence of the right gastroepiploic vein and the anterior superior pancreatoduodenal vein
7 - Lymph nodes along the trunk of the left gastric artery between its roots and the origin of its ascending branch
8a - Anterosuperior lymph nodes along the common hepatic artery
8p - Posterior lymph nodes along the common hepatic artery
9 - Celiac artery lymph nodes
10 - Splenic hilar lymph nodes, including those adjacent to the splenic artery distal to the pancreatic tail, and those on the roots of the short gastric arteries and those along the left gastroepiploic artery proximal to its first gastric branch
11p - Proximal splenic artery lymph nodes from its origin to halfway between its origin and the pancreatic tail end
11d - Distal splenic artery lymph nodes from halfway between its origin and the pancreatic tail end to the end of the pancreatic tail
12a - Hepatoduodenal ligament lymph nodes along the proper hepatic artery, in the caudal half between the confluence of the right and left hepatic ducts and the upper border of the pancreas
12b - Hepatoduodenal ligament lymph nodes along the bile duct, in the caudal half between the confluence of the right and left hepatic ducts and the upper border of the pancreas
12p - Hepatoduodenal ligament lymph nodes along the portal vein in the caudal half between the confluence of the right and left hepatic ducts and the upper border of the pancreas
13 - Lymph nodes in the posterior surface of the pancreatic head cranial to the duodenal papilla
14v - Lymph nodes along the superior mesenteric vein
15 - Lymph nodes along the middle colic vessels
16a1 - Paraaortic lymph nodes in the diaphragmatic aortic hiatus
16a2 - Paraaortic lymph nodes between the upper margin of the origin of the celiac artery and the lower border of the left renal vein
16b1 - Paraaortic lymph nodes between the lower border of the left renal vein and the upper border of the origin of the inferior mesenteric artery
16b2 - Paraaortic lymph nodes between the upper border of the origin of the inferior mesenteric artery and the aortic bifurcation
17 - Lymph nodes on the anterior surface of the pancreatic head beneath the pancreatic sheath
18 - Lymph nodes along the inferior border of the pancreatic body
19 - Infradiaphragmatic lymph nodes predominantly along the subphrenic artery
20 - Paraesophageal lymph nodes in the diaphragmatic esophageal hiatus
110 - Paraesophageal lymph nodes in the lower thorax
111 - Supradiaphragmatic lymph nodes separate from the esophagus
112 - Posterior mediastinal lymph nodes separate from the esophagus and the esophageal hiatus

Lymph Node Metastasis (N)

NX - Regional lymph nodes 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 7 or more regional lymph nodes

N3a - Metastasis in 7-15 regional lymph nodes

N3b - Metastasis in 16 or more regional lymph nodes

Presence or Absence and Sites of Distant Metastasis (M)

Mx - Distant metastasis status unknown
M0 - No distant metastasis
M1 - Distant metastasis

Peritoneal Metastasis (P)

PX - Peritoneal metastasis is unknown
P0 - No peritoneal metastasis
P1 - Peritoneal metastasis

Peritoneal Lavage Cytology (CY)

CYX - Peritoneal cytology not performed
CY0 - Peritoneal cytology negative for carcinoma cells
CY1 - Peritoneal cytology positive for carcinoma cells

Hepatic Metastasis (H)

HX - Hepatic metastasis is unknown
H0 - No hepatic metastasis
H1 - Hepatic metastasis