A diet that includes fruits and vegetables rich in vitamin C may have a protective effect.
Implicated as precursor of gastric cancer.
H. Pylori associated with atrophic gastritis, and patients with a history of prolonged gastritis have a 6-fold increase in risk.
Particularly true of tumors of antrum, body, and fundus of stomach, but not in cardia.
Implicated as risk factor, the rational being that previous gastric surgery alters normal pH of stomach.
Retrospective studies show that a small percentage of patients who have a gastric polyp removed have evidence of invasive carcinoma in the polyp.
Polyps may therefore be premalignant.
Some familial aggregation exists
Assists in determining optimal therapy.
CBC identifies anemia, with may be caused by bleeding, liver dysfunction, or poor nutrition.
30% have anemia.
Electrolyte panels and LFTs are also essential to better characterize patients clinical state.
EGD: safe, simple, providing a permanent color photographic record.
Obtains tissue for diagnosis.
UGI: detects large tumors, but only occasionally detects extension into esophagus or duodenum, especially if small or submucosal.
CXR: done to evaluate for metastases.
CT scan or MRI of chest, abdomen, pelvis: evaluate local disease process, and areas of spread. Some tumors are deemed unresectable based on the testing.
Accurately predicts stage 66-77%.
Poor nodal status prediction.
Endoscopic ultrasound: becoming extremely useful as a staging tool, when CT fails to show T3, T4, or metastatic disease.
Used with neoadjuvant chemo to stratify pts
Can achieve resolution of 0.1 mm.
Cannot reliably distinguish between tumor and fibrosis.
Overall staging accuracy of 75%
Poor for T2 lesions (38%)
Better for T1(80%), T3 (90%)
Squamous cell 1%
Adenocarcinoma is classified according to the most unfavorable microscopic element present: tubular, papillary, mucinous, signet-ring cells.
Also identified by gross appearance: ulcerative, polypoid, scirrous, superficial spreading, multicentric, or Barrett ectopic.
Variety of other schemes: Borrmann, Lauren.
Type I: polypoid or fungating
Type II: ulcerating lesions with elevated borders
Type III: ulceration with invasion of wall
Type IV: diffuse infiltration
Type V: cannot be classified
Epidemic or endemic
The intestinal, expansive epidemic type gastric cancer is associated with atrophic gastritis, retained glandular structure, little invasiveness, sharp margins. It would be a Borrmann I or II.
The epidemic or Borrmann I or II carries better prognosis, shows no family history.
The diffuse, infiltrative, endemic, is poorly differentiated, with dangerously deceptive margins, invades large areas of stomach. Younger patients, genetic factors, blood groups, and family history.
Tx- cannot be assessed
T0- no evidence
Tis- carcinoma in situ, no invasion of lamina
T1- invades lamina propria or submucosa
T2- invades muscularis or subserosa
T3- penetrates serosa, no adjacent structure
T4- invades adjacent structures
Regional Lymph Nodes
NX- cannot be assessed
N0- no nodes
N1- mets in 1-6 regional nodes
N2- mets in 7-15 regional nodes
N3- mets in more than 15 regional nodes
MX- cannot be assessed
M0- no distant metastases
Depth of invasion through gastric wall, presence or absence of regional lymph node involvement
The greater number of positive nodes, the greater the likelihood of local or systemic failure postoperatively
Directly, via lymphatics, or hematogenously
Direct extension into omentum, pancreas, diaphragm, transverse colon, and duodenum.
If lesion extends beyond wall to a free peritoneal surface, peritoneal involvement is frequent.
The visible gross lesion frequently underestimates true extent.
Abundant lymphatic channels in submucosal and subserosal layers allow for easy spread.
The submucosal plexus is prominent in esophagus, the subserosal plexus prominent in duodenum, which allows for proximal and distal spread.
Liver mets common, from hematogenous spread.
Inspect peritoneal surfaces, liver surface.
Identification of advanced disease avoids non-therapeutic laparotomy in 25%.
Patients with small volume metastases in peritoneum or liver have a life expectancy of 3-9 months, thus rarely benefit from palliative resection.
Lymph Node Dissection
AJCC: number rather than location of LN is prognostic.
Extent of dissection controversial.
Nodal involvement indicates poor prognosis, and more aggressive approaches to remove them are taking favor.
Ongoing trials regarding this in Europe.
Critics argue that the apparent benefit associated with extended LND reflects stage migration (each LN is reviewed more carefully).
Residual Disease R Status
Tumor status following resection.
Assigned based on pathology of margins.
R0- no residual gross or microscopic disease.
R1- microscopic disease only.
R2- gross residual disease.
Long term survival only in R0 resection.
Describes extent of resection and lymphadenectomy.
D1- removes all nodes within 3cm of tumor.
D2- D1 plus hepatic, splenic, celiac, and left gastric nodes.
D3- D2 plus omentectomy, splenectomy, distal pancreatectomy, clearance of porta hepatis nodes.
Current standards include a D1 dissection only.
Type of Surgery
In general most surgeons perform total gastrectomy ( if required for negative margins), esophagogastrectomy for tumors of the cardia and GE junction, and a subtotal gastrectomy for tumors of the distal stomach.
Similar 5 year rates for subtotal vs. total in tumors of distal stomach.
Extensive lymphatics require 5cm margin.
5-year survival for a curative resection is 30-50% for stage II disease, 10-25% for stage III disease.
Adjuvant therapy because of high incidence of local and systemic failure.
A recent Intergroup 0116 randomized study offers evidence of a survival benefit associated with postoperative chemoradiotherapy