Gastric Cancer

Epidemiology

Representing 10% of all gastrointestinal cancers and 10% of deaths due to gastrointestinal cancers are gastric cancer data. It represents the 10th cause of death from cancer.

In Romania in 1997 the incidence was 20 per 100,000 population and mortality 17 per 100,000 inhabitants.

In Romania the estimated incidence for 2000 was 22.18 to 100,000 inhabitants and 18.60 deaths per 100,000 inhabitants.

Risk factors:

1.       Diet. Involved:

Meat and fish dishes very salty, smoked foods.

Diet low in fruits and vegetables.

Increased intake of nitrates in drinking water.

2. Helicobacter pylori infection increases the risk of gastric cancer by 3-6 times than normal.

3. Diseases considered to be gastric cancer precursors

a) achlorhydria increases gastric cancer risk of 4-5 times the normal.

b) Pernicious anemia increases the risk 18 times the normal.

c) atrophic gastritis.

d) hypertrophic gastritis (disease Menetrier)

e) intestinal metaplasia associated with intestinal type gastric cancer

f) adenomatous polyp stomach: the risk of gastric cancer is 10-20%

4.smoking, age> 50 years, blood group

Histological Types

1. Adenocarcinoma 95%

2. Squamous cell carcinoma

3. Adenoacantoma

4. Carcinoid tumors

5. Leiomiosarcomas

6. The non-Hodgkin’s lymphoma

Classification of the most common histological gastric adenocarcinomas is Lauren’s (1965) that separates the two varieties:

a) Intestinal type is a differentiated carcinoma with a tendency to form glands. Arises in areas of intestinal metaplasia and has a good prognosis.

b) Diffuse type has a predilection for extensive submucosa disseminating, early metastasis and poor prognosis.

For patients with adenocarcinoma, advanced disease recurrence or metastatic HER2 neu overexpression evaluation by immunohistochemical is recommended (IHC) and fluorescent in situ hybridization or (FISH 0

Location:

– 51% involve the antrum;

– 18% less curvature,

– 21% of the stomach,

– 7% cardia

– 3% greater curvature.

Signs and symptoms: epigastric pain, bloating, epigastric discomfort.

In advanced stages appear anorexia, vomiting, weight loss, anemia, tumor mass. Hematemesis and melena occur in 25% of cases.

Metastasis occurs in the liver, lung, peritoneum, lymph nodes supraclavicular, navel (Sister Joseph node), ovary (krukenberg tumors).

Paraneoplastic syndromes:

1. Acantozis nigricans

2. Polymyositis and dermatomyositis

3. Erythema circinate, bullous

4. Dementia, cerebellar ataxia

5. Idiopathic venous thrombosis

For diagnosis and staging is recommended:

• History, physical examination,

• CBC, liver function tests, tumor markers (CEA), Helicobacter pylori

• gastric endoscopy with biopsy and cytology exfoliative tumor,

• endoscopic ultrasound (EUS) with FNA if it indicated

• CT abdomen / chest with oral or IV contrast

• Her 2 neu testing if proven metastasis

• laparoscopy.

The diagnosis is confirmed by histopathological examination.

Tumor markers most used are: ACE, CA 19.9 and CA 50.

TNM staging

Tx – primary tumor cannot be evaluated

T0 – no evidence of primary tumor

Tis – Carcinoma in situ: intraepithelial tumor without invasion of the lamina propria (corium)

T1 – Tumor invades lamina propria or submucosa

T2 – Tumor invades muscle and subseries

T3 – Tumor penetrates serosa (visceral peritoneum) without invasion of adjacent organs

T4 – Tumor invades adjacent structures

Adjacent structures of the stomach include the spleen, transverse colon, liver, diaphragm, pancreas, abdominal wall, adrenal, kidney, small intestine and retroperitoneum.

Regional lymph nodes (N)

Nx – regional lymph nodes cannot be assessed

N0 – no regional lymph node metastases

N1 – regional lymph node metastases 1-6

N2 – regional lymph node metastases 7-15

N3 – metastases in regional lymph nodes than 15

Distant metastasis (M)

Mx – distant metastasis cannot be assessed

M0 – no distant metastases

M1 – distant metastases

Stages:

Tis N0 M0 Std.0

T1 N0 M0 A Std.I

T1 N1 M0 Std.I B

T2 N0 M0

N2 M0 T1 Std.II

T2 N1 M0

T3 N0 M0

A T2 N2 M0 Std.III

T3 N1 M0

T4 N0 M0

T3 N2 M0 Std.III B

Std.IV T4 N1-2 M0

Any T N3 M0

Any T Any N M1

TREATMENT

Therapeutic indications. The only potentially curative treatment for localized gastric cancer is surgical resection.

I Stg.O and A (Tis and T1)

Surgical treatment is recommended only: subtotal or total gastrectomy.

Stg.I B, II, IIIA, IIIB (T2, T3, N1-2)

Surgical treatment is recommended followed by 4-6 weeks after completion of treatment by chemotherapy and radiotherapy.

3-6 weeks after surgery begins FU chemotherapy FOL type 5 FUR 425 mg / m2 / day on days 1-5 associated with leucovorin 20 mg / m2 / day IV FUR bolus before 5 days 1-5. Repeat 4 weeks for 6 cycles.

Simultaneously with the second cycle of chemotherapy begins external radiation dose of 45 Gy fractionated total dose 1.8 Gy / day. The second cycle of the chemotherapy is administered for 4 days, and the third stage for 3 days. The next three cycles administered for 5 days.

Stg.IV (T4, N3, M0) locally advanced disease, unresectable.

Neoadjuvant chemotherapy is recommended. Preoperative chemoradiotherapy has allowed a total resection further 20-70% of the disease in patients. Postoperative chemotherapy should continue.

Stg.IV (M1 metastatic disease)

It is recommended chemotherapy. Polichemotherapy has not proven to be superior to monochemotherapy.

Palliative radiotherapy is recommended in patients with pain, bone metastases or brain.

Therapeutic Methods

Surgical treatment. Subtotal gastrectomy with uninvaded 6 cm edges is recommended, with regional lymph node dissection and retrocolic gastrojejunostomy. In case of invasion of contiguous liver and pancreas partial resection recommend them. The mortality rate is 8% and 28% complication rate.

Survival at 5 years after curative resection is between 30% -40%.

Gastric resection limited palliative is useful in patients with polypoid ulcerated gastric cancer, overinfected, obstruction, bleeding.

Radiation irradiation field should include gastric bed and regional lymph nodes. The total dose of 45-50 Gy is for 5 weeks in a daily dose of 1.8 Gy.

It is used in adjuvant end stages IB – III in curative associated with chemotherapy in patients with locally advanced disease (T4, N3, M0) as definitive treatment in combination with chemotherapy in patients with advanced or unsuitable for surgery or surgical or purpose palliation in patients with metastatic disease. Survival for patients with locally advanced disease treated with radiation therapy is 16-24 months.

Chemotherapy