Tumors of the stomach

 TUMOURS OF THE STOMACH TUCOMInternal Medicine4th yearDr. Hasan. I. Sultan

Learning objectives
Classify the gastric tumours. Review the prevalence of gastric tumours. Describe the pathophysiology, causes and risk factors of gastric tumours. Explain the pathology of gastric tumours. Clarify the clinical features of gastric tumours. Understand the important investigations and staging of gastric tumours. Explain the treatment of gastric tumours.

TUMOURS OF THE STOMACH

1-GASTRIC CARCINOMA. 2-GASTRIC LYMPHOMA. 3-OTHER TUMOURS OF THE STOMACH; Gastrointestinal stromal cell tumours (GIST), a variety of polyps, and gastric carcinoid tumours.

GASTRIC CARCINOMA

Gastric carcinoma is the fourth leading cause of cancer death worldwide, but there is marked geographical variation in incidence. It is most common in China, Japan, Korea (incidence 40/100 000 males) Rates in the UK are 12/100 000 for men. Japanese migrants to the USA have much lower incidence in second-generation migrants, confirming the importance of environmental factors. It is more common in men, after 50 years of age.


Aetiology;1-H. pylori infection; is associated with chronic atrophic gastritis -- hypo- or achlorhydria --- gastric cancer. Contribute to 60–70% of cases.2-Diets; rich in salted, smoked or pickled foods and the consumption of nitrites and nitrates may increase cancer risk. Diets lacking fresh fruit and vegetables as well as vitamins C and A.3-Smoking.4-Alcohol.5-Autoimmune gastritis (pernicious anaemia).6-Adenomatous gastric polyps 7-Previous partial gastrectomy (> 20 years) 8-Mйnйtrier's disease 9-Hereditary diffuse gastric cancer families (HDC-1 mutations) 10-Familial adenomatous polyposis (FAP)

Gastric polyposis in familial adenomatous polyposis

Pathology; Microscopically; All tumours are adenocarcinomas arising from mucus-secreting cells. either 'intestinal', arising from areas of intestinal metaplasia, more common. or 'diffuse', arising from normal gastric mucosa, poorly differentiated and occur in younger patients. Macroscopically; Classified as polypoid, ulcerating, fungating or diffuse a scirrhous cancer (linitis plastica). Early gastric cancer; Is defined as cancer confined to the mucosa or submucosa, regardless of lymph node involvement often recognized in Japan due to widespread screening. Advanced gastric cancer; Over 80% of patients in the Westren present at this stage.

Early gastric cancer

Advanced gastric cancer

Ulcerating gastric cancer

polypoid gastric cancer

Fungating gastric cancer

Linitis plastica

Location; 50% in the antrum, 20-30% occur in the gastric body, 20% in the cardia, or diffuse submucosal infiltration (uncommon). Clinical features; Which depend on the location, size, and growth pattern of gastric cancer. Early gastric cancer is usually asymptomatic. 1- Dyspepsia. 2- Dysphagia. 3- Weight loss. 4- GI bleeding; Anaemia from occult bleeding, haematemesis, and melaena. 5- Palpable epigastric mass 6- Pylorus/cardia obstruction 7- Perforation


8- Metastatic spread; To left supraclavicular lymph nodes (Troisier's sign). To umbilicus ('Sister Joseph's nodule'). To ovaries (Krukenberg tumour). To the perirectal pouch (Blumer shelf). Liver ---Jaundice Bone --- Bone pain Pertonium --- Ascitis


Krukenberg tumors: Bilateral ovarian tumors (arrows). These represent ovarian metastases from a gastric adenocarcinoma.

Diagnosis and staging

Upper GI endoscopy; Is the investigation of choice in;Dyspeptic patient with 'alarm features‘New onset of dyspepsia in patient >55 yearsDyspepsia & family h/o gastric carcinomaBarium meal; is a poor alternative.CT abdomen; show evidence of intra-abdominal spread or liver metastases.Laparoscopy; is required to determine whether the tumour is resectable.

TNM staging of gastric cancer

Tis
Intaepithelial tumour
T1
Tumour invades submucosa
T2
Tumour invades muscularis propria
T3
Tumour penetrates serosa
T4
Tumour invades adjacent structures
N0
No regional lymph node metastases
N1
Metastasis in 1 to 2 regional lymph nodes
N2
Metastasis in 3 to 6 regional lymph nodes
N3
Metastasis in 7 or more regional lymph nodes
M0
No distant metastasis
M1
Distant metastasis

Management

1-Surgery; cure can be achieved in 90% of patients with early gastric cancer by total gastrectomy with lymphadenectomy, which is the operation of choice. 2-Unresectable tumours; for advanced cancer. Chemotherapy; using 5-fluorouracil and cisplatin or ECF (epirubicin, cisplatin and 5-fluorouracil). Endoscopic laser ablation for dysphagia or recurrent bleeding.

Carcinomas at the cardia; endoscopic dilatation, laser therapy or insertion of expandable metallic stents. Prognosis; Remains very poor with less than 30% surviving 5 years, with the exception of early gastric cancer. So endoscopic screening of patients with new-onset dyspepsia in those over the age of 55years, or those with 'alarm' features, are essential.

GASTRIC LYMPHOMA

Primary gastric lymphoma accounts for less than 5% of all gastric malignancies. The stomach is the most common site for extranodal non-Hodgkin's lymphoma (NHL). Lymphoid tissue is not found in the normal stomach but lymphoid aggregates develop in the presence of H. pylori infection. There are 2 types of gastric lymphoma; 1-Gastric mucosa associated lymphoid tissue lymphoma (MALToma); It is low-grade lymphoma, H. pylori infection is closely associated. 2-Extranodal manifestation of high grade NHL.

Normal gastric histology

Clinical presentation; is similar to that of gastric cancer. Endoscopically; the tumour appears as a polypoid or ulcerating mass. Treatment; Low-grade MALTomas consists of H. pylori eradication and close observation. High-grade B-cell lymphomas are treated by a combination of chemotherapy, surgery and radiotherapy. Prognosis; depends on the type and stage of lymphoma at the time of diagnosis.

The following are associated with H. pylori infection:

Gastritis PUD Gastric MALToma Gastric carcinoma