Gastric Cancer

Question 1

Gastric cancer?

Answer 1

Epidemiology

• overall incidence is decreasing, but incidence of tumours arising from the cardia is increasing
• peak age = 70-80 years
• more common in Japan, China, Finland and Colombia than the West
• more common in males, 2:1

Question 2

Histology?

Answer 2

• signet ring cells may be seen in gastric cancer.
• They contain a large vacuole of mucin which displaces the nucleus to one side.
• Higher numbers of signet ring cells are associated with a worse prognosis

Question 3

Associations?

Answer 3

• H. pylori infection
• blood group A: gAstric cAncer
• gastric adenomatous polyps
• pernicious anaemia
• smoking
• diet: salty, spicy, nitrates
• may be negatively associated with duodenal ulcer

Question 4

Investigation?

Answer 4

• diagnosis: endoscopy with biopsy
• staging: CT or endoscopic ultrasound - endoscopic ultrasound has recently been shown to be superior to CT

Question 5

Surgical aspects?

Answer 5

Evidence of a stepwise progression of the disease through intestinal metaplasia progressing to atrophic gastritis and subsequent dysplasia, through to cancer.

• The favoured staging system is TNM.
• The risk of lymph node involvement is related to size and depth of invasion;
• early cancers confined to submucosa have a 20% incidence of lymph node metastasis.
• Tumours of the gastro-oesophageal junction are classified on another card

Question 6

Tumours of the gastro-oesophageal junction?

Answer 6

Type 1

• True oesophageal cancers and may be associated with Barrett’s oesophagus.

Question 7

Tumours of the gastro-oesophageal junction?

Answer 7

Type2

• Carcinoma of the cardia, arising from cardiac type epithelium
• or short segments with intestinal metaplasia at the oesophagogastric junction.

Question 8

Tumours of the gastro-oesophageal junction?

Answer 8

Type 3

• Sub cardial cancers that spread across the junction. Involve similar nodal stations to gastric cancer.

Question 9

Treatment?

Answer 9

• Proximally sited disease greater than 5-10cm from the OG junction may be treated by sub total gastrectomy
• Total gastrectomy if tumour is <5cm from OG junction
• For type 2 junctional tumours (extending into oesophagus) oesophagogastrectomy is usual
• Endoscopic sub mucosal resection may play a role in early gastric cancer confined to the mucosa and perhaps the sub mucosa (this is debated)
• Lymphadenectomy should be performed. A D2 lymphadenectomy is widely advocated by the Japanese, the survival advantages of extended lymphadenectomy have been debated. However, the overall recommendation is that a D2 nodal dissection be undertaken.
• Most patients will receive chemotherapy either pre or post operatively.