Gastric Cancer

Question 1

Gastric Cancer - Epidemiology

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

Gastric Cancer - Histology

Answer 2

Histology
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

Gastric adenocarcinoma = Signet Ring Cells

Question 3

Gastric Cancer - Associations

Answer 3

Associations
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

Gastric Cancer - Ix

Answer 4

Investigation

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

Question 5

Gastric Ca - Mx: Example Question

Answer 5

A 75 year old women was referred for urgent upper gastrointestinal endoscopy after a two month history of recurrent post-prandial vomiting. She also reported a 10 kg weight loss over a similar period. Examination revealed cachexia but was otherwise unremarkable. Past medical history includes hypertension and a right-sided carotid endarterectomy following a transient ischaemic attack 8 years previously. Regular medications are bendroflumethiazide, clopidogrel and simvastatin. The patient is a retired schoolteacher has never smoked and drinks minimal amounts of alcohol.

Endoscopy demonstrated a 3 cm ulcer in the body of the stomach. Histology confirmed adenocarcinoma with penetration of the tumour into the subserosal connective tissue. The results of further staging investigations are given below.

CT abdomen: 3 cm mass in body of stomach along greater curve of stomach; enlargement of the right and left gastro-epiploic lymph nodes; liver, gallbladder, spleen and kidneys unremarkable.

PET: no evidence of distant metastasis or nodal involvement

Staging laparoscopy: no evidence of peritoneal or metastatic disease

What is the appropriate initial treatment for this patient?

	> Neoadjuvant chemotherapy
	Total gastrectomy
	Partial gastrectomy
	Endoscopic mucosal resection
	Palliative radiotherapy

This patient’s investigations indicate that they have T3N1M0 gastric carcinoma (Stage IIB disease). Standard of care within the UK for stage II / III disease would be for neoadjuvant chemotherapy prior to radical surgery. The MAGIC trial demonstrated significant improvement in 5 year survival for three cycles of pre-operative chemotherapy followed by three cycles of post-operation chemotherapy compared to surgery alone (36 % vs 23 %; P = 0.009).

Primary surgical resection is only appropriate for stage 1 tumours. Endomucosal resection can be considered in some early gastric cancers (T1a).

Extent of surgical resection depends on tumour location with subtotal gastrectomy feasible for some distal tumours.

Curative treatment is typically not possible in tumours with local invasion (T4) or distant metastasis (M1).

Thrumurthy S, Chaudry M, Hochhauser D, Mughal M. The diagnosis and management of gastric cancer. BMJ 2013;347:6367.

Question 6

Gastric Cancer - Mx - Example Question

Answer 6

A 65-year-old woman was referred by her General Practitioner for routine upper gastrointestinal endoscopy. The patient had been suffering from persistent epigastric discomfort induced by eating. Testing for Helicobactor pylori had been negative. The patient had not experienced any dysphagia, vomiting or weight loss. Past medical history included osteoarthritis of the left knee for which she takes ibuprofen as required. The patient manages her own cleaning business and drinks 20-25 units of alcohol per week. Clinical examination was unremarkable.

At endoscopy a generalised mild gastritis was found. In addition, biopsies were taken from a 1.5 cm diameter non-ulcerated lesion noted at the fundus. The results of histology and further investigations subsequently requested are listed below.

Histology: sample of gastric mucosa exhibiting moderately differentiated adenocarcinoma without involvement of sub-serosal connective tissue

CT abdomen: no gastric mass or ulceration identified; no evidence of abdominal lymph node enlargement; liver, gallbladder, spleen and kidneys unremarkable.

PET: no evidence of distant metastasis or nodal involvement

Staging laparoscopy: no evidence of peritoneal or metastatic disease

What is the appropriate treatment for this patient’s gastric carcinoma?

	Neoadjuvant chemotherapy
	> Endoscopic mucosal resection
	Total gastrectomy
	Partial gastrectomy
	Radical radiotherapy

Endomucosal resection can be used to treat gastric cancer confined to the mucosa (T1a) provided it is less than 2 cm in diameter, of low or moderate differentiation and with no ulceration or lymphovascular involement.

Neoadjuvant chemotherapy is the treatment of choice for stage II and stage III gastric carcinoma prior to radical surgery. Extent of surgical resection depends on tumour location with subtotal gastrectomy feasible for some distal tumours. Radiotherapy is not used as a first-line treatment of gastric carcinoma.