Introduction
Adenocarcinoma of the stomach
Epidemiology
23/100 000 per year in UK
Peak incidence 50-80yr
2x as common in men
⅔ of cases are stage 3 or 4 at presentation
Overall incidence is decreasing, but incidence of tumours arising from the cardia is increasing
Risk Factors
Blood group A
Atrophic gastritis (autoimmune / H. pylori-related)
Adenomatous polyps
Smoking
Low social class
Male>female
Partial gastrectomy for peptic ulcer disease
NB: PUD itself NOT a risk factor
Presentation
Presents late, often non-specifically. 30% are metastatic at presentation
Weight loss
Epigastric pain, which may be relieved by food and antacids
Nausea
Vomiting
Dysphagia
Examinations
Features of anaemia
Sister Mary Joseph nodule - periumbilical subcutaneous nodule, indicative of metastatic spread
Virchow’s Node - left large supraclavicular node
Epigastric mass (may be tender)
Nearly 50% have a mass at presentation
Features of hepatic metastases (hepatomegaly, jaundice, ascites)
Acanthosis nigricans
Dermatomyositis
Investigations
Blood
FBC
Anaemia
LFTs
Hepatic metastases
Other investigations
OGD
Most important investigation, allowing direct visualisation and histological diagnosis
EUS
May be done as a staging investigation to demonstrate penetration of cancer through wall and into lymph nodes
CT chest, abdomen and pelvis (with contrast)
Staging investigation - are there lymph node / hepatic metastases?
PET
Management
curative gastrectomy for local disease
D1 resection - excision of tumour and perigastric nodes
D2 resection - D1 + celiac axis nodes
endoscopic mucosal resection for early gastric carcinomas
partial gastrectomy if in distal ⅔ of stomach
Billroth I - partial gastrectomy with simple reanastomosis
Billroth II - partial gastrectomy with reanastomosis with proximal jejunum (created a blind ended duodenum - duodenal stump)
chemotherapy
combination - epirubicin, cisplatin, 5FU
often given for unresectable lesions
palliative
all of the above have their uses to alleviate obstruction, haemorrhage and pain
also can use radiotherapy
Complications
Upper gastrointestinal haemorrhage
Metastasis
Common sites: duodenum, pancreas, retroperitoneum
distant; liver, bone, brain, lung
Differential Diagnosis
peptic ulcer disease
breast and lung ca can cause a linitis plastica like appearance of the stomach
Benign gastric tumours
Prognosis
less than 10% 5 yr survival
20-50% 5 yr survival for undergoing radical surgery
better prognosis for early gastric carcinoma - 90% 5 year survival
Pathological classification
Type 1 “Intestinal”
Common, 2:1 M:F, 55 years
Associated more closely with atrophic gastritis and intestinal metaplasia
Decreasing in frequency
Intestinal type gastric adenocarcinoma
Type 2 “Diffuse”
Equal male female preponderance
Linitis plastica - leather bottle
rugal flattening and rigid thickened wall
stomach appears rigid on X Ray due to scattered cancer cells throughout submucosa
desmoplastic reaction
breast and lung mets to stomach can cause this too
histo - signet ring cells - nucleus at periphery of large cells
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
