Gastric cancer Flashcards
Define gastric cancer.
Gastric malignancy, most commonly adenocarcinomas, more rarely lymphoma, leiomyosarcoma.
How common is gastric cancer?
- More common in Asia, especially Japan.
- 6th most common cancer in UK
- Male to female ratio 2:1
- Cancer of antrum/body is decreasing while that of cardia and gastro-oesophageal junction is increasing
What are the risk factors for gastric cancer?
- Pernicious anaemia (x2-3 risk), atrophic gastritis, post-gastrectomy, Ménétrier’s disease, adenomatous polyps
- Smoked and salted food consumption
- H pylori
- N-nitroso compounds - naturally found in veg and used as food additive in cured meats
Other:
- Poor diet
- Smoking
- FH - esp E-cadherin mutation
- Increasing age
- Male sex
- Smoking
- Blood group A
- Hypogammaglobulinaemia
NB: The widespread use of refrigeration has been cited as a reason for the decrease in the incidence of gastric cancer in the US since 1930
What is the pathophysiology behind gastric cancer?
- Loss of p53 tumour suppressor gene
- Over-expression of proto-oncogenes such as ras, c-myc, and erbB2 (HER2/neu)
- H pylori causes chronic inflammation which can lead to gastric intestinal metaplasia and has been shown to increase p53 mutations (usually causes distal gastric cancer)
Kumar and Clark: The most common abnormality is a loss of heterozygosity (LOH) of tumour suppressor genes such as p53 (in 50% of cancers, as well as in pre-cancerous states) and the gene encoding adenomatous polyposis coli ( APC ) (in over one-third of gastric cancers). These abnormalities are similar to those found in colorectal cancers. Some rare families with diffuse gastric cancer have been shown to have mutations in the E-cadherin gene ( CDH-1 ). There is a higher incidence of gastric cancer in blood group A patients.
What type of gastric cancer is associated with H pylori?
Distal gastric carcinoma
Gastric B-cell lymphomas
What are the two major types of gastric cancer? (Lauren classification)
Intestinal ( type 1 ) with well-formed glandular structures (differentiated).
- The tumours are polypoid or ulcerating lesions with heaped-up, rolled edges.
Diffuse ( type 2 ) with poorly cohesive cells (undifferentiated) that tend to infiltrate the gastric wall.
- It may involve any part of the stomach, especially the cardia, and has a worse prognosis than the intestinal type.
What is a typical presentation of gastric cancer?
- Asymptomatic in early phases
- Epigastric discomfort
- Weight loss, anorexia, nausea, vomiting
- Melaena, symptoms of anaemia - from GI bleeding
- Dysphagia - proximal tumours
- Symptoms of metastases - abdo swelling (ascites) or jaundice (liver involvement)
What are the signs of gastric cancer on examination?
- Epigastric mass
- Lymphadenopathy:
- Irish node - left axillary node
- Virchow’s node/Troisier’s sign - left supraclavicular fossa node
- Sister Mary Joseph node - metastatic nodule in umbilicus
- Krukenberg’s tumour - ovarian metastases
How do you diagnose gastric cancer?
GI endoscopy +/- biopsy - DIAGNOSTIC; allows precise localisation of the tumour and tissue diagnosis
Staging CT CAP - detects lymphadenopathy and metastases
Other:
Bedside:
- Blood - FBC (for anaemia), LFT
Imaging:
- Ultrasound liver - staging
- Bone scan - staging
- Endoscopic ultrasound - assess depth of invasion and lymph node involvement
Invasive:
- Laparoscopy - may be needed to determine if tumour is resectable
What is the prognosis of gastric cancer?
~70% 5yr survival for localised disease
30% if spread to nodes
5% for distant mets
What are the complications of surgery for gastric cancer?
Early:
- Anastomotic leak
- Infection
- MI
- Pneumonia
- Gastroparesis
Late:
- Dumping syndrome - within 30mins of eating you get palpitations, diarrhoea, nausea and cramps then 2-3hrs later dizziness, cold sweats, hunger and faintness
- Fatigue
- Nutritional deficiency - B12
- Indigestion
What are the complications of gastric cancer?
- Weight loss
- Gastric obstruction
- GI bleeding
- Gastric perforation
- Small bowel obstruction
What is the management of gastric cancer?
Subtotal gastrectomy OR total gastrectomy - open or laparoscopic
+/- Lymph node dissection
Neoadjuvant or adjuvant chemotherapy - FLOT (fluorouracil, folinic acid, oxaliplatin, docetaxel) or fluorouracil+oxaliplatin respectively
Chemo +/- immunotherapy - for metastatic or advanced disease e.g. nivolumab and the above regimens.
Label A-F
Right lobe of liver
Left kidney
Hepatic flexure colon
Para-aortic adenopathy
Thick-walled stomach
Aorta
Left kidney - B
Right lobe of liver - A
Hepatic flexure colon - C
Para-aortic adenopathy - D
Thick-walled stomach - E
Aorta- F
Which three of the following statements regarding gastric carcinoma are correct?
- The majority are squamous cell carcinomas
- Tumours are most common at the gastric antrum
- Adenomatous polyps are a risk factor
- Smoking is a risk factor
- Chemotherapy does not improve survival in cases with metastatic disease
- It may present with ovarian masses
Adenomatous polyps are a risk factor
Smoking is a risk factor
It may present with ovarian masses
Adenocarcinoma is the most common type of stomach cancer, not squamous cell carcinomas.
