Gastric cancer

Gastric cancer is the 2nd highest cause of cancer related deaths, mainly as it presents very late.

Most gastric cancers are adenocarcinomas.

⚠️ Risk factors

H. Pylori infection
Male gender - 2:1 ratio of male:female
Age - more than 50% of patients are >75 years old
Smoking

High salt diet
Alcohol consumption
Atrophic gastritis
Pernicious anaemia

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Countries in the Far East such as Japan 🇯🇵 and South Korea 🇰🇷 tend to have much more significant rates. While in the West, rates have dropped significantly.

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H. Pylori is a gram negative bacteria producing urease to break down urea → CO2 and ammonia (NH3). The ammonia neutralises the gastric acid to allow for an alkaline environment in which the bacteria can proliferate and damage epithelial cells → inflammation, ulceration, neoplasia. We can diagnose an infection with a urea breath test or rapid urease test (during endoscopy). It can be treated with triple therapy of: PPI + clarithromycin + amoxicillin/metronidazole.

😷 Presentation

Symptoms tend to be vague and non-specific. Often patients only present at advanced stage.

⭐️ Dyspepsia - that is often new in onset or resistant to a PPI treatment.
⭐️ Dysphagia
Early satiety
Nausea and vomiting
Melena
Chronic haematemesis

NICE recommends referral for urgent OGD in patients with new-onset dysphagia or if they are aged >55 years old with weight loss and upper abdominal pain/reflux/dyspepsia.

On examination we might find a few things:

Troisier sign - a palpable Virchow node (left supraclavicular node). A periumbilical nodule (Sister Mary Joseph’s node) may also be palpated. These are signs of metastatic malignancy. ➡️
Palpable epigastric mass
Hepatomegaly
Jaundice
Acanthosis nigricans

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Acanthosis nigricans This is an abnormal hyperpigmentation of skin folds (such as in the inguinal region and axilla) coupled with cutaneous thickening.

🔍 Investigations

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Imaging 🏆 OGD (oesophagogastroduodenoscopy) with biopsy. Biopsies should be sent to look at: 1. Histology - looking for neoplasia. Signet ring cells may also be seen. These are cells containing large vacuoles of mucin which push the nucleus to the edge of the cell. ➡️ 2. CLO test - indicating presence of H. Pylori. 3. HER2/neu expression - allowing for herceptin therapy

Late stage markers include the non-specific cancer symptoms:

Anorexia

Weight loss

Anaemia

🔢 Staging

🏆 In order to stage patients for treatment planning, all patients require a CT chest-abdomen-pelvis + a staging laparoscopy to look for any metastasis.

Staging is done using the TNM system.

🧰 Management

Once again the only curative treatment is surgical.

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Surgery Depending on the location, the operation may differ: 1. Total gastrectomy - proximal gastric cancers. 2. Subtotal gastrectomy - for distal gastric cancers. 3. Endoscopic Mucosal Resection - for early T1a tumours, but as detection is usually late, its use is very rare. Gastrectomy is riddled with complications such as death, anastomotic leak, re-operation, dumping syndrome, vitamin B12 deficiency. Dumping syndrome is when one suffers fainting and sweating postprandially due to food with high osmotic potential being dumped into the jejunum causing rapid fluid shifts and hypovolaemia. It can be classified as either early (10-30 minutes) or late (1-3 hours).

Reconstruction of the GI tract would also be necessary. The best option for this would be a Roux-en-Y reconstruction. It allows the least bile reflux. The distal oesophagus is anastomosed to the proximal small bowel, while another region of the proximal small bowel is also anastomosed to the side of the small bowel more distally.

Palliative care is often the choice as 5 year survival rates are less than 10%.

🚨 Complications

Gastric outlet obstruction

IDA

Perforation

Malnutrition

Dumping syndrome

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Chemotherapy 3x cycles of neo-adjuvant 3x cycles of adjuvant

Neoadjuvant chemotherapy has been shown to improve outcomes in those undergoing surgery. There is no scope for radiotherapy alone, however when used in combination with chemotherapy (fluorouracil) can be used as a potential curative in a non-surgical candidate. Cisplatin is also used in advanced cancers.

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Menetrier’s disease

Hyperplasia of the gastric mucosa due to unknown causes. There are large, gastric folds on the body and stomach associated with increased mucus production. It is associated with parietal cell atrophy and hence reduced acid production. It is a pre-cancerous condition.

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Krukenberg tumour

It is known as a signet ring tumour, due to the pathological appearance of these cells. These cells readily secrete mucin and readily metastasize to the ovaries.

Patients often present with abdominal bloating, ascites or pain during intercourse.

The most common primary site is the stomach and the colon, with breast, lung and contralateral ovary being less common.

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Linitis plastica

Diffuse malignant infiltration of the stomach. The muscles of the stomach wall become thicker and more rigid. The stomach holds less food as it cannot stretch and transition of food is slower due to decreased relaxation of the stomach. It is sometimes known as leather bottle stomach.