Diagnosis and Treatment of Gastric Cancer

Diagnosis of Gastric Carcinoma

Initial investigations to diagnose Gastric Carcinoma

Full blood count
Abnormalities on full blood count are usually non-specific. Occasionally anaemia can result from chronic blood loss or from chronic disease.

Liver profile
Raised liver enzymes may indicate liver metastasis, and raised alkaline phosphatase may result from bony metastasis.

Upper gastrointestinal endoscopy

A high index of suspicion is required in the older patient with new-onset dyspepsia, and the investigation of choice is an upper gastrointestinal endoscopy, which allows direct visualization of the stomach lining and facilitates biopsies for histological examination.

Barium swallow

Where facilities are not available for gastrointestinal endoscopy, a barium swallow may suggest gastric carcinoma if an ulcerated area or a narrowed distorted region is identified.



Investigations following the diagnosis of Gastric Carcinoma

Having established the diagnosis, further investigation is needed to stage the disease and plan further management.

Staging CT abdomen

A CT scan of the abdomen is the main staging investigation, giving an indication of local extent and any intra-abdominal spread

Staging laparoscopy

Prior to major surgery, most surgeons tend to perform a staging laparoscopy to screen for peritoneal metastasis or local fixity of the tumour, as these would preclude gastric resection.

Endoluminal ultrasound is able to assess accurately the depth of tumour invasion and is gaining in popularity.




Treatment of Gastric Carcinoma:

Surgery is the only curative management option for patients with gastric carcinoma. Prior to surgery, it is necessary to evaluate pulmonary function and any concomitant disease that may increase the risk of operative mortality.

The options for patients not suitable for curative surgery include palliative gastrectomy, gastric bypass procedures and chemotherapy.


Surgical management of Gastric Carcinoma

Gastrectomy

The aims of curative surgery are to excise the lesion with adequate resection margins and to remove local and regional lymph nodes. In the majority of cases it is possible to perform the necessary resection through a midline laparotomy incision. Occasionally a left thoraco-abdominal incision may be required.
A subtotal gastrectomy is appropriate for well-circumscribed tumours located away from the cardia. A total gastrectomy is required for tumours located in close proximity to the cardia and for infiltrative lesions (5 cm resection margins are required). In general, the first tier of draining lymph nodes is also excised for curative resection.

The stomach is mobilized en bloc with the greater omentum and local lymph nodes. Proximally, the upper stomach is closed (usually with a linear stapler), or in a total gastrectomy the lower oesophagus is transected. The first part of the duodenum is stapled closed and usually oversewn. Reconstruction is usually by a Roux loop or a Polya (Billroth II) gastroenterostomy.


Surgery to relieve the symptoms (Palliative surgery)

For unresectable lesions of the antrum, gastric bypass surgery in the form of a gastro-enterostomy (i.e. stomach to intestine) may be more appropriate. Non-curative gastrectomy often provides the best form of palliation and is usually necessary in patients with bleeding or obstructive lesions.

Medical management of Gastric Cancer

Chemotherapy

Adjuvant chemotherapy (after curative resection) is not established treatment. The impact of current regimens on survival is small (9% improvement at 3 years).

Radiotherapy

Radiotherapy has a limited role in the treatment of gastric cancer. It is occasionally used to treat residual disease from unsuccessful surgery. Combination chemo-radiotherapy has been shown to improve median survival by 9 months, and may be considered in patients at high risk of recurrence.

Palliative endoscopic therapy for gastric carcinoma

For patients unfit for surgery, or those with unresectable disease, various endoscopic therapies are available. Local tissue coagulation with laser or argon plasma coagulation may be helpful to control symptoms of upper gastrointestinal bleeding. Expandable metal stents or intubation with a rigid prosthesis may be employed to relieve gastric outflow obstruction.

Prognosis of Gastric Carcinoma

Gastric carcinoma has a poor prognosis, with an overall 5-year survival rate of around 5%.




Important point to note about gastric Carcinoma
Non-specific symptoms of gastric carcinoma often 'respond' to antacid therapy. It is important not to ignore initial complaints in the older patient.

Types, causes and symptoms of gastric carcinoma

Gastric Cancer - Types, Causes and Symptoms

Gastric carcinoma is the second most common cancer in the world. The incidence is highest in Japan, China, Eastern Asia and Eastern Europe, ranging between 36.3 and 77.8 per 100 000 in men and 16.8 and 33.3 per 100 000 in women, an approximate 2:1 male preponderance. It is primarily a disease of the elderly, with a peak incidence at age 70-80.

Types of Gastric Carcinoma

Approximately 90% of stomach cancers are adenocarcinomas (the remaining 10% are non-Hodgkin's lymphomas and leiomyosarcomas). Adenocarcinomas are subdivided into intestinal and diffuse histological types (Lauren classification). The intestinal variety arises from a background of chronic gastritis and is generally well circumscribed. The diffuse type usually arises within apparently normal gastric mucosa and tends to be poorly localized, infiltrating beneath the mucosa through the muscle of the stomach wall. In the advanced stage, this leads to a thickened and shriveled stomach known as linitis plastica (leather bottle stomach). Unfortunately it is this type of disease that is often seen in the younger patient.

Causes and risk factors of Gastric carcinoma:

Risk factors for intestinal-type gastric carcinoma (those for the diffuse type are largely undefined) include smoking and diet (in particular high consumption of preserved food and high salt intake); there is a weak association with excess alcohol intake. Other diseases associated with gastric carcinoma are pernicious anaemia, atrophic gastritis, gastric adenomatous polyps and H. pylori infection, an increasingly important risk factor associated with a 2-fold increase in risk of gastric cancer.

Course of Gastric Carcinoma

Local

In the early stages, when the disease is confined to the mucosa or submucosa, it may be either a prominent nodule or a depressed ulcer. Excavated cancers may cause upper gastrointestinal bleeding and anaemia, whilst large exophytic growths near the cardia can (rarely) produce dysphagia.

Metastatic

The majority of tumours present with local or with lymph node metastases. Spread may be lymphatic, haematogenous (to the liver, lungs and brain) or transcoelomic to the peritoneum, omentum or ovaries (Krukenberg tumour).

Symptoms of Gastric Carcinoma

A common presentation is that of new-onset dyspepsia in a middle-aged patient (over 45 years). Symptoms are often non-specific such as epigastric discomfort, post-prandial fullness, loss of appetite or vague indigestion. Other symptoms include dysphagia, nausea or vomiting (especially after eating), weight loss and those of iron deficiency anaemia.

Clinical examination is often unremarkable in early stage disease. In advanced disease, clinical findings may include a mass in upper abdomen, enlarged liver, enlargement of the lymph glands, classically in the left supraclavicular fossa (Virchow's node, Troisier's sign), ascites and jaundice.

Types,Causes and Symptoms of Gastric carcinoma
Diagnosis and Treatment of Gastric Carcinoma