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