Diagnosis & Treatment for Gastric Cancer

Author : Bhadresh Bundela

Diagnosis of stomach cancer (gastric cancer)

The doctor will refer the patient for gastroscopy (where a telescope – via a flexible fibreoptic tube- is passed via the mouth into the stomach to directly view the lining and take samples, biopsies).

The alternative diagnostic test is a barium meal study, where the patient drinks some barium solution, the barium making the fluid radio-opaque such that its filling of the stomach allows the visualising radiologist to view the negative image of the stomach wall and discern whether it is irregular to the degree that he can diagnose a stomach cancer. The reason that most would now first go to endoscopy/gastroscopy is that the positive barium meal requires a subsequent endoscopy anyway for the required biopsy proof of the diagnosis.

The doctor will also wish to perform some abdominal scanning, usually CT, and chest x-ray (to check for spread outside the stomach, and blood tests.

Stages of stomach cancer (gastric cancer)

The staging of stomach cancer is largely derived from the surgical findings and the histological examination of the resected specimen. The exact nomenclature of staging is not relevant to the lay person but it is clear that if there is metastatic disease (i.e. secondaries outside the stomach) obvious on the abdominal scan, then the patient is incurable and a total removal of the stomach is not in the patient’s interest in that the disease has already ‘bolted’.

Where the disease is operable (i.e the disease is apparently confined within the stomach) then the extent of the disease by histology (i.e. microscopic exam of the resected specimen ) is the key to prognosis (the future chance of survival).

The first point of interest is as to whether the serosa (the membrane lining the outside of the stomach) has been breached by tumour, there being a 50% five year survival in those whose disease has not breached this lining membrane and only 15% in those in whom it has. The second histological point of interest is the status of the regional lymph nodes.

In patients whose disease has not reached to the regional lymph nodes, the five year survival approximates to 31%, whereas in patients whose nodes are involved microscopically by cancer, the overall likelihood of surviving five years is only 17%.

Therefore, without going into lengthy staging subcategories, the outlook is determined by whether the disease is ostensibly confined to the stomach on pre-operative scanning and then on the histological examination of the resected stomach specimen with particular regard to the serosa and the regional lymph nodes.

Outcomes of stomach cancer (gastric cancer)

Sadly, the majority of patients relapse and die, largely due to liver relapse. The chemotherapy options have been outlined above and there are no particularly encouraging new agents that are working their way through the development arena at present. Chemotherapy is never curative in this situation and its use should therefore be weighed and considered against the possible benefits; once again it’s the quality of life versus any perceived increase in length of life that has to be weighed.

Palliation of the dying patient is concentrated on pain control and then taking individual symptoms as they arise and treating on their own merits.

Treatment of stomach cancer (gastric cancer)

For disease localised to the stomach on the pre-operative tests outlined above, there is no question but that surgical removal of the stomach is the best first manoeuvre; indeed , it is the only treatment that can cure the patient.

The commonest surgical procedure is total removal of the stomach, although some will only remove a majority of the organ if there is no disease in the furthermost regions from the cancer itself. Where the disease is at the oesophago-gaastric border, then an oesophago-gastrectomy is required.

Where the disease is locally outside the stomach at operation, it may still be in the patient’s interest to have some form of surgical procedure performed if the patient cannot digest food for want of a patent pathway for food, or in whom the tumour is bleeding. However, in such patients with aggressive disease outside the stomach wall the survival is short and heroic surgery is not indicated, only occasional selected operations to overcome specific problems.

An alternative to surgery in these palliative situations is laser therapy: Used through the endoscope, the laser can vaporise cancer tissue and thermo-coagulate bleeding points, and can be a very useful tool in this situation.

As for oesophageal cancer, the use of stents for obstructing lesions may also have a role in these locally advanced cases, usually those inoperable patients with disease at the oesophago-gastric border.

Gastric cancer has a high risk of spread outside the stomach and the liver is at highest risk. Involvement of the liver is invariably fatal. Anything that could be done to reduce the chance of spread should be considered at the time of presentation to the doctor as the patient is surely incurable if the disease takes root in the liver. The problem is that, unlike the situation in breast cancer or childhood cancer, the use early of (adjuvant) chemotherapy, in the immediate post-operative period, in patients operated with curative intent for ostensible localised gastric cancer, has not been shown to be effective at improving the cure rate compared to those receiving the operation alone.

Having said this and agreeing that an ‘overview’ of all trials looking at adjuvant chemotherapy up to 1993, showed no benefit from the routine use of chemotherapy after operation, nevertheless, since then some improvements in chemotherapy have occurred and the regimens ECF (epirubicin, cis-platinum and fluorouracil) and FAMTX are the most commonly employed.

Clearly, more trials need to be established before ‘up-front’ chemotherapy in the adjuvant situation is standard practice; the same applies to primary (also called neoadjuvant) chemotherapy where the chemotherapy is used prior to any operation in order to shrink the growth down to a more operable (and hopefully curable) size.

For relapsed patients or those whose disease is beyond operability at the outset, then the chemotherapy regimes outlined above may have a chance of worthwhile response in up to half of the patients.

In reasonably fit patients, the doctor will recommend a carefully audited trial of chemotherapy where the regime is administered several times (usually at three weekly intervals) following which he will repeat some imaging test that defined the extent of the disease at the outset of chemotherapy to tell him if the therapy has helped objectively. Subsequent recommendations are based on this second scan’s findings.

Nothing has so far been mentioned concerning the use of radiotherapy in this disease and this is because it has a very limited role. Although a slight local relapse benefit was shown in some trials for giving post-operative radiotherapy to the stomach bed (presumably due the desired effect of sterilising any cells in the vicinity), any benefit was small and did not translate into a significant overall survival benefit. Currently, radiotherapy has a very limited place in the treatment of this disease.