Stomach Cancer
Definition
Stomach cancer is the 6th most common fatal cancer in the U.K. and one of
the most common malignant tumours in the world. It is very common in Japan and
in those of Japanese origin.
Incidence
In the U.K. around 15 per 100,000 males are affected per year. The number of
gastric cancer cases is falling but we do not know why this is. Men are affected
more often than women.
Causes
Patients with pernicious anaemia are at increased risk of developing gastric
cancer. It has been suggested that Helicobacter pylori (bacteria in the stomach)
may be involved in the development of gastric cancer but this has not yet been
proved. Diets which are high in alcohol, spiced, salted or pickled foods may
promote gastric cancers. People with Blood Group ‘A’ are at slightly higher
risk than other blood groups. Previous gastric ulcers do not develop into gastric
cancers.
Signs & Symptoms
Epigastric pain (pain in the top half of the abdomen) or indigestion is the
first symptom. The pain may be intermittent but can be constant and severe.
Sickness, nausea, loss of appetite and weight loss can occur and vomiting is
often a feature. Unfortunately, these symptoms are very similar to those of
peptic ulcer disease and indigestion is extremely common within the population
so that it can be hard to know at first presentation whether indigestion is
caused by a simple stomach upset, an ulcer, or by gastric cancer. If the cancer
bleeds then anaemia can be an accompanying feature. Because the symptoms are
rather vague most patients are picked up at a late stage.
Tests to Diagnose Gastric Cancer
The most common way to diagnose gastric cancer is by endoscopy. In this test
a flexible tube containing a fibre optic light source is passed through the
mouth, down the oesophagus and into the stomach where the lining is inspected.
Air is put into the stomach via a tube so that the lining can be inspected more
easily. If an ulcer or other lesion is seen then specimens of it are taken through
the endoscope so that they can be sent to the pathology laboratory and inspected
to see whether the lesion is a cancer or not.
Barium meal - Where a drink
of barium is taken and X-rays follow is another way of diagnosing gastric cancer.
A CT scan or ultrasound scan is not used to diagnose gastric cancer but may
be used to detect if it has spread to surrounding organs.
Treatment
Surgery
Surgery is the main treatment for gastric cancer since it provides the best
control of symptoms such as vomiting or bleeding and sometimes offers a cure.
The outcome currently is somewhat gloomy with a 10% 5 year survival rate, although
if an early cancer is diagnosed which has not spread to any surrounding lymph
glands or organs then the 5 year survival is much better than this.
Medical
Curative
Surgery remains the only curative treatment available in stomach cancer.
In locally advanced stomach cancer, giving (neoadjuvant) chemotherapy before
surgery to shrink the cancer may improve resection rates but this has not been
proven to improve survival. There is currently a Medical Research Council randomised
trial (MAGIC) to address this uncertainty and patients may be offered treatment
within this trial. Similarly, giving (adjuvant) chemotherapy postoperatively
has not been proven to reduce the risk of relapse or to improve survival.
Palliative
In patients who have unresectable disease or evidence of spread to other organs,
treatment is aimed at palliating symptoms and improving quality of life. This
usually consists of chemotherapy given either intermittently in 2 or 3 weekly
cycles or a combination of 3 weekly cycles with a continuous infusion of 5-fluorouracil
for the entire duration of treatment (ECF). Side-effects of chemotherapy include
hair loss, low blood count, mouth ulcers, diarrhoea, sore hands and feet (plantar-palmar
syndrome). In patients who respond well to chemotherapy, some prolongation of
life would be expected. Radiotherapy may be useful in palliating specific symptoms
such as obstruction of the oesophagus to swallowing.
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