The stomach is like a bag lined with muscle and glandular cells, and is the first place chewed food goes to after it has been chewed and swallowed. It produces acidic juices from its lining to start off the digestive process.
The vast majority of stomach cancers arise from this glandular lining of the stomach and are called adenocarcinomas. There are two broad types of stomach cancer: an intestinal type and a diffuse type. The former are like the usual adenocarcinomas found in the gut, whereas the latter have a very different appearance.
Symptoms of stomach cancer
The commonest symptoms of stomach cancer are non-deliberate weight loss and upper abdominal pain. Some may have difficulty swallowing if the tumour is near the top of the stomach. Another way patients are diagnosed with stomach cancer is if they are found to be anaemic, sometimes an endoscopy is done to check if there is a source of bleeding in the upper gastrointestinal tract. Occasionally the bleeding can be severe and patients have black tar like stools, as the blood passes though the gut. Gastric ulcers that are benign can produce the same type of bleeding.
Treatments of stomach cancer
The treatment of stomach cancer depends on the stage and the general fitness of the patient.
When the staging investigations suggest that cure is possible, and the patient is fit, it is now usual for chemotherapy to be offered before an operation. However, an operation may be the first treatment if the tumour is obstructing the passage of food, or if the tumour is thought to be very small. Otherwise, chemotherapy (see below) is used to shrink the tumour before the operation, and to start a treatment that covers the whole body sooner. Studies have shown that this approach improves the overall survival.
The operation that is done depends on where in the stomach the tumour is, usually a 'total gastrectomy' is done, where the whole stomach, along with the adjacent lymph nodes, are removed. If the tumour is in the lower part of the stomach, then a partial gastrectomy is done, which removes the lower half of the stomach, along with the lymph nodes.
After the operation, some oncologists recommend further chemotherapy, using the same drugs as were used preoperatively. However others may recommend a combination of chemotherapy and radiotherapy to where the stomach was, basing the decision on the results of the examination of the surgical specimen. Both approaches have been shown to improve outcome when compared to not receiving the extra treatment.
When the staging investigations show the best plan is to shrink the disease as much as possible, improve the quality of life but not aim to eradicate the tumour completely, then chemotherapy alone may be offered. The current standard chemotherapy uses three different drugs, Epirubicin, Cisplatin and 5-Flourouracil. The last drug may be replaced by a tablet, called Capecitabine, which is taken twice a day though the treatment. The treatment is given intravenously every 3 weeks. This chemotherapy is the same as is used before and after an operation, described above. Here, however, after 2 or 3 treatments, a scan is often repeated to see if the disease has shrunk. If it has, and the patient is not suffering unmanageable or life threatening side effects, then the treatment continues. Otherwise, it is best to stop.
Recently, a slightly different combination of chemotherapy drugs have been shown to be effective (Epirubicin, Oxaliplatin and Capecitabine). This may have some advantages, but on the other hand, the side effects are different, in particular the Oxaliplatin can cause tingling in the fingers, toes and throat particularly in the cold.
Other simple medicines or treatment may be given to help ease symptoms with or instead of chemotherapy. For example laser therapy, used through the endoscope, the laser can vaporise cancer tissue and seal off bleeding points, and can be a very useful tool in this situation.