Stomach cancer

Stomach is one part of the digestive system. It secretes gastric acid to help digest and grinds large pieces of food into small ones. The food then enters the intestine by peristalsis for further digestion process.

Mutations in stomach cells lead to development into malignant tumour called stomach cancer. The etiology of stomach cancer is so far uncertain.

Many factors increase the risk of developing stomach cancer. Research shows that helicobacter pylori (a kind of bacterium which survives in the stomach and duodenum) infection may increase the chance of stomach cancer. Other risk factors include：

• Male.
• The older the age, the higher the chance of stomach cancer. There is a sharp rise in stomach cancer rate in people over age 50.
• Consumption of high-salted, pickled and smoked food will increase the danger of having stomach cancer.
• People who have stomach polyps, had gastrectomy (stomach removal surgery) or pernicious anaemia (anaemia resulted from deficiency of vitamin B).
• Smoking.
• People whose immediate family members have had stomach cancer are twice as likely to develop stomach cancer than others.

Patients with stomach cancer can have the following symptoms. However, these symptoms can be caused by other more common illnesses, such as gastritis, stomach or duodenal ulcer. If in doubt, consult a doctor as soon as possible.

• Persistent indigestion, loss of appetite.
• Rapid weight loss.
• Swelling of abdomen.
• Feeling bloated after eating.
• Vomiting, even blood in vomitus.
• Blood in stools, or black stools.
• Anemia, fatigue, weakness.

The causes of stomach cancer are still not fully understood, but there are some risk factors for stomach cancer, including:

• Advancing age;
• Gender: Stomach cancer is more common in men;
• Infection with Helicobacter pylori (H. pylori);
• Precancerous lesion of stomach cancer (e.g. atrophic gastritis and intestinal metaplasia);
• Smoking;
• Alcohol consumption;
• High intake of salt-preserved food and salty food;
• Being overweight or obese; and
• Family history of stomach cancer and certain hereditary syndromes.

In general, adopting a healthy lifestyle through regular physical activities, having a healthy and balanced diet by avoiding salt-preserved foods and consuming adequate fruits and vegetables, maintaining a healthy body weight, no smoking and avoiding alcohol consumption may prevent or reduce the risk of stomach cancer.

Based on the available international and local scientific evidence, the Government’s Cancer Expert Working Group on Cancer Prevention and Screening has made the following recommendations on stomach cancer screening for the local population:

1. Primary prevention remains an important strategy for reducing the risk of stomach cancer. All individuals should adopt a healthy lifestyle which includes no smoking, avoiding alcohol consumption, healthy eating (with adequate intake of fruits and vegetables and avoidance of high-salt and salt-preserved foods) and maintaining healthy body weight.

For asymptomatic population at average risk

2. Screening for stomach cancer (by upper gastrointestinal series, upper endoscopy or biomarkers, such as H. pylori serology) is not recommended in asymptomatic persons at average risk. Screening for H. pylori infection (by urea breath test, serology or stool antigen test) among asymptomatic persons in the general population is also not recommended.

For symptomatic persons at increased risk

3. Persons at increased risk, e.g. with precancerous lesion of stomach cancer or family history of stomach cancer, may consider seeking advice from doctors regarding the need for and approach of screening.

People with aforementioned symptoms should consult a doctor as soon as possible and undergo tests. Detection of stomach cancer in early stages can increase the chance of cure. Tests for stomach cancer include:

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   Upper endoscopy

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   Abdominal ultrasound and computer tomography (CT) scan

   These examinations are mainly used to diagnose and stage stomach cancer.

After diagnosis of stomach cancer, doctor may suggest the following treatments according to the cancer stage:

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   Stomach removal surgery

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   Radiotherapy

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   Chemotherapy and targeted therapy

The common complications of stomach cancer and its treatments are as follows:

• Gastrointestinal bleeding

  Dizziness, palpitations, black tar-looking stool, coffee ground-looking vomitus.

• Obstruction of biliary tract

  It will cause pressure to common bile duct. The patient has symptoms of yellow eye white and skin and grey stool.

• Obstruction of pylorus

  Pylorus is a spincter structure at the end of stomach. When it is blocked by tumour, food cannot pass to duodenum through pylorus smoothly, causing upper abdominal pain and vomiting.

• Peritonitis

  Tumor can cause stomach perforation which can complicated by peritonitis. This is a life-treatening emergency in which the patient can present with acute abdominal pain.

• Complications after stomach removal surgery

  There may be leakage in the anastomosis after stomach removal surgery. On the other hand, patients may have symptoms such as vomiting after meal, diarrhea, dizziness and low blood pressure. These symptoms are caused by the reaction to the food passing too quickly to small intestine after the removal of part of or the entire stomach.

• Complications of chemotherapy

  Common side effects include weakened immunity, diarrhea, nausea, vomiting, and fatigue. Doctors will arrange regular blood tests to monitor the function of bone marrow. Doctors will also prescribe drugs to reduce the side effects of chemotherapy.

• Complications of targeted therapy

  Targeted therapy for stomach cancer may cause diarrhea, nausea, vomiting and affect cardiac function. Doctors will prescribe drugs to reduce the side effects of targeted therapy and arrange regular cardiac assessment.

After removal of stomach, patient needs to make some adjustments in diet:

• Advise frequent small meals, e.g. 6 meals a day and avoid eating too much, otherwise there may be vomiting, diarrhea, dizziness and low blood pressure. Avoid any drinks during and after meals to prolong the time the food staying in the stomach to promote absorption.
• Choose food which is easy to digest.
• Get used to chewing food slowly.
• Take a rest after meals to prevent indigestion.
• Avoid anemia, be aware of the supplement of vitamin B12 (e.g. liver, meat, fish and milk). Some patients need regular injection of vitamin B12.

• Regeneration Society Ltd
• Cancerinformation.com.hk
• Hong Kong Cancer Fund
• Hong Kong Cancer Registry
• The Hong Kong Anti-Cancer Society
• The Hong Kong Society for Rehabilitation

1. Introduction

   OGD is currently the best method in examining the lumen of the upper digestive tract; by using a flexible endoscope, oesophagus, stomach and duodenum can be examined. Compared with conventional X-ray examination, OGD is more accurate in making the diagnoses. With the use of different types of accessory equipment, endoscopist can perform biopsy and deliver surgical therapies for upper gastrointestinal tract diseases. Patients suffering from peptic ulcer disease or bleeding, suspected oesophageal and gastric cancer, symptoms of indigestion, acid reflux or difficulty in swallowing should receive OGD examination.

2. Preparation before the procedure

   • Patients need to be fasted for at least 6 hours before the procedure.
   • Dentures, spectacles and metallic objects should be removed before the procedure.
   • Patients should inform the medical staff of any major medical problems including diabetes, hypertension, valvular heart disease and pregnancy, and continue their medications as instructed.
   • Patients should also provide information concerning the current medications used especially antiplatelet and anticoagulation drugs and any allergic history.
   • Patients should avoid driving to attend the outpatient procedure and also avoid heavy drinking, smoking or use of sedative before the procedure.
   • Elderly patients and those with difficulty in walking should be accompanied by family member.

3. The procedure

   • Prior to the examination, local anaesthetics will be sprayed to the throat of patients. A flexible endoscope with a diameter of 0.9-1.2cm will then be introduced by the endoscopist through the mouth of patients to the oesophagus, stomach and the duodenum. The internal lining of the upper gastrointestinal tract will be carefully examined.
   • During the procedure, patients are fully conscious.
   • In individual cases, intravenous sedative drugs may be given depending on the clinical conditions and the patient’s tolerability to the procedure.
   • In general, the procedure will last for 5-20 minutes, but in complex cases that require additional therapies like in the control of active bleeding, the examination may be prolonged. Patients will be carefully monitored during the procedure.

4. After the procedure

   • As the effect of local anaesthetic will persist for about an hour, patients should remain fasted until anaesthesia has worn off. This prevents choking with food or fluid intake.
   • If intravenous sedation is used, patients should avoid operating heavy machinery, signing legal documents or driving for the rest of the day.
   • Patients should follow the instruction given by the medical staff in completing the drug treatment.

5. Risk and complication

   • Minor discomfort including nausea, mild sore throat and distension discomfort of the stomach is common. The effect of local anaesthetics will keep the throat numb for about an hour, during which swallowing is rendered difficult. These should disappear within a day.
   • Major complications including perforation, bleeding, death, cardiopulmonary complications and infection may happen although the chances are low. The complication risks vary depending on patients’ conditions and complexities of the diagnostic and therapeutic methods used. Patients should consult the attending physicians for the detail of the endoscopic procedures. When major complications arise, emergency surgical treatment may be needed and patient death may rarely occur.

6. Follow-up

   • Patients can contact the endoscopy unit for any discomfort after the procedure, or if the patients have any question about the examination result and drug treatment.
   • However, if serious events develop, such as passage of large amount of blood, severe abdominal pain, etc. patients should seek medical advice at the nearest Accident and Emergency Department.

7. Remarks

   For further information please contact your doctor.

1. Introduction

   Surgical resection of the stomach is most commonly performed as treatment for malignancy. It is also sometimes indicated for benign pathology in the stomach. An adequate surgical resection remains the only effective treatment which offers a chance of cure or long term survival in cancer of the stomach. Furthermore, a palliative resection whenever feasible is effective in relieving symptoms such as obstruction, bleeding and perforation.

2. Preparation before the procedure

   • Nasogastric tube and Foley's catheters are inserted with the purpose to empty the stomach and bladder fro the surgery and post-operative monitoring.
   • One to two tubal drains may be inserted into the abdominal cavity to avoid intra-abdominal collection following extensive dissection for lymphatic clearance.

3. The procedure

   • The principles underlying a potentially curative resection of gastric cancer include:
     • Adequate tumour free margins.
     • A partial, subtotal or toal gastrectomy can be performed depending on the location of the primary tumour.
     • Resection of part of the esophagus may be performed for tumour around esophagogastric junction.
     • Safe and well-functioning reconstruction.
   • Surgical approach may include conventional open or laparoscopic techniques:

     • Conventional open gastrectomy

       It is suitable for most operable gastric cancers and generally involves a midline incision in the upper abdomen. It follows the general surgical principles for stomach cancer.

     • Laparoscopic gastrectomy

       Laparoscopic approach is regarded to be suitable for some early stage gastric cancer. It generally involves about five 1 to 4 cm incisions in the upper abdomen and the procedure is carried out laparoscopically.

   • Gastrectomy is performed under general anesthesia. Very often, epidural anesthesia or patient-control-anesthesia is added to reduce post-operative pain.

4. After the procedure

   • Early ambulation, vigorous breathing and coughing exercise are much encouraged. These help to reduce the chance of chest infection, urinary retention as well as venous thrombosis.
   • Patients undergoing total resection of stomach are prone to anaemia due to impaired vitamin B12 absorption. Hence, supplement in form of regular intra-muscular injection is required.
   • According to individual’s tolerance, some form of dietary adjustment is likely required especially in the early post-operative period.
   • Post-operative adjuvant treatment, such as chemotheraphy and radiotherapy, may be indicated in suitable cases.

5. Risk and complication

   • Surgical risks associated with gastrectomy occur in 1-5% and include:
     • Intra-operative / post-operative bleeding in view of the extensive field of dissection.
     • Anastomotic leakage.
     • Intra-abdominal collection and abscess.
     • Fistulation – e.g. pancreatic fistula.
     • Chest complications such infection and pneumonia, pleural fluid collection.
   • Late sequelae – bowel disturbance, dumping, mal-nutrition, anaemia etc.
   • Mortality from gastrectomy occurs in less than 1% of cases.

6. Remarks

   For further information please contact your doctor.