Stomach Cancer

Stomach cancer, as the name suggests, is cancer in the cells of the stomach. The stomach is a muscular sac-like structure that receives food that we eat from the esophagus. The food remains in stomach for 2-3 hrs. During this time, the food starts getting digested and is then passed into the small intestines for further digestion. Stomach cancer is also known as gastric cancer and can affect any part of the stomach.

It's not clear what causes stomach cancer, though research has identified many factors that can increase the risk. Factors associated with increased risk of developing stomach cancer are as follows:

• High salt and nitrate consumption
• Low dietary intake of Vitamin A & C
• Excessive consumption of smoked or cured food
• Lack of refrigeration
• Consumption of contaminated water eg well water
• Gastro-esophageal reflux disease
• Obesity
• Workers in rubber and coal industries
• Cigarette smoking
• Infections with Helicobacter pylori or Epstein-Barr virus
• Radiation exposure
• Prior gastric surgery for benign gastric ulcer disease.
• Family history of gastric cancer
• Genetic Conditions such as the Li-Fraumeni syndrome, Familial Adenomatous Polyposis (FAP), Lynch syndrome can also predispose to stomach cancer

• Carcinoma: Cancers arising from the epithelial cells lining the stomach are called carcinomas. Carcinomas are of various types; with adenocarcinoma accounting for nearly 90 to 95 per cent of stomach cancer cases. The other rare types are squamous cell carcinoma, small cell carcinoma, adeno-squamous carcinoma, etc.
• Lymphoma: It is the cancer of the immune cells of the body, usually the T & B lymphocytes. These cells are also present in the walls of the stomach and hence can give rise to gastric lymphomas.
• Gastrointestinal stromal tumour (GIST): These cancers originate in the interstitial cells of the stomach cells, called the Cajal cells. Some of these tumours are benign, that is, non-cancerous, however, cancerous tumours may also originate.
• Gastrointestinal Carcinoid tumour: Stomach also has hormone producing cells. These cells, when become cancerous, form a carcinoid tumour.
• Sarcomas: These are relatively rare cancers and include Leiomyosarcomas, Lymphosarcomas, Fibrosarcoma, Myxosarcoma etc.

• Difficulty in swallowing
• Feeling bloated after eating or feeling full after eating small amounts of food
• Heartburn
• Indigestion
• Nausea
• Pain or fullness in upper abdomen
• Unintentional weight loss
• Vomiting with or without blood in vomitus
• Gastric outlet obstruction: This occurs when the cancerous growth obstructs the passage of food from the stomach into the small intestine. As a result, the food starts accumulating in stomach, causing distension of the stomach, fullness after meals and vomiting of food particles every few days.

Indigestion and heartburns are very common symptoms and may overlap with other gastric problems. The symptoms can appear in different forms as mentioned above and hence, if you are experiencing a combination of any of these symptoms, especially over longer periods, you should consult a doctor.

Once, you see a specialist, the following tests may be carried out:

• A physical exam: A through physical examination will be carried out, after taking a detailed history of your symptoms
• Endoscopy and / or biopsy: Usually an upper gastrointestinal endoscopy i.e. UGI scopy will carried out as first test, wherein an endoscope which has a camera at its end will be introduced through your mouth into the esophagus and stomach, to rule out any abnormal growth or ulceration.
• Biopsy: A biopsy will usually be performed at the time of UGI scopy to determine the type of stomach cancer.
• Blood tests: Routine blood tests along with special tests called tumor marker levels will be asked for eg CEA, CA 19.9.
• CT scan: A CT scan of the chest, abdomen and pelvis is done to determine the stage of disease; which in turn will help decide the best treatment sequence for a given patient.
• PET CECT scan: A PET CT scan may be suggested in advanced or recurrent cases to rule out spread of cancer to other sites, eg lungs, liver, bone, etc.
• Diagnostic laparoscopy and biopsy: In advanced cases, a diagnostic laparoscopy may be advised to document the spread of the disease. A biopsy can be performed at the same time.

Surgery: Surgical procedures to remove cancer include:

• Endoscopic Mucosal Resection (EMR) or Endoscopic submucosal dissection (ESD) which uses endoscope and special instruments to remove small early tumours present on the mucosal or submucosal layer.
• Subtotal gastrectomy: When the cancerous is bigger in size, a part of the proximal or distal stomach has to be removed along with adjacent lymph nodes. The rest of the stomach remnant is then anastomosed to the upper part of small intestine (jejunum) for establishing continuity for the food passage and digestion,
• Total gastrectomy: The whole of the stomach sometimes needs to be removed, depending upon the length of the stomach that is affected by cancer. In that case, the esophageal tube is connected directly to the small intestine (jejunum).
• Bypass surgeries: In some of advanced cases (stage IV), only bypass procedures are performed, like gastro-jejunostomy, so that the patient continues to eat well, during treatment.

Chemotherapy: Chemotherapy in the form of injections or tablets may be suggested depending on the stage of disease.

• Adjuvant chemotherapy: Is the chemotherapy given after surgery, usually, 6 cycles every 2-3 weeks
• Neoadjuvant chemotherapy: When chemotherapy is given before surgery it is called neoadjuvant chemotherapy, wherein 3 cycles are given every 3 weeks, before surgery, the remaining 3 cycles then given as adjuvant chemotherapy, after surgery.
• Chemo-radiation: It can also be recommended along with radiation treatment; called as concurrent chemo-radiotherapy, which can be used as neoadjuvant or adjuvant.
• Intra-peritoneal chemotherapy: This is a special form of delivering chemotherapy directly into the peritoneal (abdominal cavity) in patients with advanced stomach cancer. An intra-peritoneal (IP) port system is introduced underneath the skin of the abdominal wall with a tubing passed into the abdominal cavity, under general anaesthesia. This new treatment delivery system has been used successfully as neoadjuvant treatment also, especially in patients with peritoneally metastasised gastric cancer and has shown to increase the ability for complete remove all disease with consequent increase in survival, in this otherwise poor prognostic subgroup of patients.

Radiation therapy Radiation therapy either alone or in combination with chemotherapy may be suggested depending upon the surgical histopathological report.

Targeted therapy: Targeted therapy uses drugs to target specific proteins within the cancer cells, to kill them. For example, Trastuzumab targeting Her2neu protein in stomach cancer cells expressing Her2neu protein may be suggested during treatment for stomach cancer

Immunotherapy:In advanced cases, biological therapy or immunotherapy may be suggested for treatment. Immunotherapy targets the cells, which affect the body’s immune response and helps the body in killing cancer cells,

To reduce the risk of stomach cancer, you can:

• Exercise regularly and keep your weight under control
• Try to incorporate more fruits and vegetables into your diet each day
• Reduce the amount of salty and smoked foods you eat.
• Quit smoking.
• People with a family history of stomach cancer might consider tests, such as endoscopy, to look for signs of stomach cancer, after consulting their doctor.
• Do not delay seeking medical consult, when any symptoms appear.