Gastric Cancer - In a Nutshell!

Gastric (stomach) cancer occurs when malignant cells form in the lining of the stomach. By far, it is known to be the second most common cause of cancer-related deaths not only in Asia but also worldwide. Though it can affect both male and female populace, it is seen more commonly in men and in people aged 50 years or older.

1. Type: Gastric cancers can present as one of the following types - 

   1. Adenocarcinoma: Begins in the glandular cells lining the inside of the stomach. This forms a majority of the stomach cancers.
   2. Lymphoma: Begins in immune system cells present in the walls of the stomach. Occurrence of lymphoma, in the stomach, is rare.
   3. Carcinoid Tumor: Begins in hormone producing cells of the stomach.  Occurrence of carcinoid cancer, in the stomach, is rare.
   4. Gastrointestinal Stromal Tumor (GIST): begins in nervous system cells of the stomach. Occurrence of GIST, in the stomach, is rare.

2. Gender: It affects both male and female populace.

3. Etiology: The factors that are associated with increased risk of gastric cancer include the following mostly –

   • ‘Helicobacter Pylori’ bacterial infection in the stomach is a common cause of gastric cancer of both the intestinal (expanding) & diffuse (infiltrative) type. Furthermore, studies indicate that high salt intake is synergistic with H. Pylori infection in the manner that it is likely to increase the risk of gastric cancer that is induced by H. Pylori bacteria.
   • Smoking, consuming alcohol, red meat, salty/ smoked/ processed foods, low intake of fruits and vegetables, diets rich in nitroso compounds, eating foods contaminated with aflatoxin fungus etc all.
   • Atrophic gastritis characterized by chronic stomach inflammation is known to increase the risk multi-fold. Chronic gastric inflammation can lead to atrophy of the gastric mucosa, metaplasia, dysplasia and finally carcinoma.
   • History of pernicious anaemia, gastric ulcers, adenomatous gastric polyp etc all.
   • Family history of gastric cancer. Several familial syndromes that have been associated with a pre-disposition to gastric cancer include familial adenomatous polyposis, Lynch syndrome, Peutz-Jeghers syndrome and e-cadherin mutation (diffuse type)
   • Blood group A, Obesity etc all are known to be associated with diffuse or cardia gastric cancer.
   • Low socioeconomic status - persistent lifestyle issues/ irregularities including high stress coupled with an improper diet/ dietary pattern.
   • Epidemiological evidence is indicative of a risk or pre-disposition to gastric/ stomach cancer for people suffering from diabetes mellitus (DM).
   • Very high dose ionizing radiation exposure is an uncommon risk for gastric cancer.

4. Features: There are often no early stage symptoms. Early stage symptoms, if any, are non-specific and are likely to be ignored, thus delaying the diagnosis most often. Hence, gastric/ stomach cancer is often detected at an advanced stage where the disease is either locally advanced or metastatic. The various presentations (of signs & symptoms), by stage (early or advanced), of gastric cancer are as enumerated below:

   1. Early Stage – can present with one or more of the following non-specific symptoms/ signs -

      • Dyspepsia (Indigestion),
      • Stomach/ Epigastric discomfort,
      • Bloated feeling after eating,
      • Mild Nausea/ Vomiting,
      • Blood in Vomit (Haematemesis),
      • Heartburn,
      • weight loss (Cachexia)
      • Anaemia,
      • Occult blood in stool/ Melaena,
   2. Advanced Stage – presents with one or more of the following symptoms/ signs -
      • GI Bleeding with black tarry stools (Melaena),
      • Persistent Nausea/ Vomiting,
      • Blood in Vomit (Haematemesis),
      • Early Satiety,
      • Anaemia,
      • Loss of Appetite (Anorexia),
      • Weight loss (Cachexia),
      • Persistent pain in the abdomen,
      • Fluid build-up in the peritoneal cavity (Ascites),
      • Edema of the lower extremities,
      • Liver Enlargement (Hepatomegaly)/ Jaundice,
      • Difficulty swallowing food (Dysphagia)
5. Screening: Is generally recommended for asymptomatic populations in high incidence areas or as surveillance for high risk individuals. The goal of screening, as usual, is to be able to detect & diagnose gastric cancer at an early stage which is potentially curable. It is mostly endoscopic/ radiologic.

6. Diagnosis: Following are the diagnostics employed in gastic cancer -​

   • Physical Examination: May be remarkable for palpable abdominal mass, weight loss (cachexia), abdominal distension, ascites, hepatomegaly, lower extremities edema and lymphadenopathy for gastric cancers in the advanced stage. For early gastric cancers, however, physical examination is largely uninformative.
   • Blood: Hb- may be low, ESR – raised, tumor markers CEA & CA-19-9 could be raised sometimes in adenocarcinoma but are not frequently elevated. Abnormal blood test results may be indicative of malignancy, but a follow-up gastroscopy/ biopsy is always the gold standard for accurate diagnosis.
   • Stool: Occult blood may be +ve
   • Barium Meal X-Ray: Could show a filling defect at the site of the carcinoma/ cancer growth.
   • Gastroscopy/ Biopsy: Clinches the diagnosis.
   • Endoscopic Ultrasound: Maximizes tumor staging as it helps determine the depth of invasion of the tumor.
   • CT Scan: Of chest, abdomen & pelvis helps detect metastatic disease, if any, and also helps stage the disease (TNM) appropriately.
   • Bone Scan: Helps detect osseous metastasis (bone mets), if any.
7. Treatment: Conventional treatment includes surgery, chemotherapy and radiotherapy as contextually appropriate. Surgery (i.e. gastrectomy either sub-total or total), with an adjuvant chemotherapy and/ or radiotherapy as contextually relevant, is the only treatment that is known to cure the disease in light of the prognostic indicators as briefly enumerated in the section below. Chemptherapy and/ or radiation alone cannot be curative. Mostly, it can improve symptoms, and may prolong survival. Simultaneously, an adjunctive or integrative naturopathic treatment with suitable complementary & alternative medicines (CAM) too can help improve clinical outcomes and facilitate recovery as feasible contextually.

8. Prognosis: For gastric cancer is variable. Preventive measures, earlier diagnosis and right early treatment is key for an effective therapeutic management & better prognosis. Like most other cancers, the chances of cure for an early stage gastric cancer are more. The cure/ recovery chances are influenced by the grade, stage of cancer, recurrence and the patient’s general health & vitality etc all. Distal tumors are known to be cured more often than the proximal ones. Again, intestinal-type gastric cancers are known to have a better treatment outlook in comparison to the diffuse-type gastric cancers.

9. Prevention: Rightly said, prevention is always a better choice. Although genetic risks are difficult to modify, still an adherence to a relative Mediterranean diet, maintaining an ideal body weight and an active lifestyle with due emphasis on regular exercising, de-stressing and relaxation is highly recommended for reducing the risks of many cancers including gastric cancer. A healthy eating plate comprises essentially a low fat diet, fibre rich foods including whole grain cereals, green leafy vegetables cooked using healthy vegetable oils, fresh fruits of all colours as seasonally available and healthy proteins/ fats including fresh fish, poultry, beans, nuts etc all. The consumption of alcohol, if any, has to be strictly in moderation, and is best avoided in a high risk scenario. Smoking is to be avoided too. Again, red meat, butter, refined grains, sweets, sugary drinks including carbonated beverages and other high calorie foods etc all, if any, are to be taken sparingly. Not only it is important to eat healthy, but also it is equally important to eat properly. Insufficient chewing, eating until full, eating meals within a short time etc all are best avoided so as to ease off digestive burden on the stomach/ other organs in the GI tract. Last but not the least, consumption of clean and filtered water, natural probiotics like freshly prepared yogurt/ butter milk, maintenance of cleanliness & hygiene including oral hygiene etc. all can help guard against H. Pylori infections. Breastfeeding is known to be protective against H. Pylori infections too.