What is Stomach Cancer?
Stomach cancer is the formation of cancer cells in the inner layer or lining of the stomach. Cancer is the uncontrolled growth of abnormal cells. The accumulation of these extra cells forms a mass of tissue called a tumor. Stomach cancer refers to cancer of the stomach only and does not include the other organs in the abdomen.
The stomach is part of the digestive system and helps you digest food. It is divided into 5 parts: cardia, fundus, body (corpus), antrum, and pylorus. Cancer can occur in any part of the stomach. However, most commonly cancer occurs in the stomach body or the cardia (gastroesophageal junction).
Types of Stomach Cancer
Stomach cancers are categorized based on the type of tissue they begin with:
- Adenocarcinomas, which are the most common, form in the glandular stomach lining.
- Lymphomas form from lymphocytes, a type of blood cell involved in the immune system.
- Sarcomas involve the connective tissue (muscle, fat, or blood vessels).
- Other types include squamous cell carcinoma, small cell carcinoma, and carcinoid.
The majority of stomach cancers, about 95%, begin in the glandular tissue that lines the stomach. The tumor may metastasize (spread) along the stomach wall or may develop directly through the wall and shed cells into the lymphatic system or bloodstream. Once beyond the stomach, cancer can spread to other organs near the stomach such as the small intestine, colon, liver, spleen, and pancreas.
Causes of Stomach Cancer
Scientists or doctors do not know exactly what causes cancer in the stomach. However, some risk factors are known to increase your chances of developing stomach cancer. These include:
- Male gender
- You are over the age of 55
- Infection with a common bacteria called H. pylori, which causes ulcers
- Inflammation in your gut called gastritis
- A certain type of long-lasting anemia called pernicious anemia
- Growths in your stomach called polyps
- Too much alcohol consumption
- Family history of stomach cancer
- Certain genes
- A diet high in salty, fatty, pickled, or smoked foods.
- A diet low in vegetables and fruits.
- Epstein-Barr virus infection
- Working in timber, metal, coal, or rubber industries
- Exposure to asbestos
- Hereditary conditions, such as Lynch syndrome and familial adenomatous polyposis
Signs and Symptoms of Stomach Cancer
Signs and symptoms of stomach cancer may include:
- Stomach pain
- Unexplained weight loss
- Black stools
- Loss of appetite
- Stomach bloating after eating
- Feeling full after eating small amounts of food
Diagnosis of Stomach Cancer
To detect if you have stomach cancer, your physician will conduct a thorough physical examination of your stomach to elicit any specific response that may be alarming. They will also review your medical history to find out if you have any risk factors for stomach cancer or if any family members have had it. For additional details, they may also order some diagnostic tests, such as:
- Blood tests to check for signs of cancer in your body
- Upper endoscopy in which a thin, flexible tube with a small camera and light source on end called an endoscope is placed down your throat to view your stomach.
- Upper gastrointestinal (GI) series test where you will be asked to drink a chalky liquid with a substance called barium, which coats your stomach and makes inner layers of the stomach appear more clearly on X-rays.
- CT scan, a powerful X-ray that provides more detailed images of the stomach tissues than standard X-rays.
- Biopsy, a diagnostic test in which a small piece of tissue is taken from your stomach to examine under a microscope for signs of cancer cells. This test may be performed during an endoscopy.
Treatment for Stomach Cancer
Stomach cancer treatment depends on the type and the stage or spread of cancer. Your age and general state of health is also important consideration by your doctor in determining the treatment modality. Surgery is the most common treatment for stomach cancer.
Stomach cancer can spread to other tissues and organs therefore removal of the cancerous tissue is a must. Three types of surgeries are used to treat stomach cancer. The type of surgery depends on where the cancer is located and how deep the cancer cells have invaded the area in the stomach. The 3 types of surgeries are:
- Endoscopic mucosal resection: This is done only when the cancer is detected at an early stage, where the chance of it spreading to the lymph node is less. In this procedure, cancerous tissue is removed from the stomach using an endoscope, a long flexible tube with a camera at the end. During the procedure an endoscope is passed through the mouth into the stomach and surgical tools are also passed through it to remove the cancerous tissue. The surgery is done using these tools and does not involve any cuts on the body.
- Subtotal gastrectomy: As the name suggests in this surgery a part of the stomach is removed. It is mostly used when the cancer is only in the lower part of the stomach or the upper part of the stomach. During the procedure only part of the stomach is removed, sometimes a part of the esophagus is also removed along with it. Nearby lymph nodes may also be removed. The remaining part of the stomach is then reattached.
- Total gastrectomy: In this surgery, the whole stomach is removed along with nearby lymph nodes, and a new stomach pouch is recreated by the small intestine. This is usually done when cancer has spread to the whole of the stomach. Sometimes nearby organs are also removed if cancer has spread to them.
Additional treatment modalities attack cancer cells directly.
- Radiation: Radiation utilizes targeted energy beams such as X-rays to eliminate cancer cells. However, radiation alone is not effective in eradicating stomach cancer, hence it should be utilized along with chemotherapy before and after surgery. Radiation can also help mitigate symptoms.
- Chemotherapy: Chemotherapy utilizes drugs to shrink cancer cells, making them easier to eliminate before surgery. Chemotherapy can also help destroy the remaining cancer cells after surgery. It is typically employed in combination with radiation. Chemotherapy may be utilized with targeted drug therapy, also.
- Targeted drug therapy: Targeted drug therapy focuses on weaknesses in cancer cells, causing them to die. It is most commonly used with chemotherapy in cancer that is advanced or recurs (comes back).
- Immunotherapy: Immunotherapy aids your immune system to detect and kill cancer cells that may be difficult to find. It is often used in advanced or recurring cancer.
- Palliative care: Palliative care assists in improving the quality of life of patients with a cancer diagnosis. Palliative care is a specialized medical care that may include nurses, doctors, and other specialists who can help with symptom relief. They can also provide additional support that complements the care the patient receives from regular providers. A patient can receive palliative care along with other treatments.