Gastric Cancer or Stomach Cancer

Gastric Cancer / Stomach Cancer

Gastric cancer or stomach cancer is a cancer caused by mutated stomach lining cells, and abnormal division of cells which can occur in any area of the stomach.

Symptoms

The symptoms of gastric cancer depend on the stage of the disease. Most early-stage patients often do not have symptoms and may not experience any specific symptoms. In some cases, symptoms may be similar to those with gastritis or gastric ulcers, such as abdominal pain, stomach cramps, bloating, or eating and being full quickly. For the later stage of the disease or when the disease starts to progress, patients may have more severe symptoms such as gastrointestinal bleeding, vomiting with blood, and having a black defecation like asphalt. Patients may have symptoms of significant weight loss as well as obstructive symptoms of the upper digestive tract, such as severe nausea and vomiting.

Causes and risk factors

Stomach cancer is caused by an abnormal division of cells. This may be caused by stimulating factors such as gut bacterial infection, chronic inflammation of the stomach, etc.

The risk factors causing stomach cancer may include:

• Prolonged gastritis.
• Infection of helicobacter pylori that enters the body and lives in the stomach causes the stomach lining to become inflamed and stomach ulcers which increase the risk of stomach cancer.
• Patients who have had gastric surgery.
• Behavioral and environmental factors such as smoking, drinking, being obese or overweight, and consuming certain foods such as foods that are highly salty or foods that contain N-Nitrozo compounds.
• Some underlying diseases such as chronic and severe anemia (Pernicious anemia) associated with chronic gastritis.

When to see the doctor

You should consult your doctor if you have any of the above symptoms especially when having gastritis-like symptoms that are unresponsive to drug therapy for 2-3 weeks or have been found to have risk factors such as having a family member of gastric cancer. If your doctor finds a risk or indication of gastric cancer, the doctor will perform a detailed diagnostic test or may refer the patient to a specialist doctor.

Diagnosis

There are several tests used to diagnose gastric cancer including:

• Upper endoscopy. It is the primary diagnostic tool for gastric cancer diagnosis. The doctor will insert a small endoscope through the mouth straight to the stomach. The biopsy samples will be collected from the suspected area for further pathological examination. In addition, with today's advanced gastrointestinal imaging technology, early gastric cancer can be diagnosed more quickly.
  However, the doctor may make a diagnosis to assess the stage of the disease by relying on the following test
• Imaging test. The doctor may assess the stage of the disease using a CT scan and a PET/CT scan.
• Exploratory surgery. To investigate the spread of the cancer to other parts of the body, the doctor may recommend exploratory surgery. A tiny camera is inserted through several small incisions in your abdomen to investigate the signs of the spread.

Stages of gastric or stomach cancer

Stages of gastric or stomach cancer relate to the area and the spread of the cancer.

• Stage 1 The cancer or tumor that is limited to the top layer of tissue inside of the stomach line or little spread to the nearby lymph node will be determined as stage 1.
• Stage 2 Stage 2 gastric cancer is cancer that has spread from the inner epithelium to the muscle layer of the stomach wall or spread to larger lymph nodes.
• Stage 3 If the cancer has spread to the very deep muscle layers or a wide area of lymph nodes, it will be evaluated as stage 3 cancer.
• Stage 4 cancer that has spread to distant areas of the body will be determined as stage 4 cancer.

Treatment

The treatment for gastric or stomach cancer differs from the stage and condition of each patient. The treatment may include

Surgery

To remove the cancer from the healthy tissue when possible, the doctor may recommend the surgery. This procedure can be used with the cancer that has not spread to the other parts. The options may include:

• Early-stage tumors from the stomach lining removal

In early stomach cancer where the cancer has not spread to the deeper layers of the stomach wall or other organs, the cancerous skin may be able to be cut through a gastric tube alone without having to perform open abdominal surgery.

• A portion of the stomach removal (Subtotal Gastrectomy)

This surgery will remove the cancer. The doctor may also cut off some parts of the stomach and some surrounding tissues but the patient still has a stomach remaining.

• The entire stomach removal (Total Gastrectomy)

The entire stomach and some surrounding tissue will be cut off. The doctor will connect the esophagus to the small intestine to perform the function of digestion and absorption of food Instead of growing food that was cut off.

• Lymph node removal for exploring the cancer

The lymph nodes in the abdominal area will be removed. This is because the lymph node is the diffused portion of cancer cells. A sample of the removed lymph node will be analyzed to look for cancerous cells.

• Surgery to relieve signs and symptoms

To prevent and slow the growth of more severe cancers or to treat complications caused by disease, this method is done to relieve the symptoms of the disease and only makes the patient feel more comfortable. However, it's not the removal of cancer cells.

Radiation therapy

Radiation therapy is a treatment using a high-power beam of energy to kill the cancer cells or to support other treatments. There are two kinds of radiation therapy classified by the purpose of the therapy.

• Adjuvant radiation. The doctor may use radiation therapy after the surgery to kill the remaining cancer cells around the stomach or esophagus after cancerous removal.
• Neoadjuvant. To support the cancer removal surgery, the doctor may conduct a radiation therapy called neoadjuvant before performing the surgery. Neoadjuvant will decrease the size of the cancer and tumor to make it easier to remove.

There are several side effects of the treatment including diarrhea, indigestion, nausea, and vomiting. Some patients may experience difficulty or pain in swallowing after the radiation therapy to the esophagus. The doctor may consider placing a feeding tube in the stomach through a small incision until the esophagus heals.

Sometimes, radiation therapy is used together with chemoradiotherapy, especially before surgery.

Chemotherapy

Chemotherapy is the use of medications to kill the cancer cells that may spread to another area besides the stomach. There are two types of chemotherapy classified by the purpose of the treatment.

Adjuvant chemotherapy

Adjuvant chemotherapy aims to kill the cancer cells that remain in the body, especially after the surgery.

Neoadjuvant chemotherapy

This kind of chemotherapy is commonly used before the surgery to make the cancer and the tumor get smaller and make it easier to remove.

Sometimes, the doctor may use chemotherapy alone to relieve the symptoms of gastric or stomach cancer.

Targeted-drug treatment therapy

Targeted-drug treatment therapy focuses on a protein on the surface of cancer cells called human epidermal growth factor receptor 2 (HER2) which is found in some stomach cancer cells. This form of treatment only destroys cells with these receptors most of them are cancer cells. At the same time, the normal cells will remain. These receptors are responsible for feeding breast cancer cells to grow and survive. Targeted cancer drug therapy interferes directly with the mechanisms of receptor proteins.

There is also a targeted cancer drug treatment activating via Vascular endothelial growth factor receptor 2 (VEGFR) mechanisms. These targeted drugs will destroy VEGFR, a protein that helps gastric cancer divide and grow.

Immunotherapy

Immunotherapy helps the patient's immune system to fight cancer cells. When cancer cells appear in the body, the immune system that destroys cancer cells may not be able to fight cancer cells. The reason is that it is interrupted by proteins produced by cancer cells. The way immunotherapy works is that it is interrupted during the operation of the process and stimulates the immune system to fight against cancer cells.