Also referred to as stomach cancer, gastric cancer is a condition identified by the development of cancerous cells along the stomach lining. Gastric cancer is not easy to diagnose as the condition does not show any symptoms in the initial stages. Stomach cancer is not as common as other cancer types. However, what makes it dangerous is the fact that it cannot be diagnosed easily. Therefore, it can go unnoticed until the stage where it has spread to other body parts also. This can make the treatment of the condition difficult.

Signs and symptoms of gastric cancer

Typically, gastric cancer does not cause any signs or symptoms in its initial stages.

If there are any early warning signs of gastric cancer, they can include the following:

• Feeling of fullness
  In many cases of gastric cancer, patients get a feeling of fullness after light meals. This can be felt in the upper abdomen area.

Once the condition has advanced, the symptoms start to show up clearly. These can include the following:

• Heartburn that occurs frequently
• Vomiting and nausea
• Appetite loss
• Bloating
• Blood with stools
• Jaundice
• Fatigue
• Pain in the stomach which becomes worse after meals

If you have been experiencing any changes, it is recommended that you consult your doctor. The doctor will examine you and ask you about the frequency of your symptoms and other questions. This will be done to identify the root cause of the problem.

Causes of stomach cancer

Usually, cancer is a result of gene mutation which takes place in the DNA of the cell. It is because of this mutation that the cells start to develop and divide at an abnormal rate. These cells stay alive even after the healthy cells have died. When the cancerous cells are in a large number, they form a tumor that moves to invade the nearby parts of the place of origin. Cancerous cells can also detach from the tumor and then invade other parts of the body.

The cause of gastric cancer is usually associated with gastrointestinal reflux disease. It is less likely to be associated with factors such as smoking and obesity. When the stomach acid starts to flow back to the esophagus, the condition is known as GERD.

Having a diet loaded with salted and smoked foods has also been found to be a common cause of stomach cancer, affecting the stomach’s main part.

Risk factors associated with stomach cancer

There are two main risk factors associated with gastric cancer, and they are:

• GERD history
• Obesity

Several other factors increase the chances of developing gastric cancer include:

• Diet rich in smoked and salty foods
• Diet low in vegetables and fruits
• Stomach cancer running in the family
• Inflammation in the stomach that has been persistent
• Smoking
• Stomach polyps
• Pernicious anemia
• Infection accompanied by Helicobacter pylori

The stages of gastric cancer

Staging is used to identify the location of cancer and the extent it has spread. It can also determine whether the cancer is spreading to other organs or not. Different tests can determine the stage of cancer, and accordingly, the treatment is also determined. There are different ways in which the stage of cancer can be established. Let us understand an important staging system that is popularly used across the world.

TNM staging system

One of the systems used to understand and describe the stage of gastric cancer is the TNM staging system. Three main questions are answered about cancer to establish the stage according to this system.

• Tumor – How deep is cancer into the stomach wall?
• Node – Has the tumor reached the lymph nodes, and how severely?
• Metastasis – Have other parts of the body also been affected by the tumor?

The results of these three questions help in explaining the stage of cancer. Based on the information received, cancer can be placed in either of State 0, 1, 2, 3, and 4. Once the stage is understood, doctors can then work together to formulate a process of treatment.

Let us understand in little detail how each of the three questions defines the stage of cancer.

• Tumor
  Here, we understand how far into the stomach wall has the tumor grown. The measurement is done in cm. The information is then shared in a way that is generally understood by medical professionals. TX means that the evaluation of the tumor cannot be done. T0 means that there’s no evidence of the primary tumor in the stomach. This is the condition in which the cancer is only on the inner lining of the stomach, and the condition is described as carcinoma in situ. T1 signifies that cancer has grown into muscularis mucosae, submucosa, or the lamina propria. In T2, cancer has grown into the stomach’s muscle layer known as muscularis propria. In T3, cancer has reached the connective tissue outside the stomach, while in T4, it has also reached the peritoneal lining or the organs around the stomach.
• Node
  Similar to the tumor, each stage is represented by a value. NX means it’s not possible to evaluate regional lymph nodes, while N0 means cancer has not yet spread to lymph nodes. N1, N2, and N3 state that cancer has spread to 1-2, 3-6, and 7 or more regional lymph nodes, respectively.
• Metastasis
  This is to understand the spread of cancer to other parts of the body. MX means the condition in which cancer cannot be evaluated, and M0 and M1 indicate that cancer has not spread, and cancer has spread to other organs, respectively.

By combining all of these, doctors then define the overall stage of cancer.

• Stage 0
  The cancer is in situ and has only been found on the epithelium surface. It has neither spread to other layers of the stomach nor to other organs.
• Stage 1A
  Cancer has reached the inner layer of the stomach’s wall, but not to lymph nodes or surrounding organs.
• Stage 1B
  In two conditions, one can be considered on Stage 1B of gastric cancer. First, cancer has grown to one or two lymph nodes and inner layers of the stomach wall. Second, it has not spread to lymph nodes but has entered the outer muscular layer of the stomach wall.
• Stage 2A
  Any of the three conditions being met suggests that cancer has reached Stage 2A. Either cancer has reached the inner layer of the stomach wall, and between three and six lymph nodes, or it is in the outer muscular layer of the stomach wall and spread to one to two lymph nodes. The third condition is that it has grown into connective tissues around the stomach, but has not reached peritoneal lining or serosa. It has also not reached any lymph nodes.
• Stage 2B
  One of the three conditions must be satisfied in this case. One, cancer has grown to the inner layer of the stomach wall and 7-15 lymph nodes. Two, cancer has penetrated connective tissue outside the stomach and one to two lymph nodes. Three, cancer has grown into connective tissue and serosa or peritoneal lining.
• Stage 3A
  This is signified by cancer not growing to the other organs, or some organs but not to nodes.
• Stage 3B
  In this advanced stage, either cancer severely attacks the lymph nodes, or lesser lymph nodes are affected, but cancer spreads to different parts of the body.
• Stage 3C
  Here, cancer has grown to the nearby organs of the body and affected as many as seven lymph nodes. Or, in the second case, cancer affects 16 nodes, but distant parts of the body are not reached.
• Stage 4
  In this stage, the nodes, surrounding organs, and inner layers of the stomach are penetrated by cancer.

Diagnosing stomach cancer

Some several tests and procedures are used to diagnose stomach cancer. These include the following:

• Upper endoscopy
  This is a procedure that uses a tiny camera to let the doctor look inside the stomach. The camera is installed on a tiny tube that is passed down to the stomach through the throat. This will allow the doctor to look for any signs of cancer in the stomach. If any suspicious is found, a tissue sample can also be collected for a biopsy.
• Imaging tests
  The tests used to check for any signs of stomach cancer include a CT scan and a special X-ray test known as a barium swallow.

The treatment plan of the condition will largely depend on the stage of gastric cancer. Therefore, to check the stage of cancer, various procedures and tests will be ordered. These will include:

• Imaging tests
  These tests can include a positron emission tomography or PET scan and a CT scan.
• Exploratory surgery
  Surgery can be recommended to some patients. This will be done to check if cancer has spread to other parts of the body. This surgery is usually laparoscopic. The procedure is done by a surgeon who makes a small incision to the abdomen and puts a small camera inside, which sends images to a screen installed in the operation theater.

Treatment plans for stomach cancer

The treatment for stomach cancer is dependent on the stage at which cancer is diagnosed. The patient’s overall health and preferences are also taken into consideration while deciding the treatment plan.

The various treatment options for stomach cancer include the following:

• Surgery
  Stomach cancer that has not spread to other parts of the body can be treated with the help of surgery. In the procedure, that part of the stomach or esophagus is removed where the tumor has developed. The surgery aims at removing the entire cancerous tumor along with some healthy tissue. The lymph nodes in the surrounding area are also removed in most cases.
• Radiation therapy
  This is a treatment procedure in which beams with high power energy are used to eliminate cancer cells from the body. These beams are emitted from a machine that moves around the patient as they lie down on a table. In cases of gastric cancer, radiation therapy can be given before the surgery. It is done to reduce the tumor to a smaller size so that it is easy to remove it. In many cases, radiation therapy is also used post-surgery to kill the cancerous cells, which might be left out in the area around the stomach or esophagus. Usually, both chemo and radiation therapy are given together in cases of gastric cancer. It is known as chemo radiotherapy, and it is usually given before the surgery. The side effects of doing radiation therapy on the stomach can include problems with digestion, diarrhea, vomiting, and nausea. If radiation therapy is done on the esophagus, it can include side effects such as problems with swallowing and pain. To fight this side effect, the doctor can recommend installing a feeding tube in the stomach by making an incision in the abdomen. The tube will remain in the stomach until the esophagus recovers completely.
• Chemotherapy
  This is a treatment procedure that is aimed at killing cancerous cells with the use of medications. The medications involved in the treatment go through the body and kill cancer cells, which might have traveled and gone beyond the stomach area. The procedure can be used before surgery to reduce the size of the tumor so that it is removed conveniently.