Gastric Cancer
What is Gastric Cancer?
90% of Gastric cancers are adenocarcinoma. In other words, when gastric cancer is mentioned, the type of cancer that usually consists of cells lining the inner surface of the stomach comes to mind. A kind of cancer called lymphoma originates from lymph node cells and can also be seen more rarely in the stomach. More rarely, neuroendocrine tumors arising from hormone-secreting cells and gastrointestinal stromal tumors originating from the stomach wall can develop in the stomach.
What causes Gastric Cancer?
Gastric cancer occurs as a result of the complex mechanism of many environmental risk factors, such as diet and smoking, along with genetic risk factors. Around the world, 70% of gastric cancers are seen in developing countries, and their frequency is decreasing due to the increase in awareness of the risk factors that cause the disease. It is more common in men, and there is a greater predisposition in families with specific genetic characteristics. Apart from the genetic background, the most critical factor in the emergence of the disease is the environmental risk factors.
What factors increase the risk of Gastric Cancer?
Helicobacter pylori, which is directly related to stomach cancer and is popularly known as a stomach microbe, is transmitted to humans through infected water and food, usually in childhood. This bacterium, which lives quietly in the stomach for a long time, causes gastritis, ulcers, and, more rarely, stomach cancer over time. Using cigarettes and other tobacco products, excessively salty or salted products (such as pickled fish, pickles), all kinds of burned products containing carcinogenic substances called nitrites and nitrosamines (such as burnt bread, burnt part of meat), excessive consumption of smoked products (such as barbecued baked goods), consuming excessive alcohol, drinking a low-fiber diet, that is, consuming less vegetables and fruits, low citrus fruits, that is, low intake of vitamin C are risk factors for gastric cancer. In addition, obesity, which is one of the biggest problems of our age in recent studies, is another risk factor that increases gastric cancer. The risk of stomach cancer increases in those working in metal works such as coal, tin, zinc, copper, and the rubber industry. Again, gastric cancer has increased in people who had a part of their stomach removed 15-20 years ago compared to other segments of society.
What are the Symptoms of Gastric Cancer?
Since gastric cancer is usually very silent and insidious, it usually causes complaints and symptoms in the more advanced stages of the disease. For this reason, most diagnosed patients apply to the doctor in the late stage. People who have a family history and consume carcinogenic products such as cigarettes, excessive alcohol, and salty smoked foods should consult a physician as soon as possible when they have stomach-related complaints such as early satiety, swelling, stomach pain that does not go away despite treatment, nausea, vomiting, gastroenterology specialist should have the necessary examinations done. In short, gastric cancer symptoms are usually as follows:
- Loss of appetite, severe stomach pain, early satiety, nausea, vomiting
- Unexpected extreme weight loss, regardless of diet or exercise
- Difficulty in swallowing, difficulty in passing food into the stomach, the feeling of being stuck
- Weakness, fatigue, feeling of shortness, dizziness, pallor due to blood loss
- Black-colored stools, bloody vomiting
- Palpable stiffness in the stomach and abdomen
How is Gastric Cancer Diagnosed?
Upper digestive system endoscopy (gastroscopy) performed by a trained and experienced Gastroenterology doctor is the gold standard examination method in cases where gastric cancer is suspected in blood tests performed with complaints and findings and some imaging methods (such as abdominal ultrasound or tomography).
Upper Digestive System Endoscopy (Gastroscopy): Gastroscopy examines the first part of the esophagus, stomach, and small intestine by entering through the mouth with a very flexible endoscope device with a lighted video camera system at the end. If abnormal structures are detected during the procedure, a biopsy, that is, a tissue sample, can be taken using instruments passing through the endoscope. The tissue sample is examined in the pathology laboratory to determine whether there is cancer.
Imaging tests: Diagnosis and determination of the stage of the disease can be achieved with imaging methods such as ultrasound, tomography, magnetic resonance imaging (MR), and positron emission tomography (PET-CT).
Stages of Gastric Cancer
As with all cancers, the life expectancy and treatment modality of gastric cancer vary according to the stage of cancer. For this reason, it is essential to know the stage of the patient after the diagnosis of gastric cancer. While it is possible to treat and remove the cancerous tissue endoscopically without the need for surgery in the stage of the disease, which is called early gastric cancer and involves only the upper layers of the stomach, chemotherapy treatment comes to the fore in the last stage of the disease called Stage 4.
Stage 1: At this stage, the cancer has not grown further below the top layer of cells in the mucosa and has not spread to any lymph nodes or other body parts.
Stage 2: The cancer has grown under the upper layer of cells. However, it did not reach the main muscle layer. It has spread only to three to six lymph nodes near the stomach. The cancer has not yet spread to other organs far from the stomach.
Stage 3: The cancer has grown into the main muscle layer of the stomach and spread to seven or more lymph nodes, but it has not spread to tissues or organs other than the stomach.
Stage 4: This is the most advanced stage of the disease, and cancerous cells have spread to other parts of the body outside of the stomach.
Gastric Cancer Treatment
The form and method of gastric cancer treatment varies according to the stage at which the disease is diagnosed and the clinical condition of the patient. Accordingly, the success rate of the treatment varies according to the patient. It should be noted again that the earlier the cancer is diagnosed, the better the treatment success rate and the patient's life expectancy. Surgery, chemotherapy, radiotherapy, targeted therapy, or immunotherapy methods can be used alone or in combination in the treatment of gastric cancer.
Gastric Cancer and Chemotherapy
Chemotherapy is the administration of drugs developed for the treatment of cancer to the patient by intravenous or oral means. These drugs enter the body and generally show their effects by mixing with the blood and going to the first exit place where the cancerous cells are located and to other organs and tissues where cancerous cells spread, that is, metastasize. In gastric cancer, not only chemotherapy but also radiotherapy can be applied together.
If chemotherapy is given before gastric cancer surgery, it is called neoadjuvant chemotherapy. The aim is to shrink the tumor before and assist the operation.
If chemotherapy is given after surgery, it is called adjuvant chemotherapy. The aim here is to eliminate stomach cancer and prevent the cancer from recurring.
If it is given together with postoperative radiotherapy, that is, radiation therapy and chemotherapy, it is called chemoradiotherapy. This method is beneficial for cancers that surgery cannot altogether remove.
Gastric Cancer Surgery
Surgery has two primary purposes in the treatment of gastric cancer. These are to treat stomach cancer and to improve the quality of life of the patient by treating digestive system disorders such as cancer-related eating disorders, vomiting, and bleeding. For this purpose, the complete removal of the stomach called total gastrectomy, or the removal of a part of the stomach, called partial gastrectomy, can be applied.During the operation, the cancerous stomach tissue and surrounding lymph nodes are also removed. The duration of the operation may take 2-5 hours, depending on the difficulty of the procedure, the patient, and other additional factors.
Possible Risks and Complications in Gastric Cancer Surgery
As with any major surgery, gastric surgery has many risks. Some severe and fatal side effects, such as postoperative bleeding, infection, leakage from the surgical site to the surrounding tissues, and heart and lung disorders due to anesthesia, may develop.
Life After Gastric Cancer Surgery
Since part or all of the stomach is removed in the surgery, patients should be nourished frequently and in smaller portions. High-protein and low-carb light meals can help patients feel better after a meal. Adapting to a new way of eating after stomach surgery can take time and patience. Knowing that bothersome symptoms such as abdominal cramps and pain usually improve or will improve over time may be helpful. Many patients return to their regular or near-normal eating habits one year after surgery during the recovery period after gastric cancer surgery.
Nutrition of People with Gastric Cancer
In people with gastric cancer, part or all of the stomach may need to be removed. This, in turn, affects patients' appetites and the way they digest food. In many patients, it can cause loss of appetite, weight loss, stomach pain, and a feeling of early satiety. This may require people to change their eating habits by preparing a stomach cancer nutrition list under the follow-up of a dietitian.
A balanced diet is essential in the treatment of gastric cancer after surgery. For example, consuming low-fiber, non-hard fruits, cooked vegetables, and fish is recommended rather than shellfish.
Processed foods should be avoided or minimized. Foods such as pastrami and sausage should be avoided, as should sugar, packaged snacks, and processed foods with sweeteners.
Gastric Cancer Treatment Success Rate and Life Expectancy
The success rate in the treatment of gastric cancer varies according to the stage of the disease and the age and physical condition of the patient. However, the cancer stage is the most critical indicator affecting the success of treatment and life expectancy. When evaluating response to treatment, survival rates of patients within five years after treatment were taken as a basis. If the cancer is caught in the first stage, that is, if it is diagnosed and treated before it spreads beyond the stomach, the 5-year survival rate is 70%. If the cancer is in the second stage, the 5-year survival rate after treatment is 32-45%. In the third stage, it is 9-20%. If the cancer has spread to a distant part of the body other than the stomach, that is, in the fourth stage, the 5-year survival rate is 4%.
