What is stomach cancer ?
The stomach cancer , also called gastric cancer , develops from a parietal cell (cell in the stomach wall), initially normal, that multiplies uncontrollably, forming a mass called a malignant tumor .
More than 90% of tumors that cause stomach cancer are adenocarcinomas , that is, they develop from the upper inner layer of the stomach, called the mucosa . It is a cancer that progresses slowly and rarely meets before age 50.
The tumors can remain local for a long time, before spreading to other layers of the gastric wall and invading adjacent organs (pancreas, colon, spleen) or lymphatic and vascular, leaving cancer cells to invade the lymph nodes, then disseminate these cancerous cells in other organs such as the liver, and the lung (metastases).
Other forms of stomach cancer , such as gastric lymphoma (which affects the lymphatic system), sarcoma (which affects the muscle tissue) or gastrointestinal stromal tumor (which is born in the tissues of the organs that support the system digestive), are much rarer. It will not be discussed in this sheet.
Causes of stomach cancer
There is no known cause for stomach cancer, but chronic inflammation of the lining of the stomach increases the risk , as in the case of Helicobacter Pylori gastritis. Stomach cancer is also associated with the consumption, over a long period, of salty, smoked or pickled foods, a diet low in fruits and vegetables, as well as smoking.
The earlier your stomach cancer is diagnosed , the better the chances of recovery. When it is still limited to the lining of the stomach, more than 50% of sufferers will survive more than 5 years. If it has spread to the lymphatic system, muscle layers, or other organs, the 5-year survival rate is less than 10%.
Who is affected?
Its incidence is uneven. Worldwide, stomach cancer remains the 2 leading cause of cancer mortality, but is the 4cause in Europe where it has been declining for 20 years. This decrease in frequency concerns cancer of the “distal stomach”, the antrum and the body. For “proximal cancer” of the cardia, this is controversial because several studies suggest an increase in its incidence.
This cancer is more common in populations with precarious socio-economic conditions, or who rely heavily on salting and smoking for food preservation . Japan (1/1000 inhabitants), China and Korea are among the most affected countries.
In France the incidence is 12/100 000 for men and 4/100 000 for women. In 2012 there were 6556 new cases per year. In Canada and the United States, stomach cancer is uncommon . It is even declining. In 2009, it accounted for less than 2% of all new cancer cases among Canadians.
In industrialized countries, refrigeration has helped to reduce the incidence of stomach cancer.
In the beginning, stomach cancer very rarely triggers specific and obvious symptoms . It is therefore difficult to diagnose the disease at an early stage. However, it often happens that a tumor in the stomach causes the following symptoms:
- a feeling of bloating , the feeling of having a full stomach even after eating a little;
- a indigestion prolonged or recurrent;
- a loss of appetite, a food disgust;
- of abdominal pain , heartburn;
- unexplained weight loss
- nausea and vomiting, infection with the bacteria
- persistent diarrhea
- vomiting of blood ;
- difficulties to swallow.
|These symptoms do not necessarily indicate the presence of a cancerous tumor. Indeed, they may be signs of other more common problems, such as a stomach ulcer or an infection due to bacteria. If these symptoms occur, consult a doctor promptly for the doctor to make the appropriate examinations and determine the cause.|
People at risk
- People living in low socio-economic conditions , as is the case in many parts of Asia;
- People over 50 years old;
- The men are at greater risk of suffering from stomach cancer than women;
- People suffering from chronic gastritis ( inflammation of the stomach wall) or who have suffered from an infection caused by the bacterium Helicobacter pylori ( H. pylori ) are systematically sought during a high endoscopy;
- People whose parent has suffered from stomach cancer
- People who have already had stomach surgery
- Some rare diseases: Biermer’s disease;
- For reasons unknown in the studies, being a type A blood group is associated with a slightly increased risk of stomach cancer.
Several factors of food origin are incriminated, but little is known about their real impact in the West.
- For Westerners, the main risk factor is by far the inflammation of the stomach wall caused by the bacterium Helicobacter pylori , the main cause of stomach ulcers. Warning : in the vast majority of cases, an infection caused by H. Pylori does not cause gastric cancer;
- Tobacco abuse;
- Too much salt intake from a diet rich in smoked or salted meats or fish , or products marinated in vinegar;
- A diet low in vegetables;
- Too much consumption of nitrates and nitrites, used as preservatives in deli meats ;
- Prolonged exposure to certain chemicals toxic industrial used in rubber processing and in the manufacture of lead;
These measures could help reduce the risk of stomach cancer:
- Stop smoking ;
- Do not consume alcohol excessively;
- Limit salt intake
- Limit consumption of smoked or salted meats or fish;
- Consume regularly fiber, fruits and vegetables.
Medical treatments of stomach cancer
Stomach cancer treatments vary according to the stage and degree of malignancy (grade) of the cancer. Often, several therapies are combined, such as surgery, radiotherapy or chemotherapy.
The choice of treatment is the subject of a multidisciplinary consultation (at least 3 different specialists must be present: gastroenterologist, oncologist, surgeon A personalized treatment plan is developed for each person with stomach cancer , depending on the grade and extent of his illness.
The surgery is the only treatment that can eliminate the tumor and lead to a real recovery. Sometimes it is not possible to completely remove the tumor because of its size or because the cancer has spread to other organs. In these cases, treatments are available to slow the progression of the disease and relieve symptoms.
Surgery for stomach cancer
The surgery involves removing the affected part of the stomach and the nearby lymph nodes.
If the tumor is very superficial (limited to the mucosa under the control of endoscopic echo, and in selected persons), an endoscopic excision is possible in a reference center. It is to remove the tumor without opening the abdomen, but passing a flexible tube through the mouth to the stomach to slide the instruments.
Depending on the location of the tumor in the stomach, the surgeon removes some of the esophagus (proximal cancer), or the small intestine (distal cancer). There are 2 techniques: partial gastrectomy , for cancers of the distal part of the stomach, or total gastrectomy .
the surgeon performs a gastroesophageal anastomosis, which involves sewing together the two operated parts of the esophagus and stomach to restore continuity. This helps to keep a “stomach stump” (a piece of stomach) or to obtain a passage oeso-jejunal where the esophagus is directly connected to the small intestine (anastomosis of the esophagus to the small intestine).
If the cancer is more extensive, affecting other nearby organs, it may be necessary to perform more extensive surgery also on neighboring organs, mainly the spleen.
After undergoing a total gastrectomy , it is still possible to eat well . However, since the capacity of the stomach is reduced (presence of a gastric stump or total absence of stomach), the person operated must adapt his diet, for example by taking smaller but more numerous meals. Patients who have undergone gastrectomy should also take certain dietary supplements , such as vitamin B12.
In the case of stomach cancer, chemotherapy is generally used to eliminate cancer cells.
In the case of localized cancer, the medical team can offer chemotherapy before the operation ( preoperative chemotherapy ) that decreases the size of the tumor, subsequently making it easier to remove this tumor. Chemotherapy can also be performed after surgery. operation ( postoperativechemotherapy ) 6 to 8 weeks after surgery, in order to reduce the risk of recurrence.
In the case of metastatic cancer or nonoperable tumor, chemotherapy is the standard treatment. It aims to limit the progression of the disease, relieve symptoms, and improve the quality of life. This is called palliative chemotherapy .
There are many protocols, and several ongoing therapeutic trials to define the best and most effective treatments.
The cellular microbiology has provided insight tumor growth mechanisms, and to develop targeted therapies . It has been demonstrated on gastric cancer cells and on metastases, “HER2” proteins. In the case of a positive receptor, chemotherapy is used to add “monoclonal antibodies”, which block the process of division and development of cancer cells. They also have an action of stimulating the immune system to help destroy cancer cells.
Chemotherapy can be given intravenously or orally. Chemo-therapeutic drugs attack cancer cells, but they also damage some healthy cells. To give the body time to recover, chemotherapy is administered cyclically. The side effects are multiple: nausea, vomiting, fatigue, loss of appetite, hair loss and increased risk of infection.
The radiation therapy is rarely used in cases of stomach cancer . It can be before, but most often after surgery, in association or not with chemotherapy. The latter aims to be a potentiator of radiotherapy. This is called “sensitizing radio chemotherapy”. It can also be used to relieve the pain of a tumor that cannot be removed.
This treatment consists of directing ionizing rays on a specific area of the body to destroy the cancer cells that have formed there. Since high-energy rays also damage healthy cells, this therapy has different side effects that are more or less bothersome, depending on the person being treated. It may feel tired, or even notice that the skin of the irradiated area is red and sensitive. Radiation therapy for a stomach tumor can cause diarrhea, indigestion or nausea. The side effects of radiotherapy fade after treatment when healthy cells have regenerated.
Check out our Cancer fact sheet for all of the complementary approaches that have been studied in people with cancer, such as acupuncture, visualization, massage therapy and yoga. These approaches may be appropriate when used in addition to, but not substituting for, medical treatments.