I will tell you about the most common cancer – stomach cancer. Every year, almost 800 thousand new cases and 628 thousand deaths from this disease are registered. In Russia, the highest incidence rate is in the Novgorod Region and the Republic of Tuva, while the lowest rates are in the regions of the North Caucasus, the Magadan Region and the Chukotka Autonomous District. Studies comparing regions with high and low incidence of stomach cancer have revealed a relationship between dietary patterns and stomach cancer.
As I have already mentioned, the predominance of complex carbohydrates in food (potatoes, bread, flour products, which is more typical for Russia; rice-Asian countries, Japan) is associated with a reduced intake of vitamin C and fresh vegetables and fruits containing ascorbic acid. Increased consumption of salt, pickled, overcooked, smoked foods, and spicy foods also increases the risk of stomach cancer. Increased alcohol consumption, especially vodka, increases the risk of cancer in men. A direct correlation was established between the frequency of stomach cancer development and the content of copper, molybdenum, and cobalt in the soil, and an inverse correlation with the content of zinc and manganese. The relative risk of the disease in individuals who have been breastfed for less than a year is 3-4 times higher than in individuals who have been breastfed for more than a year, which may be due to a decrease in the protective function of the gastric mucosa due to a lack of immunoglobulin A and earlier infection with Helicobacter pylori. Nitrates and nitrites with a prolonged effect also have a carcinogenic effect. The main source of their intake into the human body is vegetables, depending on the method of cultivation, the type of fertilizers, water for watering, dried and smoked products, alcoholic products, spices. The use of freezing and the use of refrigerators to preserve food is also considered a factor in the dramatic decline in stomach cancer in developed countries.
Yes, it is necessary to tell you about the etiological factor of gastritis, namely about Helicobacter pylori. The discovery of Helicobacter pylori in 1983 brought to mind the prerequisites for studying the infectious factor. The role of the pathogen in the etiology of gastric ulcer disease has been proven, the inclusion of antibiotics in anti-ulcer therapy regimens has been so successful that in developed countries, surgical treatment of peptic ulcer disease has been almost completely abandoned. Over the past decade, many studies have been carried out to study the infection rate of the population, but the lack of clear research criteria and different methods cause a wide range of infection rates. The International Agency for Research on Cancer has recognized Helicobacter pylori as a first-order carcinogen, i.e. the link with the development of stomach cancer is considered proven. The exact mechanisms of the damaging effect of Helicobacter pylori on the gastric mucosa are being studied. The duration of exposure, the influence of other factors (the nature of food, alcohol consumption, smoking) have a strengthening effect. Most researchers believe that Helicobacter pylori causes stomach cancer not directly, but through the development of gastritis, intestinal metaplasia, dysplasia, etc. Why some carriers of the infection develop stomach cancer, and others do not, is still unclear. Another infectious agent found in stomach cancer is the Epstein – Bar virus, i.e. there is also the viral theory that I have already mentioned. The main contribution to the study of the genetic factor was made by the analysis of hereditary stomach cancer. The pathogenesis is complex and largely unexplored. It must be recognized that as new carcinogens are discovered, the list presented will be continuously updated, reflecting the different stages of development of the tumor cell.
The most common of the stomach diseases is chronic gastritis. Not every patient with chronic gastritis necessarily has cancer, but if you take a certain number of patients with stomach cancer, it turns out that many of them have suffered from gastritis for a long time. However, not everything is so bad: gastritis is curable, especially if the prescription of the disease is small. A cure or significant improvement can be achieved by following a certain diet, using a number of medications prescribed by a doctor, or by treatment in a specialized sanatorium. The cure relieves the patient from the rather painful symptoms of gastritis (unpleasant sensations and pain in the epigastric region, belching, heartburn) and reduces the risk of cancer. The need for constant medical supervision primarily concerns those patients in whom gastritis is accompanied by a decrease or complete absence of gastric acid. These forms of gastritis more often than gastritis with high acidity, degenerate into cancer. However, malignant degeneration of the ulcer, as a rule, occurs in cases where it exists for a long time and persistently does not respond to dietary, medical and sanatorium treatment, or when this treatment gives an unstable, short-term effect. If the conservative treatment of gastric ulcer does not give a lasting effect, surgical treatment should be applied.
The problem is that the clinical picture of early gastric cancer is poor, the symptoms are not interrelated. Non-permanent signs include unmotivated weakness, fatigue, aversion to meat food, anemia, weight loss. “Stomach discomfort” is more common in patients with advanced forms of stomach cancer. The main symptoms are pain in the epigastrium, decreased appetite, dyspeptic phenomena. Pain with radiation in the back may indicate sprouting into the pancreas, and patients are often treated with a diagnosis of “pancreatitis” or “osteochondrosis”. A thorough anamnesis of patients with early gastric cancer allows us to find out that after all, most have non-specific complaints, most often of a dyspeptic nature. Therefore, it is necessary to suspect stomach cancer in any patient over 40 years of age with new dyspeptic complaints. In each individual case, a patient over 40 and even more than 50 years old with new dyspeptic complaints should be prescribed EGDS with a biopsy of any suspicious area of the gastric mucosa. A test for Helicobacter pylori may be useful, but it is not known for sure whether infection in middle age affects the development of stomach cancer. Further endoscopic monitoring should be performed in patients with any degree of dysplasia, type II intestinal metaplasia and atrophic gastritis. Early gastric cancer is difficult to diagnose and can easily be missed with EGDS or X-rays. Histological examination of the biopsy material in such cases reveals only inflammatory changes, and inexperienced endoscopists and therapists often stop at the diagnosis of “diffuse gastritis”.
Diagnostic search-esophagogastroduodenoscopy with biopsy-is the leading diagnostic method. In recent years, to improve the examination of the mucosa before the procedure, drugs that reduce the motility of the stomach and medications that remove mucus from the mucosa are used. The method is also used to determine the adjacent enlarged lymph nodes (more often in esophageal cancer).
Roentgenoscopy of the stomach. The method plays an extremely important role in studying the spread of the tumor in the area of the cardioesophageal anastomosis to the esophagus and in the spread of the tumor to the duodenum 12, which affects the choice of surgical access and planning the scope of the operation. In cases of submucosal tumor growth, the X-ray method may be the leading one in establishing the diagnosis.
Computed tomography is sometimes performed to establish a diagnosis, but the method can not be called accurate and sensitive for stomach cancer. The main role is to determine the metastases in the liver and identify enlarged lymph nodes. There are no reliable signs of invasion of the adjacent organs, in particular, the pancreas.
Laparoscopy in most cases is used when there is a suspicion of the presence of distant metastases that are not determined by traditional methods – with a massive lesion of the stomach, suspected ascites, with enlarged ovaries in women. Other methods of studying stomach cancer are ultrasound tomography of the abdominal organs, chest X-ray.
According to the indications, a trepanobiopsy is performed to detect bone metastases.
At the end of this section, I want to say that stomach cancer in Russia remains an extremely acute problem. The death rate in our country has not decreased in recent years. The detection rate of early forms, on the one hand, is low, but, on the other hand, it is the only chance for recovery. In Russia, a national program is required to identify the most common oncological diseases, and in the conditions of modern reality, gastric cancer screening should be carried out at least in the groups of background and precancerous diseases. In this regard, it is necessary to popularize knowledge about stomach cancer among general practitioners and among the population. A special role should be given to therapists, gastroenterologists, and endoscopists. An effective measure to prevent stomach cancer can be a change in the way of eating. Patients with stomach cancer should be treated in specialized institutions. The ongoing research allows us to hope that in the near future there will be new standards for the treatment of stomach cancer.