Stomach cancer (gastric cancer): symptoms, causes, treatment, survival rate

Medically reviewed: 1, February 2024

Stomach cancer: causes, first signs and symptoms

Gastric cancer (stomach cancer) , or a malignant tumor of the stomach, is an extremely serious disease, which is very difficult to detect in the early stages. Pain in the stomach, nausea, people often take for symptoms of gastritis or peptic ulcer, not assuming that a malignant neoplasm has appeared in their body. In some cases, stomach cancer (ICD 10–C 16) begins without symptoms. Thus, the tumor of the stomach continues to grow, disrupt the functions and destroy the organ in which it is localized, and also spread throughout the body.

With late detection of pathology, tumor cells invade neighboring tissues and organs, which significantly worsens the prognosis. Therefore, early diagnosis of stomach cancer is so important, as, indeed, of all other oncological pathologies.

Stomach cancer: symptoms and treatment

Human stomach anatomy

The stomach is located in the upper part of the digestive tract, between the esophagus and the duodenum. Digestion and grinding of food coming from the esophagus is ensured by the powerful muscular layer of the stomach. The dissolution of nutrients to simpler elements, then easily absorbed in the intestines, occurs with the help of hydrochloric acid and pepsin, released from the internal mucous membrane of the organ.

Anatomically, the stomach consists of four parts:

• cardiac, adjacent to the esophagus
• pyloric – adjacent to the duodenum 12
• antral – between the pyloric and cardiac parts
• fundic – above and to the left of the cardial part.

Both the body and the bottom of the stomach have a similar mucous membrane.

Histology of the stomach involves the division of the organ into four layers: mucous, submucosal, serous and muscular. Histological examination is aimed at the earliest possible detection of the tumor process in any part of the stomach.

Most often, pathological processes develop in the cardial section of the stomach (the transition of the esophagus to the stomach). Histology helps to accurately identify the presence of cancer cells in this department at the earliest stages of development.

Expert opinion

Author: Alex McDonald, Head of Oncology Department, oncologist, chemotherapist

According to statistics provided by the Agency for the Study of Cancer, stomach cancer is one of the five most common pathologies. New cases of the disease are registered every year. A high percentage of deaths is due to late visits to the doctor. Gastric cancer is asymptomatic for a long time. Clinical manifestations are typical for late stages of the tumor.

The following statistics are disappointing. Stomach cancer at stages 3–4 is diagnosed in 60–70% of first-time applicants. The tumor is characterized by an aggressive course, rapid progression. Malignant oncological formation in 30-40% of cases is diagnosed in men, in 20% – in women.

Therapy is carried out according to the established stage of the disease. The prognosis depends on the degree of cancer development, the presence of complications and comorbidities. Due to the fact that diagnosis is most often carried out in the later stages, the prognosis is considered unfavorable. When the first pathological signs appear, doctors recommend seeking help. Stomach cancer is a dangerous disease that requires immediate treatment.

Causes of stomach cancer

An exact list of causes of stomach cancer does not exist today. There are only a number of assumptions about the most likely factors provoking gastric cancer. However, as a rule, any of the “stimulants” of the disease does not act alone, but in combination with other possible factors:

• Helicobacter Pylori infection is a pathological microorganism that can withstand such an aggressive factor as hydrochloric acid. The protective sheath created by the Helicobacter Pylori bacillus around itself prevents the harmful effects of hydrochloric acid. Due to a long stay in the stomach of this microorganism, the structure and function of the gastric mucosa are disturbed, the pathological process becomes malignant.
• Genetic factor – according to modern research, people in whose families there are cases of the disease are much more likely to develop stomach cancer. Heredity in this case is one of the most important risk factors
  toxic, chemical factors (penetration of nitrates and nitrites) – there is an assumption that various toxic substances, getting on the gastric mucosa, can cause the appearance of pathological tumor cells. Due to their chemical activity, nitrates and nitrites violate the integrity of the cells of the mucous membrane, penetrate into their structure and can cause them to degenerate into malignant cells.

These substances enter the human body mainly with food, more specifically with vegetables that have a high content of harmful chemicals. In turn, nitrates or nitrites get into vegetables due to low farming culture, when too much nitrogen fertilizer is used. In addition, a sufficiently large amount of salts of nitrous or nitric acid contains smoked and dried foods, beer, cheese, tobacco, and cosmetics. Therefore, stomach cancer can be provoked even by the excessive use of cosmetics.

• Taking medications – long-term treatment with certain medications, for example, non-steroidal anti-inflammatory and antibacterial drugs, corticosteroids, can lead to the development of side effects, one of which is a stomach ulcer. In turn, an ulcer in the absence of adequate therapy can develop into stomach cancer.
• Ionizing radiation (radiation) – the effect of radioactive rays (in small doses) on irradiated cells can be both favorable and negative. As a result of such exposure, the internal structure of the genetic apparatus of cells may be disturbed and cancerous degeneration and further development of a tumor-like formation may appear.
• Chronic alcohol abuse and smoking – these bad habits are well-known factors that provoke all kinds of complications. This is especially true of alcoholic beverages containing not only nitrites and nitrates, but also ethyl alcohol. The harmful effects of ethyl alcohol, like tobacco smoke, lead to the development of acute erosive processes on the inner walls of the stomach, which tend to become malignant. In addition, passing through the liver, ethyl alcohol causes the formation of toxic compounds that adversely affect the entire body as a whole.
• Alimentary factor – stomach cancer often develops in people with an unhealthy diet: often eating fatty and fried foods, not knowing the measure in food, having the habit of going to bed, having had a hearty dinner just before bedtime.

In addition to the impact of the above predisposing factors, the occurrence of gastric cancer may be associated with some specific diseases that lead to a change in the normal structure of the inner wall of the stomach, the appearance and development of malignant cells on it. According to statistics, stomach cancer often occurs in people suffering from the following pathologies:

• vitamin-dependent B-12 deficiency anemia – anemia of this type is also called pernicious or malignant, it is characterized by insufficient synthesis of red blood cells – erythrocytes, which include hemoglobin molecules. Vitamin B-12 takes part in hematopoiesis, and in addition, in the formation of all body cells, especially those that multiply intensively. With insufficient intake of vitamin B-12 with food in the mucous layer of the stomach, the metabolism gradually decreases. As a result, normal cells die off and cancer cells form in their place;
• atrophic chronic gastritis – as a result of the gradual extinction of the function of the gastric mucosa, atrophic processes occur (the cells die off). This disease is manifested by a feeling of a full stomach, belching, which has a rotten smell of food eaten the day before;
• adenoma of the stomach – a benign process in which glandular cells grow (with the release of mucus, enzymes for digestion), forming polyps. The presence of polypous formations may go unnoticed for a long time, however, due to the constant passage of food through the stomach, the disturbed cell structure may be subjected to additional traumatization, as a result of which the process becomes malignant, a cancerous tumor develops;
• Menetrier’s disease – the development of a malignant process in the stomach in this case is due to pathological growth and an increase in the size of the villi of the gastric mucosa;
• chronic stomach ulcer – untimely diagnosis and lack of treatment of this pathology can lead to an increase in ulcers on the inner surface of the stomach, disruption of the normal structure of the mucous membrane and malignancy of the pathological process.

Classification of Stomach Cancer

According to the histological classification of gastric cancer, there are the following types of disease:

• adenocarcinoma of the stomach
• mucinous adenocarcinoma
• tubular adenocarcinoma
• papillary adenocarcinoma
• inflammatory myofibroblastic tumor of the stomach
• cricoid cell carcinoma of the stomach (cricoid gastric cancer)
• adenosquamous cell carcinoma
• undifferentiated stomach cancer
• squamous cell carcinoma of the stomach
• small cell stomach cancer
• stomach sarcoma
• stomach lymphoma
• gastric carcinoma
• poorly differentiated gastric cancer.

The most aggressive form of stomach cancer of the above is cricoid gastric cancer.

Gastric adenocarcinoma is the most common form of gastric cancer that originates from glandular epithelial cells. In the early stages, the disease may be asymptomatic. As a malignant tumor develops, gastric adenocarcinoma manifests itself as pain in the epigastric region, loss of appetite, nausea, belching, weight loss, weakness, and apathy.

Diagnosis of gastric adenocarcinoma is carried out using the following studies: endoscopy with biopsy, radiography of the stomach, tumor markers. The only radical treatment for adenocarcinoma is surgery. An operation is performed to remove the tumor. Radiation and chemotherapy are prescribed as additional methods or if the patient has contraindications to surgical treatment.

Adenocarcinoma of the stomach, in turn, is divided into the following types:

• cancer ulcer – a saucer-shaped neoplasm with ulceration in the central part;
• scirrhus of the stomach – with the spread of the pathological process to most of the stomach and its penetration into the wall of the organ;
• pseudo-ulcer cancer – a tumor that for a long time manifests itself as symptoms of a stomach ulcer;
• polypoid cancer – a tumor formation with clear boundaries, visually resembles a polyp;
• tubular adenocarcinoma – a tumor that consists of cells of a cylindrical or cubic epithelium;
• mucosal adenocarcinoma is a neoplasm consisting of mucus-producing (mucinous) cells.

According to the histological classification, which is based on the degree of differentiation of malignant cells, adenocarcinoma has the following forms:

• undifferentiated adenocarcinoma;
• low-grade gastric adenocarcinoma (low-differentiated gastric adenocarcinoma);
• moderately differentiated gastric adenocarcinoma;
• highly differentiated adenoma of the stomach.

One of the rare forms of gastric cancer is a neuroendocrine tumor of the stomach.

Depending on the localization of the pathological process, several types of gastric cancer are known, for example:

• cancer of the antrum of the stomach;
• cardioesophageal cancer of the stomach with the transition to the esophagus;
• cancer of the esophagus and stomach;
• submucosal cancer of the stomach, etc.

However, despite the huge number of varieties of stomach cancer, the main task of the oncologist at the Yusupov hospital is to accurately determine the stage of oncopathology, due to which the most effective tactic for treating the patient is selected: radiation, chemotherapy or surgery, most often with the removal of lymph nodes (given the lymphogenous spread of malignant cells ). Lymph node dissection for gastric cancer is a preventive measure to prevent the development of relapses of the disease in the future.

What are the stages of Stomach Cancer?

Regardless of location, any neoplasm has four stages of development. Each stage of stomach cancer differs in the size of the tumor, the number of affected lymph nodes, the presence or absence of secondary foci of malignant cells (metastases) that spread throughout the body through the blood or lymph vessels.

The most common and informative in terms of accurate diagnosis is the classification according to the TNM system. The stages of gastric cancer according to TNM are differentiated by the depth of tumor germination, spread to the lymph nodes and the presence / absence of metastases.

The clinical classification of gastric cancer proposed below describes not only the four main stages, but also substages, which make it possible to describe each tumor process more accurately.

Symptoms, first signs of Stomach Cancer

Rarely, the initial stage of gastric cancer is diagnosed. Symptoms that reliably indicate a malignant tumor are practically absent in gastric cancer.

This oncopathology is characterized by a diverse and numerous clinical picture. The first signs of stomach cancer often go unnoticed for a long time. Symptoms of stomach cancer in women and men depend on the location of the tumor, its size, and in the late, advanced stages, and on the presence of metastases in certain organs. It is important to detect the first signs of stomach cancer at an early stage. In women, tumors found at advanced stages may be complicated by the development of Krukenberg metastasis, one of the most aggressive tumors.

There are a number of common features that characterize any pathological process associated with the development of a benign or malignant tumor. In addition, gastric cancer can also manifest itself with local symptoms, which are associated with the fact that the tumor grows into the walls of the stomach, compresses the surrounding tissues, disrupts the evacuation of the contents of the stomach and other functions of adjacent organs.

General symptoms of a malignant process

Cancer of any localization is characterized by certain common signs that indirectly signal the presence of a tumor-like formation in the body. The following early signs of stomach cancer and other oncopathologies should cause alertness:

• sharp weight loss;
• constant fatigue;
• anemic skin color;
• increased fatigue.

The appearance of these symptoms is inherent in any oncological disease, therefore, to diagnose stomach cancer, if there are no other clinical symptoms of any pathology, oncologists use a set of symptoms, the so-called syndrome of small signs, indicating a violation of the gastrointestinal tract.

Syndrome of small signs

Symptoms of minor signs syndrome include:

• flatulence (bloating) after eating;
• constant discomfort in the upper abdomen;
• causeless loss of appetite, resulting in a sharp decrease in weight;
• nausea accompanied by slight salivation;
• heartburn – a symptom that occurs when the neoplasm is localized in the upper part of the stomach;
• apathy, fatigue, deterioration of well-being.

Local symptoms of Stomach Cancer

The appearance of local symptoms is observed in patients with a tumor localized in the antrum of the stomach (in the place where the organ connects to the duodenum). Patients have a feeling of heaviness in the abdomen. Due to the difficulty of passing food into the next section of the gastrointestinal tract and its stagnation in the antrum, patients note the appearance of belching with air, often with a putrid odor.

With cancerous tumors localized in the cardia (the initial part of the stomach), swallowing (dysphagia) is difficult in patients, which is due to the lack of passage of the initial volume of food further down the stomach, as a result of which new portions of food cannot freely flow from the esophagus.

Irritation of the vagus nerves, located near the gastric mucosa in the cardial region, is accompanied by an increase in salivation.

Symptoms of Stomach Cancer at an early stage

Clinical manifestations of oncopathology directly depend on the stage of the pathological process. Due to the small severity, the first symptoms of stomach cancer at an early stage in men and women often go unnoticed. The first stage is characterized by an asymptomatic course or the presence of minor symptoms:

• fatigue
• depression
• periodic increase in body temperature
• aversion to protein foods
• causeless weakness.

Symptoms and manifestation of the Stomach Cancer in the stage 2

Gastric cancer in the second stage can be manifested by the following symptoms:

• stool disorder
• belching with putrid odor
• weight loss
• increased gas formation
• nausea, vomiting, which brings relief only for a short period of time
• heartburn and burning in the esophagus
• discomfort and pain in the stomach.

Symptoms and signs of Stomach Cancer in the stage 3

At the third stage of the malignant process, the following symptoms join the above described signs:

• exacerbation of symptoms of the previous stage of the disease
• iron deficiency anemia occurs
• there is a burp with an unpleasant odor (reminiscent of the smell of rotten eggs)
• profuse vomiting, sometimes with bloody impurities
• constant feeling of a full stomach
• eating small portions of food, the patient is quickly satiated
• increased pain intensity
• fatigue, loss of strength (common signs of cancer intoxication).

Symptoms of stomach cancer in the stage 4

Stomach cancer of the fourth stage is manifested by the following symptoms:

• increased symptoms of the third stage;
• severe pain, which can be stopped only for a short period of time, using narcotic analgesics;
• extreme exhaustion of the body (cachexia), as a result of which food intake is possible only with the help of a probe.

Gastric cancer of the fourth stage is also characterized by the development of metastases (secondary foci of malignant tumor growth) in various organs and systems of the human body.

Symptoms of Stomach Cancer in women

The first symptoms of stomach cancer in women are a quick feeling of satiety, heartburn, dyspepsia, decreased ability to work, heaviness in the epigastric region, and belching. Gastric cancer in women is most common after 40 years, the percentage of cases increases after 60 years. The causes of stomach cancer in women are similar to the causes of cancer in men.

Stomach Cancer symptoms in men

The first signs of stomach cancer at an early stage rarely remain noticed by a man. When a tumor grows, it has a strong negative effect on the body, manifests itself with vivid symptoms, pain and severe discomfort make a man seek help from a doctor. Often, treatment occurs late, when doctors can no longer help in the treatment of advanced oncological disease and provide only palliative care, which alleviates the suffering of the patient.

Metastases with Stomach Cancer

There are several types of metastases in stomach cancer:

1. Virchow’s metastasis – the tumor affects the left supraclavicular lymph node. This type of metastasis is typical not only for stomach cancer, but also for other tumors of the abdominal cavity. Virchow’s metastasis spreads by the lymphogenous route;
2. Krukenberg metastasis – its occurrence is characteristic exclusively for women, since one or both ovaries are affected. It can occur both in stomach cancer and in oncological pathologies of other localization, for example, in breast cancer. Differs in rapid progression, aggressive growth;
3. Metastasis of sister Mary Joseph – the tumor affects the navel. Most often it occurs in stomach cancer, but it can also develop in other types of cancer of any localization, including the gynecological sphere. Metastasis of sister Mary Joseph occurs even with tumors of the respiratory system;
4. Irish metastasis – the left axillary lymph node is affected. The propagation mechanism is similar to Virchow’s metastasis;
5. Schnitzler metastasis – a lesion of the Douglas space in women and the vesico-rectal pocket in men. It spreads mainly by contact (lower point of the abdominal cavity). According to another theory, pararectal lymph nodes are affected.

Due to the asymptomatic course and mild symptoms in the early stages, gastric cancer is rarely diagnosed. The first symptoms and manifestation of the disease should cause cancer alertness, especially if their appearance occurs for no apparent reason.

Diagnostics of Stomach Cancer

Diagnostics specialists set themselves the following tasks:

• establish an accurate diagnosis;
• find out the prevalence of the cancer process (whether there are metastases to the lymph nodes or other organs), since it is not enough to identify stomach cancer for adequate treatment, it is also necessary to determine the presence of secondary tumors;
• determine the degree of growth of the primary malignant formation itself.

Diagnosis should be carried out using all the necessary advanced methods that allow you to reliably confirm the presence or absence of a tumor process:

• esophagogastroduodenoscopy (EGDS) – to detect a defect in the gastric mucosa, to take a biopsy for histology. For biopsy, intravenous anesthesia is used, due to which the method is painless, and specialists have the opportunity to perform a high-quality and detailed study;
• endoscopic ultrasound – to accurately determine, using an ultrasonic sensor, the depth of germination of the tumor process in the walls of the stomach and nearby organs, the state of the lymph nodes located near the stomach and, if necessary, taking biomaterial from them for subsequent histological examination. For this study, a full anesthesia allowance is used, which provides the patient with maximum comfort and painlessness of the procedure. In addition, endoscopic ultrasound can determine if the tumor is resectable. For example, with a tumor of small size, but sprouting into large vessels, surgical intervention is contraindicated;
• gastroscopy – an internal examination of the stomach cavity with simultaneous sampling of a biopsy (cell sample) for
• histological examination. A thin flexible tube – a gastroscope is inserted into the stomach through the oral cavity, if necessary, after anesthetizing the patient’s throat. When the tumor is localized under the mucous layer of the stomach, biopsy is difficult.

Stomach Cancer treatment

Surgery

The most common treatment for stomach cancer is surgery. The operation can be radical, aimed at a complete cure, or palliative – affecting directly the malignant neoplasm itself and metastases.

Radical surgery aims to remove the tumor and prevent it from spreading further throughout the body. Depending on the spread of the malignant process and the localization of the tumor, subtotal gastrectomy (removal of part of the stomach) or total gastrectomy (complete removal of the stomach) is performed. In case of gastric cancer, surgeons-oncologists, first of all, reveal the degree of damage to the wall of the organ, in accordance with which they determine the necessary amount of surgical intervention.

In cases where the tumor grows into organs adjacent to the stomach (spread by contact), a combined gastrectomy is performed – partial removal of the affected adjacent organs and removal of the stomach. With cancer, the life expectancy after surgical treatment is significantly increased.

If the tumor is localized in the lower part, bordering the duodenum, the patient may be offered surgical intervention to remove part of the stomach (the so-called resection of the stomach for cancer), followed by restoration of the continuity of the digestive tract.

During any surgical intervention for stomach cancer, nearby lymph nodes that may potentially contain cancer cells are removed.

Treatment of stomach cancer is carried out using endoscopic technologies. Before the operation, endoscopic examinations are carried out – endosonography, CT, chromoendoscopy and studies using other enloscopic methods. To remove a malignant tumor of the stomach, the method of endoscopic resection of the mucosa with dissection of the submucosal layer, endoscopic resection of the mucosa (EMR) is used. Preparation for endoscopic surgery is the same as preparation for open surgery. Surgical access for gastric cancer depends on the degree of spread of the malignant tumor to the esophagus, the physical condition of the patient.

If gastric cancer develops without tumor transfer to the distal esophagus and is not involved in the process of cardia rosette, surgical intervention is performed from the middle laparotomy access. In case of total stomach cancer, esophageal lesion, the operation is performed from the abdominal-mediastinal approach. Thoracolaparotomy access is used in case of limited damage to the stomach by a tumor involving the rosette of the cardia, the transition to the distal esophagus. In this case, a wide diaphragmotomy from a laparoscopic approach can be used.

Distal subtotal resection is performed for cancer of the antrum of the stomach, provided there is no tumor in situ in other parts of the stomach, in the absence of severe dysplasia. Proximal subtotal resection of the stomach is performed for small malignant tumors (mixed and exophytic forms) of the upper third of the stomach, with damage to the cardioesophageal junction.

Palliative operations provide compensation for the most severe manifestations of the tumor, but not complete elimination of the disease. Palliative treatment of stomach cancer is carried out at late, advanced stages of the malignant process.

Specialists prefer low-traumatic laparoscopic operations, which require a camera and specialized surgical instruments that are inserted into small punctures (from 5 to 10 mm) in the abdominal cavity. Laparoscopic surgery to remove the stomach for cancer is a very effective method that has certain advantages: postoperative pain is significantly reduced, rehabilitation and the return of patients to a full life occurs in a shorter time.

Chemotherapy

Chemotherapy for gastric cancer can be used as an independent method, or combined with surgical treatment and radiotherapy.

Chemotherapy drugs for stomach cancer can be used in preparation for surgery to help shrink the tumor (neoadjuvant chemotherapy) or in the postoperative period to help kill any remaining cancer cells.

In addition, chemotherapy tablets for gastric cancer can be used to reduce pain in patients with inoperable cancer. Inoperable cancer requires the use of modern chemotherapy and targeted drugs.

Radiotherapy

Most often, radiotherapy is a component of the complex treatment of gastric cancer, which is combined with surgical and chemotherapeutic methods of treatment. Radiological method of treatment of stomach cancer helps to improve the results of surgery.

Can stomach cancer be cured?

Gastric cancer is curable only in the absence of metastases (until the malignant process begins to spread to adjacent and distant organs and tissues). To predict whether stomach cancer can be cured in each case, experts evaluate the size of the malignant neoplasm, the type of tumor, the number of affected lymph nodes, the patient’s age and his general health.

The most favorable prognosis is for cancerous tumors found in the initial (first and second) stages of development, since it is much easier to cure stomach cancer, as long as only the mucous and muscular layers of the stomach walls are affected, the tumor is small, and there are no distant metastases. However, at these stages, gastric cancer is most often asymptomatic, which makes it difficult to detect it in time. The third stage of stomach cancer is much more difficult to treat. Surgery in this case, as a rule, is powerless.

The most unfavorable prognosis is observed when a malignant tumor is detected at the fourth stage of development. The percentage of five-year survival in these cases does not exceed 5%.

Forecast – survival prognosis for Stomach Cancer

Patients diagnosed with gastric cancer have a poor survival prognosis. The effectiveness of treatment depends on the intensity of tumor growth and the degree of its germination in the walls of the stomach. Equally important is the presence / absence of metastases in regional lymph nodes, as well as in distant organs and tissues. The age of the patient diagnosed with stomach cancer is also important.

The prognosis is more favorable in younger patients than in older ones. The likelihood of a complete cure is much higher in case of early detection of stomach cancer. It is much worse to treat gastric cancer with metastases, how long patients with oncopathology of late stages live – depends on the above factors and the professionalism of the attending physician.