Stomach cancer , also known as stomach cancer , is a cancer that develops from the lining of the stomach. Early symptoms may include heartburn, upper abdominal pain, nausea and loss of appetite. Further signs and symptoms may include weight loss, yellowing of the skin and white eyes, vomiting, difficulty swallowing and blood in the stool among others. Cancer can spread from the stomach to other parts of the body, especially the liver, lungs, bones, lining of the stomach and lymph nodes.
The most common cause is infection by bacteria Helicobacter pylori , which accounts for more than 60% of cases. Certain types of H. pylori have a greater risk than others. Smoking, dietary factors such as vegetables and pickled obesity are other risk factors. Approximately 10% of cases occur in the family, and between 1% to 3% of cases are caused by genetic syndromes derived from a person's parent such as hereditally diffuse stomach cancer. Most cases of stomach cancer are gastric carcinoma. This type can be divided into subtypes. Lymphomas and mesenchymal tumors can also develop in the abdomen. Often, stomach cancer develops gradually over the years. Diagnosis is usually done with a biopsy during endoscopy. This is followed by medical imaging to determine whether the disease has spread to other parts of the body. Japan and South Korea, two countries that have high rates of illness, screen for stomach cancer.
The Mediterranean diet lowers the risk of cancer as it stops smoking. There is tentative evidence that treating H. pylori reduces future risks. If cancer is treated early, many cases can be cured. Treatment may include some combination of surgery, chemotherapy, radiation therapy and targeted therapy. If late treated, palliative care may be recommended. Results are often poor with a five-year survival rate of less than 10% globally. This is mostly because most people with the condition present with advanced disease. In the United States, the five-year survival is 28%, while in South Korea the figure is over 65%, partly because of screening efforts.
Globally, stomach cancer is the leading cause of all five cancers and the third leading cause of death from cancer, which accounts for 7% of cases and 9% of deaths. By 2012, it has just happened to 950,000 people and caused 723,000 deaths. Before the 1930s, in most parts of the world, including most developed countries in the West, it was the most common cause of death from cancer. The mortality rate has declined in many regions of the world since then. It is believed to be eating less salty and pickled foods as a result of the development of cooling as a method of keeping fresh food. Stomach cancer is most common in East Asia and Eastern Europe. This happens twice as often in men as in women.
Video Stomach cancer
Signs and symptoms
Stomach cancer is often asymptomatic (does not cause obvious symptoms) or may only cause nonspecific symptoms (symptoms that may also be present in other related or unrelated disorders) at an early stage. By the time symptoms appear, the cancer has often reached an advanced stage (see below) and may have metastasized (spread to other parts of the body, perhaps far away), which is one of the main reasons for its relatively poor prognosis. Stomach cancer can cause the following signs and symptoms:
Early cancer may be associated with indigestion or burning sensations (heartburn). However, less than 1 in every 50 people are referred for endoscopy because digestive disorders have cancer. Stomach discomfort and loss of appetite, especially for meat, can occur.
Stomach cancer that has become enlarged and invading normal tissue can cause weakness, fatigue, flatulence after eating, upper abdominal pain, nausea and occasionally vomiting, diarrhea or constipation. Further enlargement can cause weight loss or bleeding with blood vomiting or have blood in the stool, the latter seen as a change in black (melena) and occasionally causing anemia. Dysphagia indicates a tumor in the cardia or extension of the stomach tumor to the esophagus.
This can be a symptom of other problems such as stomach virus, gastric ulcer, or tropical canker sores.
Maps Stomach cancer
Cause
Stomach cancer occurs as a result of many factors. This happens twice as often in men as women. Estrogen can protect women against the development of this form of cancer.
Infection
Helicobacter pylori infection is an important risk factor in 65-80% of gastric cancers, but only 2% of people with Helicobacter infection develop stomach cancer. The mechanism by which H. pylori induces abdominal cancer potentially involves chronic inflammation, or the action of H. pylori virulence factors such as CagA. It is estimated that Epstein-Barr virus is responsible for 84,000 cases per year. AIDS is also associated with an increased risk.
Smoking
Smoking increases the risk of stomach cancer significantly, from 40% increased risk for current smokers to 82% increase for heavy smokers. Gastric cancer from smoking mostly occurs at the top of the stomach near the esophagus. Several studies have shown an increased risk with alcohol consumption as well.
Diet
Food factors are not proven cause and the relationship between stomach cancer and various foods and beverages is weak. Some foods including smoked foods, salt and salt-rich foods, red meat, processed meats, pickled vegetables, and bracken are associated with higher risk of gastric cancer. Nitrates and nitrites in preserved meat can be altered by certain bacteria, including H. pylori , into compounds that have been found to cause stomach cancer in animals.
Fresh fruit and vegetable intake, citrus intake, and antioxidant intake are associated with lower risk of stomach cancer. The Mediterranean diet is associated with lower rates of stomach cancer, such as regular aspirin use.
Obesity is a physical risk factor that has been found to increase the risk of gastric adenocarcinoma by contributing to the development of gastroesophageal reflux disease (GERD). The exact mechanism by which obesity causes GERD is not fully known. The study hypothesizes that increased dietary fat causes increased pressure on the stomach and lower esophageal sphincter, as excess adipose tissue may play a role, but no statistically significant data has been collected. However, the risk of gastric cardiac adenocarcinoma, with the presence of GERD, has been found to increase by more than 2 times for obese people. There is a correlation between iodine deficiency and stomach cancer.
Genetics
Approximately 10% of cases occur in the family and between 1% and 3% of cases are caused by genetic syndromes that are inherited from a person's parent such as hereditary diffuse stomach cancer.
The genetic risk factor for gastric cancer is a genetic defect of the CDH1 gene known as hereditary diffuse edema cancer (HDGC). The CDH1 gene, which encodes E-cadherin, is located on the 16th chromosome. When genes undergo certain mutations, gastric cancer develops through mechanisms that are not fully understood. These mutations are considered to be autosomal dominant which means that half of the transporting children are likely to experience the same mutations. The diagnosis of hereditary diffuse stomach cancer usually occurs when at least two cases involving family members, such as a parent or grandparent, are diagnosed, with at least one diagnosed before the age of 50. Diagnosis can also be made if there are at least three cases in the family, case not considered.
The International Cancer Genome Consortium leads efforts to identify genomic changes involved in stomach cancer. A very small percentage of diffuse type gastric cancers (see Histopathology below) arise from abnormal genes CDH1 innate. Genetic testing and treatment options are available for families at risk.
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Other risks include diabetes, pernicious anemia, chronic atrophic gastritis, Menetrier disease (hyperplastic, hypersecretory gastropathy), and intestinal metaplasia.
Diagnosis
To find the cause of symptoms, the doctor asks about the patient's medical history, performs a physical exam, and can order laboratory research. The patient may also have one or all of the following exams:
- The gastroscopic examination is the preferred diagnostic method. This involves inserting a fiber-optic camera into the stomach to visualize it.
- The top GI series (can be called barium roentgenogram).
- Computed tomography or abdominal CT scan may show gastric cancer. More useful to determine invasion to adjacent tissue or presence of spread to local lymph nodes. Thickening of the wall is more than 1 cm in focus, eccentric and increase the sense of ferocity.
In 2013, Chinese and Israeli scientists reported a successful pilot study of breathalyzer breath breath tests intended to diagnose stomach cancer by analyzing chemicals exhaled without the need for intrusive endoscopy. Large-scale clinical trials of this technology have been completed by 2014.
The abnormal tissue seen in gastroscopic examination will be biopsied by a surgeon or gastroenterologist. The tissue is then sent to a pathologist for histological examination under a microscope to check for the presence of cancer cells. Biopsy, with subsequent histological analysis, is the only sure way to confirm the presence of cancer cells.
Various gastroscopic modalities have been developed to improve detectable mucosal results with dyes that accentuate cell structure and to identify areas of dysplasia. Endocytoscopy involves ultra-high enlargement to visualize the cell structure to better determine the area of ​​dysplasia. Other gastroscopic modalities such as optical coherence tomography are being investigated for similar applications.
A number of skin conditions are associated with stomach cancer. The condition of dark skin hyperplasia, frequent axilla and groin, known as acanthosis nigricans, is associated with intra-abdominal cancer such as stomach cancer. Other skin manifestations of gastric cancer include tripe palms (similar darkening hyperplasia on the skin of the palms) and the Leser-Trelate sign, which is a rapid development of a skin lesion known as Seborrhoeic keratosis.
Various blood tests can be performed including a full blood count (CBC) to check for anemia, and fecal occult blood tests to check blood in the stool.
Histopathology
- gastric adenocarcinoma is a malignant epithelial tumor, derived from the gastric mucosal epithelium. Gastric cancer is highly adenocarcinoma (90%). Histologically, there are two main types of gastric adenocarcinoma (Lauren classification): intestinal type or diffuse type. Adenocarcinoma tends to invade the gastric wall aggressively, infiltrate the mucosal muscularis, submucosa and then propria muscularis. The tumor cells of adenocarcinoma of the intestine represent irregular tubular structures, saving pluristratification, some lumens, reducing stroma (aspect "back to back"). Often, it's the association of intestinal metaplasia in the neighboring mucosa. Depending on the gland architecture, cellular pleomorphism and mucosecretion, adenocarcinoma may show 3 degrees of differentiation: good, moderate and less differentiated. The type of diffuse adenocarcinoma (mucin, colloids, plastica linitis or skin bottle stomach) tumor cells are paralyzing and secreting mucus, sent in the interstitium, resulting in large mucus/colloidal ("empty" optical spaces). It is not well differentiated. If the mucus is still inside the tumor cell, it pushes the nucleus to the periphery: " taper ring cell ".
- About 5% gastric malignancy is lymphoma (MALTomas, or MALT lymphoma).
- Carcinoid and stromal tumors can occur.
Staging
If cancer cells are found in tissue samples, the next step is the stage, or find out the extent of the disease. The various tests determine whether the cancer has spread and, if so, which parts of the body are affected. Because stomach cancer can spread to the liver, pancreas, and other organs near the abdomen and lungs, doctors may order CT scans, PET scans, endoscopic ultrasound examinations, or other tests to examine this area. Blood tests for tumor markers, such as carbinoembryonic antigens (CEA) and carbohydrate antigens (CAs) can be ordered, as their levels correlate with metastatic levels, especially to the liver, and healing rates.
Staging may be incomplete until after surgery. The surgeon lifts nearby lymph nodes and possibly tissue samples from other areas of the stomach for examination by the pathologist.
Clinical stage of stomach cancer is:
- Stage 0. Limited to the inner lining of the stomach. May be treated with endoscopic mucosal resection when found very early (on routine examination); on the contrary with gastrectomy and lymphadenectomy without the need for chemotherapy or radiation.
- Phase I. Penetration to second or third layer of stomach (Stage 1A) or to the second layer and nearby lymph nodes (Stage 1B) . Stage 1A is treated with surgery, including the removal of omentum. Stage 1B can be treated with chemotherapy (5-fluorouracil) and radiation therapy.
- Stage II. Penetration to the second layer and further lymph nodes, or the third layer and only nearby lymph nodes, or all four layers but not the lymph nodes. Treated as for Stage I, occasionally with additional neoadjuvant chemotherapy.
- Phase III. Penetration to the third layer and further lymph nodes, or penetration into the fourth layer and nearby or nearby tissue or further lymph nodes. Treated as for Phase II; drugs can still be done in some cases.
- Stage IV. Cancer has spread to adjacent tissues and further lymph nodes, or has metastasized to other organs. Healing is very rare at this stage. Several other techniques for prolonging life or improving symptoms are used, including laser treatment, surgery, and/or stent to keep the digestive tract open, and chemotherapy with drugs such as 5-fluorouracil, cisplatin, epirubicin, etoposide, docetaxel, oxaliplatin, capecitabine or irinotecan.
TNM staging systems are also used.
In an open access endoscopic study in Scotland, patients were diagnosed with 7% in Phase I of 17% in Phase II, and 28% in Phase III. Minnesota Population was diagnosed with 10% in Phase I, 13% in Phase II, and 18% in Phase III. However, in high-risk populations in southern Chile's Valdivia Province, only 5% of patients are diagnosed in the first two stages and 10% in stage III.
Prevention
Getting rid of H. pylori in those infected reduces the risk of stomach cancer, at least in those who are Asian. A meta-analysis of observational studies 2014 found that a diet high in fruits, mushrooms, garlic, soybeans, and spring onions was associated with a lower risk of stomach cancer in the Korean population. Low doses of vitamins, especially from a healthy diet, reduce the risk of stomach cancer. Previous reviews of antioxidant supplementation found no supporting evidence and probably worse outcomes.
Management
Gastric cancer is difficult to cure unless it is found in the early stages (before it begins to spread). Unfortunately, because early stomach cancer causes some symptoms, the disease usually develops when the diagnosis is made.
Treatment for stomach cancer may include surgery, chemotherapy, and/or radiation therapy. New treatment approaches such as immunotherapy or gene therapy and improved ways to use current methods are being studied in clinical trials.
Surgery
Surgery remains the only curative therapy for stomach cancer. From different surgical techniques, endoscopic mucosal resection (EMR) is a treatment for early gastric cancer (tumor involving mucosa only) pioneered in Japan and available in the United States in several centers. In this procedure, the tumor, together with the inner lining of the stomach (mucosa), is removed from the stomach wall using an electrical wire loop through the endoscope. The advantage is that it is a much smaller operation than taking off the stomach. Endoscopic submucous dissection (ESD) is a similar technique pioneered in Japan, used to resect a large area of ​​the mucosa in one section. If the pathological examination of the resected specimen shows an unresolved resection or deep invasion by the tumor, the patient will need a formal gastric resection. A Cochrane review of 2016 found low-quality evidence of no difference in short-term mortality between laparoscopy and open gastrectomy (gastric removal), and that the benefits or dangers of laparoscopic gastrectomy can not be excluded.
Those who have metastatic disease at presentation may receive palliative surgery and while it remains controversial, because of the possible complications of the surgery itself and the fact that it may delay chemotherapy, the data so far are largely positive, with better survival rates. seen in those treated with this approach.
Chemotherapy
The use of chemotherapy to treat stomach cancer does not have a definite standard of care. Unfortunately, stomach cancer has not been too sensitive to these drugs, and chemotherapy, when used, usually serves to reduce palliative tumor size, relieve symptoms of illness and increase survival time. Some drugs used in the treatment of stomach cancer include: 5-FU (fluorouracil) or analogous capecitabine, BCNU (carmustine), methyl-CCNU (semustine) and doxorubicin (Adriamycin), and mitomycin C, and recently cisplatin and taxotere , often using drugs in various combinations. The relative merits of these different drugs, alone and in combination, are unclear. Clinical researchers explore the benefits of chemotherapy before surgery to shrink the tumor, or as adjuvant therapy after surgery to destroy the remaining cancer cells.
Targeted therapies
More recently, treatment with human epidermal growth factor 2 receptors ( HER2 ) inhibitors, trastuzumab, has been demonstrated to improve overall survival in advanced gastric carcinoma or inoperable excess metastases expressing the HER2 gene/neu. Specifically, HER2 is expressed in 13-22% of patients with stomach cancer. Of note, HER2 excessive expression of gastric neoplasia is heterogeneous and comprises a small percentage of tumor cells (less than 10% of gastric cancer exposes HER2 in more than 5% of tumor cells). Therefore, this heterogeneous expression must be taken into account for testing HER2 , especially in small samples such as biopsies, requiring the evaluation of more than one bioptic sample.
Radiation
Radiation therapy (also called radiotherapy) can be used to treat stomach cancer, often as an adjuvant for chemotherapy and/or surgery.
Prognosis
The prognosis of stomach cancer is generally poor, due to the fact that the tumor has metastasized frequently at the time it was discovered and the fact that most people with this condition are elderly (average age is between 70 and 75 years) at presentation. The five-year survival rate for stomach cancer is reported to be less than 10 percent.
Nearly 300 genes are associated with outcomes in stomach cancer with both unfavorable genes where high expression is associated with poor survival and favorable genes where high expression associated with longer survival time. Examples of poor prognosis genes include ITGAV and DUSP1.
Epidemiology
Worldwide, stomach cancer is the fifth most common cancer with 952,000 cases diagnosed in 2012. This is more common in men and in developing countries. In 2012, it represents 8.5% of cancer cases in men, making it the fourth most common cancer in men. Also in 2012, the number of deaths was 700,000, which fell slightly from 774,000 in 1990, making it the third leading cause of cancer-related deaths (after lung cancer and liver cancer).
Less than 5% of stomach cancers occur in people under 40 years of age with 81.1% of 5% in the 30 to 39 age group and 18.9% in the 20 to 29 age group.
In 2014, stomach cancer produces 0.61% of deaths (13,303 cases) in the US. In China, stomach cancer accounts for 3.56% of all deaths (324,439 cases). The highest stomach cancer rate in Mongolia, on 28 cases per 100,000 people.
In the UK, stomach cancer is the fifth most common cancer (about 7,100 people diagnosed with stomach cancer in 2011), and it is the 10th most common cause of cancer-related deaths (about 4,800 people died in 2012).
Incidence and mortality rates of gastric cancer vary widely in Africa. The GLOBOCAN system is currently the most widely used method for comparing this level between countries, but the incidence and mortality rates in Africa look different among countries, possibly because of the lack of universal access to the listing system for all countries. Drastic variations such as the estimated tariff of 0.3/100000 in Botswana to 20.3/100000 in Mali have been observed. In Uganda, the incidence of gastric cancer has increased from the 1960s measurement of 0.8/100000 to 5.6/100000. Gastric cancer, although now, is relatively low when compared to high incident countries such as Japan and China. One suspected cause of variation in Africa and among other countries is due to different strains of Helicobacter pylori bacteria. A trend that is often seen is H. pylori infection increases the risk of stomach cancer. However, this does not happen in Africa, giving this phenomenon the name "African puzzle." Although these bacteria are found in Africa, evidence has supported that different strains with mutations in the bacterial genotype may contribute to differences in cancer progression between African countries and others outside the continent. However, increased access to health care and treatment measures is generally associated with increased incidents, especially in Uganda.
Other animals
The abdomen is a gastrointestinal tract organ that holds food and begins the digestive process by removing the stomach. The most common gastric cancer is adenocarcinoma but other histologic types have been reported. The signs are varied but may include vomiting (especially if there is blood), weight loss, anemia, and lack of appetite. Bowel movement may be dark and stay in nature. To determine if the cancer is present in the stomach, a special X-ray and/or abdominal ultrasound can be performed. Gastroscopy, a test using a device called endoscopy to examine the stomach, is a useful diagnostic tool that can also take samples from suspected masses for histopathologic analysis to confirm or rule out cancer. The most definitive method of cancer diagnosis is through open surgical biopsy. Most stomach tumors are malignant with evidence of spreading to lymph nodes or liver, making treatment difficult. Except for lymphoma, surgery is the most frequent treatment option for stomach cancer but is associated with significant risk.
References
External links
- National Cancer Institute Guidelines for stomach cancer treatment
Source of the article : Wikipedia
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