In general, cancer begins when a mutation occurs in a cell's DNA. The error causes the cell to grow and divide at a rapid rate. The accumulating cancerous cells form a tumor which invades nearby structures. The cancerous cells then break off from the tumor to spread throughout the body. Stomach cancer typically starts in the mucus-producing cells that line the stomach. Stomach cancer starts when cancer cells grows in the inner lining of your stomach. Also known as gastric cancer, it usually grows slowly over many years. It is difficult to diagnose because most people typically don’t show symptoms in the earlier stages. It’s easiest to treat if spotted early. According to estimation there were approximately 28,000 new cases of stomach cancer in 2017. Although stomach cancer is relatively rare compared to other forms of cancer, one of the greatest disadvantages of this disease is its diagnostic difficulty. Scientists do not know exactly what is causing cancer cells to begin to grow in the stomach. But there are a few things that can raise risk for the disease. One of the important risk factor is infection with bacterium, H. pylori, which causes ulcers. Other risks are inflammation in gut called gastritis, a certain type of anaemia called pernicious anaemia, and growths in your stomach called polyps. Stomach cancer should not be confused with other cancers that may occur in the abdomen, such as colon cancer, liver cancer, pancreas, or small intestine, as these cancers may have different symptoms, and require different treatments.
Signs and symptoms of gastroesophageal junction cancer and stomach cancer may include Fatigue, Feeling bloated after eating, Feeling full after eating small amounts of food, Severe, persistent heartburn, Unexplained, persistent nausea, Stomach pain, Persistent vomiting, Unintentional weight loss. Gastroesophageal junction cancer is associated with having gastrointestinal reflux disease and, less strongly with obesity and smoking. GERD is a condition caused by frequent backflow of stomach acid into the oesophagus. As the use of refrigerator for preserving foods has increased around the world, the rates of stomach cancer have declined. The main risk factors for gastroesophageal junction cancers are a history of GERD and obesity. Factors that increase your risk of stomach cancer located in the stomach body include a diet high in salty-smoked foods, fruits and vegetables, Family history of stomach cancer, Smoking, Stomach polyps.
The location of the cancer will also influence the treatment options. For example, cancers that begin at the GE junction are staged and treated in the same way as the esophagus cancers. A cancer that begins in the stomach cardia but then grows into the GE junction is also staged and treated as a cancer of the esophagus.
Adenocarcinoma: The majority of stomach cancers are adenocarcinomas. A stomach cancer or gastric cancer is almost always an adenocarcinoma. These cancers develop from the cells that form the innermost lining of the stomach (this cancer is almost always adenocarcinoma).
Lymphoma: These are immune system tissue cancers that are occasionally found in the stomach wall. Treatment and perspective depend on the type of lymphoma.
Carcinoid tumor: These tumors begin in the stomach cells which make hormones. Most of these tumors are not propagated to other organs.
Gastrointestinal stromal tumor (GIST): These rare tumors start in very early forms of cells in the wall of the stomach called interstitial cells of Cajal. Some of these tumors are non-cancerous (benign); others are cancerous. Although GISTs can be found anywhere in the digestive tract, most are found in the stomach.
The disproportionate difference between the grave prognosis of advancing stomach cancer, and its insidious onset pattern impels caregivers to awareness about trends and modern practice recommendations for therapeutic benefit. The average age at diagnosis is 69 years, and highest incidence by race and gender categorization being in the black male population, statistically 16 per 100, 000 men. Asians/Pacific Islanders, and Hispanics closely follow with incidence rates in 2006-2010 study period being 15.5 and 14.9 per 100, 000 males respectively. The lowest male incidence is observed in white males at 9.2 per 100,000 studied males. Female gender is comparatively less affected by stomach cancer development; rates being far lower than those of males - highest observed in Asian/ Pacific Islander race with rates of 9.3 per 100,000 females and lowest observed in white females with incidence rates of 4.5 per 100, 000 females - about half the incidence observed in white males. There is a 5 year relative survival rate of 63.2 % (relative to survival of general population sample) if the cancer is diagnosed in a localized stage, with no distant or lymph node involvement. This localized stage represents only about one quarter of stomach cancer diagnoses however, and the largest percent distribution class at diagnosis falls into Distant Metastasis already existing at the time of diagnosis with a staggering 34% of cases detected in this stage. Diagnosis with distant metastasis offers 3.9% 5 year survival compared to general population. A special association exists between Helicobacter Pylori bacterial invasion of stomach lining and gastric and duodenal cancer development. A recent study demonstrated an odds ratio of 1.9% for developing gastric cancer, and odds ratio of 2.3 for developing intestinal type cancer of distal stomach in CagA Antibody patients with confidence 95% confidence interval. A significant genetic tendency for cancer is also observed, with one study showing a Relative Risk of 2.6 for those with family history of gastric cancer, RR 2.4 for intestinal cancer family history, and 1.7 in the case of positive family rectal cancer history. Recent study into carcinogenesis relationship between Melanoma Antigen Gene Family A MAGEA has demonstrated presence in 30% gastric malignant cell lines and can be used as a diagnostic prediction marker. A Taiwanese study demonstrated that Diabetes Mellitus is associated with 2.75 times risk of developing gastric malignancy compared to normal.