This condition affects men somewhat more often than women.
Dr. Navneet Sharda provides this information as an educational source. It is not intended as a substitute for a consultation with a qualified healthcare provider.
Other names for gastric cancer are cancer of the stomach, gastric carcinoma, and gastric adenocarcinoma. Stomach is the “J” shaped hollow viscus into which the food passes after it exits the esophagus.“Gastric” means of the stomach. “Carcinoma” means cancer of the cells forming linings within organs, and “adenocarcinoma” means cancer of the glandular cells within organs. In most cases of stomach cancer, the tumors develop in the inner lining (mucosa) of the stomach, grow into the submucosa, then the muscularis propria (the muscular layer that contracts and moves the stomach, churning the food) and finally spread to the outer layer (serosa) as it grows. Stomach cancer develops slowly over many years before the first symptoms are recognized. It is quite curable when diagnosed only in the mucosa before it grows into the muscularis.
Left untreated or diagnosed, stomach cancer grows and spreads to adjacent areas and organs. Once it spreads, the treatment plan becomes complicated and the outcome is not optimistic.
Gastric cancer accounts for 10% of cancers around the world. There are marked variations in the incidence of gastric cancer worldwide which make it clear that this is an environmental disease. Stomach cancer represents 1.7% of all new cancer cases in USA. Statistics show that there are about 28,000 new cases and 10,960 deaths estimated for the year 2017 in USA. The states including California, Illinois, New York, Pennsylvania and Florida have the highest incidence estimated for 2017. Usually, men are more affected than women and the incidence increases with age. The incidence of carcinoma in the proximal stomach, particularly the esophagogastric junction (Junction between esophagus and stomach), appears to be increasing. Carcinoma of the distal stomach and body of the stomach is most common in low socio-economic groups and people with Helicobacter pylori (a spiral shaped bacteria found in the stomach) infection. Proximal gastric cancers seem to affect principally higher socio-economic groups. There is an increased risk for stomach cancers in people over the age of 50 . Helicobacter pylori infection seems to be a major cause of stomach cancer, especially cancers in the lower (distal) part of the stomach. An increased risk of stomach cancer is seen in people with diets that have large amounts of smoked foods, salted fish/meat and pickled vegetables. Smoking, being overweight or obese, people with type A blood have a higher risk. People with first-degree relatives (parents, siblings, or children) who have had stomach cancer are more likely to develop this disease. Some inherited conditions may raise a person’s risk of stomach cancer like hereditary diffuse gastric cancer, Lynch syndrome and familial adenomatous polyposis. People who carry mutations of the inherited breast cancer genes (BRCA1 or BRCA2) may also have a higher rate of stomach cancer. Workers in the coal, metal, and rubber industries seem to have a higher risk of getting stomach cancer.
Unfortunately, stomach cancer is asymptomatic during its early stages which can cause an initial diagnosis to be delayed for more than 80 percent of patients. However, some of the initial signs of stomach cancers are:
Indigestion that never goes away and stomach discomfort. Bloated feeling right after eating. Feeling full too easily-doctors call that “early satiety”. Vague discomfort in the abdomen, above the navel. Mild nausea and vomiting sensation. Loss of appetite. Heartburn.
One of the first steps in establishing a cancer diagnosis is a detailed and complex medical review of the patient’s past health problems and general health state, followed by a detailed interview focused on symptoms and gastric cancer risk factors.
Physical Examination: The role of a physical examination is to confirm the general health state and to identify possible signs of the cancer. The doctor will look for any abnormal changes on the abdominal area, if there is blood in the stool after a rectal examination, if there is evidence of rapid weight loss, if there are any swollen lymph nodes in the lower neck or under the arms, if the fingernails are pale indicating lack of blood.
Blood Tests: The most common blood tests used in the diagnostic process of gastric cancer: CBC indicates if there is significant blood loss, CMP indicates if there has been organ damage and tumor markers such as CEA (carcinoembryonic antigen) and CA 19-9. The tumor markers are produced both by cancerous and normal cells. When the level of the tumor markers is higher then the normal limits, it can be a sign of gastric cancer.
Upper Endoscopy: Esophagogastroduodenoscopy (EGD) is the main test used to find stomach cancer. This lets the doctor to pass a camera through the mouth of the patient into the stomach and see the lining of the stomach. If abnormal areas are seen, biopsies (tissue samples) can be taken using instruments passed through the endoscope. The tissue samples are sent to a pathology lab for microscopic examination. The Pathologist physician will evaluate the tissue for characteristic findings of cancer and generate a biopsy report. Biopsy report will show whether they are cancer tissues and type of the cancer. Commonest type is adenocarcinoma of stomach which accounts for 90-95% of all gastric cancers. This type of endoscopy is performed to directly image the esophagus, stomach, and the first part of the small intestine . Before an endoscopy, the patient is not allowed to eat and drink for several hours. The main side effect of this procedure is a discomfort in the throat. It is an outpatient procedure with minimal risk and generally takes less than one hour total time.
Barium Upper Gastrointestinal Radiography: This test is performed in order to visualize any abnormalities or changes that occurred in the normal outlook of the stomach, esophagus and the first part of the small intestine lining (called Upper GI).
Computed Tomography (CT scan):
This image test is similar with an x-ray test and creates a detailed cross-sectional image of the body. It is one of the most commonly used tests due to speed and accuracy.
Positron Emission Tomography (PET): This is another image test used successfully in diagnosing stomach cancer. Positron Emission Tomography uses radioactive glucose to locate cancer.
Magnetic Resonance Imagining (MRI): This image test uses radio waves and strong magnets to reveal a complete image of the body targeted area. Endoscopy Procedures
Endoscopic Ultarsound (EUS): This procedure offers an accurate identification of the cancer stage by combining two classic tests: endoscopy and untrasound. The advantage of this procedure is that the transducer is placed directly near the stomach walls allowing the ultrasound to precisely determine how far the tumor has invaded the stomach walls and how many adjacent lymph nodes are affected. Before this procedure, the patient is asked to not eat and drink for at least four hours. Laparoscopy: This is a surgical procedure used to check the health state of organs within the abdominal cavity. This procedure uses a thin tube, called a laparoscope, which is inserted through a small incision into the patient’s abdomen.
There are 5 main types of stomach cancer (gastric cancer) which include:
Adenocarcinoma: This is the most common type of stomach cancer, 90 to 95 percent of stomach cancer cases, and develops in the glandular tissues of the mucosa.
Lymphoma: This is a rare type of stomach cancer that develops in the immune system tissue of the stomach wall.
Leiomyosarcoma: This is a type of stomach cancer that develops in the stomach muscle layer.
Gastrointestinal Stomal Tumors (GIST): This type of stomach cancer develops in the tissues which support the digestive organs. This type of tumor develops in the stomach wall tissues that contain a specific type of cell called intestinal cells of Cajal.
Carcinoid Tumors: This is another less common form of stomach cancer that develops in the hormone-producing tissues of the stomach. Most of these tumors do not spread to other organs.
Stage 0 (Carcinoma in Situ): In stage 0, cancer is found only in the inside lining of the mucosal layer of the stomach wall.
Stage I: Stage I gastric cancer is divided into stage IA and stage IB, depending on where the cancer has spread.
Stage IA: Cancer has spread completely through the mucosal (innermost) layer of the stomach wall.
Stage IB: Cancer has spread completely through the mucosal (innermost) layer of the stomach wall and is found in up to 6 lymph nodes near the tumor; or to the muscularis (middle) layer of the stomach wall.
Stage II: In stage II gastric cancer, cancer has spread completely through the mucosa(innermost) layer of the stomach wall and is found in 7 to 15 lymph nodes near the tumor; or to the muscularis (middle) layer of the stomach wall and is found in up to 6 lymph nodes near the tumor; or to the serosal (outermost) layer of the stomach wall but not to lymph nodes or other organs.
Stage III: Stage III gastric cancer is divided into stage IIIA and stage IIIB depending on where the cancer has spread.
Stage IIIA: Cancer has spread to the muscularis (middle) layer of the stomach wall and is found in 7 to 15 lymph nodes near the tumor; or the serosal (outermost) layer of the stomach wall and is found in 1 to 6 lymph nodes near the tumor; or organs next to the stomach but not to lymph nodes or other parts of the body.
Stage IIIB:Cancer has spread to the serosal (outermost) layer of the stomach wall and is found in 7 to 15 lymph nodes near the tumor.
Stage IV: In stage IV, cancer has spread to organs next to the stomach and to at least one lymph node; or more than 15 lymph nodes; or other parts of the body.