Stomach (Gastric) Cancer
Adenocarcinoma
There are a number of types of stomach cancer. Adenocarcinoma is the most common type of stomach cancer representing 95% of the cases. Once the leading cause of cancer death in the United States, the disease is much less common, and is now the 16th US cancer in occurrence. In California, about 3000 new cases are expected each year, and over half of these will occur in Southern California (Los Angeles, Orange, Riverside, Ventura and Kern counties combined). In fact, almost one-third of the cases that occur in California are found in Los Angeles county.
More cases occur in males than females, and in the past, commonly in people over age 60 years. However, recently, an increasing number of cases in younger patients age less than 40 years has been observed. The incidence has doubled from 1973 to 2015.
Everyone should be aware of some of the risk factors for developing gastric adenocarcinoma.
What Causes This Type of Stomach Cancer?
The exact cause is now known, however there are a number of conditions which are known to increase the risk of developing adenocarcinoma:
- Helicobacter pylori (H pylori) infection
- Diets involving large amounts of salted, preserved or smoked foods
- Ethnicity: Korean, Japanese, Chinese, Central Asian, Latin American
- Obesity
- History of abdominal radiation treatment
- Family history of gastric cancer, especially if it occurs in younger (age less than 50 years) and first and second-degree relations.
- Pernicious anemia
- Menetrier’s disease
- Type A blood group
- Hereditary cancer syndromes
What Are the Signs and Symptoms of Stomach Cancer?
Gastric adenocarcinoma begins as a small focus of cancer in the lining of the stomach. Early on, there may be no symptoms, or non-specific symptoms that could be mistaken for harmless, common conditions:
- Heartburn, indigestion, or upper abdominal discomfort that occurs frequently, or does not improve.
- Frequently feeling bloated after eating
- Persistent burping or belching
- Frequent nausea or vomiting after meals
- Feeling full early when eating
- Unexplained weight loss
What Should I Do if I Am Concerned about Stomach Cancer?
First, do see your physician and discuss your symptoms and of your concerns regarding stomach cancer and any risk factors that you may have.
The most expeditious test for gastric cancer is an upper endoscopy or EGD. This is a small diameter tube (about the thickness of your baby finger) that is inserted into the mouth and passed into the stomach. It allows the doctor to actually see the inside of the stomach, looking for any unusual findings. If something is found, then a small piece of tissue can be removed (biopsy) and sent for analysis.
How Is Stomach Cancer Treated?
If stomach cancer is found, then a number of different tests and procedures may take place to “stage” or assess the extent of the tumor to help decide what treatments will take place and in what order.
- CT (computed tomography) which are radiology tests to image the chest, abdomen and pelvis. This helps assess the tumor size and location, the presence or absence of suspicious lymph nodes, and any signs for further spread to other site (liver, lungs, peritoneum, etc.).
- PET-CT (positron emission tomography CT) which is a similar test that looks at the actual metabolic activity of the tissues being imaged. Similar to CT, this also helps assess the various aspects of the tumor. It is also an additional assessment for possible spread to other areas of the body.
- EUS (endoscopic ultrasound). Similar to EGD, this procedure also includes an ultrasound assessment of the degree of penetration of the tumor into the wall of the stomach, as well as any nearby enlarged lymph nodes. This provide an ultrasonographic staging of the tumor.
Surgery
Most patients being treated for stomach cancer will include either a partial or complete removal of the stomach (gastrectomy). The goal of surgery is complete (microscopic) removal of the tumor and any lymph nodes in the immediate vicinity that may also be involved with the cancer. The amount of stomach removed is a decision ultimately made by the surgeon based upon the location, size and cell type of the tumor. The overall health of the patient, may also be a factor in the decision. In cases of early stomach cancer, surgery may be the first treatment to take place.
- Distal subtotal gastrectomy: usually applied to tumors located in the lower one-third to one half of the stomach. The amount of stomach removed is dependent upon how far “upstream” the stomach tissue needs to be divided to achieve a “clear” (no cancer cells visible under the microscope) margin. Usually this requires a distance of 4.8 to 6 cm (about 2 to 2 ½ inches). Once the stomach is removed during the operation, the cut edges are examined under the microscope while the operation is still occurring (“frozen section”) to confirm that the margins are clear.
- Proximal gastrectomy: occasionally used for tumors located in the upper one-third of the stomach. Being able to obtain clear margins all around is the deciding factor in performing this particular operation.
- Total gastrectomy: used for tumors either located in the middle to upper third of the stomach, or at the junction of the esophagus and stomach. It may also be recommended for patients who have a hereditary condition that predisposes them to gastric cancer, or have multiple sites of gastric cancer throughout the stomach, or has a the “diffuse” cell type.
The long-term side effects of a partial or total removal of the stomach are primarily:
- Reduced body weight: partial gastrectomy usually results in about an 8% reduction compared to the usual body weight (before becoming ill). While gastrectomy does not alter the digestion or absorption of food, because the capacity of the remaining stomach is reduced, patients will have to learn to eat more frequent and smaller meals to take in enough calories each day.
- Dumping syndrome: a condition where the stomach does not delay the release of the partially digested food into the small bowel. This can produce symptoms of bloating, cramps, fullness or diarrhea about 30 to 60 minutes after eating. One can prevent or reduce how often dumping occurs by modifying how one eats. Separating the solid from the liquid food by 5 to 10 minutes and avoiding sweet, sugary foods usually works well. Only about 12% of patients experience dumping symptoms, and in most cases, the symptoms, if they occur are mild.
- Supplements: likely one will need to supplement their intake of calcium, and vitamin B12 after gastrectomy.
Chemotherapy
These are medicines that could be given either by mouth or by intravenous infusion. These medicines are designed to destroy cancer cells. For more advanced cases of stomach cancer, your oncologist may decide to offer chemotherapy before surgery. Because chemotherapy circulates through the body, it can reach a much greater area in the body and make contact with cancer cells that may have gone beyond the stomach. Given before surgery, it may also reduce the size of the tumor as well.
If surgery is performed first, then most patients who are found to have large or deep tumors, or to have tumor found in the lymph nodes, will also receive chemotherapy after they have recovered from surgery.
Radiation Therapy
In some cases, focused doses of radiation may be given in addition to other treatments. Some types of stomach cancer, usually those in the very upper stomach may be treated with both chemotherapy and radiation therapy before surgery is performed. In other situations, radiation therapy may be given after surgery to try to destroy cancer cells that may remain in the area where the stomach had been.
Faculty
Contact Information
Telephone number 310-829-5471
