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Stomach cancer, also called gastric cancer, is the name for cancer that begins in the stomach, generally the stomach lining. This type of cancer can eventually spread to lymph nodes and organs such as the liver, pancreas, colon, lungs, and ovaries. People occasionally confuse the stomach organ with the abdominal area, saying they have a "stomach ache" when really the pain could be occurring in the appendix, small intestine, colon (large intestine), or gall bladder, along with the actual stomach. The stomach is a sack-like organ located just under the diaphragm (muscle under the lungs). It can be divided into five sections, and the location of the cancer in the stomach can affect things like symptoms, prognosis, and treatment options. Doctors believe that stomach cancer develops over many years, starting with precancerous changes in the lining of the stomach. Unfortunately, these changes are difficult to detect at this early stage, and the majority of stomach cancers are detected at later stages in the disease, making them more difficult to treat. Causes Doctors do not fully understand what causes stomach cancer, but research has produced theories on how precancerous changes develop and eventually become malignant. Various conditions that change the lining of the stomach are thought to be precancerous. Atrophic gastritis is when the normal glands of the stomach are either fewer or missing. There may be inflammation caused by Helicobacter pylori infection, which can then progress to cancer for unknown reasons. Intestinal metaplasia, which can occur along with atrophic gastritis, is a condition in which the stomach-lining cells are replaced with cells that resemble those of the intestine. Again, doctors do not know how this condition leads to cancer. When a food is "high risk," it generally means that there are chemicals present in these foods that the Helicobacter pylori bacteria transform into cancer-causing chemicals that may produce mutations of cell DNA in the stomach lining. Some foods classified as "low risk," or that seem to aid cancer prevention, are classified so because they contain chemicals that seem to deactivate substances that damage a cell’s DNA. Scientists are continuing to discover ways that changes in DNA cause normal cells to become cancerous. DNA mutations can be inherited (present at birth) or acquired (develop over a person’s life). In either case, cancer can be caused by DNA mutations. These mutations usually affect oncogenes (parts of DNA that promote cell division) and/or tumor suppressor genes (parts of DNA that slow down cell division when necessary). A mutation may either turn oncogenes on or turn tumor suppressor genes off at inappropriate times, causing cancer. Some inherited DNA mutations that can lead to stomach cancer include:
However, most DNA mutations that related to stomach cancer are acquired. These mutations can result from diet among other factors. Scientists have also linked smoking and exposure to certain dusts and fumes in the workplace to a higher than average risk for stomach cancer.
In countries where stomach cancer is the leading cause of cancer death, mass screening has helped detect many cases of cancer early, reducing cancer deaths in these areas. It is difficult to detect symptoms in the early stages of stomach cancer. People with any questions about their stomach cancer risk should consult their doctor. Signs and symptoms of stomach cancer include:
It is important to remember that some of these symptoms can occur with noncancerous conditions or with cancers other than gastric cancer. You should consult your doctor if these symptoms persist, especially if you are at risk for stomach cancer. There are some commonly used procedures to detect stomach cancer once it has been determined that risk factors or symptoms are present: Upper endoscopy After sedating the patient, the doctor puts a lighted tube (endoscope) down the patient’s throat. With this instrument, the doctor can view the lining of the esophagus, stomach, and first part of the small intestine. The doctor can also use this instrument to take a biopsy, or tissue sample, if abnormalities are detected. The tissue is then examined under a microscope to determine if there are cancer cells present. A biopsy is the only sure way to determine if tissue is cancerous. Barium upper GI radiographs With this test, patients drink a barium-containing solution that coats the esophagus, stomach and part of the small intestine. The barium helps doctors spot abnormalities in the x-rays they take of the area. After the barium solution is taken, air is pumped into the stomach to make small tumors easier to see. Endoscopic Ultrasound In this newer version of the upper endoscopy, the endoscope has a small ultrasound probe on the end. The probe uses echoing sound waves that bounce off the tissue of the stomach wall. It’s actually used to detect how far cancer has spread beyond the lining into the walls of the stomach and to nearby tissues or lymph nodes. To diagnose stomach cancer, a physician may use any of the above methods, along with a complete medical history, a physical examination, and laboratory studies including a fecal occult blood test or a complete blood count (CBC). For a fecal occult blood test, a stool sample is examined for hidden (occult) blood, since stomach cancer can sometimes cause bleeding that cannot be seen. However, other conditions can cause bleeding, so having blood in the stool does not necessarily mean a person has stomach cancer. With a CBC, a doctor may take a complete blood count to determine if a patient has anemia, which is a risk factor for stomach cancer (see Risk Factors). Doctors use a process called staging to communicate how widespread a cancer may be. Staging greatly affects treatment options and prognosis (outlook) for a patient. Staging for stomach cancer is based on how far cancer has spread beyond the lining, muscle layer, or outermost layer of the stomach, or to surrounding lymph nodes or nearby tissues/organs. Risk factors Risk factors are conditions that increase a person’s chance of getting a type of cancer. Risk factors are different for various types of cancer. Doctors have determined several risk factors for stomach cancer:
Also, risk may be increased, to varying degrees, for people with pernicious anemia, achlorhydria, Menetrier’s disease, familiar cancer syndromes, stomach polyps, and blood group A. Avoiding risk factors can obviously lower stomach cancer risk, but it cannot guarantee protection. Along with avoiding risk factors, a diet high in fresh fruits and vegetables, which has been shown to decrease stomach cancer risk. Whole grain products and fruits and vegetables containing vitamins A and C appear to lower the risk of stomach cancer.
Stomach cancer can be treated with surgery, radiation therapy, chemotherapy, and biological therapy. Surgery and radiation therapy are local treatments, meaning the therapy is meant to kill cancer cells only in a certain area. Chemotherapy and biological therapy are systemic treatments, or treatments that work throughout the body, traveling through the bloodstream. Often, more than one of these methods is used to treat the cancer most effectively. The choice of method depends on many factors, such as location and stage of the tumor, and a patient’s age, general state of health, and personal preferences. It is important for patients to understand the goal of their particular treatment. Treatment may be used to cure cancer, or if a cure is not possible, to palliate, or relieve symptoms. Surgery As of now, gastrectomy, or the removal of part or all of the stomach, is the only way to cure stomach cancer. Patients in early and middle stages of cancer often undergo surgery to completely remove the cancer. With a subtotal or partial gastrectomy, the doctor removes part of the stomach and connects the remaining part of the stomach to the esophagus and small intestine. With a total gastrectomy, the stomach is removed and the doctor connects the esophagus directly to the small intestine. In each of these cases, nearby lymph nodes and fatty tissue in the abdomen may also be removed. Even if the cancer is too widespread to be removed by surgery, palliative surgery can help control bleeding and keep the stomach from becoming blocked. Gastrectomy is major surgery, and patients will probably have to make temporary or permanent dietary changes. Those who have total gastrectomies can no longer absorb vitamin B12, which is necessary for healthy blood and nerves. These patients receive regular injections of B12. Some patients experience the dumping syndrome, when food and liquid enter the small intestine too quickly, causing cramps, nausea, diarrhea, and dizziness shortly after eating. Foods containing high amounts of sugar often make this symptom worse. The symptoms usually disappear in 3 to 12 months, but they may be permanent. Chemotherapy Chemotherapy is the use of anticancer drugs that are given orally or by injection. Because they enter the bloodstream, the are able to reach all parts of the body, making this treatment useful for cancer that has metastasized, or spread, to organs beyond the stomach. Chemotherapy can be used as a primary treatment, but is also being studied as an adjuvant (before surgery) or neoadjuvant (after surgery) therapies to aid in recovery. Along with killing cancer cells, chemotherapy drugs also damage normal cells. This can lead to temporary side effects such as nausea and vomiting, loss of appetite, loss of hair, diarrhea, mouth sores, low blood count, increased chance of infection, bleeding or bruising after minor cuts/injuries, fatigue and shortness of breath. Radiation Therapy Also known as radiotherapy, radiation therapy uses high-energy rays to damage cancer cells and stop them from growing. It is sometimes given after surgery to destroy possible remaining cancer cells. Radiation therapy can also be used to relieve pain or blockage. Side effects to radiation therapy can include nausea, vomiting, diarrhea. The skin in the treated area may become red, dry, tender, and itchy. Patients should not use lotions or creams to relieve symptoms without a doctor’s advice. Biological Therapy Also known as immunotherapy, biological therapy helps the body’s immune system attack and destroy cancer cells and may also help the body recover from treatment side effects. Side effects for biological therapy vary depending on treatment, but can include flu-like symptoms (chills, fever, weakness, nausea, vomiting, diarrhea), a rash, bruising, or bleeding. Patients may need to stay in the hospital while receiving some kinds of biological therapy. There are remedies for many of the side affects treatment and therapy can cause, and it is important for patients to communicate their side effects to their doctor and/or nurse. Patients may also consider clinical trials as a means of treatment. Clinical trials are studies of promising new or experimental treatments, and are performed on patients. Clinical trials are performed only when the treatment being studied is likely to be of value to the patient. Participating in a clinical trial in completely up to the patient. Doctors and nurses will explain the study and its risks in detail and give the patient a form to read and sign, which is known as informed consent. Even after giving informed consent and beginning a clinical trial, a patient may leave the study at any time. It is always important for patients to discuss and ask questions about their condition and treatment with their cancer care team. Some questions you might ask:
Sentinel lymph node biopsy is a new technique used in breast cancer treatment. With this treatment, dye or a radioactive substance is injected near the tumor site. Doctors then observe, through surgery or scanning, to which lymph node(s) this material flows first. These nodes are the sentinel lymph nodes, where the cancer is most likely to spread from the primary tumor. The doctor then removes the node(s) to check for cancer cells. Patients should discuss and ask questions about their condition and treatment with their cancer care team. Some questions you might ask:
General Questions About Stomach Cancer
These symptoms might be caused by stomach cancer:
It is important to note, however, that many of these symptoms are more often caused by other medical conditions. It is important to consult a physician to find out what is causing symptoms.
Three kinds of treatment are used to treat stomach cancer:
A doctor may use just one method or combine methods to treat the cancer most effectively. These are some questions a person may want to ask his/her doctor before treatment begins:
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