|
Stomach cancer (also called gastric cancer) starts in the stomach. Most cancers of the stomach are of a type called adenocarcinomas. This cancer develops from cells that form the lining of the innermost layer, the mucosa. The term "stomach cancer" almost always refers to this type of cancer.
Stomach cancer probably grows slowly over many years. Before a true cancer develops, there are usually changes that take place in the lining of the stomach. These early changes rarely produce symptoms and therefore often are not noticed.
Stomach cancer can spread in several different ways. It can grow through the wall of the stomach and eventually grow into nearby organs. It can also spread to the lymph nodes (bean-sized collections of immune system cells) and then through the lymph system. If cancer spreads this way, the outlook for a cure gets worse.
When stomach cancer is more advanced, it can travel through the bloodstream and form deposits of cancer cells in organs such as the liver, lungs, and bones. But even though it has spread to other organs, it is still called stomach cancer.
Facts about Stomach Cancer- We know that there will be about 22,280 new cases of stomach cancer in the United States in 2006. About 11,430 people will die of this disease.
- Two thirds of the people found to have stomach cancer are older than 65.
- Stomach cancer is more than twice as common in men as it is in women.
- The risk of a person getting stomach cancer in their lifetime is about 1 in 100.
Stomach cancer is much more common in some countries other than the United States. It was once a leading cause of cancer deaths in this country but it is now much less common. The reasons for this decline are not completely known, but they may be linked to more use of refrigeration for food storage and less use of salted and smoked foods. Some doctors think that an important factor is the use of antibiotics to treat infections in children. These drugs can kill the bacteria (helicobacter pylori) that may be a major cause of this disease.
General Risk Factors
Scientists have found several risk factors that make a person more likely to develop stomach cancer. The major factors are listed below:
Bacteria infection: Many doctors think that infection with bacteria called Helicobacter pylori may be a major cause of stomach cancer. Long-term infection with this germ can lead to inflammation and damage to the inner layer of the stomach, a possible pre-cancerous change. This bacterium is also linked to some types of lymphoma of the stomach. But most people who carry this germ in their stomachs never develop cancer.
Diet: An increased risk of stomach cancer is linked to diets high in smoked foods, salted fish and meats, and pickled vegetables. On the other hand, eating whole grain products and fresh fruits and vegetables that contain vitamins A and C appears to lower the risk of stomach cancer.
Tobacco and alcohol abuse: Smoking just about doubles the risk of stomach cancer for smokers. While some studies have linked alcohol use to stomach cancer, this is not certain.
Earlier stomach surgery: Stomach cancer is more likely to occur in people who have had part of their stomach removed to treat other problems such as ulcers.
Stomach polyps: Polyps are small mushroom-like growths of the lining of the stomach. Most types of polyps do not increase the risk of stomach cancer. But one type (adenomatous polyps) sometimes develops into stomach cancer.
How is Stomach Cancer Found?
Because stomach cancer is not that common in the United States, mass screening for the disease has not been found to be useful. But people at high risk should talk to their doctors about the benefits of screening.
People who have stomach cancer rarely have symptoms in the early stages of the disease. This is one of the reasons why stomach cancer is so hard to find early. The signs and symptoms of this cancer can include:
unintended weight loss and lack of appetite
pain in the area of the stomach (abdominal pain)
vague discomfort in the abdomen, often above the navel
a sense of fullness just below the chest bone after eating a small meal
heartburn, indigestion, or ulcer-type symptoms
nausea
vomiting, with or without blood
swelling of the abdomen
Of course, many of these symptoms can be caused by conditions other than cancer. But if you have any of these problems and they don’t go away, you should check with your doctor.
Diagnostic Tests
The Marin Cancer Institute offers leading-edge technology for the detection and treatment of cancer. Below are specific tests your physician may use to help diagnose and treat your cancer.
Upper Endoscopy: In this test, a thin, flexible, lighted tube (called an endoscope) is placed down the patient’s throat. With this tube, the doctor can see the lining of the esophagus, stomach, and the first part of the small intestine. If anything looks not normal, tissue samples can be removed. These samples are looked at under a microscope to see if cancer is present and, if so, what type of cancer it is. A person having this test is made sleepy (sedated) before it starts, so there should be no discomfort.
Upper GI (gastrointestinal) series: People having this test drink a liquid containing barium that coats the lining of the esophagus, stomach, and first part of the small intestine. Then several x-rays are taken. Sometimes after drinking the liquid, the person swallows baking soda crystals, which creates air in the stomach. This makes the barium coating very thin so that even small abnormalities will show up.
Ultrasound: For this test, sound waves are used to produce pictures of internal organs. Most people know about ultrasound because it is used to create a picture of the baby during pregnancy. Ultrasound can also be done with a probe placed into the stomach through the mouth or nose. In this case, it can help tell how far the cancer has spread within the stomach or into nearby tissues and lymph nodes.
CT Scan (computed tomography): This test uses a special x-ray machine that takes pictures from many angles. The pictures are combined by a computer to produce detailed cross-sectional images. The CT scan can help show if and where stomach cancer has spread. It can also be used to guide a biopsy needle into an area that might be cancer. The needle is used to take a small sample of tissue for testing in the lab.
CT scans take longer than regular x-rays and you need to lay still on a table while they are being done. You may also have an IV (intravenous) line through which a contrast "dye" is injected.
PET Scan (positron emission tomography): In this test, a special kind of radioactive sugar is injected into the patient’s vein. The sugar collects in areas that have cancer and a scanner can spot these areas. This test is useful for finding cancer that has spread beyond the stomach. It may also help in staging the cancer (see below).
Laparoscopy: A thin, flexible tube is placed into the patient’s side through a small incision and transmits a picture of the inside of the abdomen to a video screen. The doctor can use this before surgery to see if all cancer can be removed and to spot spread of the cancer.
Lab Tests: These may include a blood test called a complete blood count (CBC) to look for anemia, and a fecal occult blood test, which looks for small amounts of blood in the stool.
Learn more about the latest state-of-the-art technologies available at MCI.
Treatment
The main treatments for stomach cancer are surgery, chemotherapy, and radiation therapy. Often the best approach involves using 2 or more of these treatment methods. Your recovery is one goal of your cancer care team. If a cure is not possible, treatment is aimed at relieving symptoms such as trouble eating, pain, or bleeding. Before you start treatment it is important that you understand the goal of your treatment-- whether it is to cure or to relieve symptoms.
Surgery
Depending on the type and stage of your cancer, surgery might be used to remove the cancer and that part of the stomach where it is attached. The surgeon will try to leave behind as much normal stomach as possible.
Even if the cancer is too widespread to be completely removed by surgery, an operation could help prevent bleeding from the tumor or keep the stomach from becoming blocked. This type of surgery is known as palliative, meaning that it relieves or prevents symptoms but is not expected to cure the cancer.
There are 3 main types of surgery for stomach cancer:
Endoscopic Mucosal Resection: Resection refers to the removal of a tumor or part of an organ by cutting it out. With this method, the cancer is removed through the endoscope. This can be done only for very early cancers where the chance of spread to the lymph nodes is very low.
Subtotal (partial) Gastrectomy: This approach can be used if the cancer is in the lower part of the stomach close to the intestines. Only part of the stomach is removed, sometimes along with the first part of the small intestine. Eating is much easier with this approach rather than when the whole stomach is removed.
Total Gastrectomy: This method is used if the cancer is in the middle or upper part of the stomach. The surgeon removes the entire stomach. Because the stomach holds and digests food, when it is removed a person will fill up after only a few mouthfuls. To solve this problem, the surgeon will try to make a new "stomach" out of intestinal tissue. No matter how effective this is, people who have had a total gastrectomy can only eat a small amount of food at a time. Because of this, they must eat more often.
If surgery is done to cure the cancer, the lymph nodes and some of the fatty tissue (omentum) around the stomach are removed as well. If the cancer has spread beyond the stomach to the spleen, it will be removed too.
Surgery for stomach cancer is very hard to do and can lead to serious problems. These could include bleeding from the surgery, blood clots, and damage during the operation to nearby organs such as the gallbladder and the pancreas. Rarely, the new connections between the ends of the stomach and esophagus or small intestine may not hold together completely and leak. Such complications, which could be fatal, were more common in the past. Today, only about 1% to 2% of people die after this surgery.
Chemotherapy
Chemotherapy refers to the use of drugs to kill cancer cells. Usually the drugs are given into a vein or by mouth. Once the drugs enter the bloodstream, they spread throughout the body. Chemotherapy is useful in treating cancer that has spread.
Chemotherapy may be used as the main treatment for stomach cancer that has spread to distant organs. It is being studied as an added treatment given either before or after surgery. So far, studies have found that chemotherapy may help relieve symptoms for some people, especially those whose cancer has spread to other areas of the body. There is also some evidence that chemotherapy together with radiation therapy may delay the cancer coming back and extend the life of people with advanced stomach cancer.
While chemotherapy drugs kill cancer cells, they also damage some normal cells and this can lead to side effects. These side effects depend on the type of drugs used, the amount given, and the length of treatment. You could experience some of these temporary side effects:
fatigue
nausea and vomiting
diarrhea
loss of appetite
hair loss (it grows back after treatment ends)
mouth sores
a higher risk of infection caused by a shortage of white blood cells
bruising or bleeding after minor cuts caused by a shortage of blood platelets
shortness of breath from low red blood cell counts
Most of these side effects go away when treatment is over. If you have any problems with side effects, be sure to tell your doctor or nurse, as there are often ways to help.
Radiation Therapy
Radiation therapy is treatment with high-energy rays (such as x-rays) to kill or shrink cancer cells. Radiation coming from a machine outside the body (external radiation) is the type often used to treat stomach cancer.
After surgery, radiation therapy can be used to kill very small areas of cancer that cannot be seen and removed during surgery. Some studies suggest that radiation, especially when combined with chemotherapy, can delay or prevent the cancer from coming back after surgery and may help people to live longer. Radiation can also be used to ease symptoms such as pain, bleeding, and trouble eating.
Side effects from radiation therapy can include mild skin problems, nausea, vomiting, diarrhea, or fatigue. These usually go away a few weeks after treatment is finished. Radiation therapy may make the side effects of chemotherapy worse. Talk with your doctor about these side effects since there are ways to relieve them.
Marin Cancer Institute Stomach (Gastric) Cancer Protocol
Patients with potentially curable stomach cancer are typically treated initially by surgery to remove all visible cancer from the abdomen. For certain surgeries, MCI partners with surgical colleagues at UCSF or Stanford for this phase of treatment.
If chemotherapy or radiation therapy is needed after surgery, the Marin Cancer Institute offers state-of-the-art care for the adjuvant treatments. Our goal is to provide the best care possible, while allowing our patients to remain close to home. Each case is presented at our Gastrointestinal Cancer Case Conference/Tumor Board to ensure that all of the available services are considered and the most appropriate treatments offered to each patient.
*Statistics provided by the American Cancer Society. Revised April 2006.
|
|
|
|
