It is true that stomach cancer is one of the most common cancers worldwide. In 1999, about three-quarters of a million new cases were diagnosed around the globe, but only 22,000 of those occurred in the United States. In contrast, 140,000 cases of colon cancer are diagnosed every year. Ironically, our low rate of stomach cancer is the reason it is often deadly. Because it is not a major public health threat, we spend little money on early detection or public-awareness programs, and, as a result, stomach cancer is rarely caught in the early stages when it is more easily curable. That’s why it is so important that people who are at risk for stomach cancer become aware of the symptoms, so they can monitor themselves for early signs.
What is it? • Known in medical terms as gastric cancer, stomach cancer occurs when cells in the stomach grow and divide at an accelerated rate, producing tumor that spread within the stomach or to other parts of the body. While people often use the word "stomachache" to describe pains that occur in various parts of their abdominal region, stomach cancer is a cancer that begins in the stomach, not in surrounding organs like the gallbladder or the colon. (All cancers are named for their organ of origin, no matter where they spread. For example, if cancer that begins in the stomach spreads to the liver, it is still called stomach cancer). The stomach has different parts, and the location of cancer in the stomach can affect symptoms, treatment and outcome. The most basic division is that between the distal and proximal stomach. The proximal stomach, also referred to as the cardia, is closest to the esophagus (food tube). The incidence of cancer in the part of the stomach is on the rise. The lower part of the stomach is the distal stomach, close to the intestines. Several different types of cancers affect the stomach, but over 50 percent of them are a type known as adeno carcinomas. Other, less common, stomach cancers include lymphomas and several types of tumors.
Symptoms of stomach cancer • Unfortunately, because the symptoms of stomach cancer are often associated with much milder problems, like indigestion or heartburn, it often goes undetected in its early stages. Symptoms include: heartburn, indigestion, abdominal pain, pain in chest or bones, nausea, vague discomfort in the abdomen (usually just above the navel), loss of appetite and weight loss, satiety (a sense of fullness in the upper abdomen after eating a small meal), vomiting (sometimes with blood), abdominal swelling, and jaundice (yellowing of the skin and eyes).
AGA member and associate professor of medicine and director of clinical research at Boston Medical Center, notes that distal and proximal cancer differ in their symptoms. Distal cancer often presents itself more subtly, with vague pain or discomfort, microscopic bleeding anemia and satiety. In proximal cancer, because it is so close to the esophagus, many victims complain of difficulty swallowing.
Risk factors • Of course, not everyone who has heartburn should run to the doctor to get checked for stomach cancer. Stomach cancer primarily affects people over 55, and men get it twice as often as women. There appears to be a strong environmental component to stomach cancer: it is very common in countries like Japan, Korea and parts of Eastern Europe, where many foods are preserved by drying, smoking, picking and salting. The nitrate-type chemicals used in these processes probably contribute to stomach cancer.
In the United States, stomach cancer rates have declined steadily as refrigeration has become more and more common, eliminating the need for other types of food preservation. In addition, Japanese people who migrate to Hawaii see a drop in their stomach cancer rates, and Japanese who migrate to the mainland United States have similar to those of other Americans, suggesting that their susceptibility to stomach cancer is based more on their environment (diet) than genetics.
People with family histories of stomach cancer do, however, have an increased risk of developing stomach cancer themselves and we are looking for perturbed genes that run in families. We haven’t found a gene for stomach cancer like we have for colon cancer, but it’s likely that there is one out there. People who have a family history should make absolutely sure their doctor is aware of it.
In addition, people who have blood type A are at a high risk for stomach cancer, as are those who have had a particular type of stomach polyp, called adenomatous polyps, and people who have has previous stomach surgery. If you suffer from pernicious anemia or a condition called Menetrier’s disease, you can also run a slighty higher risk of getting stomach cancer.
Finally, people with stomach cancer have a higher rate of infection with H. Pylori than people without. This bacteria causes ulcers, and it may also lead to precancerous inflammation and damage to the inner layer of the stomach. However, cautions that, while H. pylon probably creates conditions favorable to the development of cancer in the stomach, only a handful of the several billion people worldwide who are infected with H. pylori will actually develop cancer. Something else has to interact with H. pylori, perhaps diet or genetics. So while some doctors give patients antibiotics for HG. Pylori even if they exhibit no symptoms, thinks only those patients who have ulcers or risk factors for stomach cancer should be treated. He points out that some provocative studies have indicated that treating H. pylori may increase acid reflux, which may then increase the risk of esophageal cancer.
When should I see a doctor? • If you are over 55 and you have a family or medical history that puts you at risk for stomach cancer, you should be alert if you have frequent symptoms such as heartburn or indigestion. Someone in a high-risk category who has heartburn several times a week, for example, should call his or her doctor rather than self-medicating with an over-the-counter remedy. One doctor recommends that people who are over 40 or 45 consult their doctors if they suddenly begin experiencing regular heartburn with no previous history of having had it.
How is it diagnosed? • The man test used to detect stomach cancer is an upper endoscopies, in which the patient is sedated and the doctor puts a thin, flexible tube down the patient’s throat. The tube contains a light that allows the doctor to see the lining of the esophagus, stomach and some of the small intestine, Biopsies (small tissue samples) can also be taken using an endoscope. The samples are examined under a microscope to determine whether or not they are cancerous and , if so, what type of cancer is present.
In specialized centers, an endoscopic ultrasound is sometimes used when patients have an endoscopy. In this test, a small ultra ultrasound probe is attached to the end of the endoscope. It releases high frequency waves, and a computer analyses the pattern of those waves bouncing off the stomach wall. This test is used to estimate how far cancer may have spread into the stomach lining, nearby tissues and nearby lymph nodes.
Once cancer is found, it is staged before the doctor recommends treatment. Staging is a complicated process of determining how advanced the cancer is, based on how far tumors have spread within the stomach and to other organs, whether and how much it has spread stop lymph nodes and whether or not it has metastasized, – that is, spread to distant organs. A cancer’s stage determines its prognosis and treatment. Because, usually catch stomach cancer late in the United States, survival rates are low – it’s only in the early stages that surgery, the only known cure for stomach cancer is viable option. Survival rates are typically calculated by patients living at lease five years after their diagnosis. Five-year survival rates for stomach cancers caught in the early stages range from 10-50 percent. Unfortunately, one doctor says that from1992-1996; only 15-20 percent of cases were diagnosed when they were still localized to the stomach, 35-40 percent after they had spread to lymph notes. That’s why it’s important to discuss symptoms with your doctor, especially if you are older and have some of the risk factors for stomach cancer.
How is it treated? • Surgery is the only way to cure early-stage stomach cancer. There are three types of surgeries, depending on where the cancer is located. A distal subtotal gastrectomy removes the lower part of the stomach, and sometimes part of the small intestine. A proximal subtotal gastrectomy removes the upper part of the stomach, and sometimes the end of the esophagus that connects to it. In a total gastrectomy, the entire stomach is removed. Although these operations sound horrible, most people who have subtotal gastrectomies live normal lives afterwards, with their main restriction being that they often have to eat smaller, more frequent meals. After surgery, patients are put on restricted diets, slowly adding more and more solid foods and testing what they can tolerate. Patients who have total gatrectomies will need regular injections of vitamin B12. While it seems surprising to those of us used to thinking of our stomach as an indispensable organ, even people who have their entire stomach removed can still digest food and maintain weight.
In addition to surgery, radiation and chemotherapy are commonly used to treat stomach cancer. Chemotherapy is sometimes given before surgery to "downstage" cancer – to localize it and make it operable. It is also given after surgery to kill cancer that may have spread or as the main remedy when the cancer has spread to much it is no longer curable by operating, Radiation is often used after surgery to kill any cancer that was not removed. Some studies suggest that the combination of radiation and chemotherapy can delay or prevent from returning after surgery, thus helping people live longer. (To be continued)