What is stomach cancer?
Stomach cancer, also known as gastric cancer, is a type of cancer that starts in the stomach. The stomach is a hollow organ, which plays an important role in the digestion of food. After the food is chewed and swallowed, it moves from the throat through a hollow tube called esophagus into the stomach where it is mixed up with the digestive juices.
Several types of cancer can occur in the stomach depending on the section of the stomach that is affected. The most common type is called adenocarcinoma in which cells lining the outermost layer of the stomach start to change.
Stomach cancer tends to develop slowly and may not show symptoms for many years.
Stomach cancer is the fourth most common cancer in men (after lung, prostate, and colorectal cancer) and the fifth most common cancer in women (after breast, cervical, colorectal, and lung cancer) globally.1 Stomach cancer accounts for 8% of the total number of cases of cancer and 10% of annual deaths from cancer worldwide.2
In 2010, stomach cancer was the tenth most common cause of cancer-related death in the Kingdom of Saudi Arabia. 3
What are the causes and risk factors of stomach cancer?
Like other types of cancers, the causes of stomach cancer are still unknown, but researchers have identified risk factors linked to this cancer:4
- Gender: Stomach cancer is more common in men than in women.
- Age: The risk of getting stomach cancer increases with age.
- Ethnicity: Stomach cancer is more common in Hispanic, Africans and Asian Pacific Islanders than in white people.
- Location: Stomach cancer is more common in Japan, China, Southern and Eastern Europe, and South and Central America. This disease is less common in Northern and Western Africa, South Central Asia, and North America.
- Infection: It has been shown that an infection with the bacterium Helicobacter pylori may increase the risks of getting stomach cancer.
- Diet: Eating smoked foods, salted fish and meats, and pickled vegetables have been shown to increase the risk of getting stomach cancer. On the other hand, eating lots of fresh fruits and vegetables have been related to lower the risk of getting this disease.
- Smoking: Smoking can increase the risk of stomach cancer.
- Being overweight or obese is a possible cause of stomach cancer.
- Earlier stomach surgery: Prior stomach surgery or other problems like ulcers increase the risk of getting stomach cancer.
- Pernicious anemia: A decrease in red blood cells that occurs when the intestines cannot properly absorb vitamin B12 could increase the risk of getting stomach cancer.
- Type A blood: For unknown reasons, people with type A blood have a higher risk of getting stomach cancer.
- Family history: Brothers, sisters, and children, of people with stomach cancer have an increased risk of getting it themselves.
- Certain types of work: Workers in coal, metal, and rubber industries seem to have a higher risk of getting stomach cancer.
- Common variable immunodeficiency: Common variable immunodeficiency is a rare immune deficiency characterized by low levels of antibodies. The incidence of stomach cancer could be increased in patients suffering this immunodeficiency.
What are the signs and symptoms of stomach cancer?
The earliest symptoms of stomach cancer may include:5
- Indigestion, acidity and burping
- Feeling full after eating small amounts of food
- Anemia (low red blood cells counts) and feeling tired or breathless
- Blood clots causing pain or swelling in a leg or sudden chest pain and breathlessness
- Difficulty in swallowing
Symptoms of a more advanced stomach cancer can include:5
- Lack of appetite
- Unintentional weight loss
- Fluid in the abdomen
- Blood in the stool
Can stomach cancer be prevented?
Because the causes of stomach cancer are not clear, there are no certain ways for preventing this disease. Nevertheless, there are steps that one can take to reduce the risks of getting stomach cancer. For example:6
- Improvement of life style conditions and hygiene could diminish the prevalence of Helicobacter pylori infection and consequently the risk of getting stomach cancer.
- Preserving fresh healthy food, omitting salting and conserving meat ingredients may lead to a decrease in the risks of getting this disease.
- Stopping smoking
- Using Aspirin has been shown to lower the risk of stomach cancer.
- A diet high in fresh fruits and vegetables
- Exercising and staying fit
How is stomach cancer diagnosed?
Tests and procedures used to diagnose stomach cancer include:7
- Medical history and physical exam: The doctor will ask questions about the patient’s health and symptoms and do a complete physical exam.
- Upper endoscopy: A video camera will go through the throat of the patient to the stomach to see if there are any abnormalities.
- Biopsy of stomach cells
- Stomach X-ray
- Endoscopic Ultrasound: By putting the endoscope into the upper part of the stomach, the endoscopic ultrasound can create pictures.
- Computed tomography (CT scan)
- Magnetic resonance imaging (MRI scan)
- Positron emission tomography (PET scan)
- Laboratory tests to look for anemia or any signs of cancer.
How is stomach cancer treated?
Overall, there are four basic ways to treat stomach cancer:8
- Surgery: Surgery helps to remove the cancer cells from the stomach. Depending on the spread of the cancer, surgery might be used to remove a part or the entire stomach.
- Radiation therapy: Radiation therapy involves the use of high energy X-rays or other particles to destroy cancer cells.
- Chemotherapy: Chemotherapy is a drug treatment that uses chemicals to kill cancer cells. Chemotherapy can be given before surgery to help shrink a tumor so that it can be more easily removed. Chemotherapy is also used after surgery to kill any cancer cells that might remain in the body. Chemotherapy has side effects depending on the drug used like nausea and vomiting, loss of appetite, hair loss, diarrhea, mouth sores, a higher risk of infection, diarrhea, and feeling very tired.
- Targeted therapy: Chemotherapy drugs target all cells that divide quickly. However, targeted therapy is a set of drugs that target cancer cells only.
- Trastuzumab is a drug that can help some patients with stomach cancer.
- Imatinib is a drug for a rare form of stomach cancer called gastrointestinal stromal tumor.
- Sunitinib is a drug for gastrointestinal stromal tumor.
- Jemal, Ahmedin, et al. "Global cancer statistics." CA: a cancer journal for clinicians 61.2 (2011): 69-90.
- Guggenheim, Douglas E., and Manish A. Shah. "Gastric cancer epidemiology and risk factors." Journal of surgical oncology 107.3 (2013): 230-236.
- "Cancer Incidence Report Saudi Arabia 2010." Saudi Health Council. Kingdom of Saudi Arabia Ministry of Health Saudi Cancer Registry, 1 Apr. 2014. Web. 22 Nov. 2015. <http://www.chs.gov.sa/Ar/mediacenter/NewsLetter/2010 Report (1).pdf>.
- What are the risk factors for stomach cancer? (What are the risk factors for stomach cancer?). http://www.cancer.org/cancer/stomachcancer/detailedguide/stomach-cancer-risk-factors
- Stomach cancer symptoms (Stomach cancer symptoms). http://www.cancerresearchuk.org/about-cancer/type/stomach-cancer/about/stomach-cancer-symptoms
- Massarrat, Sadegh, and Manfred Stolte. "Development of gastric cancer and its prevention." Archives of Iranian medicine 17.7 (2014): 514.
- How is stomach cancer diagnosed? (How is stomach cancer diagnosed?). http://www.cancer.org/cancer/stomachcancer/detailedguide/stomach-cancer-diagnosis
- Stomach cancer (Treatments and drugs). http://www.mayoclinic.org/diseases-conditions/stomach-cancer/basics/treatment/con-20038197