Stomach Cancer
Gastric, or stomach cancer, is one of many cancers which can be found in and affect the gastrointestinal tract. Gastric cancer is the fifth most common cancer, but a difficult one to detect in early stages (Osiecki, 2012, p524; Emadi-Baygi, Sedighi, Nourbakhsh & Nikpour, 2017).
There are several types of gastric cancer, depending on the location, including (Zhao, Yin & Zhao, 2017):
The symptoms of gastric can include the following (Osiecki, 2012, p524; Cancer Australia, 2017):
The risk factors of gastric cancer include the following:
There are several types of gastric cancer, depending on the location, including (Zhao, Yin & Zhao, 2017):
- Adenocarcinoma - the most common type with 90-95% of gastric cancers, where the cancer is in the inner lining or mucosa of the stomach (American Cancer Society, 2017). This category can be further divided into subtypes such as Gastric Cardia Adenocarcinoma, Gastric Non-cardia Adenocarcinoma (Zhao, Yin & Zhao, 2017).
- Carcinoid - these tumours often secrete hormones which can affect other parts of the body. These cancers do not spread to other organs (American Cancer Society, 2017).
- Gastrointestinal stromal tumour (GIST) - these are a rare form of gastric cancer, and can be found anywhere in the gastrointestinal tract, but most commonly in the stomach (American Cancer Society, 2017).
The symptoms of gastric can include the following (Osiecki, 2012, p524; Cancer Australia, 2017):
- Unexplained weight loss
- Nausea and/or vomiting
- Pain or discomfort in the stomach area
- Indigestion or heartburn
- Blood in bowel motions, seen as black, tar colour
- Reduced appetite, or feeling full even after only eating small amounts
- Anaemia.
The risk factors of gastric cancer include the following:
- Gender - gastric cancer is twice as common in men than women (American Cancer Society, 2017; Emadi-Baygi, Sedighi, Nourbakhsh & Nikpour, 2017).
- Age - the highest incidences of gastric cancer are in those over 50 years of age, with most people diagnosed in their late 60s and 80s (American Cancer Society, 2017).
- Ethnicity - gastric cancer is more common in Japan, China, Southern and Eastern Europe, and South and Central America. It is less common in Africa, South Central Asia and North America (American Cancer Society, 2017).
- Family History - gastric cancers are common in immediate family members, and some genes associated with gastric cancer have shown to be inherited (Osiecki, 2012, p525).
- Diet – Some studies have linked the consumption of red meat and processed meat to gastric cancer, but results have been inconsistent. Red and processed meat cooked at a high temperature for a long time appears to have the highest risk, as they contain carcinogenic compounds such as heterocyclic amines, polycyclic aromatic hydrocarbons and other compounds. In addition, a high intake of meat can result in a high intake of heme iron which can cause oxidative damage (Zhao, Yin & Zhao, 2017). Smoked, processed or cured meats contain nitrites and nitrates, which can be converted by H. pylori bacteria into carcinogenic compounds (American Cancer Society, 2017).
- Helicobacter pylori infection - H. pylori is a common bacteria which can cause gastric inflammation (ie, gastritis), ulcers and reflux/heartburn which can lead to gastric cancer (Zhao, Yin & Zhao, 2017). However, most people who have this bacterium in their stomachs do not develop cancer (American Cancer Society, 2017), but H. pylori can increase the risk of gastric cancer by 3-8 times (Osiecki, 2012, p524).
- Gastro-Oesophageal Reflux Disease (GORD/GERD) - long-term reflux/heartburn as a result of H. pylori infection, or other causes such as diet or stress can lead to gastric cancer (Osiecki, 2012, p524).
- Infections - other infections such as from the Epstein-Barr Virus (EBV) can lead to some rare forms of gastric cancer (Osiecki, 2012, p524).
- Smoking and alcohol - these lifestyle choices cause irritation of the stomach and increase cancer risk (Osiecki, 2012, p525).
- Medications – use of some medications such as Proton Pump Inhibitors (PPIs) used over a long period can increase the risk (Osiecki, 2012, p524).
- Genetics – there are some types of gastric cancers which can have a hereditary cause due to genetic mutations, even in genes which are known to increase the risk of other cancer types such as in the BRCA2 gene which is more commonly associated with increased breast cancer risk (Xiao-Peng, 2017).