Stomach cancer, which is often also called gastric cancer, is a type of cancer the affects the digestive system. The part of the digestive system affected by this growth is the muscular, pear-shaped organ located below your ribs which we call the stomach. Unfortunately, once diagnosed with stomach cancer, the prospects are poor – on average one would have only around 5 years left to live.
This is largely due to their fact that their progress is often very slow, beginning with minor pre-cancerous changes in the stomach cell membranes. These changes are so small and symptoms so mild that cancer may actually develop and go unnoticed for many years. By the time diagnosis occurs, the cancer may have reached very advanced stages.
Some basic facts
- In the USA, stomach cancer is considered quite uncommon and is far more common in Eastern countries such as Japan as well as North and South Africa. In the UK it is also not too common with around 20 cancers diagnosed per day.
- This form of cancer is more common in men than women
- There are genetic links to the condition and extensive studies have been carried out to identify which genes could be responsible.
What are the symptoms?
Many of the symptoms of stomach cancer go unnoticed or the symptoms so not help lead to the diagnosis of cancer. This is because symptoms are often “non-specific” which means they could be attributed to dozens of other conditions other than cancer. Some common non-specific symptoms include fatigue, loss of appetite, abdominal discomfort and nausea.
These symptoms listed are also very common in people who are stressed or depressed which means a doctor is more likely to link these symptoms to a common scenario such as stress or depression than to something considerably uncommon such as stomach cancer. Many people also have asymptomatic cancers – which mean they may have the condition for years but not symptoms manifesting themselves at all.
In more advanced stages of cancer, the symptoms may become more obviously associated with gastric cancer. Such symptoms might include blood in stools and vomiting blood or difficulty swallowing, a condition known as dysphagia.
What are the causes of stomach cancer?
- Smoking is one of the main culprits with more than one in five cases of this type of cancer being linked to smoking.
- Scientists also suspect that people who consume a lot of salt throughout their lives are more at risk of the disease.
- Hereditary: This cancer does tend to run in families and people with a parent who has suffered from this type of cancer have a higher than average chance of developing the disease.
Genetics of Stomach cancer and DNA testing
There are today genetic predisposition health tests to determine one’s susceptibility to gastric cancer. This is essentially a DNA test that is carried out using either a blood sample or a saliva sample collected from the person. The results of this genetic test for stomach cancer will give an estimate, expressed in a probability, which will state how likely it is that someone will develop this type of cancer over the course of their life.
DNA tests and close analysis of certain genes using highly advanced DNA sequencing technology has helped single out genes of which mutations are linked to gastric cancer. The studies have mainly been pioneered in Singapore. This particular study actually analyzed 18,000 human genes and eventually honed in on two genes which are believed to be most closely related to stomach cancer: FAT4 and ARID1A.
Treatment very much depends on the stage of the cancer and how much it has grown or spread. In the earliest stages, the cancer may just be limited to the cell lining and may thus, require no drastic treatment like chemotherapy or radiation therapy. In many cases, part of the stomach or the entire stomach may be removed. This process is known as a gastrectomy. Minor cancers can also be removed by doing an endoscopy via which a surgeon can carry out endoscopic mucosal resection or the removal of small section of cancerous tissue. In later stages, again a gastrectomy might be used and the removal of lymph nodes in cases where the cancer has spread. Laser therapy, targeted drugs such as trastuzumab (Herceptin) or chemoradiation may also be used.
Caroline Hughes is an online writer specializing in writing about genetics. The author regularly contributes to many online blogs and websites delving into various, related topics including forensic testing, genetic sampling information about genetic illnesses and health tests. Many of the articles, resources and information written by the author can be found at: easyDNA South Africa.