What Is Gastric Cancer?
Gastric cancers tend to develop slowly over many years. Before a true cancer develops, pre-cancerous changes often occur in the inner lining (mucosa) of the stomach. These early changes rarely cause symptoms and therefore often go undetected.
Cancers starting in different sections of the stomach may cause different symptoms and tend to have different outcomes. The cancer’s location can also affect the treatment options. For example, cancers that start at the GE junction are staged and treated the same
as cancers of the esophagus. A cancer that starts in the cardia of the stomach but then grows into the GE junction is also staged and treated like a cancer of the esophagus.
Gastric cancers can spread (metastasize) in different ways. They can grow through the wall of the stomach and invade nearby organs. They can also spread to the lymph vessels and nearby lymph nodes. Lymph nodes are bean-sized structures that help fight infections. The stomach has a very rich network of lymph vessels and nodes. As the stomach cancer becomes more advanced, it can travel through the bloodstream and spread to organs such as the liver, lungs, and bones. If cancer has spread to the lymph nodes or to other organs, the patient’s outlook is not as good.1
Gastric Cancer: Epidemiology
Gastric cancer is the 4th most commonly diagnosed cancer and the 2nd leading cause of cancer-related death worldwide.2 Almost 1 million cases of gastric cancer were diagnosed worldwide in 2002, and nearly 750,000 patients died from the disease.2 Gastric cancer incidence is higher in males than females,2 and the highest rates of gastric cancer are seen in the Asia-Pacific region, particularly in Japan, China and Korea, as well as Central and South America, Eastern Europe and the Middle East.
How Is Gastric Cancer Diagnosed?
Two main methods are endoscopy, in which a thin tube is introduced into the stomach via the oesophagus, and radiological examination. More recently, tissue diagnostics has become one of the most important procedures of this kind.
Modern molecular diagnosis is able to detect the HER2 receptor. In about one of six gastric cancer patients, excess amounts of this protein form on the surface of the tumour cells and encourage their proliferation.
1. Stomach Cancer - American Cancer Society - Adapted from: http://www.cancer.org/acs/groups/cid/documents/webcontent/003141-pdf.pdf, Accessed 30 July 2013.
2. Ferlay J, et al. GLOBOCAN 2008. Available from: http://globocan.iarc.fr. Accessed 7 June 2010.