The exact causes of stomach cancer are still not fully understood, but researchers have identified several risk factors that may increase the likelihood of developing the disease. These include aging, obesity, smoking, and infections that go untreated. One of the most significant contributors is Helicobacter pylori (H. pylori), a bacterium that infects the stomach lining.

According to Cancer Research UK, H. pylori is linked to about 40% of stomach cancer cases in the UK. The bacteria spread through contaminated food and water and can lead to inflammation or ulcers in some individuals—both of which are associated with higher cancer risk. However, not everyone infected will experience serious symptoms.

The NHS warns that early symptoms of stomach cancer are often mild and easy to overlook. These include persistent indigestion, heartburn, frequent burping, and feeling bloated or overly full after eating. In more advanced stages, symptoms may escalate to blood in the stool, weight loss, and loss of appetite.

Interestingly, research also points to a possible connection between blood type and cancer risk. A study involving 50,000 Iranians found that individuals with blood types A, B, or AB were 55% more likely to develop stomach cancer compared to those with blood type O. This finding could have implications for future screening and prevention strategies.

Further studies suggest that AB blood type is linked to a 45% higher risk of liver cancer, while people with blood types O and AB may have a lower risk of pancreatic cancer. The biological reasons for these differences remain unclear, but ongoing research is exploring the role of blood types in cancer development.