Stomach cancer -also known as gastric cancer -is the fifth most common cancer worldwide. Men are twice as likely to develop the cancer than women, and it is more common in older adults, the report by World Cancer Research Federation said.
Stomach cancer is classified into different types according to location of the tumour -stomach cardia cancer occurs at the top part of the stomach closest to the oesophagus, and stomach noncardia cancer occurs in all other areas of the stomach.
The report analysed 89 studies from around the world, comprising 17.5 million adults and nearly 77,000 cases of stomach cancer.
Consuming meat or fish that has been preserved by smoking, curing or by the addition of preservatives also was found to increase the risk of stomach cancer. Examples include ham, bacon, pastrami and salami, as well as hot dogs and some sausages. Stomach cancer is the third most common cause of death from cancer, as symptoms often only appear at a late stage.
About 70% of cases of stomach cancer occur in less developed countries with about half of all cases in Eastern Asia, particularly China, the report said. Being overweight or obese increases the risk of stomach cardia cancer.