Maori are three to five times more likely than Pakeha to have the bacterium H Pylori in childhood which leads to stomach cancer, a new study has found.
The University of Otago research also found that 50 percent of stomach cancers in Maori could be caused by childhood poverty.
The study compared 172 Maori stomach cancer patients with 163 non-Maori patients and found that Maori patients were younger and more likely to have the disease in the lower part of their stomach.
Assistant research fellow Virginia Signal says overcrowding and deprivation contributes to the stomach bacterium H Pylori being found in children, which then creates stomach cancer in adults.
Ms Signal says Maori have less access to specialised surgical services and were less likely to survive once diagnosed.
Smoking is also a contributing factor in developing the disease, she says.