New cases of stomach cancer will likely fall 25 percent over the next 10 years in Western countries because of better living conditions, Dutch researchers said on Tuesday.

Stomach cancer is one of the most common types of cancer worldwide and usually kills within five years, said Ernst Kuipers, a researcher at the Erasmus MC University Medical Centre in Rotterdam, who led the study published in the journal Gut.

But in a study covering the past 15 years, the researchers found that the number of people showing symptoms known to be precursors to stomach cancer had fallen by 25 percent, Kuipers said.

"In the past decade if we saw a drop of the precursors in both men and women of about 25 percent, this predicts what will happen with cancer incidences in the next 10 years," he said in a telephone interview. "We predict this drop will continue."

In the Netherlands, the researchers estimated that about 2,000 people each year are diagnosed with stomach cancer while there are an estimated 760,000 new cases each year worldwide.

Kuipers said the declines stemmed from improved living conditions in the Western world that had helped prevent the spread of the Helicobacter pylori bacterium historically caught from a sibling or family member when living in close quarters.

The helicobacter pylori bacterium raises the risk of problems such as a thinning of the stomach lining, which often leads to cancer. "If you have 10 people living together in one room it is more likely people will pass the infection at an early age," he said. "Once somebody is infected it usually persists lifelong."