"The implications of this study may lead to new methods of diagnosis and treatment of many cancers -- particularly those that have been linked to chronic inflammation.

"This was an unexpected finding, which may lead to a re-evaluation of current assumptions about how all cancers originate," said Timothy C. Wang, M.D., chief, Division of Digestive and Liver Diseases and Dorothy L. and Daniel H. Silberberg Professor of Medicine at Columbia University College of Physicians and Surgeons, and senior author of the study.

"The implications of this study may lead to new methods of diagnosis and treatment of many cancers -- particularly those that have been linked to chronic inflammation such as stomach, esophagus, lung, pancreas, liver, etc," Wang said.

'Repair' Cells Morph into Cancer Cells

A common assumption among cancer specialists is that most cancers originate from tissue stem cells -- for example, the gastric stem cells contained in the lining of the stomach. However, the researchers suspected BMDC may contribute to the development or progression of cancer because they are frequently recruited to sites of tissue injury and inflammation -- areas vulnerable for cancer development.

Results found that chronic infection with Helicobacter pylori (known as H. pylori), a common type of bacteria known to cause inflammation and ulcers in the stomach and a known carcinogen, leads to the death of most normal stomach cells. As a result, BMDCs arrive in numbers in an attempt to repair the site. These BMDCs, which are somewhat prone to undergo transformation, progress over time into stomach cancer cells. The research was conducted in mouse models.

"With this clearer understanding of the connection between bone marrow derived stem cells and stomach cancer, I plan to establish screening models for people at high risk of cancer and work to translate the findings into new treatments that specifically target these cells at the Herbert Irving Comprehensive Cancer Center of Columbia University Medical Center," said Dr. Wang.

About Stomach (Gastric) Cancer

Stomach cancer is a grave problem in much of the world -- especially Asia, Eastern Europe and parts of Latin America -- where it's second only to lung cancer as a cause of cancer deaths.

In the United States and Western Europe, the incidence of stomach cancer has declined dramatically over the past 50 years; however, it remains a very deadly disease.

While the survival rate is much more favorable when diagnosed early, unfortunately it is often diagnosed at advanced stages, often because its symptoms -- which include bloating, diarrhea, nausea and fatigue -- can easily confused with other common conditions. The five-year survival rate for stomach cancer in the United States is approximately 22 percent.