Researchers of the Nutrition Research, Environment and Cancer group at IDIBELL have identified new factors that warn of an increased risk of developing gastric cancer. People who are infected with a specific variant of Helicobacter pylori and those with a particular preneoplastic gastric lesion (pre-cancer) have a much higher risk of developing the disease than the rest. The results have been published in two articles in the International Journal of Cancer and the American Journal of Gastroenterology.

These findings are the result of a prospective study in a high-risk population in Spain and should allow the development of a risk scale, and a closer monitoring of people with a greater likelihood of developing cancer, to diagnose and treat in early stages.

A poor prognosis cancer

Gastric tumors are the second cancer leading cause of death in the world, with more than one million deaths each year. In Spain, it is the fifth most common cancer with 8.200 new cases each year, and the fourth that causes more deaths.

Gastric cancer is a tumor with poor prognosis. No symptoms in early stages, it is usually diagnosed at advanced stages and has not effective treatment. Currently, the 5 year survival does not exceed 23%. Early diagnosis, when the injury is not yet malignant, for example, improves the prognosis and the survival of those affected.

The process of development of gastric cancer is slow; it can take more than twenty years. It usually begins with infection by Helicobacter pylori bacteria that produces injury, a superficial gastritis, which over time may progress to cancer occurrence.

Infection by H. pylori is very common in the population, but the vast majority of infected (more than 80%) disposed of without problems. Between 10 and 15% of the bacteria produce an ulcer and only 1 or 2% of cases pass a gastric cancer. “One of the challenges of the search is to find markers that tell us who make up this 1 or 2%, ” says Carlos Alberto Gonzalez Svatetz, Head of Nutrition, Environment and Cancer Unit at ICO and IDIBELL researcher, responsible for studies

Create a risk scale

Despite the relevance of gastric cancer worldwide, there are currently no clinical guidelines on how to act when it reaches a patient with gastric distress and an infection by Helicobacter pylori and gastric cancer precursor lesion. “Studies like these can make a risk scale and know what people are more likely to develop cancer and therefore should be subject to greater scrutiny, ” Gonzalez concluded Svatetz.

Indicators to predict the occurrence of tumor

In the first study, published in the International Journal of Cancer, they tracked more than 600 people in the Hospital of Soria who had visited the center with digestive problems and which were detected the presence of H. pylori and very initial gastric lesion. After doing a survey on health habits, they had been followed for more than 12 years. Researchers have found that patients who had an initial lesion called ‘intestinal metaplasia of incomplete type’, have much higher risk of developing the disease, up to 12 times more than those with other types of injury.

The second study, published in the American Journal of Gastroenterology, analyzed different variants of H. pylori, to determine whether some strains are more virulent than others. The results indicate that those patients infected with H. pylori cagA positive and with the gene variant vac1 s1/m1 are five times more likely to develop stomach cancer than those who are infected with H. pylori cagA negative and the gene variant vac1 s2/m2.

Article’s reference

C. A. González*, C. Figuereido, C. Bonet*, R. M. Ferreira, M. L. Pardo, J.M. Ruiz Liso, G. Capella* and J.M. Sanz-Anquela. Helicobacter pylori cagA and vacA genotypes as predictors of progression of gastric preneoplastic lessions: a long term follow-up in a high-risk area in Spain. The American Journal of Gastroenterology. doi:10.1038/ajg.2011.1 C.A. González*, M. L. Pardo, J.M. Ruiz Liso, P. Alonso, C. Bonet*, R. M. Garcia*, N. Sala*, G. Capella* and J. M. Sanz-Anquela. Gastric cancer occurrence in preneoplastic lesions: a long term follow-up in a high-risk area in Spain. The International Journal of Cancer. 2010 Dec 1;127(11):2654-60.

*IDIBELL researchers