Higher Incidence of H. pylori Infection and Gastric Lesion Found in Relatives of Gastric Cancer Patients

Gastric cancer is the fourth leading cause of cancer-related deaths in Hong Kong. In 2002, 1,000 new cases were diagnosed and over 600 patients died from this malignancy, according to the Hong Kong Cancer Registry. It is well documented that family members of gastric cancer patients have a higher risk of developing the condition, but the exact mechanism remains unclear.

(From left) Prof. Enders Ng, associate dean (clinical), and Prof. Joseph Sung, associate dean (general affairs) of the Faculty of Medicine, and Prof. Leung Wai-keung of the Department of Medicine and Therapeutics announcing the novel NBI technique on 16th March at the Postgraduate Education Centre

The Institute of Digestive Disease of the Faculty of Medicine has recently acquired a novel endoscopic imaging technique called 'narrow band imaging' (NBI) to help identify early neoplastic lesions in the gastric mucosa. It consists of a sequential electronic endoscope system and a source of light equipped with new narrow band filters.

From 2001-2004, the institute conducted a screening of 270 first-degree relatives (siblings and offsprings) of gastric cancer patients using upper gastrointestinal endoscopy to determine the prevalence of H. pylori infection and pre-neoplastic lesions in the stomach. The prevalence of H. pylori infection was found to be significantly higher in gastric cancer relatives (59.6 per cent) than age- and sex-matched controls without a family history of the disease. Moreover, 30 per cent were found to have intestinal metaplasia, a pre-neoplastic lesion, in the stomach. Risk factors associated with the presence of intestinal metaplasia include H. pylori infection, the male gender, age and a history of gastric cancer in siblings.

The institute believes that screening of relatives of patients by endoscopy may be beneficial for detecting H. pylori infection and early gastric lesions. Its researchers will conduct a study to evaluate the role of NBI in screening such lesions in the relatives of gastric cancer patients.