Distribution of gastric adenocarcinoma subtypes in different ethnicities in Kuala Lumpur, Malaysia

ABSTRACT

The multiracial population in Malaysia has lived together for almost a century, however, the risk ofgastric cancer among them varies. This study aimed to determine the distribution of different gastricadenocarcinoma subtypes and Helicobacter pylori infection status among gastric adenocarcinomapatients. Patients with gastric adenocarcinoma were enrolled from November 2013 to June 2015.Blood samples were collected for detection of H. pylori using ELISA method. Gastric adenocarcinomacases were more prevalent in the Chinese (52.8%), followed by the Malays (41.7%) and leastprevalent in the Indians (5.6%). Gastric adenocarcinoma located in the cardia was significantly moreprevalent in the Malays (66.7%) compared to the Chinese (26.3%), whereas non-cardia cancer wasdiagnosed more in the Chinese (73.7%) compared to the Malays (33.3%) [P = 0.019; OR = 5.6, 95CI 1.27 to 24.64]. The Malays also had significantly higher prevalence of gastric tumour locatedat the cardia or fundus than other gastric sites compared to the Chinese (P = 0.002; OR 11.2, 95%CI 2.2 to 56.9). Among the cardia gastric cancer patients, 55.6% of the Malays showed intestinalhistological subtype, whereas all the Chinese had the diffuse subtype. More than half of the patients(55.3%) with gastric adenocarcinoma were positive for H. pylori infection and among them, 66.7%were Chinese patients. The risk of gastric adenocarcinoma in our population is different amongethnicities. Further studies on host factors are needed as it might play an important role in gastriccancer susceptibility in our population.