GSTM-1 Gene Polymorphism and Age Characteristics in Oral Cancer Patients

Objectives: To determine and compare the frequencies of GSTM-1 gene polymorphism in Malaysian Indians and Taiwanese oral cancer patients with betel-quid chewing habits; and to compare the mean age differences between these patients. Methods: A total of 31 oral cancer patients (20 Malaysian Indians, 11 Taiwanese) with betel-quid chewing habits were included in this study. The Malaysian Indian oral cancer subjects are all females (20 subjects) with the mean age 62.50 years old and the Taiwanese oral cancer subjects are mostly males (10 subjects) with the mean age 48.18 years old. The results from these patients were compared to 18 Taiwanese non-cancer patients (11 males, 7 females) with betel-quid chewing habits (mean age 49.11 years old). Polymerase chain reaction-based techniques were carried out using DNA extracted from the subjects' blood to detect GSTM-1 gene polymorphism. Results: A total of six Malaysian Indian oral cancer patients (30%), three Taiwanese oral cancer patients (27.3%) and five Taiwanese non-cancer patients (27.8%) show GSTM-1 gene polymorphism. These differences are not significant when tested by 2-sample t test. The mean age of Malaysian Indians and Taiwanese oral cancer patients is 62.50 and 48.18 years old respectively. This difference is significant (P<0.05) when tested by 2-sample t test. Conclusions: No significant differences in GSTM-1 gene polymorphism were found between Malaysian Indians and Taiwanese oral cancer patients and between Taiwanese cancer and non-cancer patients. However, this study is preliminary in nature and requires a larger sample to validate the association between GSTM-1 gene polymorphism and susceptibility to oral cancer. The significant difference in the mean age of the oral cancer patients could be attributed to the development of betel-quid chewing habits at a younger age amongst the Taiwanese. This study is supported by the IRPA grant -06-02-03-0174 PR 0054/05-05 and NSC 93-2314-B-037-072