Abstract B07: A meta-analysis of GSTM1 human genome as risk factor in lung cancer prevention

Abstract

Abstract Purpose: Lung cancer is the highest cause of cancer related death in the United States. Its development is attributed to environmental and genetic factors. Smoking, diet, and occupation are environmental factors that can affect its development. Besides the environmental elements, the genetic aspect of this risk has also been identified as a major factor. Polymorphism in an individual's genotype has been recognized as a possible risk for lung cancer. GSTM1 has been one of the genes being studied with regards to genetic polymorphism affecting lung cancer development. A meta-analysis was conducted to examine the association of GSTM1 human genome as a risk factor for lung cancer. Procedure: Literature searches were completed by searching at three different times using keyword related to human GSTM1 and lung cancer. The searches generated 326 papers. The preliminary count includes 138 case-control studies. Quality rating of the literatures included will be based on Quality of Reporting of Meta-analysis (QUOROM). GSTM1 genes are categorized into present and null deletion genotype. Each category will be grouped by country and ethnicity. Inter-rater evaluation will be done for quality rating and gene count to ensure accurate appraisal of data collected. Pooled relative risks will be computed for each genotype and ethnicity to determine association with lung cancer. Findings: With the total cases of 12,288 and control subjects of 16,836, this meta-analysis is able to ascertain the association of GSTM1 with lung cancer risk. The present genotype of GSTM1 has been established as protective in nature (P < 0.05). In addition, the relative risk for the null genotype showed significance (P < 0.05) affirming its association to increased risk of developing lung cancer. In examining the subgroups for the study, only the Asian group shows a significant relative risk for both present and null genotype. Additionally, among the three Asian countries in the group, only China showed a significant relative risk for lung cancer development in the null genotype and it did not show significant relative risk for the protective genotype. On the contrary, Japan showed significance in association with the protective genotype. Further reviews confirmed that dietary factor such as intake of cruciferous vegetables, fruits, and green teas affect the development of lung cancer. Conclusion: The association between GSTM1 and lung cancer has been established through this meta-analysis. The results from this meta-analysis prompt the need for further studies that examine GSTM1 genotypes with inclusion of more studies for various race-ethnicity groups and countries. GSTM1 present genotype has an essential role in preventing lung cancer. There is a need to identify ways to enhance or maintain this GSTM1 genotype in future studies. Dietary intake of cruciferous vegetables is a promising factor in preventing lung cancer. Citation Format: Maria Suarez, S. Pamela Shiao, Mildred Gonzales, Amanda Lie, Ching-Yi Chiu. A meta-analysis of GSTM1 human genome as risk factor in lung cancer prevention. [abstract]. In: Proceedings of the Twelfth Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2013 Oct 27-30; National Harbor, MD. Philadelphia (PA): AACR; Can Prev Res 2013;6(11 Suppl): Abstract nr B07.