Meta-Analyses of Epigenetics Risk Factors for Lung Cancer Prevention: MPO and GSTM1 Human Gene Variations Across Different Race-Ethnicity Groups

Monday, 28 July 2014: 7:20 AM

Po-Jui Yu, MSN, RN1
Shyang-Yun Pamela K. Shiao, PhD, RN, FAAN2
Maria Suarez, MSN, RN2
(1)Departmet of Nursing, College of Medicine, National Taiwan University, Taipei, Taiwan
(2)School of Nursing, Azusa Pacific University, Azusa, CA

Purpose: The purpose of this presentation is to disseminate current evidence on population genome health, through meta-analyses of epigenetic risk factors, for lung cancer (LC) prevention. LC is one of the most common cancers worldwide and has the highest mortality rate among all cancers. Glutathione S-transferase that belongs to the mu class (GSTM1) and myeloperoxidase (MPO) gene polymorphisms have been cumulating in the literature, associating epigenetics factors and LC.

Methods: Literature searches, quality scores for the studies, and inter-rater evaluation on data coding was completed to ensure data accuracy for pooled meta-analyses.

Results: Preliminary analyses included 31,146 LC cases and 38,736 controls from 122 studies. The MPO gene mutations (GA and AA subtypes) in Asians were lower (16.7-33.3%) than Caucasians (31.8-49.1%) across the world, for control and case groups. However, the GSTM1 gene mutation variation (null subtype) was highest in Italians (87.5%) than other populations. Pollution indicators were checked and shown worse in Asia than other countries. For lifestyle related meta-analyses, smoking was associated with an increased risk of LC (98 studies, 28,831 cases, 35,069 controls, RR=1.40, p < 0.0001). Low vegetable intakes were associated with increased LC risk (RR = 1.26, P < 0.05) in 7 studies. No second hand smoking (6 studies) and limiting indoor pollution (3 studies) were protective for LC (RR=0.73 and 0.77, both P<0.05).

Conclusion: For association of GSTM1 gene variations, genotype present (44.3% cases, 47.9% controls) was protective against LC for all populations combined in the world (RR = 0.94, p < 0.0001). Future studies are needed to examine epigenetic factors for population health associated with MPO and GSTM1 gene variations in the prevention of LC.