To identify common genetic variants that contribute to lung cancer susceptibility, we conducted a multistage genome-wide association study of lung cancer in Asian women who never smoked. We scanned 5,510 never-smoking female lung cancer cases and 4,544 controls drawn from 14 studies from mainland China, South Korea, Japan, Singapore, Taiwan, and Hong Kong. We genotyped the most promising variants (associated at P < 5 × 10-6) in an additional 1,099 cases and 2,913 controls. We identified three new susceptibility loci at 10q25.2 (rs7086803, P = 3.54 × 10-18), 6q22.2 (rs9387478, P = 4.14 × 10-10) and 6p21.32 (rs2395185, P = 9.51 × 10-9). We also confirmed associations reported for loci at 5p15.33 and 3q28 and a recently reported finding at 17q24.3. We observed no evidence of association for lung cancer at 15q25 in never-smoking women in Asia, providing strong evidence that this locus is not associated with lung cancer independent of smoking.

DNA repair genes play an important role in maintaining stability and integrity of genomic DNA. Polymorphisms in nucleotide excision repair genes may cause variations in DNA repair capacity phenotype and thus contribute to cancer risk. In this case-control study of 1,125 gastric cancer cases and 1,196 cancer-free controls, we investigated the association between three functional single nucleotide polymorphisms (SNPs, rs2296147T > C, rs2094258C > T and rs873601G > A) in the xeroderma pigmentosum group G (XPG) gene and gastric cancer risk. We used the Taqman assays to genotype these three SNPs and logistic regression models to estimate odds ratios (ORs) and 95% confidence intervals (95% CIs). We found that only the rs873601A variant genotypes were associated with a significant higher risk for gastric adenocarcinoma (adjusted OR = 1.30, 95% CI = 1.03-1.64 for AA vs. GG and adjusted OR = 1.23, 95% CI = 1.01-1.49 for AA vs. GG/AG). Stratification analysis indicated that this risk was more pronounced in subgroups of older age (>59 years), males, ever-smokers, and patients with NGCA. All these were not found for the other two SNPs (rs2296147T > C and rs2094258C > T). We then performed expression analysis using gastric cancer adjacent normal tissues from 141 patients and found that the A variant allele was associated with non-significantly reduced expression of XPG mRNA (P(trend) = 0.107). Further analysis using mRNA expression data from the HapMap suggested that the A allele was associated with significantly reduced expression of XPG mRNA in normal cell lines for 45 Chinese (P(trend) = 0.003) as well as for 261 subjects with different ethnicities (P(trend) = 0.001). These support the hypothesis that functional XPG variants may contribute to the risk of gastric cancer. Larger studies with different ethnic populations are warranted to validate our findings.

Background: Studies of related individuals have consistently demonstrated notable familial aggregation of cancer. We aim to estimate the heritability and genetic correlation attributable to the additive effects of common single-nucleotide polymorphisms (SNPs) for cancer at 13 anatomical sites.

Analyses of genome-wide association study (GWAS) data have revealed that detectable genetic mosaicism involving large (>2 Mb) structural autosomal alterations occurs in a fraction of individuals. We present results for a set of 24,849 genotyped individuals (total GWAS set II [TGSII]) in whom 341 large autosomal abnormalities were observed in 168 (0.68%) individuals. Merging data from the new TGSII set with data from two prior reports (the Gene-Environment Association Studies and the total GWAS set I) generated a large dataset of 127,179 individuals; we then conducted a meta-analysis to investigate the patterns of detectable autosomal mosaicism (n = 1,315 events in 925 [0.73%] individuals). Restricting to events >2 Mb in size, we observed an increase in event frequency as event size decreased. The combined results underscore that the rate of detectable mosaicism increases with age (p value = 5.5 × 10(-31)) and is higher in men (p value = 0.002) but lower in participants of African ancestry (p value = 0.003). In a subset of 47 individuals from whom serial samples were collected up to 6 years apart, complex changes were noted over time and showed an overall increase in the proportion of mosaic cells as age increased. Our large combined sample allowed for a unique ability to characterize detectable genetic mosaicism involving large structural events and strengthens the emerging evidence of non-random erosion of the genome in the aging population.

Mammalian target of rapamycin complex 1 (mTORC1) plays an important role in maintaining proper cellular functions, and genetic variations in this complex may affect cancer risk. In this study, we examined the associations between eight potential functional single nucleotide polymorphisms in the mTORC1 genes (rs2536T>C and rs1883965G>A for mTOR, rs3160T>C, and rs26865A>G for mLST8, rs3751934C>A, rs1062935T>C, rs3751932T>C, and rs12602885G>A for Raptor, not included in published gastric cancer genome-wide association studies) and gastric cancer risk in 1125 gastric cancer cases and 1196 cancer-free controls. We performed conditional logistic regression and multifactor dimensionality reduction (MDR) analyses to assess their associations with gastric cancer risk. We also used false-positive report probabilities (FPRP) for assessing significant findings. We found that only the rs1883965A variant genotypes were associated with an increased risk of gastric cancer (AG vs. GG: adjusted odds ratio (OR) = 1.26, 95% confidence interval (CI) = 1.00-1.59; AA vs. GG: adjusted OR = 1.85, 95% CI = 0.67-5.16 and dominant model: adjusted OR = 1.28, 95% CI = 1.03-1.61). Patients with ≥1 risk genotypes of mTOR had significant increased risk (adjusted OR = 1.25, 95% CI = 1.04-1.49), compared with those having zero risk genotypes. In the stratified analysis, the risk effect of the rs1883965 AG/AA genotypes was evident in subgroups of ever-smokers, non-gastric cardia adenocarcinoma and clinical stage I + II, which were noteworthy findings as evaluated by FPRP. The MDR analysis identified smoking status and rs1883965 as the strongest two-factors for gastric cancer risk. These data support the hypothesis that functional polymorphisms of mTOR may contribute to gastric cancer risk. Clearly, our results require validation in larger studies with different ethnic populations.