Severe radiation-induced toxicities limit treatment efficacy and compromise outcomes of lung cancer. We aimed to identify microRNA-related genetic variations as biomarkers for the prediction of radiotherapy-induced acute toxicities. We genotyped 233 SNPs (161 in microRNA binding site and 72 in processing gene) and analyzed their associations with pneumonitis and esophagitis in 167 stage III NSCLC patients received definitive radiation therapy. Sixteen and 11 SNPs were associated with esophagitis and pneumonitis, respectively. After multiple comparison correction, RPS6KB2:rs10274, SMO:rs1061280, SMO:rs1061285 remained significantly associated with esophagitis, while processing gene DGCR8:rs720014, DGCR8:rs3757, DGCR8:rs1633445 remained significantly associated with pneumonitis. Patients with the AA genotype of RPS6KB2:rs10274 had an 81% reduced risk of developing esophagitis (OR: 0.19, 95% CI: 0.07–0.51, p = 0.001, q = 0.06). Patients with the AG+GG genotype of SMO:rs1061280 had an 81% reduced risk of developing esophagitis (OR: 0.19, 95% CI: 0.07–0.53, p = 0.001, q = 0.06). Patients with the GG+GA genotype of DGCR8:rs720014 had a 3.54-fold increased risk of pneumonitis (OR: 3.54, 95% CI: 1.65–7.61, p <0.05, q <0.1). Significantly cumulative effects of the top SNPs were observed for both toxicities (P-trend <0.001). Using bioinformatics tools, we found that the genotype of rs10274 was associated with altered expression of the RPS6KB2 gene. Gene-based analysis showed DGCR8 (p = 0.010) and GEMIN4 (p = 0.039) were the top genes associated with the risk of developing pneumonitis. Our results provide strong evidence that microRNA-related genetic variations contribute to the development of radiotherapy-induced acute esophagitis and pneumonitis and could thus serve as biomarkers to help accurately predict radiotherapy-induced toxicity in NSCLC patients.
Chronic lymphocytic leukemia (CLL) is a common lymphoid malignancy with strong heritability. To further understand the genetic susceptibility for CLL and identify common loci associated with risk, we conducted a meta-analysis of four genome-wide association studies (GWAS) composed of 3,100 cases and 7,667 controls with follow-up replication in 1,958 cases and 5,530 controls. Here we report three new loci at 3p24.1 (rs9880772, EOMES, P=2.55 × 10−11), 6p25.2 (rs73718779, SERPINB6, P=1.97 × 10−8) and 3q28 (rs9815073, LPP, P=3.62 × 10−8), as well as a new independent SNP at the known 2q13 locus (rs9308731, BCL2L11, P=1.00 × 10−11) in the combined analysis. We find suggestive evidence (P<5 × 10−7) for two additional new loci at 4q24 (rs10028805, BANK1, P=7.19 × 10−8) and 3p22.2 (rs1274963, CSRNP1, P=2.12 × 10−7). Pathway analyses of new and known CLL loci consistently show a strong role for apoptosis, providing further evidence for the importance of this biological pathway in CLL susceptibility.
Chronic lymphocytic leukemia is a highly inheritable cancer. Here the authors conduct a metaanalysis of four genome-wide association studies and identify three novel loci located near EOMES, SERPINB6 and LPP associated with risk of this disease.
Radiation therapy (RT)-induced pneumonitis and esophagitis are commonly developed side effects in non-small cell lung cancer (NSCLC) patients treated with definitive RT. Identifying patients who are at increased risk for these toxicities would help to maximize treatment efficacy while minimizing toxicities. Here, we systematically investigated single nucleotide polymorphisms (SNPs) within double-strand break (DSB) repair pathway as potential predictive markers for radiation-induced esophagitis and pneumonitis. We genotyped 440 SNPs from 45 genes in DSB repair pathways in 250 stage I–III NSCLC patients who received definitive radiation or chemoradiation therapy, followed by internal validation in 170 additional patients. We found that 11 SNPs for esophagitis and 8 SNPs for pneumonitis showed consistent effects between discovery and validation populations (same direction of OR and reached significance in meta-analysis). Among them, rs7165790 in the BLM gene was significantly associated with decreased risk of esophagitis in both discovery (OR = 0.59, 95% CI: 0.37–0.97, p = 0.037) and validation subgroups (OR = 0.45, 95% CI: 0.22–0.94, p = 0.032). A strong cumulative effect was observed for the top SNPs, and gene-based tests revealed 12 genes significantly associated with esophagitis or pneumonitis. Our results support the notion that genetic variations within DSB repair pathway could influence the risk of developing toxicities following definitive RT in NSCLC.
NSCLC; radiation pneumonitis and esophagitis; DNA double-stranded break repair pathway; single nucleotide polymorphism
Depression is associated with an increased risk of mortality in cancer patients; it has been hypothesized that depression-associated alterations in cell aging mechanisms in particular, the telomere/telomerase maintenance system, may underlie this increased risk. We evaluated the association of depressive symptoms and telomere length to mortality and recurrence/progression in 464 bladder cancer patients.
We used the CES-D and SCID to assess current depressive symptoms and lifetime MDD, respectively, and telomere length was assessed from peripheral blood lymphocytes. Multivariate Cox regression was used to assess the association of depression, and telomere length to outcomes and the joint effect of both. Kaplan-Meier plots and log rank tests were used to compare survival time of subgroups by depression variables and telomere length.
Patients with depressive symptoms (CES-D ≥16) had a 1.83-fold (95%CI= 1.08 to 3.08, P=0.024) increased risk of mortality compared to patients without depressive symptoms (CES-D < 16) and shorter disease-free survival time (P=0.004). Patients with both depressive symptoms and lifetime history of MDD were at 4.88-fold (95%CI=1.40 to 16.99; P=0.013) increased risk compared to patients with neither condition. Compared to patients without depressive symptoms and long telomere length, patients with depressive symptoms and short telomeres exhibited a 4-fold increased risk of mortality (HR=3.96, 95% CI=1.86 to 8.41, P=0.0003) and significantly shorter disease-free survival time (P<0.001).
Short telomere length and depressive symptoms are associated with bladder cancer mortality individually and jointly.
Further investigation of interventions that impact depression and telomere length may be warranted in cancer patients.
Depression; telomere length; bladder cancer
We hypothesized that telomere length in peripheral blood would have significant predictive value for risk of recurrence after curative resection in non-small cell lung cancer (NSCLC).
This prospective study included 473 patients with histologically confirmed early stage NSCLC who underwent curative resection at MD Anderson Cancer Center between 1995 and 2008. Relative telomere length (RTL) of peripheral leukocytes was measured by real-time PCR. The risk of recurrence was estimated as hazard ratios (HRs) and 95% confidence intervals (CIs) using a multivariable Cox proportional hazard regression model.
Median duration of follow-up was 61 months and 151 patients (32%) had developed recurrence at time of analysis. Patients who developed recurrence had significantly longer mean RTL compared to those without recurrence (1.13 vs 1.07, P=0.046). A subgroup analysis indicates that women had longer RTL compared to males (1.12 vs 1.06, P=0.025), and the patients with adenocarcinoma demonstrated longer RTL compared to those with other histologic types (1.11 vs 1.05, P=0.042). To determine if longer RTL in women and adenocarcinoma subgroup would predict risk of recurrence, multivariate Cox analysis adjusting for age, gender, stage, pack year and treatment regimens was performed. Longer telomeres were significantly associated with higher risk of developing recurrence in female (HR=2.25; 95% CI, 1.02-4.96, P=0.044) and adenocarcinoma subgroups (HR=2.19; 95% CI, 1.05-4.55, P=0.036). The increased risk of recurrence due to long RTL was more apparent in females with adenocarcinoma (HR=2.67; 95% CI, 1.19-6.03, P=0.018).
This is the first prospective study to suggest that long RTL is associated with recurrence in early stage NSCLC after curative resection. Women and adenocarcinoma appear to be special subgroups in which telomere biology may play an important role.
We investigated genetic variation in CYP2A6 in relation to lung cancer risk among African American smokers, a high-risk population. Previously, we found that CYP2A6, a nicotine/nitrosamine metabolism gene, was associated with lung cancer risk in European Americans, but smoking habits, lung cancer risk and CYP2A6 gene variants differ significantly between European and African ancestry populations. Herein, African American ever-smokers, drawn from two independent lung cancer case–control studies, were genotyped for reduced activity CYP2A6 alleles and grouped by predicted metabolic activity. Lung cancer risk in the Southern Community Cohort Study (n = 494) was lower among CYP2A6 reduced versus normal metabolizers, as estimated by multivariate conditional logistic regression [odds ratio (OR) = 0.44; 95% confidence interval (CI) = 0.26–0.73] and by unconditional logistic regression (OR = 0.62; 95% CI = 0.41–0.94). The association was replicated in an independent study from MD Anderson Cancer Center (n = 407) (OR = 0.64; 95% CI = 0.42–0.98), and pooling the studies yielded an OR of 0.64 (95% CI = 0.48–0.86). Exploratory analyses revealed a significant interaction between CYP2A6 genotype and sex on the risk for lung cancer (Southern Community Cohort Study: P = 0.04; MD Anderson: P = 0.03; Pooled studies: P = 0.002) with a CYP2A6 effect in men only. These findings support a contribution of genetic variation in CYP2A6 to lung cancer risk among African American smokers, particularly men, whereby CYP2A6 genotypes associated with reduced metabolic activity confer a lower risk of developing lung cancer.
We aimed to identify serum metabolites as potential valuable biomarkers for lung cancer and to improve risk stratification in smokers.
We performed global metabolomic profiling followed by targeted validation of individual metabolites in a case-control design of 386 lung cancer cases and 193 matched controls. We then validated bilirubin, which consistently showed significant differential levels in cases and controls, as a risk marker for lung cancer incidence and mortality in a large prospective cohort comprised of 425,660 participants.
Through global metabolomic profiling and following targeted validation, bilirubin levels consistently showed a statistically significant difference among healthy controls and lung cancer cases. In the prospective cohort, the inverse association was only seen in male smokers, regardless of smoking pack-years and intensity. Compared with male smokers in the highest bilirubin group (>1 mg/dL), those in the lowest bilirubin group (<0.75 mg/dL) had 55% and 66% increase in risks of lung cancer incidence and mortality, respectively. For every 0.1 mg/dL decrease of bilirubin, the risks for lung cancer incidence and mortality increased by 5% and 6% in male smokers, respectively (both P < 0.001). There was a significant interaction between low serum bilirubin level and smoking on lung cancer risk (P for interaction = 0.001).
Low levels of serum bilirubin are associated with higher risks of lung cancer incidence and mortality in male smokers and can be used to identify higher risk smokers for lung cancer.
lung cancer; smokers; metabolomics; bilirubin; cohort
Genome-wide association studies (GWAS) have mapped risk alleles for at least 10 distinct cancers to a small region of 63 000 bp on chromosome 5p15.33. This region harbors the TERT and CLPTM1L genes; the former encodes the catalytic subunit of telomerase reverse transcriptase and the latter may play a role in apoptosis. To investigate further the genetic architecture of common susceptibility alleles in this region, we conducted an agnostic subset-based meta-analysis (association analysis based on subsets) across six distinct cancers in 34 248 cases and 45 036 controls. Based on sequential conditional analysis, we identified as many as six independent risk loci marked by common single-nucleotide polymorphisms: five in the TERT gene (Region 1: rs7726159, P = 2.10 × 10−39; Region 3: rs2853677, P = 3.30 × 10−36 and PConditional = 2.36 × 10−8; Region 4: rs2736098, P = 3.87 × 10−12 and PConditional = 5.19 × 10−6, Region 5: rs13172201, P = 0.041 and PConditional = 2.04 × 10−6; and Region 6: rs10069690, P = 7.49 × 10−15 and PConditional = 5.35 × 10−7) and one in the neighboring CLPTM1L gene (Region 2: rs451360; P = 1.90 × 10−18 and PConditional = 7.06 × 10−16). Between three and five cancers mapped to each independent locus with both risk-enhancing and protective effects. Allele-specific effects on DNA methylation were seen for a subset of risk loci, indicating that methylation and subsequent effects on gene expression may contribute to the biology of risk variants on 5p15.33. Our results provide strong support for extensive pleiotropy across this region of 5p15.33, to an extent not previously observed in other cancer susceptibility loci.
In the current study we present a validated miRNA signature to predict pathologic complete response (pCR) to neoadjuvant chemoradiation in esophageal adenocarcinoma.
Three patient cohorts (discovery n=10, model n=43, and validation n=65) with locally advanced esophageal adenocarcinoma were analyzed. In the discovery cohort 754 miRNAs were examined in pre-treatment tumor biopsy specimens using a TaqMan array. Of these, the 44 most significantly altered between tumors with pCR and non-pCR were examined in an additional 43 tumors using a Fluidigm 48.48 array. The four miRNAs (mir-505*, mir-99b, mir-451, and mir-145*) significantly predicting pCR in both cohorts were examined in an additional validation cohort (n=65) using Illumina array. These four miRNAs were used to generate a miRNA expression profile (MEP) score.
The four miRNAs profiled are highly significantly associated with pCR in the model cohort (ptrend=0.008), the validation cohort (ptrend=0.025), and the combined cohort (ptrend=4.6×10−4). The receiver-operator characteristic area under the curves (AUCs) for the MEP score was 0.78 (model cohort), 0.71 (validation cohort) and 0.72 (combined). When combined with clinical variables, the MEP score AUCs increased to 0.89 (model cohort), 0.77 (validation cohort) and 0.81 (combined). Estimates from logistic regression based upon the MEP were determined and used to generate a probability of pCR plot, which identifies a group of patients with very high (≥ 80%) and very low (≤10%) probability of pCR.
The MEP score provides a validated means of predicting pCR to neoadjuvant chemoradiotherapy in esophageal adenocarcinoma that is robust across several analysis platforms.
miRNA; esophageal cancer; response; chemotherapy; radiation
Definitive radiotherapy improves locoregional control and survival in inoperable non-small cell lung cancer (NSCLC) patients. However, radiation-induced toxicities (pneumonitis/esophagitis) are common dose-limiting inflammatory conditions. We therefore conducted a pathway-based analysis to identify inflammation-related SNPs associated with radiation-induced pneumonitis or esophagitis. 11,930 SNPs were genotyped in 201 stage I-III NSCLC patients treated with definitive radiotherapy. Validation was performed in an additional 220 NSCLC cases. After validation, 19 SNPs remained significant. A polygenic risk score (PRS) was generated to summarize the effect from validated SNPs. Significant improvements in discriminative ability were observed by adding the PRS into the clinical/epidemiological variable-based model. We then used 277 lymphoblastoid cell-lines to assess radiation sensitivity and eQTL relationships of the identified SNPs. Three genes (PRKCE,DDX58 and TNFSF7) were associated with radiation sensitivity. We concluded that inflammation-related genetic variants could contribute to the development of radiation-induced toxicities. These loci could assist in predicting those unfavorable events.
NSCLC; inflammation; radiation; pneumonitis; esophagitis; single nucleotide polymorphism
Cancers are composed of populations of cells with distinct molecular and phenotypic features, a phenomenon termed intra-tumor heterogeneity (ITH). ITH in lung cancers has not been well studied. We applied multi-region whole exome sequencing (WES) on 11 localized lung adenocarcinomas. All tumors showed clear evidence of ITH. On average, 76% of all mutations and 20/21 known cancer gene mutations were identified in all regions of individual tumors suggesting single-region sequencing may be adequate to identify the majority of known cancer gene mutations in localized lung adenocarcinomas. With a median follow-up of 21 months post-surgery, 3 patients have relapsed and all 3 patients had significantly larger fractions of subclonal mutations in their primary tumors than patients without relapse. These data indicate larger subclonal mutation fraction may be associated with increased likelihood of postsurgical relapse in patients with localized lung adenocarcinomas.
accurate prognostic prediction is challenging for advanced-stage non-small cell lung cancer (NSCLC) patients.
we systematically investigated genetic variants within inflammation pathway as potential prognostic markers for advanced-stage NSCLC patients treated with first-line chemotherapy. A discovery phase in 502 patients and an internal validation in 335 patients were completed at MD Anderson Cancer Center. External validation was performed in 371 patients at Harvard University.
a missense SNP (HLA-DOB:rs2071554) predicted to influence protein function was significantly associated with poor survival in the discovery (HR:1.46, 95% CI:1.02-2.09), internal validation (HR:1.51, 95% CI:1.02-2.25), and external validation (HR:1.52, 95% CI:1.01-2.29) populations. KLRK1:rs2900420 was associated with a reduced risk in the discovery (HR:0.76, 95% CI:0.60-0.96), internal validation (HR:0.77, 95% CI:0.61-0.99), and external validation (HR:0.80, 95% CI:0.63-1.02) populations. A strong cumulative effect was observed for these SNPs on overall survival.
Genetic variations in inflammation-related genes could have potential to complement prediction of prognosis.
NSCLC; advanced stage; overall survival; inflammation; single nucleotide polymorphism
Dietary factors may affect risk of renal cell carcinoma (RCC). In an ongoing case-control study of RCC initiated in Houston, Texas, in 2002, we identified 3 empirically derived dietary patterns: “fruits and vegetables,” “American/Western,” and “Tex-Mex.” Among 659 RCC cases and 699 controls, we evaluated associations of these dietary patterns with RCC risk and whether the associations varied by obesity status, smoking status, physical activity level, history of hypertension, and genetic variants previously identified via genome-wide association studies. Among persons in the highest categories of adherence versus the lowest, the “fruits and vegetables” dietary pattern was associated with an approximately 50% lower RCC risk (Ptrend < 0.001), while “American/Western” dietary pattern scores were positively associated with a 2-fold higher risk (Ptrend < 0.001). We observed synergistic interaction between the American/Western pattern and hypertension status: The odds ratio (highest tertile vs. lowest) among persons with hypertension was 2.23 (95% confidence interval: 1.43, 3.45), as compared with 1.76 (95% confidence interval: 1.16, 2.70) among persons without hypertension (additive Pinteraction = 0.01). A variant (rs718314) in the inositol 1,4,5-trisphosphate receptor, type 2 gene (ITPR2) was found to interact with the American/Western dietary pattern in relation to RCC risk (additive Pinteraction = 0.03). ITPR2 has been shown to affect nutrient metabolism and central obesity. Dietary patterns, genetic variants, and host characteristics may individually and jointly influence susceptibility to RCC.
case-control studies; dietary patterns; gene-diet interaction; renal cell carcinoma
Post-operative pulmonary complications are the most common morbidity associated with lung resection in non-small cell lung cancer (NSCLC) patients. The TNF/TRAF2/ASK1/p38 kinase pathway is activated by stress stimuli and inflammatory signals. We hypothesized that genetic polymorphisms within this pathway may contribute to risk of complications. In this case-only study, we genotyped 173 germline genetic variants in a discovery population of 264 NSCLC patients who underwent a lobectomy followed by genotyping of the top variants in a replication population of 264 patients. Complications data was obtained from a prospective database at MD Anderson. MAP2K4:rs12452497 was significantly associated with a decreased risk in both phases, resulting in a 40% reduction in the pooled population (95% CI:0.43–0.83, P = 0.0018). In total, seven variants were significant for risk in the pooled analysis. Gene-based analysis supported the involvement of TRAF2, MAP2K4, and MAP3K5 as mediating complications risk and a highly significant trend was identified between the number of risk genotypes and complications risk (P = 1.63 × 10−8). An inverse relationship was observed between association with clinical outcomes and complications for two variants. These results implicate the TNF/TRAF2/ASK1/p38 kinase pathway in modulating risk of pulmonary complications following lobectomy and may be useful biomarkers to identify patients at high risk.
Marginal zone lymphoma (MZL) is the third most common subtype of B-cell non-Hodgkin lymphoma. Here we perform a two-stage GWAS of 1,281 MZL cases and 7,127 controls of European ancestry and identify two independent loci near BTNL2 (rs9461741, P=3.95×10−15) and HLA-B (rs2922994, P=2.43×10−9) in the HLA region significantly associated with MZL risk. This is the first evidence that genetic variation in the major histocompatibility complex influences MZL susceptibility.
NSCLC is often a lethal disease but potentially curative at early stages. In this study, we showed that genetic variants in the developmental and stem cell-related Wnt signaling pathway may influence disease recurrence and survival in early-stage NSCLC patients.
Early-stage non-small cell lung cancer (NSCLC) is potentially curative. Nevertheless, many patients will show disease recurrence after curative treatment. The Wnt signaling pathway is a developmental and stem cell pathway that plays an important role in tumorigenesis and may affect cancer progression. We hypothesize that genetic variants of the Wnt pathway may influence clinical outcome in early-stage NSCLC patients. We genotyped 441 functional and tagging single nucleotide polymorphisms (SNPs) from 54 genes of the Wnt pathway in 535 early-stage NSCLC patients treated with curative intent therapy including surgery and chemotherapy. For validation, 4 top SNPs were genotyped in 301 early-stage NSCLC patients from the Mayo Clinic. Cox proportional hazard model and combined SNP analyses were performed to identify significant SNPs correlated with recurrence-free and overall survival. Results from discovery group showed a total of 40 SNPs in 20 genes correlated with disease recurrence (P < 0.05). After correction for multiple comparisons, rs2536182 near Wnt16 remained significant (q < 0.1), which was validated in the replication population. Thirty-nine SNPs in 16 genes correlated with overall survival (P < 0.05) in the discovery group, and seven remained significant after multiple comparisons were considered (q < 0.1). In patients receiving surgery-only treatment, rs10898563 of FZD4 gene was associated with both recurrence-free and overall survival. Joint SNP analyses identified predictive markers for recurrence stratified by treatment. Our findings suggest inherited genetic variation in the Wnt signaling pathway may contribute to variable clinical outcomes for patients with early-stage NSCLC.
Telomere length is a heritable trait and short telomere length has been associated with multiple chronic diseases. We investigated the relationship of relative leukocyte telomere length (RTL) with cardiometabolic risk and performed the first GWAS and meta-analysis to identify variants influencing RTL in a population of Sikhs from South Asia.
Methods and Results
Our results revealed a significant independent association of shorter RTL with type 2 diabetes (T2D) and heart disease. Our discovery GWAS (n=1,616) was followed by Stage 1 replication of 25 top signals (P<10−6) in an additional Sikhs (n=2,397). On combined discovery and Stage 1 meta-analysis (n= 4013), we identified a novel RTL locus at chromosome 16q21 represented by an intronic variant (rs74019828) in the CSNK2A2 gene (β −0.38, P=4.5×10−8). We further tested 3 top variants by genotyping in UKCVD (Caucasians n=2,952) for Stage 2. Next we performed in silico replication of 139 top signals (p<10−5) in UKTWIN, NHS, PLCO and MDACC (n=10,033) and joint meta-analysis (n=16,998). The observed signal in CSNK2A2 was confined to South Asians and could not be replicated in Caucasians due to significant difference in allele frequencies (P<0.001). CSNK2A2 phosphorylates TRF1 and plays an important role for regulation of telomere length homoeostasis.
By identification of a novel signal in telomere pathway genes, our study provides new molecular insight into the underlying mechanism that may regulate telomere length and its association with human aging and cardiometabolic pathophysiology.
telomere genetics; type 2 diabetes mellitus; Genome Wide Association Study; cardiovascular disease
Wnt/β-catenin pathway alterations in non-small cell lung cancer (NSCLC) are associated with poor prognosis and resistance. In 598 stage III-IV NSCLC patients receiving platinum-based chemotherapy at MD Anderson Cancer Center (MDACC), we correlated survival with 441 host SNPs in 50 Wnt pathway genes. We then assessed the most significant SNPs in 240 Mayo Clinic patients receiving platinum-based chemotherapy for advanced NSCLC, 127 MDACC patients receiving platinum-based adjuvant chemotherapy and 340 early stage MDACC patients undergoing surgery alone (cohorts 2–4). In multivariate analysis, survival correlates with SNPs for AXIN2 (rs11868547 and rs4541111, of which rs11868547 was assessed in cohorts 2–4), Wnt-5B (rs12819505), CXXC4 (rs4413407) and WIF-1 (rs10878232). Median survival was 19.7, 15.6, and 10.7 months for patients with 1, 2, and 3–5 unfavorable genotypes, respectively (p= 3.8×10−9). Survival tree analysis classified patients into two groups (MST 11.3 vs 17.3 months, p=4.7×10−8). None of the SNPs achieved significance in cohorts 2–4; however, there was a trend in the same direction as cohort 1 for 3 of the SNPs. Using online databases, we found rs10878232 displayed expression quantitative trait loci (eQTL) correlation with the expression of LEMD3, a neighboring gene previously associated with NSCLC survival. In conclusion, results from cohort 1 provide further evidence for an important role for Wnt in NSCLC. Investigation of Wnt inhibitors in advanced NSCLC would be reasonable. Lack of a SNP association with outcome in cohorts 2–4 could be due to low statistical power, impact of patient heterogeneity, or false positive observations in cohort 1.
Wnt; pharmacogenetics; NSCLC
The fibroblast growth factor (FGF) and FGF receptor (FGFR) axis plays a critical role in tumor-igenesis, but little is known of its influence in ovarian cancer. We sought to determine the association of genetic variants in the FGF pathway with risk, therapeutic response, and survival of patients with ovarian cancer.
We matched 339 non-Hispanic white ovarian cancer cases with 349 healthy controls and geno-typed them for 183 single-nucleotide polymorphisms (SNPs) from 24 FGF (fibroblast growth factor) and FGFR (fibroblast growth factor receptor) genes. Genetic associations for the main effect, gene– gene interactions, and the cumulative effect were determined.
Multiple SNPs in the FGF–FGFR axis were associated with an increased risk of ovarian cancer. In particular, FGF1 [fibroblast growth factor 1 (acidic)] SNP rs7727832 showed the most significant association with ovarian cancer (odds ratio, 2.27; 95% CI, 1.31–3.95). Ten SNPs were associated with a reduced risk of ovarian cancer. FGF18 (fibroblast growth factor 18) SNP rs3806929, FGF7 (fibroblast growth factor 7) SNP rs9920722, FGF23 (fibroblast growth factor 23) SNP rs12812339, and FGF5 (fibroblast growth factor 5) SNP rs3733336 were significantly associated with a favorable treatment response, with a reduction of risk of nonresponse of 40% to 60%. Eleven SNPs were significantly associated with overall survival. Of these SNPs, FGF23 rs7961824 was the most significantly associated with improved prognosis (hazard ratio, 0.55; 95% CI, 0.39 – 0.78) and was associated with significantly longer survival durations, compared with individuals with the common genotype at this locus (58.1 months vs. 38.0 months, P = 0.005). Survival tree analysis revealed FGF2 rs167428 as the primary factor contributing to overall survival.
Significant associations of genetic variants in the FGF pathway were associated with ovarian cancer risk, therapeutic response, and survival. The discovery of multiple SNPs in the FGF–FGFR pathway provides a molecular approach for risk assessment, monitoring therapeutic response, and prognosis.
Candidate gene and genome-wide association studies (GWAS) have identified 11 independent susceptibility loci associated with bladder cancer risk. To discover additional risk variants, we conducted a new GWAS of 2422 bladder cancer cases and 5751 controls, followed by a meta-analysis with two independently published bladder cancer GWAS, resulting in a combined analysis of 6911 cases and 11 814 controls of European descent. TaqMan genotyping of 13 promising single nucleotide polymorphisms with P < 1 × 10−5 was pursued in a follow-up set of 801 cases and 1307 controls. Two new loci achieved genome-wide statistical significance: rs10936599 on 3q26.2 (P = 4.53 × 10−9) and rs907611 on 11p15.5 (P = 4.11 × 10−8). Two notable loci were also identified that approached genome-wide statistical significance: rs6104690 on 20p12.2 (P = 7.13 × 10−7) and rs4510656 on 6p22.3 (P = 6.98 × 10−7); these require further studies for confirmation. In conclusion, our study has identified new susceptibility alleles for bladder cancer risk that require fine-mapping and laboratory investigation, which could further understanding into the biological underpinnings of bladder carcinogenesis.
We conducted multilevel analyses to identify potential susceptibility loci for renal cell carcinoma (RCC), which may be overlooked in traditional genome-wide association studies (GWAS). A gene set enrichment analysis was performed utilizing a GWAS dataset comprised of 894 RCC cases and 1,516 controls using GenGen, SNP ratio test, and ALIGATOR. The antigen processing and presentation pathway was consistently significant (P = 0.001, = 0.004, and < 0.001, respectively). Versatile gene-based association study approach was applied to the top-ranked pathway and identified the driven genes. By comparing the expression of the genes in RCC tumor and adjacent normal tissues, we observed significant overexpression of HLA genes in tumor tissues, which was also supported by public databases. We sought to validate genetic variants in antigen processing and presentation pathway in an independent GWAS dataset comprised of 1,311 RCC cases and 3,424 control subjects from the National Cancer Institute; one SNP, rs1063355, was significant in both populations (Pmeta-analysis = 9.15 × 10−4, Pheterogeneity = 0.427). Strong correlation indicated that rs1063355 was a cis-expression quantitative trait loci which associated with HLA-DQB1 expression (Spearman's rank r = −0.59, p = 5.61 × 10−6). The correlation was further validated using a public dataset. Our results highlighted the role of immune-related pathway and genes in the etiology of RCC.
RCC; GWAS; GSEA; eQTL
Marginal zone lymphoma (MZL) is the third most common subtype of B-cell non-Hodgkin lymphoma. Here we perform a two-stage GWAS of 1,281 MZL cases and 7,127 controls of European ancestry and identify two independent loci near BTNL2 (rs9461741, P=3.95 × 10−15) and HLA-B (rs2922994, P=2.43 × 10−9) in the HLA region significantly associated with MZL risk. This is the first evidence that genetic variation in the major histocompatibility complex influences MZL susceptibility.
Marginal zone lymphoma (MZL) is a common subtype of B-cell non-Hodgkin lymphoma. Here the authors carry out a two-stage genome-wide association study in over 8,000 Europeans and identify two new MZL risk loci at chromosome 6p, implicating the major histocompatibility complex in the disease for the first time.
Genome-wide association studies (GWAS) of renal cell carcinoma (RCC) in populations of European ancestry have identified four susceptibility loci. No GWAS has been conducted among African Americans (AAs), who experience a higher incidence of RCC. We conducted a GWAS in which we analyzed 1,136,723 common single-nucleotide polymorphisms (SNPs) among 255 cases and 375 controls of African ancestry, and further investigated 16 SNPs in a replication set (140 cases, 543 controls). The 12p11.23 variant rs10771279, located 77kb from the European-ancestry RCC marker rs718314, was associated with RCC risk in the GWAS (P=1.2 × 10−7) but did not replicate (P=0.99). Consistent with European-ancestry findings, the A allele of rs7105934 on 11q13.3 was associated with decreased risk [odds ratio (OR)=0.76, 95% confidence interval (CI)=0.64–0.91; P=0.0022]. The frequency of this allele was higher than that observed in the European-ancestry GWAS (0.56 and 0.07 respectively among controls). The rs7105934 association was stronger for clear cell RCC (ccRCC: OR=0.56; P=7.4 × 10−7) and absent for cases of other or unknown histology (OR=1.02; P=0.86). Analyses of rs7105934 by subtype among European-ancestry participants from these studies yielded similar findings (ORs 0.69 and 0.92 respectively). This study provides, to our knowledge, the first evidence that rs7105934 is an RCC susceptibility locus among AAs. Our finding that the association with this SNP may be specific to ccRCC is novel and requires additional investigation. Additional investigation of rs10771279 and other suggestive GWAS findings is also needed.
We conducted imputation to the 1000 Genomes Project of four genome-wide association studies of lung cancer in populations of European ancestry (11,348 cases and 15,861 controls) and genotyped an additional 10,246 cases and 38,295 controls for follow-up. We identified large-effect genome-wide associations for squamous lung cancer with the rare variants of BRCA2-K3326X (rs11571833; odds ratio [OR]=2.47, P=4.74×10−20) and of CHEK2-I157T (rs17879961; OR=0.38 P=1.27×10−13). We also showed an association between common variation at 3q28 (TP63; rs13314271; OR=1.13, P=7.22×10−10) and lung adenocarcinoma previously only reported in Asians. These findings provide further evidence for inherited genetic susceptibility to lung cancer and its biological basis. Additionally, our analysis demonstrates that imputation can identify rare disease-causing variants having substantive effects on cancer risk from pre-existing GWAS data.