FinnGen provides genetic insights from a well-phenotyped isolated population

Population isolates such as those in Finland benefit genetic research because deleterious alleles are often concentrated on a small number of low-frequency variants (0.1% ≤ minor allele frequency < 5%). These variants survived the founding bottleneck rather than being distributed over a large number of ultrarare variants. Although this effect is well established in Mendelian genetics, its value in common disease genetics is less explored^1,2. FinnGen aims to study the genome and national health register data of 500,000 Finnish individuals. Given the relatively high median age of participants (63 years) and the substantial fraction of hospital-based recruitment, FinnGen is enriched for disease end points. Here we analyse data from 224,737 participants from FinnGen and study 15 diseases that have previously been investigated in large genome-wide association studies (GWASs). We also include meta-analyses of biobank data from Estonia and the United Kingdom. We identified 30 new associations, primarily low-frequency variants, enriched in the Finnish population. A GWAS of 1,932 diseases also identified 2,733 genome-wide significant associations (893 phenome-wide significant (PWS), P < 2.6 × 10^-11) at 2,496 (771 PWS) independent loci with 807 (247 PWS) end points. Among these, fine-mapping implicated 148 (73 PWS) coding variants associated with 83 (42 PWS) end points. Moreover, 91 (47 PWS) had an allele frequency of <5% in non-Finnish European individuals, of which 62 (32 PWS) were enriched by more than twofold in Finland. These findings demonstrate the power of bottlenecked populations to find entry points into the biology of common diseases through low-frequency, high impact variants.

Multiomic Characterization of High-Grade Serous Ovarian Carcinoma Enables High-Resolution Patient Stratification

PURPOSE

High-grade serous ovarian carcinoma (HGSOC) is the most common ovarian cancer type; most patients experience disease recurrence that accumulates chemoresistance, leading to treatment failure. Genomic and transcriptomic features have been associated with differential outcome and treatment response. However, the relationship between events at the gene sequence, copy number, and gene-expression levels remains poorly defined.

EXPERIMENTAL DESIGN

We perform multiomic characterization of a large HGSOC cohort (n = 362) with detailed clinical annotation to interrogate the relationship between patient subgroups defined by specific molecular events.

RESULTS

BRCA2-mutant (BRCA2m) and EMSY-overexpressing cases demonstrated prolonged survival [multivariable hazard ratios (HR) 0.40 and 0.51] and significantly higher first- and second-line chemotherapy response rate. CCNE1-gained (CCNE1g) cases demonstrated underrepresentation of FIGO stage IV cases, with shorter survival but no significant difference in treatment response. We demonstrate marked overlap between the TCGA- and Tothill-derived subtypes. IMR/C2 cases displayed higher BRCA1/2m frequency (25.5%, 32.5%) and significantly greater immune cell infiltration, whereas PRO/C5 cases had the highest CCNE1g rate (23.9%, 22.2%) and were uniformly low in immune cell infiltration. The survival benefit for cases with aberrations in homologous recombination repair (HRR) genes was apparent across all transcriptomic subtypes (HR range, 0.48-0.68). There was significant co-occurrence of RB loss and HRR gene aberrations; RB loss was further associated with favorable survival within HRR-aberrant cases (multivariable HR, 0.50).

CONCLUSIONS

These data paint a high-resolution picture of the molecular landscape in HGSOC, better defining patients who may benefit most from specific molecular therapeutics and highlighting those for whom novel treatment strategies are needed to improve outcomes.

Integrated analyses of growth differentiation factor-15 concentration and cardiometabolic diseases in humans

Growth differentiation factor-15 (GDF15) is a stress response cytokine that is elevated in several cardiometabolic diseases and has attracted interest as a potential therapeutic target. To further explore the association of GDF15 with human disease, we conducted a broad study into the phenotypic and genetic correlates of GDF15 concentration in up to 14,099 individuals. Assessment of 772 traits across 6610 participants in FINRISK identified associations of GDF15 concentration with a range of phenotypes including all-cause mortality, cardiometabolic disease, respiratory diseases and psychiatric disorders, as well as inflammatory markers. A meta-analysis of genome-wide association studies (GWAS) of GDF15 concentration across three different assay platforms (n=14,099) confirmed significant heterogeneity due to a common missense variant (rs1058587; p.H202D) in GDF15, potentially due to epitope-binding artefacts. After conditioning on rs1058587, statistical fine mapping identified four independent putative causal signals at the locus. Mendelian randomisation (MR) analysis found evidence of a causal relationship between GDF15 concentration and high-density lipoprotein (HDL) but not body mass index (BMI). Using reverse MR, we identified a potential causal association of BMI on GDF15 (IVW pFDR = 0.0040). Taken together, our data derived from human population cohorts do not support a role for moderately elevated GDF15 concentrations as a causal factor in human cardiometabolic disease but support its role as a biomarker of metabolic stress.

Dynamic biomarker and imaging changes from a phase II study of pre- and post-surgical sunitinib

OBJECTIVE

To explore translational biological and imaging biomarkers for sunitinib treatment before and after debulking nephrectomy in the NeoSun (European Union Drug Regulating Authorities Clinical Trials Database [EudraCT] number: 2005-004502-82) single-centre, single-arm, single-agent, Phase II trial.

PATIENTS AND METHODS

Treatment-naïve patients with metastatic renal cell carcinoma (mRCC) received 50 mg once daily sunitinib for 12 days pre-surgically, then post-surgery on 4 week-on, 2 week-off, repeating 6-week cycles until disease progression in a single arm phase II trial. Structural and dynamic contrast-enhanced magnet resonance imaging (DCE-MRI) and research blood sampling were performed at baseline and after 12 days. Computed tomography imaging was performed at baseline and post-surgery then every two cycles. The primary endpoint was objective response rate (Response Evaluation Criteria In Solid Tumors [RECIST]) excluding the resected kidney. Secondary endpoints included changes in DCE-MRI of the tumour following pre-surgery sunitinib, overall survival (OS), progression-free survival (PFS), response duration, surgical morbidity/mortality, and toxicity. Translational and imaging endpoints were exploratory.

RESULTS

A total of 14 patients received pre-surgery sunitinib, 71% (10/14) took the planned 12 doses. All underwent nephrectomy, and 13 recommenced sunitinib postoperatively. In all, 58.3% (seven of 12) of patients achieved partial or complete response (PR or CR) (95% confidence interval 27.7-84.8%). The median OS was 33.7 months and median PFS was 15.7 months. Amongst those achieving a PR or CR, the median response duration was 8.7 months. No unexpected surgical complications, sunitinib-related toxicities, or surgical delays occurred. Within the translational endpoints, pre-surgical sunitinib significantly increased necrosis, and reduced cluster of differentiation-31 (CD31), Ki67, circulating vascular endothelial growth factor-C (VEGF-C), and transfer constant (KTrans , measured using DCE-MRI; all P < 0.05). There was a trend for improved OS in patients with high baseline plasma VEGF-C expression (P = 0.02). Reduction in radiological tumour volume after pre-surgical sunitinib correlated with high percentage of solid tumour components at baseline (Spearman's coefficient ρ = 0.69, P = 0.02). Conversely, the percentage tumour volume reduction correlated with lower baseline percentage necrosis (coefficient = -0.51, P = 0.03).

CONCLUSION

Neoadjuvant studies such as the NeoSun can safely and effectively explore translational biological and imaging endpoints.

The WIRE study a phase II, multi-arm, multi-centre, non-randomised window-of-opportunity clinical trial platform using a Bayesian adaptive design for proof-of-mechanism of novel treatment strategies in operable renal cell cancer - a study protocol

BACKGROUND

Window-of-opportunity trials, evaluating the engagement of drugs with their biological target in the time period between diagnosis and standard-of-care treatment, can help prioritise promising new systemic treatments for later-phase clinical trials. Renal cell carcinoma (RCC), the 7th commonest solid cancer in the UK, exhibits targets for multiple new systemic anti-cancer agents including DNA damage response inhibitors, agents targeting vascular pathways and immune checkpoint inhibitors. Here we present the trial protocol for the WIndow-of-opportunity clinical trial platform for evaluation of novel treatment strategies in REnal cell cancer (WIRE).

METHODS

WIRE is a Phase II, multi-arm, multi-centre, non-randomised, proof-of-mechanism (single and combination investigational medicinal product [IMP]), platform trial using a Bayesian adaptive design. The Bayesian adaptive design leverages outcome information from initial participants during pre-specified interim analyses to determine and minimise the number of participants required to demonstrate efficacy or futility. Patients with biopsy-proven, surgically resectable, cT1b+, cN0-1, cM0-1 clear cell RCC and no contraindications to the IMPs are eligible to participate. Participants undergo diagnostic staging CT and renal mass biopsy followed by treatment in one of the treatment arms for at least 14 days. Initially, the trial includes five treatment arms with cediranib, cediranib + olaparib, olaparib, durvalumab and durvalumab + olaparib. Participants undergo a multiparametric MRI before and after treatment. Vascularised and de-vascularised tissue is collected at surgery. A ≥ 30% increase in CD8+ T-cells on immunohistochemistry between the screening and nephrectomy is the primary endpoint for durvalumab-containing arms. Meanwhile, a reduction in tumour vascular permeability measured by Ktrans on dynamic contrast-enhanced MRI by ≥30% is the primary endpoint for other arms. Secondary outcomes include adverse events and tumour size change. Exploratory outcomes include biomarkers of drug mechanism and treatment effects in blood, urine, tissue and imaging.

DISCUSSION

WIRE is the first trial using a window-of-opportunity design to demonstrate pharmacological activity of novel single and combination treatments in RCC in the pre-surgical space. It will provide rationale for prioritising promising treatments for later phase trials and support the development of new biomarkers of treatment effect with its extensive translational agenda.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT03741426 / EudraCT: 2018-003056-21 .

Structural Variants at the BRCA1/2 Loci are a Common Source of Homologous Repair Deficiency in High-grade Serous Ovarian Carcinoma

PURPOSE

The abundance and effects of structural variation at BRCA1/2 in tumors are not well understood. In particular, the impact of these events on homologous recombination repair deficiency (HRD) has yet to be demonstrated.

EXPERIMENTAL DESIGN

Exploiting a large collection of whole-genome sequencing data from high-grade serous ovarian carcinoma (N = 205) together with matched RNA sequencing for the majority of tumors (N = 150), we have comprehensively characterized mutation and expression at BRCA1/2.

RESULTS

In addition to the known spectrum of short somatic mutations (SSM), we discovered that multi-megabase structural variants (SV) were a frequent, unappreciated source of BRCA1/2 disruption in these tumors, and we found a genome-wide enrichment for large deletions at the BRCA1/2 loci across the cohort. These SVs independently affected a substantial proportion of patients (16%) in addition to those affected by SSMs (24%), conferring HRD and impacting patient survival. We also detail compound deficiencies involving SSMs and SVs at both loci, demonstrating that the strongest risk of HRD emerges from combined SVs at both BRCA1 and BRCA2 in the absence of SSMs. Furthermore, these SVs are abundant and disruptive in other cancer types.

CONCLUSIONS

These results extend our understanding of the mutational landscape underlying HRD, increase the number of patients predicted to benefit from therapies exploiting HRD, and suggest there is currently untapped potential in SV detection for patient stratification.

The kidney hepcidin/ferroportin axis controls iron reabsorption and determines the magnitude of kidney and systemic iron overload

The hepcidin/ferroportin axis controls systemic iron homeostasis by regulating iron acquisition from the duodenum and reticuloendothelial system, respective sites of iron absorption and recycling. Ferroportin is also abundant in the kidney, where it has been implicated in tubular iron reabsorption. However, it remains unknown whether endogenous hepcidin regulates ferroportin-mediated iron reabsorption under physiological conditions, and whether such regulation is important for kidney and/or systemic iron homeostasis. To address these questions, we generated a novel mouse model with an inducible kidney-tubule specific knock-in of fpnC326Y, which encodes a hepcidin-resistant ferroportin termed FPNC326Y. Under conditions of normal iron availability, female mice harboring this allele had consistently decreased kidney iron but only transiently increased systemic iron indices. Under conditions of excess iron availability, male and female mice harboring this allele had milder kidney iron overload, but greater systemic iron overload relative to controls. Additionally, despite comparable systemic iron overload, kidney iron overload occurred in wild type mice fed an iron-loaded diet but not in hemochromatosis mice harboring a ubiquitous knock-in of fpnC326Y. Thus, our study demonstrates that endogenous hepcidin controls ferroportin-mediated tubular iron reabsorption under physiological conditions. It also shows that such control is important for both kidney and systemic iron homeostasis in the context of iron overload.

The contribution of germline DNA damage response mutations on prostate cancer risk and prognosis: A UK Biobank whole-exome analysis

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Background: Germline mutations in DNA Damage Response (DDR) genes such as BRCA2 and ATM have been associated with prostate cancer risk and aggressiveness. These associations are largely based on studies that ascertain for cancer diagnosis and family history and provide risk estimates with limited population-level accuracy. Here we evaluate the clinical significance of germline pathogenic variants in 20 DDR genes and a high-risk susceptibility coding variant in HOXB13 using whole exome sequences from (1) the UK Biobank (UKBB), a population-based cohort (300,000 participants) and (2) patients recruited in AZ clinical trials. Methods: Whole exomes from 6,987 prostate cancer patients (5,921 UKBB and 1,066 AZ) and 88,499 cancer-free males were analysed. Known and novel pathogenic variants were identified and associations with disease risk, age of onset, family history, response to hormonal therapy and overall survival were estimated (multiplicity corrected P value < 0.005). Results: HOXB13 G48E (1.36%), ATM (1.03%) and BRCA2 (0.99%) were the largest contributors to prostate cancer risk, each conferring an increase of ~4-fold, followed by CHEK2 with a moderate contribution (0.46%). No significant contributions to prostate cancer risk were observed for any of the other genes analysed. Family history of prostate cancer was not significantly enriched in any of the gene subpopulations of prostate cancer carriers and compared with non-carriers, there was no significant difference in the median age of disease onset. Analysis of clinical outcomes showed that BRCA2 carriers had a 4-fold increased risk of death (Cox PH HR p = 4.11E-12) and poorer overall survival (Log-Rank p = 4.60E-14), with 88% dying from prostate cancer compared to 49% of non- BRCA2 carriers (UKBB analysis). BRCA2 pathogenic mutations were also associated with early failure to hormonal therapy (Cox PH HR 2.38; p = 9.48E-04; AZ cohort analysis). HOXB13, ATM and CHEK2 mutations were not significantly associated with clinical outcomes. Conclusions: This is the largest study to date providing population-based estimates of prostate cancer risk and prognosis, highlighting BRCA2 carriers as a population in clinical need of early identification and targeted intervention. Updated analyses with data from the full 450,000 UKBB participants (9,000 prostate cancers) will be presented.

Abstract 3522: Population estimates of prostate cancer risk and prognosis for carriers of germline pathogenic variants in disease implicated genes, using 200,000 UK Biobank whole exomes

Germline deleterious variants in DNA Damage Response (DDR) genes such as BRCA2 and ATM have been associated with high risk of disease, poor prognosis and the development of metastatic prostate cancer. These associations have been reported in studies of individuals selected for family history or cancer diagnosis and, therefore, with limited potential to estimate accurate population disease risk. Here we evaluate the clinical significance of germline deleterious variants in 20 DDR genes and four known prostate cancer susceptibility coding variants in POUF51B, HOXB13 and KLK3 using germline whole exome sequencing (WES) data from (1) the UK Biobank (UKBB), a population-based cohort (200,000 with WES) and (2) prostate cancer patients recruited in AZ clinical trials.

WES data from 4,975 prostate cancer patients (3,954 UKBB and 1,021 AZ) and 44,818 controls (cancer-free UKBB male participants) was analysed. We identified 218 carriers with deleterious variants in DDR genes. Of these, 190 carried known pathogenic variants (ClinVar, BIC and ENIGMA consortium) and 28 had novel, pathogenic protein truncating variants. Population disease risk, risk of metastatic disease and overall survival (UKBB patients only) were estimated (multiplicity corrected P value &lt;0.005).

Analysis of deleterious variants revealed significant associations with prostate cancer risk for ATM (OR 4.14, 95% CI 2.97-5.72, p=1.77E-15) and BRCA2 (OR 3.47, 95% CI 2.49-4.77, p=1.70E-12), each contributing to a similar number of cases (1.15% vs 1.11%, respectively). Damaging variants within the remaining DDR genes were less frequent with none reaching significance. A trend for increased disease risk was observed in CHEK2 carriers (OR 2.03, 95% CI 1.18-3.33, p=9.30E-03). Coding variant analysis confirmed associations between variants in POU5F1B, HOXB13 and KLK3 and prostate cancer risk. HOXB13 G84E carriers (1.29%) were at comparable risk to BRCA2 and ATM carriers (OR 3.88, 95% CI 2.85-5.24, p=4.29E-16).

Assesment of patient outcomes showed that BRCA2 carriers were more likely to develop metastatic disease (OR 3.32, 95% CI 1.74-6.45, p=9.94E-05) and had poorer overall survival (Log Rank p=1.33E-08; 85% of patients dying from prostate cancer vs 53% of non BRCA2 carriers). No other gene reached significance. A trend towards poorer survival was observed for PALB2 carriers (Log Rank p=7.91E-03) suggesting that PALB2 could act as a modifier gene once the disease has developed.

This is the largest study to date providing population based estimates of prostate cancer risk, metastasis and survival highlighting mutations in BRCA2, ATM and HOXB13 G48E as the largest contributors to disease risk and confirming the poor prognosis of BRCA2 carriers. Analyses will be updated with data from the full 500,000 UKBB participants (expected January 2020; total of 11,000 prostate cancer cases).

Citation Format: Niedzica Camacho, Liqin Dong, Athena Matakidou. Population estimates of prostate cancer risk and prognosis for carriers of germline pathogenic variants in disease implicated genes, using 200,000 UK Biobank whole exomes [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3522.

Abstract CT217: POLO: Homologous recombination repair gene mutations (HRRm) in metastatic pancreatic cancer (mPaC) tumors

mPaC patients (pts) with HRRm, including BRCA1 and/or BRCA2 mutations (BRCAm), derive benefit from platinum-based treatment (Pishvaian. J Clin Oncol 2019). In the Phase III POLO trial (NCT02184195) maintenance olaparib conferred a progression-free survival benefit over placebo in pts with a germline (g) BRCAm and mPaC. A prespecified exploratory analysis was conducted to determine the prevalence of tumor tissue biomarkers in pts screened for inclusion in POLO.

Archival tumor samples were provided if available and, irrespective of subsequent pt randomization, DNA was analyzed using a gene panel from Foundation Medicine Inc. (FMI) or exome sequencing by Human Longevity Inc. (HLI). Results were compared with cohorts from FMI (mPaC; FoundationOne CDx panel) and The Cancer Genome Atlas (TCGA; primary and mPaC; exome sequencing).

Tumor samples from 187/3315 (5.6%) pts screened for entry into POLO were available and sequenced. Prevalence of tumor HRRm in the POLO, FMI and TCGA cohorts are presented in the Table. The higher BRCAm prevalence observed in the POLO and FMI cohorts compared with TCGA may be due to sample size or differences in ethnicity or tumor sample location (primary vs metastatic). Mutations in BRCA2, BRCA1 and ATM were most common and were generally mutually exclusive. The prevalence of somatic (s) BRCAm in POLO was consistent with the FMI dataset (~2%); g and s BRCAm were mutually exclusive. Of the HRRm observed in non-BRCA genes, mutations in ATM were most prevalent. Prevalence of mutations in non-HRR genes (CDKN2A, SMAD4, KRAS, TP53) in POLO was consistent with that seen in other pancreatic cancer cohorts.

TablePrevalence, %*POLO (N=187)FMI (N=1046)TCGA (N=146)BRCA24.84.32.1BRCA13.22.10ATM5.32.55.5PALB21.10.90.7CDK1200.50RAD51C00.10RAD51B00.20RAD54L00.20RAD51D00.20BRIP10.50.30.7FANCI00.30FANCL0.50.10BARD10.50.20.7CHEK100.20CHEK200.62.1Any HRR15.512.011.0Non-BRCA HRR7.55.68.9*Some tumors had a mutation in &gt;1 gene

In summary, based on the subgroup of pts with analyzed tumor tissue, the genetic profile of the screened POLO population is reflective of that seen in the overall pancreatic cancer population. ~8% of pts had tumors harboring a BRCAm, with mutations in BRCA2 more prevalent than BRCA1; ~7% of pts had tumors harboring a non-BRCA HRRm, most commonly in ATM (~5%).

Citation Format: Zhongwu Lai, Talia Golan, Hedy L. Kindler, Brian Dougherty, Athena Matakidou, Liqin Dong, Gershon Locker, Elizabeth A. Harrington. POLO: Homologous recombination repair gene mutations (HRRm) in metastatic pancreatic cancer (mPaC) tumors [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr CT217.

Treatment patterns and health outcomes in metastatic renal cell carcinoma patients treated with targeted systemic therapies in the UK

BACKGROUND

Patients with metastatic renal cell carcinoma (mRCC) treated with targeted systemic therapies have demonstrated favourable outcomes in randomised controlled trials, however real-world evidence is limited. Thus, this study aimed to determine the effectiveness of targeted systemic therapies for patients with mRCC in routine clinical practice in the UK.

METHODS

A retrospective, observational, longitudinal study based on chart review of newly diagnosed adult mRCC patients treated at two UK hospitals from 2008 to 2015 was conducted. Targeted systemic therapies recommended for use in mRCC patients were evaluated across first to third lines of therapy (1LOT-3LOT). Important exclusions were treatment with cytokine therapy and within non-standard of care clinical trials. Primary outcome measure was overall survival (OS); data were analysed descriptively and using Kaplan-Meyer analysis.

RESULTS

652 patients (65.3% male, 35.0% ≥70 years) were included. In 1LOT, 98.5% of patients received sunitinib or pazopanib. In 2LOT and 3LOT, 99.0 and 94.4% received axitinib or everolimus. Median OS was 12.9, 6.5 and 5.9 months at 1LOT, 2LOT and 3LOT respectively. Estimated OS at 1-year was 52.4% (95% CI: 48.6-56.4%) in 1LOT, 31.5% (25.2-39.5%) in 2LOT and 23.8% (10.1-55.9%) in 3LOT. Median OS from 1LOT in favourable, intermediate and poor MSKCC were 39.7, 15.8 and 6.1 months respectively.

CONCLUSIONS

In this study, treatment was consistent with current National Institute for Health and Care Excellence (NICE) guidelines for mRCC patients. Although the study population favoured poorer prognosis patients, outcomes were more favourable than those for England at the same time. However, overall survival in this 'real-world' population remains poor and indicates significant unmet need for effective and safe treatment options to improve survival among mRCC patients.

Molecular biomarkers to identify patients (pts) who may benefit from durvalumab (D; anti-PD-L1) ± tremelimumab (T; anti-CTLA-4) in recurrent/metastatic head and neck squamous cell carcinoma (R/M HNSCC) from HAWK and CONDOR studies

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Background: Baseline tumor and germline biomarkers in R/M HNSCC were analyzed for predictive potential in pts benefitting from D or D+T. Methods: In HAWK (NCT02207530), 112 pts (PD-L1 tumor cells [TC]≥25%) received D (10 mg/kg Q2W for ≤12 m); in CONDOR (NCT02319044), 67 pts (PD-L1 TC < 25%) received D (10 mg/kg Q2W for ≤12 m), 133 pts received D+T (D 20 mg/kg Q4W, T 1 mg/kg Q4W for ≤12 m), and 67 pts received T (10 mg/kg Q4W [7 doses] then Q12W [2 doses] for ≤12 m) VENTANA PD-L1 (SP263) Assay determined PD-L1 status. Paired FFPE archival tumor and PBMC samples (as germline control) in the HAWK and CONDOR trials were evaluated by whole exome sequencing (WES). Tumor mutation burden (TMB) was number of somatic mutations/megabase. HLA class I types were obtained via WES of PBMCs (CONDOR only). HPV and neutrophil-to-lymphocyte ratio (NLR) were tested locally in CONDOR. Wilcoxon, log-rank tests, and COX-PH models were used. Pooled D & D+T data were analyzed unless noted. Results: 153 pts had paired evaluable FFPE tumor and PBMC samples (HAWK, n = 48; CONDOR, n = 105). TMB distributions were similar between studies ( P= 0.43). TMB correlated with smoking ( P= 0.02) but not HPV ( P= 0.24), NLR ( P= 0.66), or PD-L1 status ( P= 0.43). Overall, high TMB (≥upper tertile) trended with longer OS vs low TMB in all evaluable pts (N = 153; 9.0 vs 5.6 m; HR = 0.70; 95% CI = 0.48-1.01); P= 0.06). In HAWK, there was no association of TMB with OS. In CONDOR, pts (D and D+T arms) with high TMB vs low had significantly longer OS (N = 76; 16.3 vs 5.3 m; HR = 0.53; 95% CI = 0.31-0.92). TMB and OS association was further assessed by increasing TMB cutoffs. Improved HRs trended with higher cutoffs; cutoffs ≥upper quartile significantly linked to OS.TMB was not associated with PFS or ORR. Pts with low PD-L1 and low TMB had worse OS compared to pts with high PD-L1 or high TMB. Pts with high NLR (≥median) and low TMB had significantly worse OS than pts with low NLR and high TMB (HR = 2.63, P< 0.001). Analysis of germline HLA alleles revealed significantly poorer survival for carriers of the HLA-B*15:01 allele (9.4%) (HLA-B variant status did not affect TMB and OS association in CONDOR). Germline HLA heterozygosity did not impact OS. Pts with mutations in ATM (5%), a DNA damage repair gene, also trended with prolonged OS. Conclusions: TMB is a possible predictive biomarker of IO HNSCC therapy. Combined analysis of NLR and TMB may provide additional PD-L1 data in assessing pts most likely to have long-term benefit. Clinical trial information: NCT002207530, NCT02319044 .

Comprehensive characterization of cell-free tumor DNA in plasma and urine of patients with renal tumors

BACKGROUND

Cell-free tumor-derived DNA (ctDNA) allows non-invasive monitoring of cancers, but its utility in renal cell cancer (RCC) has not been established.

METHODS

Here, a combination of untargeted and targeted sequencing methods, applied to two independent cohorts of patients (n = 91) with various renal tumor subtypes, were used to determine ctDNA content in plasma and urine.

RESULTS

Our data revealed lower plasma ctDNA levels in RCC relative to other cancers of similar size and stage, with untargeted detection in 27.5% of patients from both cohorts. A sensitive personalized approach, applied to plasma and urine from select patients (n = 22) improved detection to ~ 50%, including in patients with early-stage disease and even benign lesions. Detection in plasma, but not urine, was more frequent amongst patients with larger tumors and in those patients with venous tumor thrombus. With data from one extensively characterized patient, we observed that plasma and, for the first time, urine ctDNA may better represent tumor heterogeneity than a single tissue biopsy. Furthermore, in a subset of patients (n = 16), longitudinal sampling revealed that ctDNA can track disease course and may pre-empt radiological identification of minimal residual disease or disease progression on systemic therapy. Additional datasets will be required to validate these findings.

CONCLUSIONS

These data highlight RCC as a ctDNA-low malignancy. The biological reasons for this are yet to be determined. Nonetheless, our findings indicate potential clinical utility in the management of patients with renal tumors, provided improvement in isolation and detection approaches.

Abstract 749: Multi-layer molecular characterization of high grade serous ovarian carcinomas

High grade serous ovarian carcinomas (HGSOCs) are molecularly and clinically heterogeneous malignancies. Currently, molecular stratification of patient care is limited to tumors rendered homologous recombination deficient (HRD) by BRCA1/2 mutation (BRCAm). Here we explore the overlap, interplay and clinical impact of molecular subgrouping layers in a cohort of 362 FFPE HGSOCs. We overlay genomic subgrouping and tumor-infiltrating lymphocyte (TIL) burden with the three transcriptionally-defined subtypes (Immune, Angio and AngioImmune) we have previously reported as associated with survival and bevacizumab sensitivity.

The BRCAm group, the Immune subtype and those with high CD8+ TIL burden demonstrated prolonged overall survival (OS) as previously reported. The OS benefit of CD8+ TILs was abrogated in the context of gross residual disease following debulking [multivariable hazard ratio (mHR)=0.51 (0.34-0.78) vs 0.93 (0.76-1.52)]. BRCAwild-type patients demonstrating high expression of EMSY, encoding the BRCA2-binding protein EMSY, demonstrated prolonged OS [mHR=0.48 (0.29-0.79)]. BRCA2m and high-EMSY patients displayed greater chemosensitivity (first-line CA125-CR 94.4% and 81.3% vs 48.2%, P&lt;0.001 and P=0.016; CA125-CR at relapse 58.3% and 50.0% vs 14.3%, P=0.002 and P=0.015).

There was significant enrichment and depletion of BRCAm and CCNE1-gain (CCNE1g) in the Immune subtype (28.9% vs 6.3%, P=0.001 and 9.1% vs 17.4%, P=0.050). The Angio subtype harboured far fewer CD8+ TILs compared to the Immune and AngioImmune subtypes (P&lt;0.0001 for both). The frequency of RB1 loss and nonsense TP53 mutation was significantly higher in BRCAm versus BRCA wild-type cases (33.3% vs 13.5%, P=0.020 and 21.4% vs 10.3%, P=0.019).

The clinical impact of CCNE1g was modulated by transcriptomic subtype: in the Immune group, CCNE1g was associated with poor OS [mHR=3.32 (1.49-7.41)], while in the Angio group CCNE1g cases had favourable outcome [PFS mHR=0.26 (0.10-0.68)]. CD8+ TIL burden was not associated with outcome in CCNE1g cases. Missense TP53 mutation was associated with better outcome versus TP53-null mutations in BRCAm patients [PFS mHR=0.43 (0.14-0.82)], but not in the context of HR proficiency [mHR=0.90 (0.67-1.22)].

Integrated classification using the consensus of favourable and unfavourable HR-centric (HRD favourable, HR-proficient unfavourable) and transcriptomic (Immune favourable, Angio/AngioImmune unfavourable) subgrouping yielded three groups with distinct OS [favourable vs unfavourable mHR=0.49 (0.34-0.74); favourable vs no-consensus mHR=0.64 (0.42-0.98); unfavourable vs no-consensus mHR=1.31 (1.00-1.70)].

Together, these data paint a more granular picture of the clinical impact of HGSOC subgroups and demonstrate novel candidate interactions between subgrouping layers. The poorest outcome groups represent those with most to gain from trials of novel treatment regimens.

Citation Format: Robert L. Hollis, Alison M. Meynert, Michael Churchman, Tzyvia Rye, Patricia Roxburgh, Daniel Stetson, Athena Matakidou, Brian Dougherty, J. Carl Barrett, Ruth E. March, Colin A. Semple, C. Simon Herrington, Charlie Gourley. Multi-layer molecular characterization of high grade serous ovarian carcinomas [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 749.

Dose escalation of axitinib on disease progression as a strategy in the treatment of metastatic renal cell carcinoma

Introduction

The AXIS trial established axitinib as a standard of care treatment for patients with metastatic renal cell carcinoma (mRCC) after failure of a prior tyrosine kinase inhibitor. Axitinib dosing begins at 5  mg twice daily, with escalation of doses to 7  and 10  mg after consecutive 2-week intervals if tolerated (as per the drug label). Given clinical concerns about drug-related toxicity, we have used a pragmatic strategy where dose escalations were made only after disease progression or where rapid responses were clinically required.

Methods

We performed a retrospective review of electronic health records and radiology of all patients with mRCC treated with axitinib for >2 weeks at Addenbrooke’s Hospital, Cambridge, UK, over a 37 -month period to determine the clinical and radiological effects of dose escalations made according to the above strategy.

Results

42 patients fitting these criteria were identified, 29 having ≥1  dose escalation event (DEE). 60 DEEs were identified (median of two per patient), and the objective radiological consequences of 53 DEEs could be evaluated. The disease control rate (partial response or stable disease) after the first DEE instituted for disease progression was similar to that after the second DEE (68.8% vs 70%). 56.6 % of all DEEs and 63.6 % of DEEs made as a result of disease progression resulted in disease control. The median OS from the commencement of axitinib for all dose-escalated patients was 19.9 months, and 16.5 months for the entire cohort. The mean dose (for all patients) at 90 days after starting axitinib was 5.92  mg.

Conclusion

These data suggest that dose escalation of axitinib after disease progression may be an effective dosing strategy for patients with mRCC, and this may be a preferred option in patients in whom there are particular concerns about drug-related toxicity, quality of life optimisation or healthcare-associated costs.

Loss of PBRM1 rescues VHL dependent replication stress to promote renal carcinogenesis

Inactivation of the VHL (Von Hippel Lindau) tumour suppressor has long been recognised as necessary for the pathogenesis of clear cell renal cancer (ccRCC); however, the molecular mechanisms underlying transformation and the requirement for additional genetic hits remain unclear. Here, we show that loss of VHL alone results in DNA replication stress and damage accumulation, effects that constrain cellular growth and transformation. By contrast, concomitant loss of the chromatin remodelling factor PBRM1 (mutated in 40% of ccRCC) rescues VHL-induced replication stress, maintaining cellular fitness and allowing proliferation. In line with these data we demonstrate that combined deletion of Vhl and Pbrm1 in the mouse kidney is sufficient for the development of fully-penetrant, multifocal carcinomas, closely mimicking human ccRCC. Our results illustrate how VHL and PBRM1 co-operate to drive renal transformation and uncover replication stress as an underlying vulnerability of all VHL mutated renal cancers that could be therapeutically exploited.

A phase II clinical study evaluating the efficacy and safety of neoadjuvant and adjuvant sunitinib in previously untreated patients with metastatic renal cell carcinoma (mRCC)(NeoSun)

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Background: Sunitinib improves clinical outcomes in patients (pts) with mRCC. The single arm phase II NeoSun trial was designed to investigate its added value to nephrectomy, and to explore translational biological and imaging biomarkers. Methods: Pts with mRCC, scheduled for nephrectomy, no prior systemic therapy were recruited to receive 50mg OD sunitinib for 12 days, then post-surgery on a 4 week-on, 2 week-off, repeating 6 week cycle until disease progression. Diffusion-weighted, BOLD and dynamic contrast enhanced MR imaging (DW-MRI, DCE-MRI) and research blood sample collection were performed at baseline and end of 12 days. CT Imaging was performed at baseline, pre- and post-surgery, and then every 2 cycles. The primary endpoint was objective response rate (RECIST). Secondary endpoints included changes in diffusion DW-MRI, DCE- MRI of the tumour following 12 days suntinib, overall survival (OS), progression-free survival (PFS), response duration, surgical morbidity/mortality, and toxicity. Results: 14 pts received pre-surgery sunitinib, 71% (10/14) took the planned 12 doses. All 14 underwent total nephrectomy, and 13 recommenced sunitinib post-operatively. The mean number of post-surgery cycles was 11 (range 2 – 22). 58.3% (7/12) of pts achieved confirmed response (95% CI: 27.7 - 84.8%).91.7% (11/12) achieved objective clinical benefit (95% CI: 61.5 - 99.8%). Median OS is 33.7m and median PFS is 15.7m. Amongst those achieving PR/CR, median response duration is 8.7m. No unexpected surgical or sunitinib-related toxicities or complications were observed and the mean number of days from surgery to hospital discharge was 5.9 (range 3.0 – 17.0).There was a trend forOS to be better in pts with high baseline plasma VEGF-A (p = 0.06) or VEGF-C (p = 0.02) expression. A larger % tumour volume reduction after 12 days treatment is correlated with a smaller baseline % necrosis (coefficient = -0.51, p = 0.03). Conclusions: Sunitinib is effective and safe when given before and after nephrectomy to previously untreated pts with mRCC. Neoadjuvant studies such as NeoSun can safely explore translational biological and imaging endpoints. Clinical trial information: 2005-004502-82.

A novel strategy for axitinib dosing in the treatment of metastatic renal cell carcinoma

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Background: The AXIS trial established axitinib as an effective second line treatment for patients with metastatic renal cell carcinoma (mRCC). The dosing schedule of axitinib in this trial begins at 5mg twice daily, with escalation of individual doses to 7mg and 10mg after consecutive 2 week intervals if tolerated. We observed significant drug-related toxicity using this dosing strategy, particularly after dose escalations, while clinical responses were often observed at the starting dose. We therefore switched to a pragmatic strategy where dose escalations were made only after disease progression or where a rapid response was deemed clinically pertinent. Methods: We performed a retrospective review of electronic health records and radiology of all patients with mRCC treated with axitinib for greater than 2 weeks at Addenbrooke’s Hospital, Cambridge, UK (a tertiary referral center), over a 40 month period to determine the clinical and radiological effects of dose escalations made according to the above strategy. Results: 42 patients fitting these criteria were identified; of these, 29 had at least one dose escalation event (DEE). A total of 58 DEEs were identified, with a median of 2 per patient, and the objective radiological consequences of 50 of these could be determined. The disease control rate (partial response or stable disease) after the first DEE instituted for disease progression was similar to that after the second DEE (68.8% versus 70%). 56% of all DEEs, and 62.5% of DEEs made as a result of disease progression, resulted in disease control. The median overall survival from the commencement of axitinib for all dose-escalated patients was 19.9 months, and 6.7 months for non-dose-escalated patients. The median survival for dose-escalated patients with a higher than median time on a prior tyrosine kinase inhibitor has not been reached at the time of data cut-off. The mean dose (for all patients) at 90 days after starting axitinib was 5.92 mg. Conclusions: These data suggest that dose escalation of axitinib after disease progression may be an effective dosing strategy for patients with mRCC, and may reduce toxicity through lower drug exposure. Our survival data compares favourably to the AXIS trial in a real practice population.

Cytochrome P450 Allele CYP3A7*1C Associates with Adverse Outcomes in Chronic Lymphocytic Leukemia, Breast, and Lung Cancer

CYP3A enzymes metabolize endogenous hormones and chemotherapeutic agents used to treat cancer, thereby potentially affecting drug effectiveness. Here, we refined the genetic basis underlying the functional effects of a CYP3A haplotype on urinary estrone glucuronide (E1G) levels and tested for an association between CYP3A genotype and outcome in patients with chronic lymphocytic leukemia (CLL), breast, or lung cancers. The most significantly associated SNP was rs45446698, an SNP that tags the CYP3A7*1C allele; this SNP was associated with a 54% decrease in urinary E1G levels. Genotyping this SNP in 1,008 breast cancer, 1,128 lung cancer, and 347 CLL patients, we found that rs45446698 was associated with breast cancer mortality (HR, 1.74; P = 0.03), all-cause mortality in lung cancer patients (HR, 1.43; P = 0.009), and CLL progression (HR, 1.62; P = 0.03). We also found borderline evidence of a statistical interaction between the CYP3A7*1C allele, treatment of patients with a cytotoxic agent that is a CYP3A substrate, and clinical outcome (Pinteraction = 0.06). The CYP3A7*1C allele, which results in adult expression of the fetal CYP3A7 gene, is likely to be the functional allele influencing levels of circulating endogenous sex hormones and outcome in these various malignancies. Further studies confirming these associations and determining the mechanism by which CYP3A7*1C influences outcome are required. One possibility is that standard chemotherapy regimens that include CYP3A substrates may not be optimal for the approximately 8% of cancer patients who are CYP3A7*1C carriers.

Prospective study evaluating the relative sensitivity of 18F-NaF PET/CT for detecting skeletal metastases from renal cell carcinoma in comparison to multidetector CT and 99mTc-MDP bone scintigraphy, using an adaptive trial design

BACKGROUND

The detection of occult bone metastases is a key factor in determining the management of patients with renal cell carcinoma (RCC), especially when curative surgery is considered. This prospective study assessed the sensitivity of (18)F-labelled sodium fluoride in conjunction with positron emission tomography/computed tomography ((18)F-NaF PET/CT) for detecting RCC bone metastases, compared with conventional imaging by bone scintigraphy or CT.

PATIENTS AND METHODS

An adaptive two-stage trial design was utilized, which was stopped after the first stage due to statistical efficacy. Ten patients with stage IV RCC and bone metastases were imaged with (18)F-NaF PET/CT and (99m)Tc-labelled methylene diphosphonate ((99m)Tc-MDP) bone scintigraphy including pelvic single photon emission computed tomography (SPECT). Images were reported independently by experienced radiologists and nuclear medicine physicians using a 5-point scoring system.

RESULTS

Seventy-seven lesions were diagnosed as malignant: 100% were identified by (18)F-NaF PET/CT, 46% by CT and 29% by bone scintigraphy/SPECT. Standard-of-care imaging with CT and bone scintigraphy identified 65% of the metastases reported by (18)F-NaF PET/CT. On an individual patient basis, (18)F-NaF PET/CT detected more RCC metastases than (99m)Tc-MDP bone scintigraphy/SPECT or CT alone (P = 0.007). The metabolic volumes, mean and maximum standardized uptake values (SUV mean and SUV max) of the malignant lesions were significantly greater than those of the benign lesions (P < 0.001).

CONCLUSIONS

(18)F-NaF PET/CT is significantly more sensitive at detecting RCC skeletal metastases than conventional bone scintigraphy or CT. The detection of occult bone metastases could greatly alter patient management, particularly in the context when standard-of-care imaging is negative for skeletal metastases.

Germline polymorphisms and survival of lung adenocarcinoma patients: a genome-wide study in two European patient series

In lung cancer, the survival of patients with the same clinical stage varies widely for unknown reasons. In this two-phase study, we examined the hypothesis that germline variations influence the survival of patients with lung adenocarcinoma. First, we analyzed existing genotype and clinical data from 289 UK-resident patients with lung adenocarcinoma, identifying 86 single nucleotide polymorphisms (SNPs) that associated with survival (p < 0.01). We then genotyped these candidate SNPs in a validation series of 748 patients from Italy that resulted genetically compatible with the UK series based on principal component analysis. In a Cox proportional hazard model adjusted for age, sex and clinical stage, four SNPs were confirmed on the basis of their having a hazard ratio (HR) indicating the same direction of effect in the two series and p < 0.05. The strongest association was provided by rs2107561, an intronic SNP of PTPRG, protein tyrosine phosphatase, receptor type, G; the C allele was associated with poorer survival in both patient series (pooled analysis loge HR = 0.31; 95% CI: 0.15-0.46, p = 8.5 × 10(-5) ). PTPRG mRNA levels in 43 samples of lung adenocarcinoma were 40% of those observed in noninvolved lung tissue from the same patients. PTPRG overexpression significantly inhibited the clonogenicity of A549 lung carcinoma cells and the anchorage-independent growth of the NCI-H460 large cell lung cancer line. These four germline variants represent promising candidates that, with further study, may help predict clinical outcome. In addition, the PTPRG locus may have a role in tumor progression.

Rare variants of large effect in BRCA2 and CHEK2 affect risk of lung cancer

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 BRCA2 p.Lys3326X (rs11571833, odds ratio (OR) = 2.47, P = 4.74 × 10(-20)) and CHEK2 p.Ile157Thr (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 that had been previously reported only 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 with substantive effects on cancer risk from preexisting genome-wide association study data.

Carboplatin AUC 10 for IGCCCG good prognosis metastatic seminoma

OBJECTIVE

Metastatic seminoma is a highly curable disease. Standard treatment comprises of combination chemotherapy. The short- and long-term toxicities of this treatment are increasingly recognised and the possibility of over treatment in such a curable disease should be considered. We have therefore assessed the use of single agent carboplatin at a dose of AUC 10 in patients with good prognosis metastatic seminoma.

MATERIALS AND METHODS

Patients with good prognosis metastatic seminoma treated with carboplatin (AUC 10) were identified at our institution and affiliated institutions. Treatment was three weekly for a total of three or four cycles. Outcome and toxicities were analysed.

RESULTS

With a median follow-up of 36 months, 61 patients in total were treated with carboplatin AUC 10, all good prognosis by the IGCCCG criteria. Forty-eight percent had stage IIA/IIB disease and 52% had greater than stage IIB disease. Thirty-one patients (51%) had a complete response following treatment. Three-year survival was 96.3% with a three-year progression free survival of 93.2%. The main treatment toxicity was haematological with 46% having grade 3, 24% having grade 4 neutropenia and 54% experiencing grade 3/4 thrombocytopenia. There were no treatment related deaths.

CONCLUSION

Single agent carboplatin at a dose of AUC 10 is an effective treatment for good prognosis metastatic seminoma. The outcome compares favourably to previously published outcomes of combination chemotherapy. Although haematological toxicity is a concern, single agent carboplatin treatment for good prognosis metastatic seminoma could be considered a treatment option and is associated with less toxicity than combination regimens currently used.

Variation in TP63 is associated with lung adenocarcinoma in the UK population

BACKGROUND

Variation at TP63 has recently been shown to be associated with lung adenocarcinoma in the Asian population.

METHODS

To investigate how this finding translates to the European population we compared the genotypes of SNPs annotating the TP63 locus at 3q28 in 4,462 lung cancer patients, including 911 with adenocarcinoma, and 8,235 controls from the United Kingdom.

RESULTS

A statistically significant association between adenocarcinoma risk and SNP genotype was shown: rs10937405, OR = 1.21, P = 1.82 × 10(-4); rs17429138, OR = 1.23, P = 7.49 × 10(-5); and rs4396880, OR = 1.21, P = 2.03 × 10(-4). Haplotype analysis was consistent with a single TP63 risk locus defined by SNPs rs10937405, rs17429138, and rs4396880. While no association between SNPs and small cell lung cancer was shown, the rs10937405 and rs439680 associations were significant for squamous cancer (respective P-values, 0.0022 and 0.02).

CONCLUSIONS

These findings show TP63 variation is a risk factor for the development of lung adenocarcinoma in the UK population. Furthermore, they provide additional insight into the subtype-specificity of the 3q28 lung cancer association.

IMPACT

Our data confirm the association of 3q28 with lung adenocarcinoma and that this association is not confined to the Asian population. Elucidating the functional basis of this association will be contingent on future fine mapping of the TP63 loci.

Chromosome 15q25 (CHRNA3-CHRNA5) variation impacts indirectly on lung cancer risk

Genetic variants at the 15q25 CHRNA5-CHRNA3 locus have been shown to influence lung cancer risk however there is controversy as to whether variants have a direct carcinogenic effect on lung cancer risk or impact indirectly through smoking behavior. We have performed a detailed analysis of the 15q25 risk variants rs12914385 and rs8042374 with smoking behavior and lung cancer risk in 4,343 lung cancer cases and 1,479 controls from the Genetic Lung Cancer Predisposition Study (GELCAPS). A strong association between rs12914385 and rs8042374, and lung cancer risk was shown, odds ratios (OR) were 1.44, (95% confidence interval (CI): 1.29–1.62, P = 3.69×10⁻¹⁰) and 1.35 (95% CI: 1.18–1.55, P = 9.99×10⁻⁶) respectively. Each copy of risk alleles at rs12914385 and rs8042374 was associated with increased cigarette consumption of 1.0 and 0.9 cigarettes per day (CPD) (P = 5.18×10⁻⁵ and P = 5.65×10⁻³). These genetically determined modest differences in smoking behavior can be shown to be sufficient to account for the 15q25 association with lung cancer risk. To further verify the indirect effect of 15q25 on the risk, we restricted our analysis of lung cancer risk to never-smokers and conducted a meta-analysis of previously published studies of lung cancer risk in never-smokers. Never-smoker studies published in English were ascertained from PubMed stipulating - lung cancer, risk, genome-wide association, candidate genes. Our study and five previously published studies provided data on 2,405 never-smoker lung cancer cases and 7,622 controls. In the pooled analysis no association has been found between the 15q25 variation and lung cancer risk (OR = 1.09, 95% CI: 0.94–1.28). This study affirms the 15q25 association with smoking and is consistent with an indirect link between genotype and lung cancer risk.

Role of 5p15.33 (TERT-CLPTM1L), 6p21.33 and 15q25.1 (CHRNA5-CHRNA3) variation and lung cancer risk in never-smokers

Genome-wide association studies have provided evidence that common variation at 5p15.33 (TERT-CLPTM1L), 6p21.33 and 15q25.1 (CHRNA5-CHRNA3) influences lung cancer risk. To examine if variation at any of these loci influences the risk of lung cancer in never-smokers, we compared 5p15.33-TERT (rs2736100), 5p15.33-CLPTM1L (rs4975616), 6p21.33-BAT3 (rs3117582), 15q25.1-CHRNA3 (rs8042374) and 15q25.1-CHRNA3 (rs12914385) genotypes in a series of 239 never-smoker lung cancer cases and 553 never-smoker controls. A statistically significant association between lung cancer risk and 5p15.33 genotypes was found: rs2736100 (odds ratio = 0.78, 95% confidence interval: 0.63-0.97; P = 0.02), rs4975616 (odds ratio = 0.69, 95% confidence interval: 0.55-0.85; P = 7.95 x 10(-4)), primarily for adenocarcinoma. There was no evidence of association between 6p21.33 or 15q25.1 variation and risk of lung cancer. This analysis provides evidence that TERT-CLPTM1L variants may influence the risk of lung cancer outside the context of tobacco smoking.

Deciphering the impact of common genetic variation on lung cancer risk: a genome-wide association study

To explore the impact of common variation on the risk of developing lung cancer, we conducted a two-phase genome-wide association (GWA) study. In phase 1, we compared the genotypes of 511,919 tagging single nucleotide polymorphisms (SNP) in 1,952 cases and 1,438 controls; in phase 2, 30,568 SNPs were genotyped in 2,465 cases and 3,005 controls. SNP selection was based on best supported P values from phase 1 and two other GWA studies of lung cancer. In the combined analysis of phases 1 and 2, the strongest associations identified were defined by SNPs mapping to 15q25.1 (rs12914385; P = 3.19 x 10(-16)), 5p15.33 (rs4975616; P = 6.66 x 10(-7)), and 6p21.33 (rs3117582; P = 9.13 x 10(-7)). Variation at 15q25.1, but not 5p15.33 or 6p21.33, was strongly associated with smoking behavior with risk alleles correlated to higher consumption. Variation at 5p15.33 was shown to significantly influence induction of lung cancer histology. Pooling data from the four series provided 21,620 genotypes for 7,560 cases and 8,205 controls. A meta-analysis provided increased support that variation at 15q25.1 (rs8034191; P = 3.24 x 10(-26)), 5p15.33 (rs4975616; P = 2.99 x 10(-9)), and 6p21.33 (rs3117582; P = 4.46 x 10(-10)) influences lung cancer risk. The next best-supported associations were attained at 15q15.2 (rs748404: P = 1.08 x 10(-6)) and 10q23.31 (rs1926203; P = 1.28 x 10(-6)). These data indicate few common variants account for 1% of the excess familial risk underscoring the necessity of having additional large sample series for gene discovery.

Identification of low penetrance alleles for lung cancer: the GEnetic Lung CAncer Predisposition Study (GELCAPS)

Background

Part of the inherited risk to lung cancer is likely to include common, low risk alleles. The identification of this class of susceptibility is contingent on association-based analyses. We established GEnetic Lung CAncer Predisposition Study (GELCAPS) to collect DNA and clinico-pathological data from a large series of cases and a series of spouse/partner controls, thereby generating a key resource for the identification of low risk alleles.

Methods

GELCAPS was one of the first genetic epidemiological trials in the UK to be adopted by the National Cancer Research Network (NCRN) onto its portfolio with the participation of over 100 oncology departments specialising in the management of lung cancer.

Results

Samples from over 5,000 independent lung cancer cases and 2,000 controls have so far been assembled through GELCAPS.

Conclusion

GELCAPS represents one of the largest datasets of its type in the world capable of informing on the contribution of low penetrance alleles to the development of lung cancer and the influence of genetic variation on outcome. In addition our experience in developing the GELCAPS serves to illustrate how large DNA biobanks for genetic analyses can be rapidly generated within the UK using the NCRN.

Genetic variation in the DNA repair genes is predictive of outcome in lung cancer

To assess whether DNA repair gene variants influence the clinical behaviour of lung cancer we examined the impact of a comprehensive panel of 109 non-synonymous single-nucleotide polymorphisms (nsSNPs) in 50 DNA repair genes on overall survival (OS) in 700 lung cancer patients. Fifteen nsSNPs were associated with OS, significantly greater than that expected (P = 0.04). SNPs associated with prognosis mapped primarily to two repair pathways--nucleotide excision repair (NER): ERCC5 D1104H (P = 0.004); ERCC6 G399D (P = 0.023), ERCC6 Q1413R (P = 0.025), POLE (P = 0.014) and base excision repair: APEX1 D148E (P = 0.028); EXO1 E670G (P = 0.007); POLB P242R (P = 0.018). An increasing number of variant alleles in EXO1 was associated with a poorer prognosis [hazard ratio (HR) = 1.24; P = 0.0009]. A role for variation in NER and BRCA2/FA pathway genes as determinants of OS was provided by an analysis restricted to the 456 patients treated with platinum-based agents. Our data indicate that the pathway-based approach has the potential to generate prognostic markers of clinical outcome.

Prognostic significance of folate metabolism polymorphisms for lung cancer

Functional nonsynonymous single-nucleotide polymorphisms (nsSNPs) of folate metabolism genes can influence the methylation of tumour suppressor genes, thereby potentially impacting on tumour behaviour. To investigate whether such polymorphisms influence lung cancer survival, we genotyped 14 nsSNPs mapping to methylene-tetrahydrofolate reductase (MTHFR), methionine synthase (MTR), methionine synthase reductase (MTRR); DNA methyltransferase (DNMT2), methylenetetrahydrofolate dehydrogenase (MTHFD1) and methenyltetrahydrofolate synthetase (MTHFS) in 619 Caucasian women with incident disease, 465 with non-small cell (NSCLC) and 154 with small cell lung cancer (SCLC). The most significant association detected was with MTHFS Thr202Ala, with carriers of variant alleles having a worse prognosis (hazard ratio (HR)=1.49; 95% confidence interval: 1.14-1.94). Associations were also detected between overall survival (OS) in SCLC and homozygosity for MTHFR 222Val (HR=1.92; 1.03-3.58) and between OS from NSCLC and MTRR 175Leu carrier status (HR=1.36; 1.06-1.75). While there is evidence that variation in the folate metabolism genes may influence prognosis from lung cancer, current data are insufficiently robust to distinguish individual patient outcome.

Further observations on the relationship between the FGFR4 Gly388Arg polymorphism and lung cancer prognosis

The Gly388Arg polymorphism in the fibroblast growth factor receptor 4 (FGFR4) gene has been reported to influence prognosis in a wide variety of cancer types. To determine whether Gly388Arg is a marker for lung cancer prognosis, we genotyped 619 lung cancer patients with incident disease and examined the relationship between genotype and overall survival. While we employed a comprehensive set of statistical tests, including those sensitive to the detection of differences in early survival, our data provide little evidence to support the tenet that the FGFR4 Gly388Arg polymorphism is a clinically useful marker for lung cancer prognosis.

Lack of evidence that p53 Arg72Pro influences lung cancer prognosis: an analysis of survival in 619 female patients

The prognostic significance of the Arg72Pro polymorphism of the p53 tumour suppressor gene in cancer is controversial. To determine whether Arg72Pro is a marker for lung cancer prognosis we genotyped 619 female lung cancer patients with incident disease and examined the relationship between genotype and overall survival (OS). Nonparametric tests provided no evidence for a relationship between SNP genotype and OS (P-values 0.131, 0.161, and 0.156 for log rank, Wilcoxon and Fleming-Harrington test statistics, respectively). Under the Cox proportional hazards model the HRs associated with Arg/Pro, Pro/Pro and Pro-carrier status were: 0.98 (95%CI: 0.79-1.22), 0.76 (95%CI: 0.51-1.15) and 0.93 (95%CI: 0.76-1.15), respectively. Despite employing a comprehensive set of statistical tests including those sensitive to the detection of differences in early survival our data provide little evidence to support the tenet that the p53 Arg72Pro polymorphism is a clinically useful prognostic marker for lung cancer.

Evaluation of xeroderma pigmentosum XPA, XPC, XPD, XPF, XPB, XPG and DDB2 genes in familial early-onset lung cancer predisposition

Epidemiological data has implicated heterozygosity for xeroderma pigmentosum (XP) as a risk factor for lung cancer. XP has 8 known complementation groups, 7 of which are caused by mutations in genes encoding components of the nucleotide excision repair (NER) pathway. To formally investigate the role of XP-related NER genes in lung cancer susceptibility, we screened germline DNA from 92 familial early-onset lung cancer patients for mutations in all coding regions and intron-exon boundaries of XPA, XPC, XPD, XPF, XPB, XPG and DDB2. Forty-one exonic variants were identified. Twenty-four were nonsynonymous, of which 14 were previously documented polymorphisms. Ten missense variants had not been previously described; none of which were detected in germline DNA from 278 cancer-free controls. Two of the novel missense changes are predicted to be functionally deleterious. Our findings are compatible with XP heterozygosity being a risk factor for lung cancer susceptibility.

Variants in the GH-IGF axis confer susceptibility to lung cancer

We conducted a large-scale genome-wide association study in UK Caucasians to identify susceptibility alleles for lung cancer, analyzing 1529 cases and 2707 controls. To increase the likelihood of identifying disease-causing alleles, we genotyped 1476 nonsynonymous single nucleotide polymorphisms (nsSNPs) in 871 candidate cancer genes, biasing SNP selection toward those predicted to be deleterious. Statistically significant associations were identified for 64 nsSNPs, generating a genome-wide significance level of P=0.002. Eleven of the 64 SNPs mapped to genes encoding pivotal components of the growth hormone/insulin-like growth factor (GH-IGF) pathway, including CAMKK1 E375G (OR=1.37, P=5.4x10(-5)), AKAP9 M463I (OR=1.32, P=1.0x10(-4)) and GHR P495T (OR=12.98, P=0.0019). Significant associations were also detected for SNPs within genes in the DNA damage-response pathway, including BRCA2 K3326X (OR=1.72, P=0.0075) and XRCC4 I137T (OR=1.31, P=0.0205). Our study provides evidence that inherited predisposition to lung cancer is in part mediated through low-penetrance alleles and specifically identifies variants in GH-IGF and DNA damage-response pathways with risk of lung cancer.

Nucleotide excision repair polymorphisms modulate overall lung cancer survival and responsiveness to platinum based chemotherapy agents

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Background: The role of DNA repair in maintaining genomic stability and its role in modulating response to chemotherapy agents raises the possibility that variation in these genes may affect lung cancer prognosis. Methods: To comprehensively evaluate the impact of variation in the nucleotide excision repair (NER) pathway on lung cancer prognosis, we analysed 408 lung cancer patients for all coding, non-synonymous single nucleotide polymorphisms (SNPs) within NER-related genes. Results: Mean age of lung cancer diagnosis among patients was 63 years, 105 patients with small cell lung cancer (SCLC) and 299 with non-small cell lung cancer (NSCLC). The mean follow-up time was 24 months and a total of 234 deaths were observed. Mean survival time was 17.3 and 18.6 months for SCLC and NSCLC respectively. The XPG H1104D minor allele homozygote and the tightly linked CSB M1097V, R1213G, and Q1413R heterozygote genotypes were associated with decreased overall survival, irrespective of whether patients were treated with or without platinum chemotherapy (HRs of 2.22, 95% CI: 1.19–4.16; p=0.013 and 1.39, 95% CI: 1.05–1.84; p=0.02 respectively). No statistically significant interaction was detected between the at-risk genotypes and histology and/or stage of disease at diagnosis. To assess the predictive value of these SNPs in relation to platinum based chemotherapy, genotype-survival associations were evaluated in non-platinum and platinum treated patients. In non-platinum treated patients the RAD23B A249V and CSB M1097V minor allele genotypes were associated with decreased overall survival (p=0.004 and 0.002 respectively), whilst the XPC K939Q minor allele genotype was predictive of improved survival (p=0.03). In platinum-treated patients, carriers of the XPG H1104D minor allele were found to have a statistically significant decrease in their overall survival (p=0.04 and 0.004 for minor allele heterozygote and homozygote patients respectively). Conclusions: These findings suggest that genetic polymorphisms in the NER genes may modulate overall lung cancer prognosis as well as response to platinum-based chemotherapy agents, independent of histological diagnosis and stage of disease at presentation.

No significant financial relationships to disclose.

Time and chemotherapy treatment trends in the treatment of elderly patients (age >/=70 years) with small cell lung cancer

Platinum-based treatment for small cell lung cancer (SCLC) has been established since 1995. This study investigates treatment outcome of elderly patients (age ⩾70 years) with SCLC over the past 20 years in a large UK cancer centre. Comparison of all-cause survival was assessed in patients presenting between two predefined time periods: 1982–1994 and 1995–2003. All the survival analysis were adjusted for stage and performance status and age if appropriate. Survival between different chemotherapy treatment regimens was compared. A total of 322 elderly patients (31% of all) registered between 1982–2003 received chemotherapy for SCLC. Patients presenting in 1995–2003 had an overall better median survival (43 vs 25 weeks) and a 1-year survival (37 vs 14%) than patients presenting in 1982–1994 (P<0.001). This applied to patients with both limited and extensive stage disease and all age groups. There was a trend towards the use of more platinum-based treatments in the later cohort but the use of radiotherapy remained constant. Patients who received platinum combinations (Carboplatin or Cisplatin) had significantly improved survival over those who received single agents or other combinations (P<0.001) and there was no significant difference between carboplatin and cisplatin (P=0.7). The analysis demonstrates that there has been a significant improvement in survival for elderly patients with lung cancer treated by chemotherapy in the past 20 years despite more very elderly patients being treated with a poorer performance status. This change is probably multifactorial and may be due to the increased use of platinum-based treatment and improved supportive care.

Systematic review of the relationship between family history and lung cancer risk

We performed a systematic review of 28 case–control, 17 cohort and seven twin studies of the relationship between family history and risk of lung cancer and a meta-analysis of risk estimates. Data from both case–control and cohort studies show a significantly increased lung cancer risk associated with having an affected relative. Risk appears to be greater in relatives of cases diagnosed at a young age and in those with multiple affected family members. Increased lung cancer risk was observed in association with an affected spouse and twin studies, while limited, favour shared environmental exposures. The limitations of the currently published epidemiological studies to infer genetic susceptibility are discussed.

Case-control study of familial lung cancer risks in UK women

Family history data from a case-control study of lung cancer conducted in the United Kingdom between 1999 and 2004 were analysed to estimate familial risks of the disease. Comparison of lung cancer prevalence in first-degree relatives of 1,482 female lung cancer cases and 1,079 female controls was undertaken using logistic regression adjusting for age and tobacco exposure. Overall, lung cancer in a first-degree relative was associated with a significant increase in the risk of lung cancer [odds ratio (OR) 1.49; 95% confidence interval (CI), 1.13-1.96]. For cases with early onset of the disease (< 60 years), the OR of lung cancer was 2.02 (95% CI, 1.22-3.34). Having 2 or more affected relatives was associated with an OR of 2.68 (95% CI, 1.29-5.55), with a significant trend in risk according to the number of relatives affected (p = 0.001). An increased risk of lung cancer associated with family history of the disease was observed when analysis was restricted to lifetime nonsmokers, although this did not reach significance (OR 1.23; 95% CI, 0.65-2.31). Results confirm previous findings and support the role of a familial predisposition to lung cancer.

Thymidylate synthase expression and prognosis in colorectal cancer: a systematic review and meta-analysis

PURPOSE

A number of studies have investigated the relationship between thymidylate synthase (TS) expression and survival in colorectal cancer (CRC) patients. Although most have reported poorer overall and progression-free survival with high TS expression, estimates of the hazard ratio (HR) between studies differ wildly. To derive a more precise estimate of the prognostic significance of TS expression, we have reviewed published studies and carried out a meta-analysis.

MATERIALS AND METHODS

Twenty studies stratifying overall survival and/or progression-free survival in CRC patients by TS expression status were eligible for analysis. The principal outcome measure was the HR. Data from these studies were pooled using standard meta-analysis techniques.

RESULTS

Thirteen studies investigated outcome in a total of 887 cases with advanced CRC, and seven studies investigated outcome in a total of 2,610 patients with localized CRC. A number of methods were used both to assess TS expression and to assign TS status. Sample sizes varied greatly, small sample sizes being a feature of the advanced disease studies. The combined HR estimate for overall survival (OS) was 1.74 (95% CI, 1.34 to 2.26) and 1.35 (95% CI, 1.07 to 1.80) in the advanced and adjuvant settings, respectively, but there was evidence of heterogeneity and possible publication bias.

CONCLUSION

Tumors expressing high levels of TS appeared to have a poorer OS compared with tumors expressing low levels. Additional studies with consistent methodology are needed to define the precise prognostic value of TS.