Circulating tumour DNA and its clinical utility in predicting treatment response or survival in patients with metastatic colorectal cancer: a systematic review and meta-analysis.

BACKGROUND: We investigate the current knowledge on circulating tumour DNA (ctDNA) and its clinical utility in predicting outcomes in patients with metastatic colorectal cancer (mCRC). METHODS: PubMed, Embase, Cochrane Database of Systematic Reviews and Cochrane Central Register of Controlled Trials were searched. Last search 16/12/2020. We included studies on patients with mCRC reporting the predictive or prognostic value of ctDNA. We performed separate random-effects meta-analyses to investigate if baseline ctDNA and early changes in ctDNA levels during treatment were associated with survival. The risk of bias was assessed according to the Quality in Prognosis Studies tool. RESULTS: Seventy-one studies were included with 6930 patients. Twenty-four studies were included in meta-analyses. High baseline ctDNA level was associated with short progression-free survival (PFS) (HR = 2.2; 95% CI 1.8-2.8; n = 509) and overall survival (OS) (HR = 2.4; 95% CI 1.9-3.1; n = 1336). A small or no early decrease in ctDNA levels during treatment was associated with short PFS (HR = 3.0; 95% CI 2.2-4.2; n = 479) and OS (HR = 2.8; 95% CI 2.1-3.9; n = 583). Results on clonal evolution and lead-time were inconsistent. A majority of included studies (n = 50/71) had high risk of bias in at least one domain. CONCLUSIONS: Plasma ctDNA is a strong prognostic biomarker in mCRC. However, true clinical utility is lacking.

Clinicopathological factors associated with tumour-specific mutation detection in plasma of patients with RAS-mutated or BRAF-mutated metastatic colorectal cancer.

Detection of tumour-specific circulating cell-free DNA in plasma (ctDNA) fails in a significant number of cases depending on the clinical context. The primary aim was to investigate clinicopathological factors associated with detection of ctDNA in patients with RAS-/BRAF-mutated metastatic colorectal cancer (mCRC) prior to first-line therapy. A secondary aim was to evaluate the prognostic impact of ctDNA compared to other biomarkers. Patients were included from the NORDIC-VII study (N = 253). ctDNA was sampled prior to treatment and analysed for hotspot tissue mutations (KRAS, NRAS, and BRAF) using droplet digital PCR. Multivariable regression models were constructed to predict the probability of mutation detection and survival. Increasing radiological size of target lesions by increments of 1 cm (odds ratio [OR] = 1.18; 95% confidence interval [CI] 1.09-1.27; P < .001), intact primary tumour (OR = 3.17; 95% CI 1.22-8.22; P = .018) and more than one metastatic site (OR = 3.08; 95% CI 1.32-7.19; P = .009) were associated with mutation detection in plasma. Metastatic involvement of the lung was associated with non-detection (OR = 0.26; 95% CI 0.12-0.58; P = .001). Preanalytical and analytical factors modulated detection. High allele frequencies of ctDNA indicated poor prognosis independently of CEA and CA19-9 (hazard ratio [HR] = 2.38; 95% CI 1.74-3.26; P < .001; N = 206). Clinicopathological characteristics should be carefully considered when evaluating ctDNA results from mCRC patients, especially when confronted with a plasma negative result. ctDNA may prove to be a clinically useful marker in the evaluation of mCRC treatment.

Tumour exosome integrins determine organotropic metastasis.

Ever since Stephen Paget's 1889 hypothesis, metastatic organotropism has remained one of cancer's greatest mysteries. Here we demonstrate that exosomes from mouse and human lung-, liver- and brain-tropic tumour cells fuse preferentially with resident cells at their predicted destination, namely lung fibroblasts and epithelial cells, liver Kupffer cells and brain endothelial cells. We show that tumour-derived exosomes uptaken by organ-specific cells prepare the pre-metastatic niche. Treatment with exosomes from lung-tropic models redirected the metastasis of bone-tropic tumour cells. Exosome proteomics revealed distinct integrin expression patterns, in which the exosomal integrins α6ß4 and α6ß1 were associated with lung metastasis, while exosomal integrin αvß5 was linked to liver metastasis. Targeting the integrins α6ß4 and αvß5 decreased exosome uptake, as well as lung and liver metastasis, respectively. We demonstrate that exosome integrin uptake by resident cells activates Src phosphorylation and pro-inflammatory S100 gene expression. Finally, our clinical data indicate that exosomal integrins could be used to predict organ-specific metastasis.

Molecular characterisation of TP53 mutated squamous cell carcinomas of the lung to identify putative targets for therapy.

Personalised cancer treatment depends on identification of therapeutically relevant biological subgroups of patients for assessing effect of treatment and to discover new therapeutic options. By analyses in heterogeneous patient populations, the effects may be lost in noise. Squamous cell carcinoma of the lung is a major killer worldwide. Despite recent advances, mortality is high and response to therapies varies greatly from patient to patient. Target search in biologically relevant subgroups may identify treatment options not so far discovered. A total of 198 patients undergoing surgery for squamous cell carcinomas of the lung were included in the study. The tumours were analysed for copy number alterations (n = 152) and gene expression from tumour (n = 188) and normal lung (n = 21), with both data levels present in 140 patients. We studied alterations in tumours harbouring mutations in TP53 and in previously published gene expression subtypes. Genes with consistent alterations in both genomic levels were identified as putative biomarkers. Results were validated in TCGA. The most convincing biomarker in TP53 mutated squamous cell carcinomas of the lung was BIRC5 with amplification in 36% of mutated samples, 5% in wild-type samples and a 17%-fold change of expression between TP53 mutated tumours and normal lung tissue. BIRC5 was significantly altered in the classical and primitive subtypes. We suggest BIRC5 as a putative predictive biomarker and putative druggable target in squamous cell lung carcinomas harbouring TP53 mutation or classified as classical and primitive subtypes.

Distribution of allele frequencies for genes associated with physical activity and/or physical capacity in a homogenous Norwegian cohort- a cross-sectional study.

BACKGROUND: There are large individual differences in physical activity (PA) behavior as well as trainability of physical capacity. Heritability studies have shown that genes may have as much impact on exercise participation behavior as environmental factors. Genes that favor both trainability and participation may increase the levels of PA. The present study aimed to assess the allele frequencies in genes associated with PA and/or physical capacity, and to see if there is any association between these polymorphisms and self-reported PA levels in a cohort of middle-aged Norwegians of Scandinavian descent (n = 831; mean age mean age (± SD) 55.5 ± 3.8 years). RESULTS: The genotype distributions of the ACTN3 R577X, ACE I/D and MAOA uVNTR polymorphisms were similar to other populations of European descent. When comparing the genotype distribution between the low/medium level PA group (LMPA) and high level PA groups (HPA), a significant difference in ACTN3 577X allele distribution was found. The X allele frequency was 10% lower in the HPA level group (P = 0.006). There were no differences in the genotype distribution of the ACE I/D or MAOA uVNTR polymorphism. Education and previous participation in sports or outdoor activities was positively associated with the self-reported PA levels (P ≤ 0.001). CONCLUSIONS: To the best of our knowledge, this is the first study to report association between ACTN3 R577X genotype and PA level in middle-aged Scandinavians. Nevertheless, the contribution of a single polymorphism to a complex trait, like PA level, is likely small. Socioeconomic variables, as education and previous participation in sports or outdoor activities, are positively associated with the self-reported PA levels.

Prognostic role of carcinoembryonic antigen and carbohydrate antigen 19-9 in metastatic colorectal cancer: a BRAF-mutant subset with high CA 19-9 level and poor outcome.

BACKGROUND: Mutation status of RAS and BRAF, as well as serum levels of carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA 19-9), are biomarkers used in clinical management of patients with gastrointestinal cancers. This study aimed to examine the prognostic role of these biomarkers in a patient population that started first-line chemotherapy for unresectable metastatic colorectal cancer (mCRC) in the NORDIC-VII study. METHODS: CEA and CA 19-9 were measured in serum samples from 545 patients obtained before the start of chemotherapy. Four hundred and ninety-four patients had detectable levels of carbohydrate antigen 19-9 (CA 19-9). RAS (exons 2-4) and BRAF (V600E) mutation status were available from 440 patients. Overall survival (OS) was estimated in patient groups defined by serum CEA or CA 19-9 levels using cut-off values of 5 µg/L and 35 kU/L, respectively, in the total population and in subgroups according to RAS and BRAF mutation status. RESULTS: For both CEA and CA 19-9, elevated serum levels were associated with reduced OS in adjusted analyses which included RAS and BRAF mutation status, baseline World Health Organization performance status, and levels of alkaline phosphatase and C-reactive protein. The negative prognostic information provided by an elevated CA 19-9 level was particularly marked in patients with BRAF mutation (hazard ratio = 4.35, interaction P = 0.003, in an adjusted model for OS). CONCLUSIONS: High baseline serum concentrations of CEA and CA 19-9 provide independent information of impaired prognosis in mCRC. In patients with BRAF-mutant tumours, elevated serum CA 19-9 may identify a subgroup with highly aggressive disease and could contribute to improving therapeutic decisions.

Circulating microRNAs associated with prolonged overall survival in lung cancer patients treated with nivolumab.

BACKGROUND: The introduction of immune check-point inhibition in non-small cell lung cancer (NSCLC) therapy represents improved prospects for the patients. The response rates to check-point inhibitors are approximately 20% in unselected NSCLC patients. Increasing levels of tumor PD-L1 expression are associated with higher response rates. However, patients with low PD-L1 levels may also have durable responses, and improved strategies for patient stratification are needed. MATERIAL AND METHODS: In this study, we investigated circulating microRNAs aiming to identify circulating predictive biomarkers associated with increased overall survival after immune check-point treatment. Using next generation sequencing, we performed microRNA profiling in serum from NSCLC patients (n = 20) treated with nivolumab. Serum samples from 31 patients were used for validation using qPCR assays. Serum samples were collected prior to immune therapy initiation. RESULTS: Based on multivariate regression analysis, we identified a signature of seven microRNAs (miR-215-5p, miR-411-3p, miR-493-5p, miR-494-3p, miR-495-3p, miR-548j-5p and miR-93-3p) significantly associated with overall survival (OS) > 6 months in discovery cohort (p = .0003). We further validated this in another similar set of samples (n = 31) and the model was significantly associated with overall survival (OS) > 6 months (p = .001) with sensitivity and specificity of 71% and 90%, respectively. CONCLUSIONS: In this study of circulating microRNAs, we have identified a 7-miR signature associated with survival in nivolumab-treated NSCLC patients. This signature may lead to better treatment options for patients with NSCLC, but a validation in an independent cohort is needed to confirm the predicted potential.

Cetuximab in treatment of metastatic colorectal cancer: final survival analyses and extended RAS data from the NORDIC-VII study.

BACKGROUND: The NORDIC-VII study is a randomised phase III trial of cetuximab plus continuous or intermittent fluorouracil, folinic acid, and oxaliplatin (Nordic FLOX) vs FLOX alone in first-line treatment of metastatic colorectal cancer. The present report presents an updated and final survival analysis with BRAF and extended RAS mutational status, 5 years after the primary analysis. METHODS: A total of 566 patients were included in the intention-to-treat (ITT) population of the NORDIC-VII study. Updated survival status was obtained from 176 patients who were alive in the primary survival analyses. Samples from 223 tumours previously found to be KRAS (exon 2) and BRAF (V600E) wild-type, were re-analysed for KRAS (exons 3 and 4) and NRAS (exons 2-4) mutations. RESULTS: Including the extended RAS analyses, RAS and BRAF mutational status was available from 457 patients (81% of the ITT population). RAS was mutated in 46% and BRAF in 12% of the tumours. RAS and BRAF, if mutated, were negative prognostic factors. The updated analyses confirmed the finding of the primary report that cetuximab did not provide any additional benefit when added to FLOX in patients with RAS/BRAF wild-type tumours, neither on progression-free nor overall survival. However, the outcomes in a subset of patients, which, after the first eight treatment cycles, received cetuximab alone, suggested a beneficial effect of cetuximab monotherapy. CONCLUSIONS: Adding cetuximab to Nordic FLOX did not provide any clinical benefit, but the data suggested an effect of cetuximab monotherapy in patients with RAS/BRAF wild-type tumours in the NORDIC-VII cohort. The data were compatible with a negative interaction between cetuximab and the Nordic FLOX chemotherapy backbone.

Impact of early disease progression and surgical complications on adjuvant chemotherapy completion rates and survival in patients undergoing the surgery first approach for resectable pancreatic ductal adenocarcinoma - A population-based cohort study.

BACKGROUND: Multimodality treatment (MMT) improves survival for patients with pancreatic ductal adenocarcinoma (PDAC). The surgery-first (SF) strategy is the most universally accepted approach. MATERIAL AND METHODS: Population-based retrospective cohort study of all cases of resectable PDAC from 2006 to 2012. Patients were planned for adjuvant chemotherapy (AC) with the Nordic 5-fluorouracil/leucovorin regimen. Reasons for and rates of failure to complete AC, postoperative major complications (PMC), and overall survival (OS) were analysed. RESULTS: Of 203 patients, 85 (41.9%) completed AC, 41 (20.2%) failed to complete AC, and 77 (37.9%) never initiated AC. Primary reasons for not initiating or completing AC were early disease progression (34.7%), postoperative complications/poor performance status (32.2%), and age > 75 years (24.6%). Median OS in the whole cohort was 17.0 months, and 20.0 months in patients who initiated AC. Median OS in patients who completed AC was higher than in patients who did not (25.0 months vs. 12.0 months, p < 0.001). PMC (n = 41) were associated with decreased initiation rate (p < 0.001) and completion rate (p = 0.007) of AC, and decreased median OS (11.0 months vs. 19.0 months, p = 0.028). Among patients with R1 resection, PMC again were associated with worse median OS (8.0 months vs. 16.0 months, p = 0.028). Multivariate analysis demonstrated that completion of MMT and tumour grade (G1/G2) were related to mortality rate (p < 0.001). Mortality risk for patients who completed AC was reduced also when adjusting for competing risk (SHR 0.426, p < 0.001). CONCLUSIONS: MMT completion is strongly associated with reduced mortality risk in patients with resectable PDAC undergoing the SF approach. Early disease progression and PMC/poor performance status preclude MMT completion in more than one third of the patients. These reasons for failure to complete MMT underscore the need for strategies to improve patient selection and reduce surgical morbidity in patients with resectable PDAC.

Preoperative cognitive function predicts survival in patients with resectable pancreatic ductal adenocarcinoma.

BACKGROUND: The purpose of this prospective study was to evaluate whether pre-surgery health-related quality of life (HRQoL) and subjectively rated symptom scores are prognostic factors for survival in patients with resectable pancreatic ductal adenocarcinoma (PDAC). METHODS: Patients undergoing pancreatic resection for PDAC completed the Edmonton Symptom Assessment System (ESAS) and the EORTC QLQ-C30 and QLQ-PAN26 questionnaires preoperatively. Patient, tumor and treatment characteristics, recurrence and survival were registered. RESULTS: Sixty-six consecutive patients underwent R0/R1 resection for PDAC. Baseline ESAS and EORTC questionnaire compliance was 44/66 (67%) with no statistically significant differences between compliers (n = 44) and non-compliers (n = 22) when comparing clinicopathological parameters and survival. Univariable analyses showed that three symptoms (nausea, dry mouth, cognitive function) and two clinicopathological factors (CA 19-9 > 400 U/ml, lymph node ratio > 0.1) were significantly associated with shorter survival (p < 0.05). In multivariable analysis, cognitive function was the only independent predictor for survival: hazard ratio = 0.35 (95%CI 0.13-0.93) for high vs low cognitive function. Median survival times for patients with high and low cognitive function were 21 and 10 months, respectively (p < 0.001). CONCLUSION: Presurgery cognitive function is a significant independent predictor of survival in patients with resectable PDAC. Thus, presurgery patient reported outcomes may provide as strong prognostic information as clinicopathological factors.

Serum N-Glycome Characterization in Patients with Resectable Periampullary Adenocarcinoma.

Serum N-glycans are promising biomarkers for systemic disease states. Better understanding of the serum N-glycome of patients with resectable periampullary adenocarcinoma may identify novel prognostic markers for this disease. Serum N-glycans in 70 patients with resectable periampullary adenocarcinoma, 15 patients with benign periampullary tumor, and 129 healthy individuals were quantified using ultra performance liquid chromatography. High-sensitivity C-reactive protein (hsCRP) was analyzed for all samples using an immunoturbidimetric method. The N-glycome was compared to clinical and histopathological data, and to the acute phase response as measured by hsCRP. Whole-genome tumor tissue mRNA expression data were used for correlation and enrichment analysis to investigate underlying biological processes giving rise to changes in the serum N-glycome. Significant changes were found in the serum N-glycome of patients with periampullary adenocarcinoma (n = 70) compared to healthy individuals (n = 129). No significant differences were found between patients with benign (n = 15) and malignant periampullary tumors (n = 70). Many alterations in the N-glycome correlated with systemic acute phase response as measured by hsCRP. Enrichment analysis indicated that immunologic pathways of the cancer microenvironment correlate with specific features of the serum N-glycome. Certain glycans were associated with poor overall and disease free survival in patients with pancreatobiliary type of periampullary adenocarcinoma. Our study supports the hypothesis that certain factors secreted by the tumor affect liver and plasma cells to orchestrate the changes in the serum N-glycome observed. The serum N-glycome could potentially reflect modified phenotypes of the host and/or tumor microenvironment. The prognostic impact of the serum N-glycome should be evaluated in larger, prospective studies.

FCGR2A and FCGR3A polymorphisms and clinical outcome in metastatic colorectal cancer patients treated with first-line 5-fluorouracil/folinic acid and oxaliplatin +/- cetuximab.

BACKGROUND: Polymorphisms of genes encoding the Fcy receptors (Fc fragment of IgG receptor 2A (FCGR2A) and 3A (FCGR3A)), which influence their affinity for the Fc fragment, have been linked to the pharmacodynamics of monoclonal antibodies. Most studies have been limited by small samples sizes and have reported inconsistent associations between the FCGR2A and the FCGR3A polymorphisms and clinical outcome in metastatic colorectal cancer (mCRC) patients treated with cetuximab. We investigated the association of these polymorphisms and clinical outcome in a large cohort of mCRC patients treated with first-line 5-fluorouracil/folinic acid and oxaliplatin (Nordic FLOX) +/- cetuximab in the NORDIC-VII study (NCT00145314). METHODS: 504 and 497 mCRC patients were evaluable for the FCGR2A and FCGR3A genotyping, respectively. Genotyping was performed on TaqMan ABI HT 7900 (Applied Biosystems, Foster City, CA, USA) with pre-designed SNP genotyping assays for FCGR2A (rs1801274) and FCGR3A (rs396991). RESULTS: The response rate for patients with the FCGR2A R/R genotype was significantly increased when cetuximab was added to Nordic FLOX (31% versus 53%, interaction P = 0.03), but was not significantly different compared to the response rate of patients with the FCGR2A H/H or H/R genotypes given the same treatment. A larger increase in response rate with the addition of cetuximab to Nordic FLOX in patients with KRAS mutated tumors and the FCGR2A R/R genotype was observed (19% versus 50%, interaction P = 0.04). None of the FCGR3A polymorphisms were associated with altered response when cetuximab was added to Nordic FLOX (interaction P = 0.63). Neither of the FCGR polymorphisms showed any significant associations with progression-free survival or overall survival. CONCLUSION: Patients with KRAS mutated tumors and the FCGR2A R/R polymorphism responded poorly when treated with chemotherapy only, and experienced the most benefit of the addition of cetuximab in terms of response rate.

Let-7 miRNA-binding site polymorphism in the KRAS 3'UTR; colorectal cancer screening population prevalence and influence on clinical outcome in patients with metastatic colorectal cancer treated with 5-fluorouracil and oxaliplatin +/- cetuximab.

BACKGROUND: Recent studies have reported associations between a variant allele in a let-7 microRNA complementary site (LCS6) within the 3'untranslated region (3'UTR) of KRAS (rs61764370) and clinical outcome in metastatic colorectal cancer (mCRC) patients receiving cetuximab. The variant allele has also been associated with increased cancer risk. We aimed to reveal the incidence of the variant allele in a colorectal cancer screening population and to investigate the clinical relevance of the variant allele in mCRC patients treated with 1st line Nordic FLOX (bolus 5-fluorouracil/folinic acid and oxaliplatin) +/- cetuximab. METHODS: The feasibility of the variant allele as a risk factor for CRC was investigated by comparing the LCS6 gene frequencies in 197 CRC patients, 1060 individuals with colorectal polyps, and 358 healthy controls. The relationship between clinical outcome and LCS6 genotype was analyzed in 180 mCRC patients receiving Nordic FLOX and 355 patients receiving Nordic FLOX + cetuximab in the NORDIC-VII trial (NCT00145314). RESULTS: LCS6 frequencies did not vary between CRC patients (23%), individuals with polyps (20%), and healthy controls (20%) (P = 0.50). No statistically significant differences were demonstrated in the NORDIC-VII cohort even if numerically increased progression-free survival (PFS) and overall survival (OS) were found in patients with the LCS6 variant allele (8.5 (95% CI: 7.3-9.7 months) versus 7.8 months (95% CI: 7.4-8.3 months), P = 0.16 and 23.5 (95% CI: 21.6-25.4 months) versus 19.5 months (95% CI: 17.8-21.2 months), P = 0.31, respectively). Addition of cetuximab seemed to improve response rate more in variant carriers than in wild-type carriers (from 35% to 57% versus 44% to 47%), however the difference was not statistically significant (interaction P = 0.16). CONCLUSIONS: The LCS6 variant allele does not seem to be a risk factor for development of colorectal polyps or CRC. No statistically significant effect of the LCS6 variant allele on response rate, PFS or OS was found in mCRC patients treated with 1st line Nordic FLOX +/- cetuximab.

Survival Trends of Right- and Left-Sided Colon Cancer across Four Decades: A Norwegian Population-Based Study.

BACKGROUND: Patients with right-sided colon cancer (RCC) and left-sided colon cancer (LCC) differ clinically and molecularly. The main objective was to investigate stage-stratified survival and recurrence of RCC and LCC across four 10-year periods. METHODS: Patients diagnosed from 1977 to 2016 with colon adenocarcinoma were included from the Cancer Registry of Norway. Primary tumor location (PTL) was defined as RCC if proximal and LCC if distal to the splenic flexure. Multivariable regressions were used to estimate HRs for overall survival (OS), recurrence-free survival (RFS), survival after recurrence (SAR), and excess HRs (eHR) for relative survival (RS). RESULTS: 72,224 patients were eligible for analyses [55.1% (n = 39,769/72,224) had RCC]. In 1977 to 1986, there was no difference between LCC and RCC in OS [HR, 1.01; 95% confidence interval (CI), 0.97-1.06; P = 0.581] or RS (eHR, 0.96; 95% CI, 0.90-1.02; P = 0.179). In 2007 to 2016, LCC had significantly better OS (HR, 0.84; 95% CI, 0.80-0.87; P < 0.001) and RS (eHR, 0.76; 95% CI, 0.72-0.81; P < 0.001) compared with RCC. The gradually diverging and significantly favorable prognosis for LCC was evident for distant disease across all time periods and for regional disease from 2007 onward. There was no difference in RFS between LCC and RCC in patients less than 75 years during 2007 to 2016 (HR, 0.99; 95% CI, 0.91-1.08; P = 0.819); however, SAR was significantly better for LCC (HR, 0.61; 95% CI, 0.53-0.71; P < 0.001). CONCLUSIONS: A gradually diverging and increasingly favorable prognosis was observed for patients with LCC with advanced disease over the past four decades. IMPACT: Current PTL survival disparities stress the need for further exploring targetable molecular subgroups across and within different PTLs to further improve patient outcomes.

Prognostic Significance of the Loss of Heterozygosity of KRAS in Early-Stage Lung Adenocarcinoma.

Lung cancer is a common disease with a poor prognosis. Genomic alterations involving the KRAS gene are common in lung carcinomas, although much is unknown about how different mutations, deletions, and expressions influence the disease course. The first approval of a KRAS-directed inhibitor was recently approved by the FDA. Mutations in the KRAS gene have been associated with poor prognosis for lung adenocarcinomas, but implications of the loss of heterozygosity (LOH) of KRAS have not been investigated. In this study, we have assessed the LOH of KRAS in early-stage lung adenocarcinoma by analyzing DNA copy number profiles and have investigated the effect on patient outcome in association with mRNA expression and somatic hotspot mutations. KRAS mutation was present in 36% of cases and was associated with elevated mRNA expression. LOH in KRAS was associated with a favorable prognosis, more prominently in KRAS mutated than in wild-type patients. The presence of both LOH and mutation in KRAS conferred a better prognosis than KRAS mutation alone. For wild-type tumors, no difference in prognosis was observed between patients with and without LOH in KRAS. Our study indicates that LOH in KRAS is an independent prognostic factor that may refine the existing prognostic groups of lung adenocarcinomas.

Proteome Analysis of Pancreatic Tumors Implicates Extracellular Matrix in Patient Outcome.

Pancreatic cancer remains a disease with unmet clinical needs and inadequate diagnostic, prognostic, and predictive biomarkers. In-depth characterization of the disease proteome is limited. This study thus aims to define and describe protein networks underlying pancreatic cancer and identify protein centric subtypes with clinical relevance. Mass spectrometry-based proteomics was used to identify and quantify the proteome in tumor tissue, tumor-adjacent tissue, and patient-derived xenografts (PDX)-derived cell lines from patients with pancreatic cancer, and tissues from patients with chronic pancreatitis. We identified, quantified, and characterized 11,634 proteins from 72 pancreatic tissue samples. Network focused analysis of the proteomics data led to identification of a tumor epithelium-specific module and an extracellular matrix (ECM)-associated module that discriminated pancreatic tumor tissue from both tumor adjacent tissue and pancreatitis tissue. On the basis of the ECM module, we defined an ECM-high and an ECM-low subgroup, where the ECM-high subgroup was associated with poor prognosis (median survival months: 15.3 vs. 22.9 months; log-rank test, P = 0.02). The ECM-high tumors were characterized by elevated epithelial-mesenchymal transition and glycolytic activities, and low oxidative phosphorylation, E2F, and DNA repair pathway activities. This study offers novel insights into the protein network underlying pancreatic cancer opening up for proteome precision medicine development. Significance: Pancreatic cancer lacks reliable biomarkers for prognostication and treatment of patients. We analyzed the proteome of pancreatic tumors, nonmalignant tissues of the pancreas and PDX-derived cell lines, and identified proteins that discriminate between patients with good and poor survival. The proteomics data also unraveled potential novel drug targets.

Influence of GSTM1, GSTT1, GSTP1, NAT1, NAT2, EPHX1, MTR and MTHFR polymorphism on chromosomal aberration frequencies in human lymphocytes.

We have studied the influence of genetic polymorphisms in the xenobiotic-metabolizing genes GSTM1, GSTP1, GSTT1, EPHX1, NAT1 and NAT2 and the folate-metabolizing genes MTR and MTHFR on the frequencies of cells with chromosomal aberrations (CAs) in peripheral lymphocytes of Norwegian men. Log-linear Poisson regression models were applied on 357 subjects of whom data on all the polymorphisms examined were available. Total CAs and chromosome-type aberrations (CSAs) were significantly increased by higher age alone, whereas chromatid-type aberrations (CTAs) were elevated by the GSTT1-null genotype and MTHFR codon 222 variant allele and chromatid gaps (CTGs) by EPHX1 high activity genotype and occupational exposure. Stratification by smoking and age (<40 and ≥40 years) showed that the effect of the GSTT1 null and EPHX1 high activity genotypes only concerned (older) smokers, in agreement with the roles of the respective enzymes in detoxification and metabolic activation. The MTHFR codon 222 variant allele was associated with high CTGs in smokers, the MTR codon 919 variant allele with high CTAs in older smokers and the NAT2 fast acetylator genotype with high CTGs in older subjects. Among younger nonsmokers, however, carriers of the MTHFR codon 222 and MTR codon 919 variant alleles showed a decrease in the level of CTGs and total CAs, respectively. In conclusion, polymorphisms of GSTT1, EPHX1, MTHFR, MTR and NAT2 differentially affect the frequency of CTAs, CSAs and CTGs, showing interaction with smoking and age. It appears that CA subtypes rather than total CAs should be considered in this type of studies.

The level of claudin-7 is reduced as an early event in colorectal carcinogenesis.

BACKGROUND: Compromised epithelial barriers are found in dysplastic tissue of the gastrointestinal tract. Claudins are transmembrane proteins important for tight junctions. Claudins regulate the paracellular transport and are crucial for maintaining a functional epithelial barrier. Down-regulation of the oncogenic serine protease, matriptase, induces leakiness in epithelial barriers both in vivo and in vitro. We found in an in-silico search tight co-regulation between matriptase and claudin-7 expression. We have previously shown that the matriptase expression level decreases during colorectal carcinogenesis. In the present study we investigated whether claudin-7 expression is likewise decreased during colorectal carcinogenesis, thereby causing or contributing to the compromised epithelial leakiness of dysplastic tissue. METHODS: The mRNA level of claudin-7 (CLDN7) was determined in samples from 18 healthy individuals, 100 individuals with dysplasia and 121 colorectal cancer patients using quantitative real time RT-PCR. In addition, immunohistochemical stainings were performed on colorectal adenomas and carcinomas, to confirm the mRNA findings. RESULTS: A 2.7-fold reduction in the claudin-7 mRNA level was found when comparing the biopsies from healthy individuals with the biopsies of carcinomas (p < 0.001). Reductions in the claudin-7 mRNA levels were also detected in mild/moderate dysplasia (p < 0.001), severe dysplasia (p < 0.01) and carcinomas (p < 0.01), compared to a control sample from the same individual. The decrease at mRNA level was confirmed at the protein level by immunohistochemical stainings. CONCLUSIONS: Our results show that the claudin-7 mRNA level is decreased already as an early event in colorectal carcinogenesis, probably contributing to the compromised epithelial barrier in adenomas.

Collagen mRNA levels changes during colorectal cancer carcinogenesis.

BACKGROUND: Invasive growth of epithelial cancers is a complex multi-step process which involves dissolution of the basement membrane. Type IV collagen is a major component in most basement membranes. Type VII collagen is related to anchoring fibrils and is found primarily in the basement membrane zone of stratified epithelia. Immunohistochemical studies have previously reported changes in steady-state levels of different alpha(IV) chains in several epithelial cancer types. In the present study we aimed to quantitatively determine the mRNA levels of type IV collagen (alpha1/alpha 4/alpha 6) and type VII collagen (alpha1) during colorectal cancer carcinogenesis. METHODS: Using quantitative RT-PCR, we have determined the mRNA levels for alpha1(IV), alpha 4(IV), alpha 6(IV), and alpha1(VII) in colorectal cancer tissue (n = 33), adenomas (n = 29) and in normal tissue from the same individuals. In addition, corresponding tissue was examined from healthy volunteers (n = 20). mRNA levels were normalized to beta-actin. Immunohistochemical analysis of the distributions of type IV and type VII collagens were performed on normal and affected tissues from colorectal cancer patients. RESULTS: The alpha1(IV) and alpha1(VII) mRNA levels were statistically significantly higher in colorectal cancer tissue (p < 0.001) as compared to corresponding tissue from healthy controls. This is an early event as tissue from adenomas also displayed a higher level. There were small changes in the levels of alpha 4(IV). The level of alpha 6(IV) was 5-fold lower in colorectal cancer tissue as compared to healthy individuals (p < 0.01). The localisation of type IV and type VII collagen was visualized by immunohistochemical staining. CONCLUSION: Our results suggest that the down-regulation of alpha 6(IV) mRNA coincides with the acquisition of invasive growth properties, whereas alpha1(IV) and alpha1(VII) mRNAs were up-regulated already in dysplastic tissue. There are no differences in collagen expression between tissues from healthy individuals and normal tissues from affected individuals.

Expression of prostasin and its inhibitors during colorectal cancer carcinogenesis.

BACKGROUND: Clinical trials where cancer patients were treated with protease inhibitors have suggested that the serine protease, prostasin, may act as a tumour suppressor. Prostasin is proteolytically activated by the serine protease, matriptase, which has a very high oncogenic potential. Prostasin is inhibited by protease nexin-1 (PN-1) and the two isoforms encoded by the mRNA splice variants of hepatocyte growth factor activator inhibitor-1 (HAI-1), HAI-1A, and HAI-1B. METHODS: Using quantitative RT-PCR, we have determined the mRNA levels for prostasin and PN-1 in colorectal cancer tissue (n = 116), severe dysplasia (n = 13), mild/moderate dysplasia (n = 93), and in normal tissue from the same individuals. In addition, corresponding tissues were examined from healthy volunteers (n = 23). A part of the cohort was further analysed for the mRNA levels of the two variants of HAI-1, here denoted HAI-1A and HAI-1B. mRNA levels were normalised to beta-actin. Immunohistochemical analysis of prostasin and HAI-1 was performed on normal and cancer tissue. RESULTS: The mRNA level of prostasin was slightly but significantly decreased in both mild/moderate dysplasia (p < 0.001) and severe dysplasia (p < 0.01) and in carcinomas (p < 0.05) compared to normal tissue from the same individual. The mRNA level of PN-1 was more that two-fold elevated in colorectal cancer tissue as compared to healthy individuals (p < 0.001) and elevated in both mild/moderate dysplasia (p < 0.01), severe dysplasia (p < 0.05) and in colorectal cancer tissue (p < 0.001) as compared to normal tissue from the same individual. The mRNA levels of HAI-1A and HAI-1B mRNAs showed the same patterns of expression. Immunohistochemistry showed that prostasin is located mainly on the apical plasma membrane in normal colorectal tissue. A large variation was found in the degree of polarization of prostasin in colorectal cancer tissue. CONCLUSION: These results show that the mRNA level of PN-1 is significantly elevated in colorectal cancer tissue. Future studies are required to clarify whether down-regulation of prostasin activity via up regulation of PN-1 is causing the malignant progression or if it is a consequence of it.