Exploring Gut Microbiome Composition and Circulating Microbial DNA Fragments in Patients with Stage II/III Colorectal Cancer: A Comprehensive Analysis

BACKGROUND

Colorectal cancer (CRC) significantly contributes to cancer-related mortality, necessitating the exploration of prognostic factors beyond TNM staging. This study investigates the composition of the gut microbiome and microbial DNA fragments in stage II/III CRC.

METHODS

A cohort of 142 patients with stage II/III CRC and 91 healthy controls underwent comprehensive microbiome analysis. Fecal samples were collected for 16S rRNA sequencing, and blood samples were tested for the presence of microbial DNA fragments. De novo clustering analysis categorized individuals based on their microbial profiles. Alpha and beta diversity metrics were calculated, and taxonomic profiling was conducted.

RESULTS

Patients with CRC exhibited distinct microbial composition compared to controls. Beta diversity analysis confirmed CRC-specific microbial profiles. Taxonomic profiling revealed unique taxonomies in the patient cohort. De novo clustering separated individuals into distinct groups, with specific microbial DNA fragment detection associated with certain patient clusters.

CONCLUSIONS

The gut microbiota can differentiate patients with CRC from healthy individuals. Detecting microbial DNA fragments in the bloodstream may be linked to CRC prognosis. These findings suggest that the gut microbiome could serve as a prognostic factor in stage II/III CRC. Identifying specific microbial markers associated with CRC prognosis has potential clinical implications, including personalized treatment strategies and reduced healthcare costs. Further research is needed to validate these findings and uncover underlying mechanisms.

LKB1 Loss Correlates with STING Loss and, in Cooperation with β-Catenin Membranous Loss, Indicates Poor Prognosis in Patients with Operable Non-Small Cell Lung Cancer

To investigate the incidence and prognostically significant correlations and cooperations of LKB1 loss of expression in non-small cell lung cancer (NSCLC), surgical specimens from 188 metastatic and 60 non-metastatic operable stage I-IIIA NSCLC patients were analyzed to evaluate their expression of LKB1 and pAMPK proteins in relation to various processes. The investigated factors included antitumor immunity response regulators STING and PD-L1; pro-angiogenic, EMT and cell cycle targets, as well as metastasis-related (VEGFC, PDGFRα, PDGFRβ, p53, p16, Cyclin D1, ZEB1, CD24) targets; and cell adhesion (β-catenin) molecules. The protein expression levels were evaluated via immunohistochemistry; the RNA levels of LKB1 and NEDD9 were evaluated via PCR, while KRAS exon 2 and BRAFV600E mutations were evaluated by Sanger sequencing. Overall, loss of LKB1 protein expression was observed in 21% (51/248) patients and correlated significantly with histotype (p < 0.001), KRAS mutations (p < 0.001), KC status (concomitant KRAS mutation and p16 downregulation) (p < 0.001), STING loss (p < 0.001), and high CD24 expression (p < 0.001). STING loss also correlated significantly with loss of LKB1 expression in the metastatic setting both overall (p = 0.014) and in lung adenocarcinomas (LUACs) (p = 0.005). Additionally, LKB1 loss correlated significantly with a lack of or low β-catenin membranous expression exclusively in LUACs, both independently of the metastatic status (p = 0.019) and in the metastatic setting (p = 0.007). Patients with tumors yielding LKB1 loss and concomitant nonexistent or low β-catenin membrane expression experienced significantly inferior median overall survival of 20.50 vs. 52.99 months; p < 0.001 as well as significantly greater risk of death (HR: 3.32, 95% c.i.: 1.71-6.43; p <0.001). Our findings underscore the impact of the synergy of LKB1 with STING and β-catenin in NSCLC, in prognosis.

Unraveling the Role of Molecular Profiling in Predicting Treatment Response in Stage III Colorectal Cancer Patients: Insights from the IDEA International Study

BACKGROUND

This study aimed to investigate the molecular profiles of 237 stage III CRC patients from the international IDEA study. It also sought to correlate these profiles with Toll-like and vitamin D receptor polymorphisms, clinicopathological and epidemiological characteristics, and patient outcomes.

METHODS

Whole Exome Sequencing and PCR-RFLP on surgical specimens and blood samples, respectively, were performed to identify molecular profiling and the presence of Toll-like and vitamin D polymorphisms. Bioinformatic analysis revealed mutational status.

RESULTS

Among the enrolled patients, 63.7% were male, 66.7% had left-sided tumors, and 55.7% received CAPOX as adjuvant chemotherapy. Whole exome sequencing identified 59 mutated genes in 11 different signaling pathways from the Kyoto Encyclopedia of Genes and Genomes (KEGG) CRC panel. On average, patients had 8 mutated genes (range, 2-21 genes). Mutations in ARAF and MAPK10 emerged as independent prognostic factors for reduced DFS (p = 0.027 and p < 0.001, respectively), while RAC3 and RHOA genes emerged as independent prognostic factors for reduced OS (p = 0.029 and p = 0.006, respectively). Right-sided tumors were also identified as independent prognostic factors for reduced DFS (p = 0.019) and OS (p = 0.043). Additionally, patients with tumors in the transverse colon had mutations in genes related to apoptosis, PIK3-Akt, Wnt, and MAPK signaling pathways.

CONCLUSIONS

Molecular characterization of tumor cells can enhance our understanding of the disease course. Mutations may serve as promising prognostic biomarkers, offering improved treatment options. Confirming these findings will require larger patient cohorts and international collaborations to establish correlations between molecular profiling, clinicopathological and epidemiological characteristics and clinical outcomes.

Evaluation of Microsatellite Instability Molecular Analysis versus Immuno-Histochemical Interpretation in Malignant Neoplasms with Different Localizations

MMR gene germline mutations are considered a major genetic disorder in patients with hereditary nonpolyposis colon cancer (HNPCC) or Lynch syndrome; A total of 15% of sporadic colon carcinomas are MSI-High. MSI has also been observed in other cancers, such as endometrial, gastric, and ovarian cancer. The aim of the current study was to correlate and outline the optimal method between the molecular testing of the instability of microsatellite DNA regions (MSI status) and the loss of protein expression by immunehistochemistry (MMR). A total of 242 paraffin-embedded tissues from gastrointestinal, gynecological, genitourinary, lung, breast, and unknown primary cancer patients were analyzed for the expression of MLH1/MSH2/MSH6/PMS2 by immunohistochemistry, as well as for the molecular analysis of MSI status using PCR-based molecular fragment analysis. A total of 29 MSI-High patients were detected molecularly, while 23 patients were detected by immunohistochemistry, with rates that are comparable according to the literature. Based on the agreement coefficient of the two methods, a substantial agreement emerged (Kappa = 0.675 with standard error = 0.081, p < 0.001). Despite the substantial agreement, both methods ought to be established to determine MSI-H/dMMR status in all cancer types as a first-line screening test.

Investigation of Microbial Translocation, TLR and VDR Gene Polymorphisms, and Recurrence Risk in Stage III Colorectal Cancer Patients

Gut microbial dysbiosis and microbial passage into the peripheral blood leads to colorectal cancer (CRC) and disease progression. Toll-like (TLR) and vitamin D (VDR) receptors play important role in the immune modulation and polymorphisms that may increase CRC risk and death rates. The aim of the current study was to demonstrate the prognostic value of microbial DNA fragments in the blood of stage III CRC patients and correlate such microbial detection to TLR/VDR polymorphisms. Peripheral blood was collected from 132 patients for the detection of microbial DNA fragments, and TLR/VDR gene polymorphisms. In the detection of various microbial DNA fragments, TLR and VDR polymorphisms was significantly higher compared to healthy group. Homozygous individuals of either TLR or VDR polymorphisms had significantly higher detection rates of microbial DNA fragments. Mutational and MSI status were significantly correlated with TLR9 and VDR polymorphisms. Significantly shorter disease-free survival was associated with patients with BRAF mutated tumors and ApaI polymorphisms, whereas shorter overall survival was associated with the detection of C. albicans. The detection of B. fragilis, as demonstrated by the multivariate analysis, is an independent poor prognostic factor for shorter disease-free survival. TLR/VDR genetic variants were significantly correlated with the detection of microbial fragments in the blood, and this in turn is significantly associated with tumorigenesis and disease progression.

Prognostic Value of KRAS Mutations in Colorectal Cancer Patients

Simple Summary

Kirsten rat sarcoma viral oncogene homolog (KRAS)-mutated colorectal cancer (CRC) seems to have a different biological behavior and therapeutic approach compared with non-KRAS mutated CRC. Except for the proven predictive significance of KRAS mutations in CRC patients, their prognostic significance is still under evaluation. Our study shows that 93.2% of RAS-mutated patients were KRAS mutants, with G12D being the most common subtype. KRAS G12D mutation is correlated with better overall survival (OS). KRAS G12C mutations may indicate worse prognosis regarding progression free (PFS) and OS, as well as exon 4 and exon 3 KRAS mutations for PFS and OS, respectively. Further studies are warranted to confirm these results.

Abstract

Colorectal cancer (CRC) remains a major public health issue. The detection of parameters that affect CRC prognosis is of great significance. KRAS mutations, play a crucial role in tumorigenesis with a strong predictive value. KRAS-mutated stage-IV CRC patients gain no benefit of the anti-EGFR therapy. The KRAS G12C mutation subtype is under investigation for treatment regimens. The present study aimed to detect various RAS mutations in a cohort of 578 RAS-mutated CRC patients; 49% of them had de novo metastatic disease; 60% were male; 71.4% had left-sided tumors; and 94.6% had a good performance status. KRAS mutations were detected in 93.2% of patients, with KRAS G12D being the most common subtype (30.1%). KRAS mutations presented shorter progression-free (PFS) and overall survival (OS), compared with NRAS mutations, although not significantly (PFS: 13.8 vs. 18.5 months; p = 0.552; OS: 53.1 vs. 60.9 months; p = 0.249). KRAS G12D mutations presented better OS rates (p = 0.04). KRAS G12C mutation, even though not significantly, presented worse PFS and OS rates. KRAS exon 3 and 4 mutations presented different PFS and OS rates, although these were not significant. Concluding, KRAS G12D and G12C mutations lead to better and worst prognosis, respectively. Further studies are warranted to validate such findings and their possible therapeutic implication.

Microbial translocation, toll-like and vitamin D receptor polymorphisms in blood and risk of recurrence in stage III colorectal cancer

3531

Background: Microbial translocation from the intestinal lumen into the blood circulation is significantly linked to intestinal dysbiosis; thus, leading to colorectal cancer (CRC), disease progression and decreased survival. Toll-like (TLRs) and vitamin D receptors (VDRs) play essential role in immunity and gut microbiome determination. Polymorphisms in such receptors have been associated with increased CRC incidence risk and mortality. The aim was to evaluate the microbial translocation in the blood of stage III CRC patients and correlate the presence of TLR and VDR genetic variants with microbial DNA fragments at risk of CRC development and progression. Methods: A total of 132 stage III CRC patients and 100 healthy donors were enrolled in the study. Peripheral blood DNA was analyzed using PCR for the amplification of microbial DNA encoding 16S rRNA, β-galactosidase gene of Escherichia coli, glutamine synthase of Bacteroides fragilis, and 5.8S rRNA of Candida albicans. Moreover, DNA from patients and controls was analyzed using PCR and PCR-RFLP for genotyping functional polymorphisms of both TLR (TLR2, TLR4, TLR9) and VDR ( TaqI, ApaI, FokI and BsmI) genes. Results: Median age of patients was 62 years, 59.8% were males, 92.7% had a colon/sigmoid tumor, 24.4% had a right colon tumor and 99.2% had a good performance status. Microbial DNA fragments from 16S rRNA, E. coli, B. fragilis, and C. albicans were detected in 43.2%, 20.5%, 31.8% and 36.4% of patients, respectively. Significantly higher rates of all microbial fragments, but E. coli, were detected in the group of patients in comparison to healthy donors ( p < 0.001). Similarly, higher rates of both TLR and VDR genetic variants were detected in CRC patients compared to healthy donors ( p < 0.001). Moreover, individuals with homozygous mutant alleles of either TLR or VDR polymorphisms had significantly higher detection rates of microbial DNA fragments. KRAS, BRAF and MSI status were significantly correlated with TLR9 genetic variants ( p= 0.001, p= 0.013 and p= 0.011, respectively) and MSI status was significantly correlated with all four VDR polymorphisms ( TaqI, p= 0.044; ApaI, p= 0.037; FokI, p= 0.002 and BsmI, p< 0.001). Cox regression analysis revealed that BRAF mutations, histology type and ApaI genetic variants are significantly associated with shorter disease-free survival (DFS). C. albicans detection is significantly associated with shorter overall survival, and B. fragilis is an independent poor prognostic factor for decreased DFS (HR = 33.85; p = 0.018). Conclusions: The detection of higher frequencies of the TLR/ VDR genetic variants was correlated with significantly higher detection rates of microbial DNA fragments. The detection of these TLR/VDR polymorphisms and microbial DNA fragments in CRC patients highlighted their role in cancer development, progression, and patients’ survival.

Evaluation of circulating tumor cells in stage III colorectal cancer patients under three or six months of adjuvant therapy

e15601

Background: The duration of adjuvant oxaliplatin-combination treatment in stage III colorectal cancer (CRC) patients is still debatable. Circulating Tumor Cells (CTCs) have been proposed as a potential markers for detection of micrometastatic disease. The aim was to compare the elimination rate of CTCs in patients treated with three- and six-months treatment with FOLFOX or CAPOX, in stage III CRC patients. Methods: Peripheral blood samples were collected from 132 patients at baseline, after three (for all patients) and after six months (for those under six months treatment). Surgical specimens were collected from all patients for the evaluation of their genetic profiling using Sanger sequencing (Ras/Raf) and fragment analysis (microsatellite instability status). The detection and number of circulating tumor cells (CTCs) were evaluated using double immunofluorescence and a real time-polymerase chain reaction assay, at all three time points. Results: Median age of the patients was 62 years, 59.8% were males, 92.7% had a colon/sigmoid tumor location, 24.4% had tumor on the right colon and 99.2% had a good performance status (PS). Of all patients, 44.3% and 55.7% were treated with FOLFOX and CAPOX, respectively; patients received treatment for three and six months, were equally distributed. KRAS, NRAS and BRAFmutations were detected in 41.5%, 2.1% and 12.8%, respectively; whereas MSI-High status was detected in 9.8% of the patients. CTCs were detected in 43.2%, 42.4% and 54.2% of the patients, at baseline, after three and six months of treatment, respectively. Both positivity rate ( p< 0.001) and absolute number of CTCs ( p= 0.022) were decreased between baseline and three months of treatment. Moreover, a significant increase was observed both on the positivity rate ( p= 0.053) and absolute number of CTCs ( p< 0.001) between three and six months of treatment. Following Cox regression analysis, BRAF status and the detection of CTCs are significantly correlated with decreased time to progression. Conclusions: To conclude, the current study indicates that 3 months of adjuvant treatment is at least as efficacious as 6 months in eliminating CTCs. However, the increase of both the rate and number of positive CTCs after three months of treatment might highlight the emergence of resistant cancer cell clones.

Resectable Colorectal Cancer: Current Perceptions on the Correlation of Recurrence Risk, Microbiota and Detection of Genetic Mutations in Liquid Biopsies

Metastatic colorectal cancer (mCRC) remains a highly lethal malignancy, although considerable progress has resulted from molecular alterations in guiding optimal use of available treatments. CRC recurrence remains a great barrier in the disease management. Hence, the spotlight turns to newly mapped fields concerning recurrence risk factors in patients with resectable CRC with a focus on genetic mutations, microbiota remodeling and liquid biopsies. There is an urgent need for novel biomarkers to address disease recurrence since specific genetic signatures can identify a higher or lower recurrence risk (RR) and, thus, be used both as biomarkers and treatment targets. To a large extent, CRC is mediated by the immune and inflammatory interplay of microbiota, through intestinal dysbiosis. Clarification of these mechanisms will yield new opportunities, leading not only to the appropriate stratification policies, but also to more precise, personalized monitoring and treatment navigation. Under this perspective, early detection of post-operative CRC recurrence is of utmost importance. Ongoing trials, focusing on circulating tumor cells (CTCs) and, even more, circulating tumor DNA (ctDNA), seem to pave the way to a promising, minimally invasive but accurate and life-saving monitoring, not only supporting personalized treatment but favoring patients' quality of life, as well.

Evaluation of the Role of Circulating Tumor Cells and Microsatellite Instability Status in Predicting Outcome of Advanced CRC Patients

Colorectal cancer (CRC) remains one of the leading causes of cancer-related death due to its high metastatic potential. This study aimed to investigate the detection and heterogeneity of circulating tumor cells (CTCs) and the microsatellite instability (MSI) status in advanced CRC patients prior to any systemic front-line treatment. Peripheral whole blood was obtained from 198 patients. CTCs were detected using double immunofluorescence and a real time-polymerase chain reaction assay; whereas MSI status was evaluated using fragment analysis. Median age of the patients was 66 years, 63.1% were males, 65.2% had a colon/sigmoid tumor location and 90.4% had a good performance status (PS). MSI-High status was detected in 4.9% of the patients; 33.3%, 56.1% and 8.6% patients had at least one detectable CEACAM5⁺/EpCAM⁺, CEACAM5⁺/EpCAM^- and CEACAM5^-/EpCAM⁺ CTC, respectively, and 9.1% of the patients had CEACAM5mRNA-positive CTCs. Following multivariate analysis, age, PS and MSI were confirmed as independent prognostic factors for decreased time to progression, whereas age, PS and CTC presence were confirmed as independent prognostic factors for decreased overall survival. In conclusion, our data support the use of CEACAM5 as a dynamic adverse prognostic CTC biomarker in patients with metastatic CRC and MSI-High is considered an unfavorable prognostic factor in metastatic CRC patient tumors.

The Prognostic Value of the Detection of Microbial Translocation in the Blood of Colorectal Cancer Patients

Dysbiosis has been associated with various diseases and is of major health importance. Dysbiosis leads to microbial translocation, which is the passage of microorganisms, their fragments, or their metabolites from the intestinal lumen into the blood circulation and other sites. The aim of the study was to determine whether microbial translocation occurs in stage II/III-IV colorectal cancer (CRC) patients. The aim was also to evaluate the usefulness of blood PCR for diagnosis of such translocation and correlate the presence of toll-like receptor/vitamin D receptor (TLR/VDR) gene polymorphisms with microbial DNA fragments detected in the blood of CRC patients. Three hundred and ninety-seven CRC patients enrolled in the study. Peripheral blood DNA was analyzed using PCR for the amplification of genomic DNA encoding 16S rRNA, the β-galactosidase gene of Escherichia coli, glutamine synthase gene of Bacteroides fragilis, and 5.8S rRNA of Candida albicans. Significantly higher rates of all microbial fragments, but E. coli, detected were observed in the CRC patients (p < 0.001); such detection of all four microbial fragments was also significantly associated with the metastatic disease (p < 0.001), leading to shorter survival rates (p < 0.001). Tumor location in the right colon also significantly correlated with shorter survival (p = 0.016). Individuals with homozygous mutant alleles of TLR/VDR polymorphisms had significantly higher detection rates of microbial DNA fragments. The detection of microbial DNA fragments in CRC patients highlighted the role of these microbes in cancer development, progression, and patients' survival.

Correlation of PKM2 and CD44 Protein Expression with Poor Prognosis in Platinum-Treated Epithelial Ovarian Cancer: A Retrospective Study

CD44, a surface marker for cancer stem cells, interacts with PKM2, a key regulator of aerobic glycolysis, and enhances the glycolytic phenotype of cancer cells leading to antioxidant protection and macromolecules’ synthesis. To clarify the clinical importance of this “cross-talk” as a mechanism of drug resistance, we assessed the expression both of PKM2 and of CD44 in cancer cells of patients with epithelial ovarian cancer (EOC) treated with platinum-based treatment. One hundred and seventy-one patients with EOC were assessed for PKM2mRNA expression and PKM2 and CD44 proteins detection. Associations with progression-free survival (PFS) and overall survival (OS) were assessed with Kaplan–Meier and adjusted Cox regression models. PKM2mRNA and protein as well as CD44 protein were detectable in the majority of patients. Positive correlation between PKM2 and CD44 protein expression was observed (Spearman rho = 0.2, p = 0.015). When we used the median to group patients into high versus low expression, high PKM2mRNA and protein levels were significantly associated with lower progression-free survival (PFS; p = 0.003 and p = 0.002, respectively) and shorter overall survival (OS; p ≤ 0.001 and p = 0.001, respectively). However, high CD44 protein expression was significantly correlated only with shorter OS (p = 0.004). Moreover, patients with both high PKM2 and CD44 protein levels experienced shorter PFS and OS (p = 0.007 and p = 0.003, respectively) compared to patients with low expression of both proteins. Finally, higher PKM2mRNA and protein expression as well as CD44 protein expression (HR: 2.16; HR: 1.82; HR: 1.01, respectively) were independent prognostic factors for decreased median OS (mOS), whereas only PKM2 protein expression (HR: 1.95) was an independent prognostic factor for decreased median PFS (mPFS). In conclusion, PKM2 expression is a negative prognostic factor in EOC patients, but the interaction between CD44 and PKM2 that may be implicated in EOC platinum-resistance needs further investigation.

Immunotherapy in Metastatic Colorectal Cancer: Could the Latest Developments Hold the Key to Improving Patient Survival?

Immunotherapy has considerably increased the number of anticancer agents in many tumor types including metastatic colorectal cancer (mCRC). Anti-PD-1 (programmed death 1) and cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) immune checkpoint inhibitors (ICI) have been shown to benefit the mCRC patients with mismatch repair deficiency (dMMR) or high microsatellite instability (MSI-H). However, ICI is not effective in mismatch repair proficient (pMMR) colorectal tumors, which constitute a large population of patients. Several clinical trials evaluating the efficacy of immunotherapy combined with chemotherapy, radiation therapy, or other agents are currently ongoing to extend the benefit of immunotherapy to pMMR mCRC cases. In dMMR patients, MSI testing through immunohistochemistry and/or polymerase chain reaction can be used to identify patients that will benefit from immunotherapy. Next-generation sequencing has the ability to detect MSI-H using a low amount of nucleic acids and its application in clinical practice is currently being explored. Preliminary data suggest that radiomics is capable of discriminating MSI from microsatellite stable mCRC and may play a role as an imaging biomarker in the future. Tumor mutational burden, neoantigen burden, tumor-infiltrating lymphocytes, immunoscore, and gastrointestinal microbiome are promising biomarkers that require further investigation and validation.

Detection of microbial DNA in the blood of colorectal cancer patients for the diagnosis of microbial translocation

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Background: Dysbiosis has been associated with diseases and is of a major public health importance. Can lead to the passage of viable bacteria, their products or their fragments from the intestinal lumen through the mesenteric lymph nodes and other sites, known as bacterial translocation. The aim of the study was to determine whether microbial translocation occurs in stage II/III-IV colorectal cancer (CRC) patients and evaluate the usefulness of blood PCR for diagnosis of such translocation. Also to correlate the presence of Toll-Like Receptor and Vitamin D Receptor polymorphisms with the detection of microbial DNA fragments in the blood of CRC patients. Methods: Peripheral blood was obtained from 397 CRC patients (adjuvant n = 202 and metastatic n = 195) and 32 healthy individuals. DNA from all subjects was analyzed using PCR for amplification of genomic DNA encoding 16S rRNA, β-galactosidase gene of E. coli, Glutamine synthase gene of B. fragilis and 5.8S rRNA found in C. albicans. Results: Significantly higher rates of 16S rRNA, β-galactosidase, Glutamine synthase and 5.8S rRNA detection was observed in the pool of CRC patients than the controls ( p< 0.001). All microbial DNA fragments detected were also significantly associated with the metastatic disease ( p< 0.001) leading to shorter survival rates ( p< 0.001). Moreover, individuals with the homozygous mutant alleles of either TLR or VDR gene polymorphisms had significantly higher detection rates of microbial DNA fragments. Conclusions: The detection of microbial DNA fragments in patients with CRC highlights the role of these microbes in cancer development, progression and therefore in patients’ survival.

Evaluation of global simulations of aerosol particle and cloud condensation nuclei number, with implications for cloud droplet formation

A total of 16 global chemistry transport models and general circulation models have participated in this study; 14 models have been evaluated with regard to their ability to reproduce the near-surface observed number concentration of aerosol particles and cloud condensation nuclei (CCN), as well as derived cloud droplet number concentration (CDNC). Model results for the period 2011-2015 are compared with aerosol measurements (aerosol particle number, CCN and aerosol particle composition in the submicron fraction) from nine surface stations located in Europe and Japan. The evaluation focuses on the ability of models to simulate the average across time state in diverse environments and on the seasonal and short-term variability in the aerosol properties. There is no single model that systematically performs best across all environments represented by the observations. Models tend to underestimate the observed aerosol particle and CCN number concentrations, with average normalized mean bias (NMB) of all models and for all stations, where data are available, of -24% and -35% for particles with dry diameters > 50 and > 120nm, as well as -36% and -34% for CCN at supersaturations of 0.2% and 1.0%, respectively. However, they seem to behave differently for particles activating at very low supersaturations (< 0.1 %) than at higher ones. A total of 15 models have been used to produce ensemble annual median distributions of relevant parameters. The model diversity (defined as the ratio of standard deviation to mean) is up to about 3 for simulated N3 (number concentration of particles with dry diameters larger than 3 nm) and up to about 1 for simulated CCN in the extra-polar regions. A global mean reduction of a factor of about 2 is found in the model diversity for CCN at a supersaturation of 0.2% (CCN0.2) compared to that for N3, maximizing over regions where new particle formation is important. An additional model has been used to investigate potential causes of model diversity in CCN and bias compared to the observations by performing a perturbed parameter ensemble (PPE) accounting for uncertainties in 26 aerosol-related model input parameters. This PPE suggests that biogenic secondary organic aerosol formation and the hygroscopic properties of the organic material are likely to be the major sources of CCN uncertainty in summer, with dry deposition and cloud processing being dominant in winter. Models capture the relative amplitude of the seasonal variability of the aerosol particle number concentration for all studied particle sizes with available observations (dry diameters larger than 50, 80 and 120 nm). The short-term persistence time (on the order of a few days) of CCN concentrations, which is a measure of aerosol dynamic behavior in the models, is underestimated on average by the models by 40% during winter and 20% in summer. In contrast to the large spread in simulated aerosol particle and CCN number concentrations, the CDNC derived from simulated CCN spectra is less diverse and in better agreement with CDNC estimates consistently derived from the observations (average NMB -13% and -22% for updraft velocities 0.3 and 0.6 ms-1, respectively). In addition, simulated CDNC is in slightly better agreement with observationally derived values at lower than at higher updraft velocities (index of agreement 0.64 vs. 0.65). The reduced spread of CDNC compared to that of CCN is attributed to the sublinear response of CDNC to aerosol particle number variations and the negative correlation between the sensitivities of CDNC to aerosol particle number concentration (∂N d/∂N a) and to updraft velocity (∂N d/∂w). Overall, we find that while CCN is controlled by both aerosol particle number and composition, CDNC is sensitive to CCN at low and moderate CCN concentrations and to the updraft velocity when CCN levels are high. Discrepancies are found in sensitivities ∂N d/∂N a and ∂N d/∂w; models may be predisposed to be too "aerosol sensitive" or "aerosol insensitive" in aerosol-cloud-climate interaction studies, even if they may capture average droplet numbers well. This is a subtle but profound finding that only the sensitivities can clearly reveal and may explain inter-model biases on the aerosol indirect effect.

Loss of LKB1 Protein Expression Correlates with Increased Risk of Recurrence and Death in Patients with Resected, Stage II or III Colon Cancer

PURPOSE

The purpose of this study was to investigate the prognostic significance of liver kinase b1 (LKB1) loss in patients with operable colon cancer (CC).

Materials and Methods

Two hundred sixty-two specimens from consecutive patients with stage III or high-risk stage II CC, who underwent surgical resection with curative intent and received adjuvant chemotherapy with fluoropyrimidine and oxaliplatin, were analyzed for LKB1 protein expression loss, by immunohistochemistry as well as for KRAS exon 2 and BRAFV600E mutations by Sanger sequencing and TS, ERCC1, MYC, and NEDD9 mRNA expression by real-time quantitative reverse transcription polymerase chain reaction.

RESULTS

LKB1 expression loss was observed in 117 patients (44.7%) patients and correlated with right-sided located primaries (p=0.032), and pericolic lymph nodes involvement (p=0.003), BRAFV600E mutations (p=0.024), and TS mRNA expression (p=0.041). Patients with LKB1 expression loss experienced significantly lower disease-free survival (DFS) (hazard ratio [HR], 1.287; 95% confidence interval [CI], 1.093 to 1.654; p=0.021) and overall survival (OS) (HR, 1.541; 95% CI, 1.197 to 1.932; p=0.002), compared to patients with LKB1 expressing expressing tumors. Multivariate analysis revealed LKB1 expression loss as independent prognostic factor for both decreased DFS (HR, 1.217; 95% CI, 1.074 to 1.812; p=0.034) and decreased OS (HR, 1.467; 95% CI, 1.226 to 2.122; p=0.019).

CONCLUSION

Loss of tumoral LKB1 protein expression, constitutes an adverse prognostic factor in patients with operable CC.

ERCC1 SNPs as Potential Predictive Biomarkers in Non-Small Cell Lung Cancer Patients Treated With Platinum-Based Chemotherapy

Polymorphisms in ERCC1, XPD, and XRCC1 were examined for (a) association with the clinical outcome of 107 non-small cell lung cancer patients receiving front-line platinum-based chemotherapy, and (b) correlation with the ERCC1 mRNA levels of 176 chemo-naive primary tumors. The ERCC1-C8092 allele and the number of ERCC1 polymorphic variants (C8092A and Asn118Asn) were associated with progression-free survival. In non-squamous histology, tumoral ERCC1 mRNA levels were lower in patients homozygous for ERCC1-C8092 as compared with the patients carrying the A allele (p = .024). These findings merit investigation in larger cohorts of patients treated with uniform regimens.

PKM2 as a biomarker for chemosensitivity to front-line platinum-based chemotherapy in patients with metastatic non-small-cell lung cancer

BACKGROUND

Tumour cells exclusively express the embryonic M2 isoform of pyruvate kinase (PKM2). PKM2 expression levels have been correlated with the effect of platinum compounds in cancer cell lines and xenograft models. The potential predictive role of PKM2 in patients with metastatic/advanced non-small-cell lung cancer (NSCLC) receiving platinum-based chemotherapy as first-line was investigated.

METHODS

Quantitative real-time PCR was used to assess the expression of PKM2 in tumour samples from 148 and 157 NSCLC patients in the training and the validation set, respectively. All patients received front-line platinum-based chemotherapy. PKM2 mRNA expression was also analysed in a control group of 85 NSCLC patients treated with non-platinum containing regimens.

RESULTS

In the training set, high PKM2 mRNA levels were associated with decreased progression-free survival (PFS; 4.9 months vs 6.4, P=0.006), overall survival (OS; 10.1 vs 17.0 months, P=0.01) and disease control rate (DCR; 57.7% vs 74.3%; P=0.021) compared to patients with low PKM2 levels. In the validation set, high PKM2 mRNA levels were also associated with deceased PFS (3.7 vs 5.9 months, P=0.006), OS (8.3 vs 16.8 months, P=0.003) and DCR (57.7% vs 70.9%; P=0.049) compared to those with low PKM2 mRNA levels. There was no correlation between the PKM2 mRNA levels and the PFS (5.6 vs 5.9, P=0.43) or the OS (9.8 vs 10.1, P=0.51) in the control group. Multivariate analysis revealed high PKM2 mRNA expression as an independent predictive factor for the poor patients' outcome.

CONCLUSIONS

PKM2 expression may be a predictive biomarker of platinum sensitivity in advanced NSCLC patients treated with platinum-based chemotherapy.

BRAFV600E mutation analysis in patients with metastatic colorectal cancer (mCRC) in daily clinical practice: correlations with clinical characteristics, and its impact on patients' outcome

Background

To prospectively evaluate the usefulness of the BRAFV600E mutation detection in daily clinical practice in patients with metastatic Colorectal Cancer (mCRC).

Patients and Methods

504 mCRC patients treated with systemic chemotherapy ± biologics were analyzed.

Results

A statistically significant higher incidence of the BRAF mutation was observed in patients with ECOG-PS 2 (p=0.001), multiple metastatic sites (p=0.002),> 65 years old (p=0.004), primary tumors located in the colon (p<0.001), high-grade tumors (p=0.001) and in those with mucinous features (p=0.037). Patients with BRAFV600E mutated tumors had a statistically significantly reduced progression-free survival (PFS) compared to wild-type (wt) ones (4.1 and 11.6 months, respectively; p<0.001) and overall survival (OS) (14.0 vs. 34.6 months, respectively; p<0.001). In the multivariate analysis the BRAFV600E mutation emerged as an independent factor associated with reduced PFS (HR: 4.1, 95% CI 2.7–6.2; p<0.001) and OS (HR: 5.9, 95% CI 3.7–9.5; p<0.001). Among the 273 patients treated with salvage cetuximab or panitumumab, the BRAFV600E mutation was correlated with reduced PFS (2.2 vs. 6.0 months; p<0.0001) and OS (4.3 vs. 17.4 months; p<0.0001).

Conclusions

The presence of BRAFV600E-mutation in mCRC characterizes a subgroup of patients with distinct biologic, clinical and pathological features and is associated with very poor patients’ prognosis.

Predictive value of BRCA1, ERCC1, ATP7B, PKM2, TOPOI, TOPΟ-IIA, TOPOIIB and C-MYC genes in patients with small cell lung cancer (SCLC) who received first line therapy with cisplatin and etoposide

BACKGROUND

The aim of the study was to evaluate the predictive value of genes involved in the action of cisplatin-etoposide in Small Cell Lung Cancer (SCLC).

METHODS

184 SCLC patients' primary tumour samples were analyzed for ERCCI, BRCA1, ATP7B, PKM2 TOPOI, TOPOIIA, TOPOIIB and C-MYC mRNA expression. All patients were treated with cisplatin-etoposide.

RESULTS

The patients' median age was 63 years and 120 (65%) had extended stage, 75 (41%) had increased LDH serum levels and 131 (71%) an ECOG performance status was 0-1. Patients with limited stage, whose tumours expressed high ERCC1 (p=0.028), PKM2 (p=0.046), TOPOI (p=0.008), TOPOIIA (p=0.002) and TOPOIIB (p<0.001) mRNA had a shorter Progression Free Survival (PFS). In limited stage patients, high expression of ERCC1 (p=0.014), PKM2 (p=0.026), TOPOIIA (p=0.021) and TOPOIIB (p=0.019) was correlated with decreased median overall survival (mOS) while in patients with extended stage, only high TOPOIIB expression had a negative impact on Os (p=0.035). The favorable expression signature expression signature (low expression of ERCC1, PKM2, TOPOIIA and TOPOIIB) was correlated with significantly better PFS and Os in both LS-SCLC (p<0.001 and p=0.007, respectively) and ES-SCLC (p=0.007 and (p=0.011, respectively) group. The unfavorable expression signature was an independent predictor for poor PFS (HR: 3.18; p=0.002 and HR: 3.14; p=0.021) and Os (HR: 4.35; p=0.001and HR: 3.32; p=0.019) in both limited and extended stage, respectively.

CONCLUSIONS

Single gene's expression analysis as well as the integrated analysis of ERCC1, PKM2, TOPOIIA and TOPOIIB may predict treatment outcome in patients with SCLC. These findings should be further validated in a prospective study.

Predictive value of BRCA1, ERCC1, ATP7B, PKM2, TOPO-I, TOPO-iia, TOPO-iib, and c-MYC genes in patients with small cell lung cancer (SCLC) who received first-line therapy with cisplatin and etoposide

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Background: to evaluate the predictive value of genes correlated with cisplatin-etoposide (EP) metabolism or mode of function in patients with SCLC. Methods: Tumor samples from 184 patients, with SCLC were analyzed for ERCCI, BRCA1, ATP7B, TOPOI, TOPOIIA, TOPOIIB PKM2 and C-MYC mRNA expression by quantitative real-time PCR, from microdissected cells derived from patients’ primary tumors. All patients were treated with EP (plus radiotherapy for patients with limited disease-LS) in the department of Medical Oncology of the University Hospital of Heraklion. Results: The median age of the patients was 63 years (min-max: 33-78). One hundred-twenty (65%) patients presented with extended stage (ES), LDH was above the UNL in 75 (41%), while ECOG performance status was 0-1 in 131 (71%) of them. Shorter progression free survival (PFS) was observed in patients with LS-SCLC whose tumors expressed high ERCC1 (p=0.028), PKM2 (p=0.046), TOPO-I (p=0.008), TOPO-IIA (p=0.002) and TOPO-IIB (p<0.001) expression. High expression of ERCC1 (p=0.014), PKM2 (p=0.026), TOPO-IIA (p=0.021) and TOPO-IIB (p=0.019) was correlated with shortened median overall survival (OS) in LS-SCLC patients. In patients with ES-SCLC, only high TOPO-IIB expression was associated with decreased OS (p=0.035). The favorable genotype (low expression of ERCC1, PKM2, TOPO-IIA and TOPO-IIB) was correlated with significantly improved PFS in both LS-SCLC (p<0.001) and ES-SCLC (p=0.007) patients as well as with improved OS in the LS-SCLC (p=0.007) and ES-SCLC (p=0.011) group. Unfavorable genotype was independent predictor of poor PFS (HR: 3.18; p=0.002) and OS (HR: 4.35; p=0.001) in LS-SCLC as well as for both PFS (HR: 3.14; p=0.021) and OS (HR: 3.32; p=0.019) in ES-SCLC. Conclusions: Single gene’s expression analysis as well as the integrated analysis of ERCC1, PKM2, TOPO-IIA and TOPO-IIB may predict treatment outcome in patients with SCLC. The results of our study, if validated prospectively, may help in selecting patients for personalized therapeutic strategies.

Residual renal function in hemodialysis patients: the role of Angiotensin-converting enzyme inhibitor in its preservation

Residual Renal function (RRF) has an important role in the overall morbidity and mortality in hemodialysis patients. The role of angiotensin-converting enzyme inhibitor (ACEi) in preserving renal function in chronic proteinuric nephropathies is well documented. We test the hypothesis that enalapril (an ACEi) slows the rate of decline of RRF in patients starting hemodialysis. A prospective, randomized open-label study was carried out. 42 patients were randomized in two groups either in treatment with enalapril or no treatment at all. Our study has proven that enalapril has a significant effect on preserving residual renal function in patients starting dialysis at least during the first 12 months from the initiation of the hemodialysis. Further studies are necessary in order to investigate the potential long-term effect of ACEi on residual renal function and on morbidity and mortality in patients starting hemodialysis.

PKM2 mRNA expression to predict disease recurrence in patients with stage II or III colon cancer treated with oxaliplatin in combination with fluoropyrimidines

468

Background: Tumor cells have been shown to express exclusively the embryonic M2 isoform of pyruvate kinase (PKM2), which is a key enzyme that regulates aerobic glycolysis in tumor cells. Use of RNA interfering (RNAi) targeting PKM2 significantly inhibits tumor growth when combined with cisplatin in xenograft models. We evaluated the predictive significance of PKM2 in patients with “high” risk stage II or stage III colon cancer treated with oxaliplatin-fluoropyrimidines chemotherapy adjuvant treatment.

Methods: FFPE primary tumours from 261 patients with stage II or III colon cancer with colon cancer were analyzed for PKM2 mRNA expression by RT-qPCR. All patients had received adjuvant treatment with an oxaliplatin and fluoropyrimidine combination. Also, match normal mucosas from 50 of these patients have been analyzed. Finally, 50 polyps (20 with low grade dysplasia, 20 high grade dysplasia and 10 serrated adenomas) from non-colon cancer patients were included in the for PKM2 mRNA expression by RT-qPCR. The analysis was performed with a set of primers and probes which amplify only the M2 isoform.

Results: PKM2 mRNA expression was significantly higher in tumor areas in comparison with normal mucosa (p=0.001) and low-grade adenomas (p=0.001) as well as in tumors with BRAF mutations (p=0.001). Adenomas with high-grade dysplasia (p=0.002) and serrated adenomas (p=0.001) presented significantly higher PKM2 mRNA expression. Overexpression of PKM2 was associated with significantly lower Disease Free (p=0.018) and Overall Survival (p=0.031). Multivariate analysis revealed PKM2 high mRNA expression as independent prognostic factors for decreased DFS (HR: 2.1, p=0.003) and OS (HR: 1.8, p=0.019).

Conclusions: These results provide evidence that the PKM2 mRNA expression could be used as prognostic/predictive marker for disease recurrence in patients with operable colon cancer. Analysis of the PKM2 mRNA expression in patients treated with non-oxaliplatin containing adjuvant treatment is currently performed.

Folinic acid, 5-fluorouracil, irinotecan (FOLFIRI) plus chemoradiation (CRT) with 5-fluorouracil (5FU) as adjuvant treatment for patients with operable gastric cancer (OGC): A feasibility study with pharmacogenetic analysis

44

Background: To evaluate the efficacy and safety of FOLFIRI plus CRT with 5FU as adjuvant treatment for patients with OGC.

Methods: Patients received treatment with FOLFIRI (irinotrecan 150 mg/m2, d1, LV 200 mg/m2, d1+2 and 5FU [400 mg/m2/d bolus and 600 mg/m2/d, 22 h infusion, d1+2]) for 2 15-day cycles followed by RT (45Gy) with 5FU continuous infusion (325 mg/m2/d in the 1st and 5th week) administration. Eight additional cycles of FOLFIRI were administered after the completion of CRT. BRCA1, ERCC1, XPD, TOPO-I, TOPO-IIA and B and TS mRNA expression was determined in the primary tumor where available.

Results: The median age of the 171 enrolled patients was 62 years, 114 (66%) were males, 136 (79%) had R0 resections and 152 (89%) had at least a D1 resection. Treatment was completed as per protocol in 107 (63%) of the patients. CRT was completed in all but 5 (3%) patients. The median rate of drug exposure was 93% for irinotecan, 87% for 5FU and 91% for LV. The most common grade 3/4 adverse events were neutropenia (32%), febrile neutropenia (3.5%) and diarrhea (7%). After a median follow-up of 45.7 months 84 had relapsed and 70 were deceased. The median disease-free survival (DFS) was 30 months (95% CI: 18-41 months), while the projected median overall survival (mOS) was 53.7 months (95% CI: 30-77 months). The recurrence free probability at 5 years was 44% while the probability of survival at 5 years was 46%. From the studied pharmacogenetic markers only TS low expression was correlated with a trend towards improved DFS and OS in patients with R0 resections.

Conclusions: These results show that the administration of FOLFIRI plus CRT with 5FU as adjuvant treatment in OGC is a feasible approach with acceptable toxicity and challenging efficacy which merits further evaluation in a randomized trial.

No significant financial relationships to disclose.

PKM2 as a biomarker for sensitivity to oxaliplatin-based chemotherapy in metastatic colorectal cancer (mCRC)

434

Background: Tumour cells have been shown to express exclusively the embryonic M2 isoform of pyruvate kinase (PKM2), which is a key enzyme that regulates aerobic glycolysis in tumor cells. Use of RNA interfering (RNAi) targeting PKM2 significantly inhibits tumor growth when combined with cisplatin in xenograft models. We evaluated the predictive significance of PKM2 in patients with mCRC treated with oxaliplatin- based chemotherapy in the first-line setting.

Methods: FFPE primary tumors from 140 mCRC patients were analyzed for PKM2 mRNA expression by RT-qPCR. The analysis was performed with a set of primers and probes which amplify only the M2 isoform.

Results: The patients' characteristics were all typical for mCRC (median age 65 years, 61% males, 75% colon cancer 25% rectal cancer, 41% undifferentiated tumors, 21% mucinous features). PKM2 was successfully amplified in all specimens. Time to tumor progression (TTP) was significantly lower in patients with overexpression of PKM2 (6.7 vs. 9.1 months for high and low expression, respectively, p=0.004). Similarly, median overall survival (mOS) was significantly decreased in patients with upregulation of PKM2 (21.9 vs. 30.2 months for high and low expression, respectively, p=0.004). Multivariate analysis revealed PKM2 high mRNA expression (HR: 1.7, p=0.005) and the presence of undifferantited tumors (HR: 2.2, p<0.0001) as independent prognostic factors for decreased TTP. Similarly, PKM2 high mRNA expression (HR: 1.8, p=0.005) and the presence of undifferantited tumors (HR: 2.5, p<0.0001) were revealed as independent prognostic factors for decreased mOS.

Conclusions: These results provide evidence that the PKM2 mRNA expression could be used as a predictive factor for sensitivity to oxaliplatin-based chemotherapy. The results should be validated prospectively in an independent patient cohort.

No significant financial relationships to disclose.

Impact of KRAS, BRAF, and PIK3CA mutations, PTEN, AREG, and EREG expression, and skin rash in metastatic colorectal cancer patients treated with cetuximab-containing salvage treatment

445

Background: To investigate the predictive significance of KRAS exon 2, BRAF V600E, PIK3CA exon 9 and 20 mutational status, AREG- EREG mRNA expression, PTEN protein expression and skin rash in patients with metastatic colorectal cancer (mCRC) treated with cetuximab containing salvage chemotherapy.

Methods: Primary tumors from 112 mCRC patients were analyzed. The worst skin toxicity during treatment was recorded.

Results: KRAS, BRAF and PIK3CA mutations were present in 37 (33%), 8 (7.2%) and 11 (9.8%) cases, respectively, PTEN was lost in 21 (19.8%) cases, AREG and EREG were overexpressed in 48 (45%) and 51 (49%) cases. In the whole study population, time to tumor progression (TTP) and overall survival (OS) was significantly lower in patients with KRAS (p=0.001 and p=0.026, respectively) or BRAF (p=0.001 and p<0.0001, respectively) mutant tumors, downregulation of AREG (p=0.018 and p=0.013, respectively) or EREG (p=0.002 and p=0.004, respectively) and in those with grade 0-1 skin rash (p<0.0001 and p<0.0001, respectively). In KRAS wt patients TTP and OS was significantly lower in patients with BRAF (p=0.0001 and p<0.0001, respectively) mutant tumors, downregulation of AREG (p=0.021 and p=0.004, respectively) or EREG (p=0.0001 and p<0.0001, respectively) and grade 0-1 skin rash (p<0.0001 and p<0.0001, respectively). TTP was significantly lower in patients with PIK3CA mutations (p=0.01) or lost PTEN (p=0.002). Multivariate analysis revealed KRAS (hazard ratio [HR] 4.3, p<0.0001), BRAF mutation (HR: 5.1, p<0.0001), EREG low mRNA expression (HR: 1.6, p=0.021) and absence of severe/moderate skin rash (HR: 4.0, p<0.0001) as independent prognostic factors for decreased TTP. Similarly, KRAS (HR 2.9, p=0.01), BRAF mutation (HR: 3.0, p=0.001), EREG low mRNA expression (HR: 1.7, p=0.021), absecence of severe/moderate skin rash (HR: 3.7, p<0.0001) and the presence of undifferantited tumours (HR: 2.2, p=0.001) were revealed as independent prognostic factors for decreased OS.

Conclusions: These results underscore the potential of advanced CRCs genetic profiling in order to identify patients with different treatment response.

No significant financial relationships to disclose.

Impact of KRAS, BRAF, PIK3CA mutations, PTEN, AREG, EREG expression and skin rash in ≥ 2 line cetuximab-based therapy of colorectal cancer patients

Background

To investigate the predictive significance of KRAS, BRAF, PIK3CA mutational status, AREG- EREG mRNA expression, PTEN protein expression and skin rash in metastatic colorectal cancer (mCRC) patients treated with cetuximab containing salvage chemotherapy.

Methods

Primary tumors from 112 mCRC patients were analyzed. The worst skin toxicity during treatment was recorded.

Results

KRAS, BRAF and PIK3CA mutations were present in 37 (33%), 8 (7.2%) and 11 (9.8%) cases, respectively, PTEN was lost in 21 (19.8%) cases, AREG and EREG were overexpressed in 48 (45%) and 51 (49%) cases. In the whole study population, time to tumor progression (TTP) and overall survival (OS) was significantly lower in patients with KRAS (p = 0.001 and p = 0.026, respectively) or BRAF (p = 0.001 and p<0.0001, respectively) mutant tumors, downregulation of AREG (p = 0.018 and p = 0.013, respectively) or EREG (p = 0.002 and p = 0.004, respectively) and grade 0-1 skin rash (p<0.0001 and p<0.0001, respectively). In KRAS wt patients TTP and OS was significantly lower in patients with BRAF (p = 0.0001 and p<0.0001, respectively) mutant tumors, downregulation of AREG (p = 0.021 and p = 0.004, respectively) or EREG (p = 0.0001 and p<0.0001, respectively) and grade 0-1 skin rash (p<0.0001 and p<0.0001, respectively). TTP was significantly lower in patients with PIK3CA mutations (p = 0.01) or lost PTEN (p = 0.002). Multivariate analysis revealed KRAS (Hazard Ratio [HR] 4.3, p<0.0001), BRAF mutation (HR: 5.1, p<0.0001), EREG low expression (HR: 1.6, p = 0.021) and absence of severe/moderate skin rash (HR: 4.0, p<0.0001) as independent prognostic factors for decreased TTP. Similarly, KRAS (HR 2.9, p = 0.01), BRAF mutation (HR: 3.0, p = 0.001), EREG low expression (HR: 1.7, p = 0.021), absecence of severe/moderate skin rash (HR: 3.7, p<0.0001) and the presence of undifferantited tumours (HR: 2.2, p = 0.001) were revealed as independent prognostic factors for decreased OS.

Conclusions

These results underscore that KRAS-BRAF mutations and EREG expression can be used as biomarkers to further select patients undergoing anti-EGFR treatment.

Prognostic significance of the detection of peripheral blood CEACAM5mRNA-positive cells by real-time polymerase chain reaction in operable colorectal cancer

PURPOSE

To evaluate the clinical relevance of circulating CEACAM5mRNA-positive cells in patients with operable colorectal cancer (CRC).

METHODS

Peripheral blood was obtained from 265 patients with operable CRC before the initiation of adjuvant systemic therapy from 96 normal donors and RNA prepared from the Lovo and ARH-77 CRC and leukemic cell lines, respectively, was used as positive and negative controls. The detection of CEACAM5mRNA-positive cells was done using a real-time PCR assay. The association with known prognostic factors and the effect of CEACAM5mRNA-positive cells on patients' prognosis was investigated.

RESULTS

The analytical detection limit of the method was found to correspond to 0.7 Lovo cell equivalence/5 μg RNA, with a sensitivity of 1 tumor cell/10(5) normal cells and a specificity of 97%. Ninety-eight (37%) patients had detectable circulating CEACAM5mRNA-positive cells. Detection of CEACAM5mRNA-positive cells was significantly associated with higher relapse rate (P < 0.001), decreased disease-free survival (DFS; P < 0.001), higher death rate (P = 0.017), and decreased median overall survival (P = 0.025). Multivariate analysis revealed that the detection of circulating CEACAM5mRNA-positive cells was an independent prognostic factor for decreased DFS [HR = 3.4; 95% CI: 2.0-5.9; P < 0.001].

CONCLUSIONS

Detection of peripheral blood CEACAM5mRNA-positive cells is an adverse prognostic factor correlated with poor clinical outcome in patients with operable CRC.

Type 1 diabetes is associated with alexithymia in nondepressed, non-mentally ill diabetic patients: a case-control study

OBJECTIVE

Alexithymia refers to difficulty in identifying and expressing emotions, and it is a characteristic common to several psychiatric and medical conditions, including autoimmune disorders. Type 1 diabetes (T1D) is an autoimmune disorder with increased psychiatric comorbidity. Previously reported associations between alexithymia and T1D may have been confounded by the presence of depression. The central aim of this study was to examine alexithymia levels in psychiatrically uncomplicated T1D outpatients with that of nondiabetic controls.

METHODS

Ninety-six T1D patients without any DSM-IV Axis I diagnoses and 105 age- and sex-matched healthy controls entered the study. Alexithymia and depressive symptoms were assessed with the Toronto Alexithymia Scale (TAS-20) and the Beck Depression Inventory (BDI-21), respectively. Multivariate regression models were used to evaluate the association of alexithymia with the presence of diabetes, duration of diabetes, diabetes control, parameters of treatment intensification, and diabetic complications.

RESULTS

T1D was positively associated with the TAS-20 "identifying feelings" (beta coefficient=2.64, P=.003) and "externally oriented thinking" (beta coefficient=1.73, P=.011) subscales. The prevalence of overall alexithymia (TAS-20 total score, > or =60) was 22.2% in T1D patients and 7.6% in the controls (OR, 4.6; 95% CI, 1.7-12.8). TAS-20 scores were positively associated with diabetes duration and negatively with treatment intensification parameters.

CONCLUSIONS

Alexithymia is higher in psychiatrically uncomplicated T1D patients than in healthy controls even after adjustment for confounding depressive symptoms; it is greater with longer diabetes duration and is associated with some reduced parameters of treatment intensification but not with worse outcome in terms of glycemic control or somatic complications.

An unusual cause of severe hyperkalemia in a dialysis patient

Hyperkalemia is a common clinical problem in dialysis patients. We wish to present an unusual case of severe hyperkalemia caused by fragmentation haemolysis in a dialysis patient with a prosthetic aortic valve. A 45-year-old man with a 5-year history of end-stage renal disease under dialysis, a known history of paroxysmal atrioventricular nodal re-entrant tachycardia and aortic valve replacement, presented to our department with a recent history of palpitation and profound generalized muscle weakness. The laboratory evaluation revealed severe hyperkalemia (potassium 8.5 mEq/l), anaemia, high levels of lactate dehydrogenase, indirect bilirubin and low levels of haptoglobin, and the peripheral blood smear showed a high percentage of schistocytes (3.8%). A diagnosis of hyperkalemia caused by fragmentation haemolysis attributed to the haemodynamic turbulence on an artificial surface caused by the supraventricular tachycardia was established. After normal sinus rhythm was restored the patient presented with complete remission to the pre-event values of all haemolysis indices.

The involvement of LHCII-associated polyamines in the response of the photosynthetic apparatus to low temperature

The influence of low temperature on the structure and function of the photosynthetic apparatus was investigated in Phaseolus vulgaris L. Ten-day-old plants (grown at 26 degrees C) have been exposed to low temperature (6 degrees C) for 52 h and, then, transferred to the initial temperature (26 degrees C) for additional 30 h. Biochemical and physico-chemical measurements performed in the low temperature-treated plants showed that the response of the photosynthetic apparatus to low temperature is affected by the changes occurring in the pattern of LHCII-associated putrescine (Put) and spermine (Spm) which adjust the size of LHCII. The decrease of Put/Spm ratio, mainly due to the reduction in the quantity of LHCII-associated Put led to an increase of the LHCII, especially of the oligomeric forms. These alterations in the structure of the photosynthetic apparatus combined with the reduction in the photosynthetic electron transfer rate resulted in the inactivation of active reaction centers and the increase of dissipated energy which diminished the photosynthetic efficiency and the maximal photosynthetic rate. The transfer of plants at 26 degrees C after the low temperature treatment showed that, structurally and functionally, the photosynthetic mechanism recovered quite fast to the initial condition.