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Background: Physical activity and obesity are well-established factors of colorectal cancer risk and prognosis. Here, we investigate associations of individual and combined physical activity and body mass index (BMI) groups with proinflammatory biomarkers in colorectal cancer patients., Methods: Self-reported physical activity levels were classified as "active" (≥8.75 MET-hours/week) versus "inactive" (<8.75 MET-hours/week) in n = 579 stage I-IV colorectal cancer patients enrolled in the ColoCare Study. BMI [normal weight (≥18.5-<25 kg/m2), overweight (≥25-<30 kg/m2), and obese (≥30 kg/m2)] was abstracted from medical records. Patients were classified into four combinations of physical activity levels and BMI. Biomarkers [C-reactive protein (CRP), SAA, IL6, IL8, and TNFα] in presurgery serum samples were measured using the Mesoscale Discovery Platform. Regression models were used to compute relative percent differences in biomarker levels by physical activity and BMI groups., Results: "Inactive" patients had non-statistically significant higher IL6 levels compared with "active" patients (+36%, P = 0.10). "Obese" patients had 88% and 17% higher CRP and TNFα levels compared with "normal weight" patients (P = 0.03 and 0.02, respectively). Highest CRP levels were observed among "overweight or obese/inactive" compared with "normal weight/active" patients (P = 0.03)., Conclusions: We provide evidence of associations between individual and combined physical activity and BMI groups with proinflammatory biomarkers. Although BMI was identified as the key driver of inflammation, biomarker levels were higher among "inactive" patients across BMI groups., Impact: This is the largest study in colorectal cancer patients investigating associations of energy balance components with inflammatory biomarkers. Our results suggest that physical activity may reduce obesity-induced inflammation in colorectal cancer patients and support the design of randomized controlled trials testing this hypothesis., (©2022 American Association for Cancer Research.)

Background: Folate-mediated 1-carbon metabolism requires several nutrients, including vitamin B6. Circulating biomarker concentrations indicating high vitamin B6 status are associated with a reduced risk of colorectal cancer (CRC). However, little is known about the effect of B6 status in relation to clinical outcomes in CRC patients., Objectives: We investigated survival outcomes in relation to vitamin B6 status in prospectively followed CRC patients., Methods: A total of 2031 patients with stage I-III CRC participated in 6 prospective patient cohorts in the international FOCUS (folate-dependent 1-carbon metabolism in colorectal cancer recurrence and survival) Consortium. Preoperative blood samples were used to measure vitamin B6 status by the direct marker pyridoxal 5'-phosphate (PLP), as well as the functional marker HK-ratio (HKr)[3'-hydroxykynurenine: (kynurenic acid + xanthurenic acid + 3'-hydroxy anthranilic acid + anthranilic acid)]. Using Cox proportional hazards regression, we examined associations of vitamin B6 status with overall survival (OS), disease-free survival (DFS), and risk of recurrence, adjusted for patient age, sex, circulating creatinine concentrations, tumor site, stage, and cohort., Results: After a median follow-up of 3.2 y for OS, higher preoperative vitamin B6 status as assessed by PLP and the functional marker HKr was associated with 16-32% higher all-cause and disease-free survival, although there was no significant association with disease recurrence (doubling in PLP concentration: HROS, 0.68; 95% CI: 0.59, 0.79; HRDFS, 0.84; 95% CI: 0.75, 0.94; HRRecurrence, 0.96; 95% CI: 0.84, 1.09; HKr: HROS, 2.04; 95% CI: 1.67, 2.49; HRDFS, 1.56; 95% CI: 1.31, 1.85; HRRecurrence, 1.21; 95% CI: 0.96,1. 52). The association of PLP with improved OS was consistent across colorectal tumor site (right-sided colon: HROS, 0.75; 95% CI: 0.59, 0.96; left-sided colon: HROS, 0.71; 95% CI: 0.55, 0.92; rectosigmoid junction and rectum: HROS, 0.61; 95% CI: 0.47, 0.78)., Conclusion: Higher preoperative vitamin B6 status is associated with improved OS among stage I-III CRC patients., (© The Author(s) 2022. Published by Oxford University Press on behalf of the American Society for Nutrition.)

A distinct group of colorectal carcinomas (CRCs) referred to as the "CpG island methylator phenotype" (CIMP) shows an extremely high incidence of de novo DNA methylation and may share common pathological, clinical or molecular features. However, there is limited consensus about which CpG islands (CGIs) define a CIMP, particularly in microsatellite stable (MSS) carcinomas. To study this phenotype in a systematic manner, we analyzed genome-wide CGI DNA methylation profiles of 19 MSS CRC using methyl-CpG immunoprecipitation (MCIp) and hybridization on 244K CGI oligonucleotide microarrays, determined KRAS and BRAF mutation status and compared disease-related DNA methylation changes to chromosomal instability as detected by microarray-based comparative genomic hybridization. Results were validated using mass spectrometry analysis of bisulfite-converted DNA at a subset of 76 individual CGIs in 120 CRC and 43 matched normal tissue samples. Both genome-wide profiling and CpG methylation fine mapping segregated a group of CRC showing pronounced and frequent de novo DNA methylation of a distinct group of CGIs that only partially overlapped with previously established classifiers. The CIMP group defined in our study revealed significant association with colon localization, either KRAS or BRAF mutation, and mostly minor chromosomal losses but no association with known histopathological features. Our data provide a basis for defining novel marker panels that may enable a more reliable classification of CIMP in all CRCs, independently of the MS status., (© 2021 The Authors. International Journal of Cancer published by John Wiley & Sons Ltd on behalf of UICC.)

Based on new trial data regarding immune checkpoint inhibitors (ICIs), the detection of high-grade microsatellite instability (MSI-H) or underlying deficient mismatch repair protein (dMMR) is now becoming increasingly important for predicting treatment response. For the first time, a PD‑1 ICI (pembrolizumab) has been approved by the European Medicines Agency (EMA) for first-line treatment of advanced (stage IV) dMMR/MSI‑H colorectal cancer (CRC). Further indications, such as dMMR/MSI‑H endometrial carcinoma (EC), have already succeeded (Dostarlimab, 2nd line treatment) and others are expected to follow before the end of 2021. The question of optimal testing in routine diagnostics should therefore be re-evaluated. Based on a consideration of the strengths and weaknesses of the widely available methods (immunohistochemistry and PCR), a test algorithm is proposed that allows quality assured, reliable, and cost-effective dMMR/MSI‑H testing. For CRC and EC, testing is therefore already possible at the primary diagnosis stage, in line with international recommendations (NICE, NCCN). The clinician is therefore enabled from the outset to consider not only the predictive but also the prognostic and predispositional implications of such a test when counseling patients and formulating treatment recommendations. As a basis for quality assurance, participation in interlaboratory comparisons and continuous documentation of results (e.g., QuIP Monitor) are strongly recommended.

Since metastatic colorectal cancer (CRC) is a leading cause of cancer-related death, therapeutic approaches overcoming primary and acquired therapy resistance are an urgent medical need. In this study, the efficacy and toxicity of high-affinity inhibitors targeting antiapoptotic BCL-2 proteins (BCL-2, BCL-XL, and MCL-1) were evaluated. By RNA sequencing analysis of a pan-cancer cohort comprising >1500 patients and subsequent prediction of protein activity, BCL-XL was identified as the only antiapoptotic BCL-2 protein that is overactivated in CRC. Consistently, pharmacologic and genetic inhibition of BCL-XL induced apoptosis in human CRC cell lines. In a combined treatment approach, targeting BCL-XL augmented the efficacy of chemotherapy in vitro, in a murine CRC model, and in human ex vivo derived CRC tissue cultures. Collectively, these data show that targeting of BCL-XL is efficient and safe in preclinical CRC models, observations that pave the way for clinical translation.

Obesity and obesity-driven cancer rates are continuing to rise worldwide. We hypothesize that adipocyte-colonocyte interactions are a key driver of obesity-associated cancers. To understand the clinical relevance of visceral adipose tissue in advancing tumor growth, we analyzed paired tumor-adjacent visceral adipose, normal mucosa, and colorectal tumor tissues as well as presurgery blood samples from patients with sporadic colorectal cancer. We report that high peroxisome proliferator-activated receptor gamma ( PPARG ) visceral adipose tissue expression is associated with glycoprotein VI (GPVI) signaling-the major signaling receptor for collagen-as well as fibrosis and adipogenesis pathway signaling in colorectal tumors. These associations were supported by correlations between PPARG visceral adipose tissue expression and circulating levels of plasma 4-hydroxyproline and serum intercellular adhesion molecule 1 (ICAM1), as well as gene set enrichment analysis and joint gene-metabolite pathway results integration that yielded significant enrichment of genes defining epithelial-to-mesenchymal transition-as in fibrosis and metastasis-and genes involved in glycolytic metabolism, confirmed this association. We also reveal that elevated prostaglandin-endoperoxide synthase 2 ( PTGS2 ) colorectal tumor expression is associated with a fibrotic signature in adipose-tumor crosstalk via GPVI signaling and dendritic cell maturation in visceral adipose tissue. Systemic metabolite and biomarker profiling confirmed that high PTGS2 expression in colorectal tumors is significantly associated with higher concentrations of serum amyloid A and glycine, and lower concentrations of sphingomyelin, in patients with colorectal cancer. This multi-omics study suggests that adipose-tumor crosstalk in patients with colorectal cancer is a critical microenvironment interaction that could be therapeutically targeted. See related spotlight by Colacino et al., p. 803 ., (©2020 American Association for Cancer Research.)

Colorectal cancer is the second most common cause of cancer-related death globally, with marked differences in prognosis by disease stage at diagnosis. We studied circulating metabolites in relation to disease stage to improve the understanding of metabolic pathways related to colorectal cancer progression. We investigated plasma concentrations of 130 metabolites among 744 Stages I-IV colorectal cancer patients from ongoing cohort studies. Plasma samples, collected at diagnosis, were analyzed with liquid chromatography-mass spectrometry using the Biocrates AbsoluteIDQ™ p180 kit. We assessed associations between metabolite concentrations and stage using multinomial and multivariable logistic regression models. Analyses were adjusted for potential confounders as well as multiple testing using false discovery rate (FDR) correction. Patients presented with 23, 28, 39 and 10% of Stages I-IV disease, respectively. Concentrations of sphingomyelin C26:0 were lower in Stage III patients compared to Stage I patients (p FDR  < 0.05). Concentrations of sphingomyelin C18:0 and phosphatidylcholine (diacyl) C32:0 were statistically significantly higher, while citrulline, histidine, phosphatidylcholine (diacyl) C34:4, phosphatidylcholine (acyl-alkyl) C40:1 and lysophosphatidylcholines (acyl) C16:0 and C17:0 concentrations were lower in Stage IV compared to Stage I patients (p FDR  < 0.05). Our results suggest that metabolic pathways involving among others citrulline and histidine, implicated previously in colorectal cancer development, may also be linked to colorectal cancer progression., (© 2019 The Authors. International Journal of Cancer published by John Wiley & Sons Ltd on behalf of UICC.)

Background: Xenobiotic-metabolizing enzymes (XME) play a critical role in the activation and detoxification of several carcinogens. However, the role of XMEs in colorectal carcinogenesis is unclear., Methods: We investigated the expression of XMEs in human colorectal tissues among patients with stage I-IV colorectal cancer ( n = 71) from the ColoCare Study. Transcriptomic profiling using paired colorectal tumor and adjacent normal mucosa tissues of XMEs ( GSTM1, GSTA1, UGT1A8, UGT1A10, CYP3A4, CYP2C9 , GSTP1 , and CYP2W1 ) by RNA microarray was compared using Wilcoxon rank-sum tests. We assessed associations between clinicopathologic, dietary, and lifestyle factors and XME expression with linear regression models., Results: GSTM1, GSTA1, UGT1A8, UGT1A10 , and CYP3A4 were all statistically significantly downregulated in colorectal tumor relative to normal mucosa tissues (all P ≤ 0.03). Women had significantly higher expression of GSTM1 in normal tissues compared with men (β = 0.37, P = 0.02). By tumor site, CYP2C9 expression was lower in normal mucosa among patients with rectal cancer versus colon cancer cases (β = -0.21, P = 0.0005). Smokers demonstrated higher CYP2C9 expression levels in normal mucosa (β = 0.17, P = 0.02) when compared with nonsmokers. Individuals who used NSAIDs had higher GSTP1 tumor expression compared with non-NSAID users (β = 0.17, P = 0.03). Higher consumption of cooked vegetables (>1×/week) was associated with higher CYP3A4 expression in colorectal tumor tissues (β = 0.14, P = 0.007)., Conclusions: XMEs have lower expression in colorectal tumor relative to normal mucosa tissues and may modify colorectal carcinogenesis via associations with clinicopathologic, lifestyle, and dietary factors., Impact: Better understanding into the role of drug-metabolizing enzymes in colorectal cancer may reveal biological differences that contribute to cancer development, as well as treatment response, leading to clinical implications in colorectal cancer prevention and management., (©2019 American Association for Cancer Research.)

Context: Adipose tissue inflammation and dysregulated energy homeostasis are key mechanisms linking obesity and cancer. Distinct adipose tissue depots strongly differ in their metabolic profiles; however, comprehensive studies of depot-specific perturbations among patients with cancer are lacking., Objective: We compared transcriptome profiles of visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) from patients with colorectal cancer and assessed the associations of different anthropometric measures with depot-specific gene expression., Design: Whole transcriptomes of VAT and SAT were measured in 233 patients from the ColoCare Study, and visceral and subcutaneous fat area were quantified via CT., Results: VAT compared with SAT showed elevated gene expression of cytokines, cell adhesion molecules, and key regulators of metabolic homeostasis. Increased fat area was associated with downregulated lipid and small molecule metabolism and upregulated inflammatory pathways in both compartments. Comparing these patterns between depots proved specific and more pronounced gene expression alterations in SAT and identified unique associations of integrins and lipid metabolism-related enzymes. VAT gene expression patterns that were associated with visceral fat area poorly overlapped with patterns associated with self-reported body mass index (BMI). However, subcutaneous fat area and BMI showed similar associations with SAT gene expression., Conclusions: This large-scale human study demonstrates pronounced disparities between distinct adipose tissue depots and reveals that BMI poorly correlates with fat mass-associated changes in VAT. Taken together, these results provide crucial evidence for the necessity to differentiate between distinct adipose tissue depots for a correct characterization of gene expression profiles that may affect metabolic health of patients with colorectal cancer., (Copyright © 2019 Endocrine Society.)

Background: DNA mismatch repair (MMR) deficiency is a major pathway of genomic instability in cancer. It leads to the accumulation of numerous mutations predominantly at microsatellite sequences, a phenotype known as microsatellite instability (MSI). MSI tumors have a distinct clinical behavior and commonly respond well to immune checkpoint blockade, irrespective of their origin. Data about the prevalence of MSI among gallbladder cancer (GBC) have been conflicting. We here analyzed a well-characterized cohort of 69 Western-world GBCs., Methods: We analyzed the mononucleotide MSI marker panel consisting of BAT25, BAT26, and CAT25 to determine the prevalence of MMR deficiency-induced MSI., Results: MSI was detected in 1/69 (1.4%) of analyzed GBCs. The detected MSI GBC had a classical histomorphology, i.e. of acinar/tubular/glandular pancreatobiliary phenotype, and showed nuclear expression of all four MMR proteins MLH1, MSH2, MSH6, and PMS2. The MSI GBC patient showed a prolonged overall survival, despite having a high tumor stage at diagnosis. The patient had no known background or family history indicative of Lynch syndrome., Conclusions: Even though the overall number of MSI tumors is low in GBC, the potentially therapeutic benefit of checkpoint blockade in the respective patients may justify MSI analysis of GBC.

Assessment of Tumor Mutational Burden (TMB) for response stratification of cancer patients treated with immune checkpoint inhibitors is emerging as a new biomarker. Commonly defined as the total number of exonic somatic mutations, TMB approximates the amount of neoantigens that potentially are recognized by the immune system. While whole exome sequencing (WES) is an unbiased approach to quantify TMB, implementation in diagnostics is hampered by tissue availability as well as time and cost constrains. Conversely, panel-based targeted sequencing is nowadays widely used in routine molecular diagnostics, but only very limited data are available on its performance for TMB estimation. Here, we evaluated three commercially available larger gene panels with covered genomic regions of 0.39 Megabase pairs (Mbp), 0.53 Mbp and 1.7 Mbp using i) in silico analysis of TCGA (The Cancer Genome Atlas) data and ii) wet-lab sequencing of a total of 92 formalin-fixed and paraffin-embedded (FFPE) cancer samples grouped in three independent cohorts (non-small cell lung cancer, NSCLC; colorectal cancer, CRC; and mixed cancer types) for which matching WES data were available. We observed a strong correlation of the panel data with WES mutation counts especially for the gene panel >1Mbp. Sensitivity and specificity related to TMB cutpoints for checkpoint inhibitor response in NSCLC determined by wet-lab experiments well reflected the in silico data. Additionally, we highlight potential pitfalls in bioinformatics pipelines and provide recommendations for variant filtering. In summary, our study is a valuable data source for researchers working in the field of immuno-oncology as well as for diagnostic laboratories planning TMB testing., (© 2018 UICC.)

Background: A major molecular pathway of genetic instability in cancer is DNA mismatch repair deficiency. High-level microsatellite instability (MSI-H) is currently the best predictor of responsiveness towards immune checkpoint blockade. Data about the prevalence of high-level microsatellite instability in cholangiocarcinoma (CCA) has been conflicting., Methods: We employed a cohort comprising 308 Western-world, non-liver fluke-associated CCAs (159 intrahepatic, 106 perihilar, and 43 distal). We analysed the mononucleotide microsatellite instability marker panel consisting of BAT25, BAT26, and CAT25 and detected MSI-H in 4/308 CCAs (1.3%)., Results: Patients affected by MSI-H CCA had mostly an atypical histomorphology (p = 0.004), showed a longer overall survival, although having a high tumour stage, and were of younger age. Correlation analysis of microsatellite instability status with tumour-infiltrating immune cells, MHC I, and PD-L1 expression in the same cholangiocarcinoma cohort showed higher numbers of CD8 + T cells, FOXP3 + regulatory T cells, CD20 + B cells and high or at least moderate MHC I expression levels in MSI-H CCAs., Conclusions: Even though the overall number of MSI-H CCAs is low, the dismal prognosis of the disease and the therapeutic option of immune checkpoint blockade in the respective patients justify MSI testing of cholangiocarcinoma, particularly in younger patients showing an atypical histomorphology.

DNA methylation is recognized as one of several epigenetic regulators of gene expression and as potential driver of carcinogenesis through gene-silencing of tumor suppressors and activation of oncogenes. However, abnormal methylation, even of promoter regions, does not necessarily alter gene expression levels, especially if the gene is already silenced, leaving the exact mechanisms of methylation unanswered. Using a large cohort of matching DNA methylation and gene expression samples of colorectal cancer (CRC; n = 77) and normal adjacent mucosa tissues (n = 108), we investigated the regulatory role of methylation on gene expression. We show that on a subset of genes enriched in common cancer pathways, methylation is significantly associated with gene regulation through gene-specific mechanisms. We built two classification models to infer gene regulation in CRC from methylation differences of tumor and normal tissues, taking into account both gene-silencing and gene-activation effects through hyper- and hypo-methylation of CpGs. The classification models result in high prediction performances in both training and independent CRC testing cohorts (0.92

Liver metastasis in colorectal cancer is common and the primary treatment is chemotherapy. To date, there is no routinely used test in clinical practice to predict the effectiveness of conventional chemotherapy. Therefore, biomarkers with predictive value for conventional chemotherapy would be of considerable benefit in treatment planning. We analysed three proteins [excision repair cross-complementing 1 (ERCC1), ribonucleoside-diphosphate reductase 1 (RRM1) and class III β-tubulin (TUBB3)] in colorectal cancer liver metastasis. We used tissue microarray slides with 101 liver metastasis samples, stained for ERCC1, RRM1 and TUBB3 and established scoring systems (fitted for tissue microarray) for each protein. In statistical analysis, we compared the expression of ERCC1, RRM1 and TUBB3 to mismatch proteins (MLH1, MSH2, MSH6 and PMS2), p53 and to apoptosis repressor protein (ARC). Statistically significant correlations were found between ERCC1, TUBB3 and MLH1, MSH2 and RRM1 and MSH2, MSH6. Noteworthy, our analysis revealed a strong significant correlation between cytoplasmic ARC expression and RRM1, TUBB3 (p=0.000 and p=0.001, respectively), implying an additional role of TUBB3 and RRM1 not only in therapy resistance, but also in the apoptotic machinery. Our data strengthens the importance of ERCC1, TUBB3 and RRM1 in the prediction of chemotherapy effectiveness and suggest new functional connections in DNA repair, microtubule network and apoptotic signaling (i.e. ARC protein). In conclusion, we showed the importance and need of predictive biomarkers in metastasized colorectal cancer and pointed out the relevance not only of single predictive markers but also of their interactions with other known and newly explored relations between different signaling pathways.

Smoking tobacco is a known risk factor for the development of colorectal cancer and for mortality associated with the disease. Smoking has been reported to be associated with changes in DNA methylation in blood and in lung tumour tissues, although there has been scant investigation of how epigenetic factors may be implicated in the increased risk of developing colorectal cancer. To identify epigenetic changes associated with smoking behaviours, we performed epigenome-wide analysis of DNA methylation in colorectal tumours from 36 never-smokers, 47 former smokers, and 13 active smokers, and in adjacent mucosa from 49 never-smokers, 64 former smokers, and 18 active smokers. Our analyses identified 15 CpG sites within the APC 1A promoter that were significantly hypermethylated and 14 CpG loci within the NFATC1 gene body that were significantly hypomethylated (pLIS < 1 × 10 -5 ) in the tumours of active smokers. The APC 1A promoter was hypermethylated in 7 of 36 tumours from never-smokers (19%), 12 of 47 tumours from former smokers (26%), and 8 of 13 tumours from active smokers (62%). Promoter hypermethylation was positively associated with duration of smoking (Spearman rank correlation, ρ = 0.26, p = 0.03) and was confined to tumours, with hypermethylation never being observed in adjacent mucosa. Further analysis of adjacent mucosa revealed significant hypomethylation of four loci associated with the TNXB gene in tissue from active smokers. Our findings provide exploratory evidence for hypermethylation of the key tumour suppressor gene APC being implicated in smoking-associated colorectal carcinogenesis. Further work is required to establish the validity of our observations in independent cohorts. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd., (Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.)

Targeted deep massive parallel sequencing has been implemented in routine molecular diagnostics for high-throughput genetic profiling of formalin-fixed paraffin-embedded (FFPE) cancer samples. This approach is widely used to interrogate simple somatic mutations but experience with the analysis of copy number variations (CNV) is limited. Here, we retrospectively analyzed CNV in 822 cancer cases (135 melanoma, 468 non-small cell lung cancers (NSCLC), 219 colorectal cancers (CRC)). We observed a decreasing frequency of CNV in clinically actionable genes from melanoma to NSCLC to CRC. The overall cohort displayed 168 (20%) amplifications in 17 druggable targets. The majority of BRAF mutant melanomas (54%) showed co-occurring CNV in other genes, mainly affecting CDKN2A. Subsets showed clustered deletions in ABL1, NOTCH1, RET or STK11, GNA11, and JAK3. Most NRAS mutant melanomas (49%) harbored CNVs in other genes with CDKN2A and FGFR3 being most frequently affected. Five BRAF/NRASwt tumors had co-amplifications of KDR, KIT, PDGFRA and another six mutated KIT. Among all NSCLC, we identified 14 EGFRamp (with ten EGFRmut) and eight KRASamp (with seven KRASmut). KRASmut tumors displayed frequent amplifications of MYC (n = 10) and MDM2 (n = 5). Fifteen KRAS/EGFR/BRAFwt tumors had MET mutations/amplifications. In CRC, amplified IGF2 was most prevalent (n = 13) followed by MYC (n = 9). Two cases showed amplified KRAS wildtype alleles. Two of the KRASmut cases harbored amplifications of NRAS and three KRASwt cases amplification of EGFR. In conclusion, we demonstrate that our approach i) facilitates detection of CNV, ii) enables detection of known CNV patterns, and iii) uncovers new CNV of clinically actionable genes in FFPE tissue samples across cancers. © 2016 Wiley Periodicals, Inc., (© 2016 Wiley Periodicals, Inc.)

Cancer precision medicine has opened up new avenues for the treatment of colorectal cancer (CRC). To fully realize its potential, high-throughput sequencing platforms that allow genotyping beyond KRAS need to be implemented and require performance assessment. We comprehensively analyzed first-year data of 202 consecutive formalin-fixed paraffin embedded (FFPE) CRC samples for which prospective genotyping at our institution was requested. Deep targeted genotyping was done using a semiconductor-based sequencing platform and a self-designed panel of 30 CRC-related genes. Additionally, microsatellite status (MS) was determined. Ninety-seven percent of tumor samples were suitable for sequencing and in 88% MS could be assessed. The minimal drop-out rates of 6 and 25 cases, respectively were due to too low amounts or heavy degradation of DNA. Of 557 nonsynonymous mutations, 90 (16%) have not been described in COSMIC at the time of data query. Forty-three cases (22%) had double- or triple mutations affecting a single gene. Sixty-four percent had genetic alterations influencing oncological therapy. Eight percent of patients (MSI phenotype: 6%; mutated POLE: 2%) were potentially eligible for treatment with immune checkpoint inhibitors. Of 56% of KRASwt CRC that potentially qualified for anti-EGFR treatment, 30% presented with mutations in BRAF/NRAS. Mutated PIK3CA was detected in 21%. In conclusion, we here present real-life routine diagnostics data that not only demonstrate the robustness and feasibility of deep targeted sequencing and MS-analysis of FFPE CRC samples but also contribute to the understanding of CRC genetics. Most importantly, in more than half of the patients our approach enabled the selection of the best treatment currently available. © 2016 Wiley Periodicals, Inc., (© 2016 Wiley Periodicals, Inc.)

Introduction: Apoptotic signaling is one of the most important processes in the measurement of chemotherapeutic effectiveness. In apoptotic machinery, various pathways and proteins are involved (i.e., mismatch repair proteins, p53). One of the regulatory proteins is ARC, which can inhibit not only the extrinsic but also the intrinsic apoptotic signaling., Materials and Methods: In this study, we investigated the expression levels of ARC in colorectal liver metastasis and compared them with the expression of mismatch repair proteins and p53. Furthermore, we investigated ARC expression level depending on sex, age, tumor grade, mucin production, tumor size and number of liver metastasis., Results: ARC expression level in colorectal cancer liver metastasis was independent from clinical data (i.e., age, gender, tumor size, tumor number or mucin production) but strongly correlated with MSH2 and MSH6 expression, which further supported the evidence for the regulatory role of MSH2 and MSH6 in apoptosis; i.e., in case of sufficient MSH2 and MSH6 expression, significantly higher ARC level is required to suppress the apoptosis. A regulatory interaction between ARC and p53 has been described, but we found no correlation between p53 expression levels and ARC levels., Conclusion: Further studies are needed to define the exact role of ARC in apoptotic signaling and thus its role in chemoresistance and survival of tumor cells.

Background: Metabolic and transcriptomic differences between visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) compartments, particularly in the context of obesity, may play a role in colorectal carcinogenesis. We investigated the differential functions of their metabolic compositions., Objectives: Biochemical differences between adipose tissues (VAT compared with SAT) in patients with colorectal carcinoma (CRC) were investigated by using mass spectrometry metabolomics and gene expression profiling. Metabolite compositions were compared between VAT, SAT, and serum metabolites. The relation between patients' tumor stage and metabolic profiles was assessed., Design: Presurgery blood and paired VAT and SAT samples during tumor surgery were obtained from 59 CRC patients (tumor stages I-IV) of the ColoCare cohort. Gas chromatography time-of-flight mass spectrometry and liquid chromatography quadrupole time-of-flight mass spectrometry were used to measure 1065 metabolites in adipose tissue (333 identified compounds) and 1810 metabolites in serum (467 identified compounds). Adipose tissue gene expression was measured by using Illumina's HumanHT-12 Expression BeadChips., Results: Compared with SAT, VAT displayed elevated markers of inflammatory lipid metabolism, free arachidonic acid, phospholipases (PLA2G10), and prostaglandin synthesis-related enzymes (PTGD/PTGS2S). Plasmalogen concentrations were lower in VAT than in SAT, which was supported by lower gene expression of FAR1, the rate-limiting enzyme for ether-lipid synthesis in VAT. Serum sphingomyelin concentrations were inversely correlated (P = 0.0001) with SAT adipose triglycerides. Logistic regression identified lipids in patients' adipose tissues, which were associated with CRC tumor stage., Conclusions: As one of the first studies, we comprehensively assessed differences in metabolic, lipidomic, and transcriptomic profiles between paired human VAT and SAT and their association with CRC tumor stage. We identified markers of inflammation in VAT, which supports prior evidence regarding the role of visceral adiposity and cancer., (© 2015 American Society for Nutrition.)

Colorectal cancer guidelines recommend adjuvant chemotherapy in stage II disease when less than 12 lymph nodes are assessed. The recommendation bases on previous studies showing an association of a low lymph node count and adverse outcome. Compared to current standards, however, the quality of lymph node examination in the studies was low. We, therefore, investigated the prognostic role of <12 lymph nodes in cancers diagnosed adherent to current quality measures. Stage I-IV colorectal cancers from 1,899 patients enrolled into a population-based cohort study were investigated for the prognostic impact of a lymph node count <12. The stage specific share of patients diagnosed with ≥12 nodes (stage I-IV: 62, 85, 85, 78%, respectively) was used to compare lymph node examination quality to other studies. We found no impact of a lymph node count <12 on overall, cancer-specific or recurrence-free survival for any tumour stage. Compared to studies reporting an adverse prognostic impact of a low lymph node count in stages II and III the stage-specific shares of patients with ≥12 nodes were markedly higher in this study (85% vs. 24-58% in previous analyses) and this correlated with increased rates of stage III compared to stage II cancers. In conclusion our data indicate, that the previously reported effect of a low lymph node count on the patients' outcomes is eliminated by improved lymph node examination quality and thus question the general applicability of a 12 lymph node cut off for adjuvant chemotherapy decision making in stage II disease., (© 2014 UICC.)

The myristoylated alanine-rich C-kinase substrate (MARCKS) acts as a tumor suppressor in a variety of human neoplasms. In colorectal cancers (CRCs), MARCKS has been shown to be a preferential target of mutational inactivation in tumors following the microsatellite instability (MSI-H) pathway but little is known about its impact on intestinal carcinogenesis. To investigate the relevance of MARCKS inactivation in more detail, we analyzed 926 MSI-typed CRCs for MARCKS expression by immunohistochemistry and studied the functional consequences of MARCKS depletion in colorectal cancer cell lines. We found that loss of MARCKS expression was not restricted to MSI-H cancers but also occurred in microsatellite stable (MSS) tumors, where it was associated with an adverse outcome regarding overall survival, cancer-specific and disease-free survival (P=0.002, P=0.0018, P=0.0001, respectively; univariate analysis). In MARCKS-positive MSS colon cancer cell lines (SW480 and SW707) small interfering RNA (siRNA)-mediated knockdown of MARCKS conferred resistance to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis. This was accompanied by the downregulation of the TRAIL receptors DR4 and DR5 at the cell surface and activation of AKT signaling. Inhibition of AKT signaling and transient overexpression of wild-type MARCKS, but not of MARCKS lacking the effector domain (ED), abolished the anti-apoptotic effect. In conclusion, our data show that inactivation of MARCKS is common in CRCs and is associated with adverse outcome in MSS cancers. The finding that MARCKS acts as a mediator of apoptosis in MSS CRC cells adds a novel tumor-suppressing function to the so far established roles of MARCKS in cell motility and proliferation and can explain the prognostic effect of MARCKS depletion in MSS CRC.

Background: pN1c is a novel N-category introduced for colorectal cancer (CRC) in current TNM (Tumour, Node, Metastasis) classification. It represents cancers displaying tumour deposits (TDs) in the fat but no involvement of lymph nodes. pN1c is integrated into the UICC (International Union Against Cancer) staging system and shifts previous stage II cancers (6th edition) to stage III. We investigated the frequency of upstaging and TD prognostic significance., Methods: 414 CRCs, consecutively collected during a population-based epidemiological study, TNM classified and UICC staged according to the 6th TNM edition were reinvestigated for TD presence. The association with survival was investigated after a median follow-up time of 5years in multivariate analyses among nodal negative and positive cases., Results: TDs were found in 103 (24.9%) cancers and were strongly associated with T-, N- and M-stages (p<0.0001, each). Upstaging of previous stage II cancers by the presence of TDs (pN1c) was found in six of 140 cases (4.3% of stage II, 1.4% of all tumours). For stage III CRC, strongly reduced overall, CRC-specific and recurrence-free survival were observed with the presence of TDs (hazard ratios (HR) 2.29, 95% confidence interval 1.27-4.10, HR 2.51, 1.27-4.98, and HR 2.43, 1.32-4.48, respectively)., Conclusions: Upstaging of CRCs through the introduction of pN1c occurs in less than 5% of previous stage II and less than 2% of all cancers. Given the biologic relevance of TDs, integration into the UICC staging relevant N-category is justified. The high prognostic impact of TDs, however, is not reflected in nodal positive cancers in both the TNM and UICC staging systems., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Background: Advances in neoadjuvant therapy enabled novel strategies for treating resectable and initially unresectable colorectal cancer liver metastases. Although it is well known that chemotherapeutic agents cause certain types of liver parenchymal injury, the actual contribution of chemotherapy-associated hepatotoxicity to postoperative morbidity remains poorly defined. The aim of this study was to define all kinds of chemotherapy-associated liver injury and to examine its impact on postoperative morbidity., Patients and Methods: We included 119 patients who were treated between 2002 and 2010. Chemotherapy-associated changes of the liver were subclassified in 11 different categories and correlated with postoperative morbidity with the ultimate aim of generating a liver injury risk score., Results: On univariate analysis severity (P = .004) and localization of parenchymal inflammation (P = .04) were associated with morbidity. Steatosis did not correlate with postoperative outcome (P = .69), whereas steatohepatitis (as assessed by the nonalcoholic fatty liver disease activity score score) was related with morbidity (P = .03). On multivariate analysis, the severity of inflammation (95% confidence interval, 1.008-6.526; odds ratio, 2.56; P = .04) was significantly correlated with postoperative morbidity. The newly developed liver injury risk score was highly associated with postoperative complications (P = .006)., Conclusion: In this study, the induction of inflammation by conventional chemotherapy and its relevance for the development of clinical complications could be demonstrated. The proposed risk score for liver injury-related morbidity might help to better select patients eligible for an operation., (Copyright © 2014 Mosby, Inc. All rights reserved.)

Background: Previous studies reported a positive association of body mass index (BMI) with microsatellite-stable (MSS) but not with microsatellite-instable (MSI-high) colorectal cancer. However, information from population-based studies conducted in representative age groups is so far limited., Methods: We conducted a population-based case-control study (DACHS) in Southern Germany, including 1,215 patients with incident colorectal cancer and 1,891 matched controls with no upper age limit. Information on risk factors of colorectal cancer was obtained in standardized interviews. Microsatellite instability was analyzed using a mononucleotide marker panel., Results: Median age among cases was 69 years, and 115 cases were classified MSI-high (9.5%). In multivariate analyses, BMI was positively associated with both risk of MSI-high colorectal cancer [per 5 kg/m(2): OR, 1.71; 95% confidence interval (CI), 1.35-2.17] and risk of MSS colorectal cancer (OR, 1.20; 95% CI, 1.07-1.33). The association with MSI-high colorectal cancer was limited to women (OR, 2.04; 95% CI, 1.50-2.77; P interaction = 0.02) and most pronounced among ever users of postmenopausal hormone replacement therapy (OR, 4.68; 95% CI, 2.36-9.30; P interaction = 0.01). In case-only analyses, BMI was more strongly associated with MSI-high colorectal cancer than with MSS colorectal cancer among women (OR, 1.84; 95% CI, 1.13-1.82; P interaction = 0.01)., Conclusions: This population-based study confirms previous findings of increased risk of MSS colorectal cancer with obesity between both sexes and suggests that overweight and obesity may also be associated with increased risk of MSI-high colorectal cancer among women., Impact: These findings extend available data on the association of BMI and microsatellite instability in colorectal cancer and may suggest a link between overweight and obesity with sporadic MSI-high colorectal cancer in women., (©2013 AACR.)

Tumors from colorectal cancer (CRC) are generally immunogenic and commonly infiltrated with T lymphocytes. However, the details of the adaptive immune reaction to these tumors are poorly understood. We have accrued both colon tumor samples and adjacent healthy mucosal samples from 15 CRC patients to study lymphocytes infiltrating these tissues. We apply a method for detailed sequencing of T-cell receptor (TCR) sequences from tumor-infiltrating lymphocytes (TILs) in CRC tumors at high throughput to probe T-cell clones in comparison with the TCRs from adjacent healthy mucosal tissue. In parallel, we captured TIL counts using standard immunohistochemistry. The variation in diversity of the TIL repertoire was far wider than the variation of T-cell clones in the healthy mucosa, and the oligoclonality was higher on average in the tumors. However, the diversity of the T-cell repertoire in both CRC tumors and healthy mucosa was on average 100-fold lower than in peripheral blood. Using the TCR sequences to identify and track clones between mucosal and tumor samples, we determined that the immune response in the tumor is different than in the adjacent mucosal tissue, and the number of shared clones is not dependent on distance between the samples. Together, these data imply that CRC tumors induce a specific adaptive immune response, but that this response differs widely in strength and breadth between patients.

The PEA-15/PED (phosphoprotein enriched in astrocytes 15kD/phosphoprotein enriched in diabetes) protein is a multifunctional phosphoprotein involved in various signaling pathways which determine survival, proliferation, and migration of cancer cells. Here, we investigated the expression and cellular functions of PEA-15 in colorectal carcinoma (CRC). PEA-15 is expressed in the majority of human CRC, predominantly in well differentiated tumor areas. A tissue microarray analysis of 1262 human CRC specimens from the DACHS study showed that PEA-15 expression is significantly associated with a low pT stadium as defined by limited invasion into the bowel wall. Moreover, patients with PEA-15-positive CRC exhibited a significantly longer tumor-specific survival time. To investigate the functional relevance of PEA-15 expression on a cellular level, we over-expressed PEA-15 in several CRC cell lines. Increased expression of PEA-15 resulted in a strong inhibition of clonogenicity, proliferation, and invasiveness of CRC cells. These effects were associated with a PEA-15-dependent down-regulation of integrin αvβ5 as well as with elevated levels of the phosphorylated MAP kinase ERK1/2. Moreover, expression of PEA-15 resulted in significant protection from cell death induced by cytotoxic drugs (5-FU, cisplatin), by the death ligand TRAIL, or by serum withdrawal. In conclusion, the PEA-15 protein regulates invasiveness, proliferation, and apoptosis resistance in CRC cells. PEA-15 might play an important role in chemoresistance, progression and metastasis in CRC., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

The risk of colorectal cancer is reduced among users of oral contraceptives or menopausal hormone therapy, but associations with reproductive characteristics that are markers of a woman's endogenous hormone milieu have not been consistently observed. To help understand possible mechanisms through which exogenous and endogenous hormonal exposures are involved in colorectal cancer, we assessed the risk of these malignancies according to tumor expression of estrogen receptor-β (ESR2). In a population-based study of postmenopausal women (503 cases and 721 controls matched for sex and age), immunohistochemical expression of ESR2 was determined in 445 cases of incident colorectal cancer. Unconditional logistic regression was used in case-case analyses to assess heterogeneity between risk associations according to ESR2 status and in case-control analyses to estimate associations separately for ESR2-negative and ESR2-positive tumors. For ESR2-positive tumors but not ESR2-negative tumors, colorectal cancer risk significantly decreased with duration of oral contraceptive use [per five-year increments OR ESR2-positive, 0.87, 95% confidence interval (CI), 0.77-0.99; OR ESR2-negative, 1.02, 95% CI, 0.91-1.15; Pheterogeneity = 0.07] and with duration of menopausal hormone therapy use (per five-year increments OR ESR2-positive, 0.84, 95% CI, 0.74-0.95; OR ESR2-negative, 0.94, 95% CI 0.84-1.05; Pheterogeneity = 0.06). Significant heterogeneity according to ESR2 expression was found for the association with current use of menopausal hormone therapy (<0.5 years ago; Pheterogeneity = 0.023) but not for associations with reproductive factors. In conclusion, our results suggest that hormone use decreases risk for ESR2-positive but not ESR2-negative colorectal cancer., (©2013 AACR.)

Germline deletions affecting the epithelial cell adhesion molecule (EPCAM) gene lead to silencing of MSH2 and cause Lynch syndrome. We have recently reported that lack of EPCAM expression occurs in many, but not all tumors from Lynch syndrome patients with EPCAM germline deletions. The differences in EPCAM expression were not related to the localization of EPCAM germline deletions. We therefore hypothesized that the type of the second somatic hit, which leads to MSH2 inactivation during tumor development, determines EPCAM expression in the tumor cells. To test this hypothesis and to evaluate whether lack of EPCAM expression can already be detected in Lynch syndrome-associated adenomas, we analyzed four carcinomas and two adenomas from EPCAM germline deletion carriers for EPCAM protein expression and allelic deletion status of the EPCAM gene region by multiplex ligation-dependent probe amplification. In four out of six tumors we observed lack of EPCAM expression accompanied by biallelic deletions affecting the EPCAM gene. In contrast, monoallelic retention of the EPCAM gene was observed in the remaining two tumors with retained EPCAM protein expression. These results demonstrate that EPCAM expression in tumors from EPCAM deletion carriers depends on the localization of the second somatic hit that inactivates MSH2. Moreover, we report lack of EPCAM protein expression in a colorectal adenoma, suggesting that EPCAM immunohistochemistry may detect EPCAM germline deletions already at a precancerous stage.

As part of ongoing studies to obtain a global picture of invasion related events in colorectal liver metastases, here, we report our findings on gene expression of the pro-angiogenic subgroup of chemokines, the CXCL-ELR+ chemokines. Apart from their pro-angiogenic and chemoattractant function, these chemokines appear to also contribute to tumor cell transformation, growth and invasion. In our nude mouse model of colorectal liver metastases, we found CXCL1,2,3,5 and 8 (IL-8) to be up-regulated in the tumor cells of the invasion front as compared to the tumor cells in the inner parts of the tumor. ShRNA mediated down-regulation of the most prominently up-regulated group member, CXCL1/gro-alpha resulted in inhibition of cell viability, invasion and proliferation. In vivo, down-regulation of CXCL1 resulted in a nearly complete prevention of tumor growth in nude mice. Mechanistically, auto-regulatory mechanisms involving NF-kappaB and Akt appear to be involved in pro-tumorigenic functions of CXCL1., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Background: Patients with PSC and IBD have a high incidence of colonic carcinomas (CRC), and the annual incidence of CRC increases with duration of disease. UDCA treatment has been suggested to reduce colonic dysplasias and carcinomas., Aims: The annual incidence of colorectal carcinomas after long-term UDCA treatment was studied., Methods: Patients included in a prospective study on the outcome after ursodeoxycholic acid (UDCA) treatment were evaluated., Results: A total of 120 of 171 PSC patients included had IBD (108 UC and 12 CD). All patients were treated with UDCA for a median time of 6.7 years. Seven patients with PSC and IBD developed a CRC yielding a prevalence of 5.8%. In years 0-3 (n = 120) after the start of UDCA, the annual incidence rate of CRC was 0.62/100 patient years; in years 3-6 (n = 93) it increased to 1.28 and decreased thereafter in years 6-9 (n = 67) to 1.17, then in years 9-12 (n = 42) to 0 and after >12 years (n = 24) it remained 0. In PSC with IBD, Kaplan-Meier estimate of CRC formation increased with time in the first years of treatment and reached a plateau after 9 years; after treatment for ≥ 9 years, no further CRC were observed., Conclusion: After the start of UDCA, the annual incidence of CRC increased up to 6 years and subsequently decreased. In PSC with IBD treated with UDCA, most colonic carcinomas develop in the first years after the start of treatment.

Analysis of tumor-infiltrating lymphocytes (TIL) in primary human colorectal cancer (CRC) by in situ immunohistochemical staining supports the hypothesis that the adaptive immune response influences the course of human CRC. Specifically, high densities of TILs in the primary tumor are associated with good prognosis independent of other prognostic markers. However, the prognostic role of TILs in metastatic CRC lesions is unknown, as is their role in response or resistance to conventional chemotherapy. We analyzed the association of TIL densities at the invasive margin of CRC liver metastases with response to chemotherapy and progression-free survival in a set of 101 large section samples. High-resolution automated microscopy on complete tissue sections was used to objectively generate cell densities for CD3, CD8, granzyme B, or FOXP3 positive immune cells. A predictive scoring system using TIL densities was developed in a training set and tested successfully in an independent validation set. TIL densities at the invasive margin of liver metastases allowed the prediction of response to chemotherapy with a sensitivity of 79% and specificity of 100%. The association of high density values with longer progression-free survival under chemotherapy was statistically significant. Overall, these findings extend the impact of the local immune response on the clinical course from the primary tumor also to metastatic lesions. Because detailed quantification of TILs in metastatic lesions revealed a strong association with chemotherapy efficacy and prognosis, we suggest that the developed scoring system may be used as a predictive tool for response to chemotherapy in metastatic CRC., (©2011 AACR.)

Background: The invasion front of colorectal liver metastases is an area of intensive tumor cell-host cell contact., Materials and Methods: In a xenograft nude mouse model, we analyzed whether apoptosis induction is a prominent feature in this active area, perhaps offering new modalities of therapeutic intervention., Results: Using global gene expression technology, an over-representation of apoptosis-related biological themes in the invasion front was observed. A combination of apoptosis-specific TUNEL/DAPI staining and cell type-specific staining showed that all examined cell types, including tumor cells, hepatocytes, endothelial cells, macrophages and hepatic stellate cells, displayed increased apoptosis in the invasion front. Evaluation of gene expression of the death receptor/ligand pairs TRAILR2 /TRAIL and FAS/FASL indicated that tumor cells overexpressed TRAILR2 and FAS, whereas host cells expressed TRAIL and FASL., Conclusion: This data indicates that the invasion front of colorectal liver metastases is an area of prominent pro-apoptotic activity, involving known death receptor/ligand interactions.

Purpose: Tumor infiltrating T lymphocytes in colorectal cancer (CRC) have prognostic impact, but the role of natural killer (NK) cells in CRC tissue is unclear. The contribution of intratumoral cytokines and chemokines in shaping the composition of the inflammatory lymphocytic infiltrate is also unclear., Experimental Design: In this study, localization and densities of NK and T cells within primary CRC, CRC liver metastases, adenomas, and normal tissues were analyzed on whole tissue sections from 112 patients. In a subset of these patients, the most important 50 cytokines and chemokines were quantified in paired serum, primary CRC and adjacent mucosa samples and in CRC liver metastases and correlated with NK and T-cell infiltration, respectively., Results: The various compartments displayed characteristic differences like significantly higher chemokine concentrations in CRC tissue. Most importantly, despite high local chemokine levels, NK cells were generally scarce within CRC tumor tissues, independent of human leukocyte antigen (HLA) class I expression. Adjacent normal mucosa contained normal levels of NK cells. In contrast, corresponding T-cell numbers varied substantially and were positively correlated with higher chemokine levels., Conclusions: Our findings indicate a distinct regulation of NK cells versus T cells in the CRC tumor microenvironment. NK-cell migration into CRC tumor tissue is obviously impaired early during tumor development by mechanisms that do not affect T-cell infiltration., (©2011 AACR.)

Until recently, two major types of colorectal epithelial polyps were distinguished: the adenoma and the hyperplastic polyp. While adenomas - because of their cytological atypia - were recognized as precursor lesions for colorectal carcinoma, hyperplastic polyps were perceived as harmless lesions without any potential for malignant progression, mainly because hyperplastic polyps lack cytological atypia. Meanwhile, it is evident that the lesions formerly classified as hyperplastic represent a heterogeneous group of polyps, some of which exhibit a significant risk of neoplastic progression. These lesions show characteristic epigenetic alterations not commonly seen in colorectal adenomas and progress to colorectal carcinoma via the so-called serrated pathway (CIMP pathway). This group of polyps is comprised not only of hyperplastic polyps, but also of sessile serrated adenomas (SSA), traditional serrated adenomas (TSA) and mixed polyps, showing serrated and "classical" adenomatous features. In a consensus conference of the working group of gastroenterological pathology of the German Society of Pathology, standardization of nomenclature and diagnostic criteria as well as recommendations for clinical management of these serrated polyps were formulated and are presented herein.

Objective: To analyze intratumoral heterogeneity of immune cells and the resulting impact of heterogeneity on the level of individual patient prediction., Study Design: Using whole slide imaging by virtual microscopy, we present the first spatial quantitative study of immune cells in a set of colorectal cancer primary tumors. We generated "tumor maps" based on cell densities in fields of 1 mm2, visualizing intratumoral heterogeneity. In this example, cutoffs of marker-based cell stains identified by tissue microarray (TMA) led to ambiguous decisions in 11 of the 20 patients studied. Classic TMA analysis can be used in large patient cohorts to generate clinically significant predictors. The transfer of these predictors from large-scale TMA to individualized predictions thus far has not been investigated. In colorectal cancer, TMA-based quantitative immune cell counts using immune cell surface molecules (CD3, CD8, Granzyme B, and CD45RO) have been shown to be potentially better predictors for patient survival than the classical TNM system., Results: Our results make clear that for individualized prognostic evaluations, whole slide imaging by virtual microscopy is irreplaceable during identification of prognostic markers as well as in their subsequent application., Conclusion: In the future, spatial marker signatures could contribute to individual patient classifiers.

Background and Aims: Liver metastases are the leading cause of death in colorectal cancer. To gain better insight into the biology of metastasis and possibly identify new therapeutic targets we systematically investigated liver-metastasis-specific molecular aberrations., Methods: Primary colorectal cancer (pCRC) and matched liver metastases (LMs) from the same patients were analysed by microarray-based comparative genomic hybridisation in 21 pairs and gene expression profiling in 18 pairs. Publicly available databases were used to confirm findings in independent datasets., Results: Chromosome aberration patterns and expression profiles of pCRC and matched LMs were strikingly similar. Unsupervised cluster analysis of genomic data showed that 20/21 pairs were more similar to each other than to any other analysed tumour. A median of only 11 aberrations per patient was found to be different between pCRC and LM, and expression of only 16 genes was overall changed upon metastasis. One region on chromosome band 11p15.5 showed a characteristic gain in LMs in 6/21 patients. This gain could be confirmed in an independent dataset of LMs (n=50). Localised within this region, the growth factor IGF2 (p=0.003) and the intestinal stem cell specific transcription factor ASCL2 (p=0.029) were found to be over-expressed in affected LM. Several ASCL2 target genes were upregulated in this subgroup of LM, including the intestinal stem cell marker OLFM4 (p=0.013). The correlation between ASCL2 expression and four known direct transcriptional targets (LGR5, EPHB3, ETS2 and SOX9) could be confirmed in an independent expression dataset (n=50)., Conclusions: With unprecedented resolution a striking conservation of genomic alterations was demonstrated in liver metastases, suggesting that metastasis typically occurs after the pCRC has fully matured. In addition, we characterised a subset of liver metastases with an ASCL2-related stem-cell signature likely to affect metastatic behaviour of tumour cells.

Nonsteroidal anti-inflammatory drugs are known to reduce the risk and mortality from colorectal carcinoma by inhibiting cyclo-oxygenases (COX). COX-2 expression was investigated immunohistologically in 57 patients with colorectal carcinomas and in the corresponding liver metastases using tissue microarray analysis. Ex vivo COX-2 inhibition with assessment of apoptosis was performed using precision-cut tissue slices of three human liver metastases. Following stimulation with different concentrations of the selective COX-2 inhibitor meloxicam, apoptosis was assessed immunohistochemically after 6 h and 12 h. All primary carcinomas and 56 out of the 57 liver metastases showed various degrees of cytoplasmatic COX-2 expression being with a reduction and in the liver metastases. There was a time- and concentration-dependent change in the number of apoptotic cells in tissue slices, however, this was without statistical significance. COX-2 is constantly involved in the carcinogenesis and metastatic process of colorectal cancer. The antineoplastic effect of COX-2 inhibition may be based on different pathways, including changes in sensitivity to apoptosis.

Background: Determining the correct number of positive immune cells in immunohistological sections of colorectal cancer and other tumor entities is emerging as an important clinical predictor and therapy selector for an individual patient. This task is usually obstructed by cell conglomerates of various sizes. We here show that at least in colorectal cancer the inclusion of immune cell conglomerates is indispensable for estimating reliable patient cell counts. Integrating virtual microscopy and image processing principally allows the high-throughput evaluation of complete tissue slides., Methodology/principal Findings: For such large-scale systems we demonstrate a robust quantitative image processing algorithm for the reproducible quantification of cell conglomerates on CD3 positive T cells in colorectal cancer. While isolated cells (28 to 80 microm(2)) are counted directly, the number of cells contained in a conglomerate is estimated by dividing the area of the conglomerate in thin tissues sections (< or =6 microm) by the median area covered by an isolated T cell which we determined as 58 microm(2). We applied our algorithm to large numbers of CD3 positive T cell conglomerates and compared the results to cell counts obtained manually by two independent observers. While especially for high cell counts, the manual counting showed a deviation of up to 400 cells/mm(2) (41% variation), algorithm-determined T cell numbers generally lay in between the manually observed cell numbers but with perfect reproducibility., Conclusion: In summary, we recommend our approach as an objective and robust strategy for quantifying immune cell densities in immunohistological sections which can be directly implemented into automated full slide image processing systems.

beta-Catenin is a pivotal molecule of the Wnt-signalling pathway, involved in regulation of developmental and oncogenic processes as well as in intercellular adhesion. So far, beta-catenin has been thought to be regulated mainly at the protein level. Here, we provide evidence for a transcriptional mechanism of beta-catenin regulation at the invasion front of colorectal liver metastases. In a nude mouse/LS174T cell xenograft model of colorectal liver metastases, we observed beta-catenin up-regulation at the mRNA and protein levels and a 13.7-fold increase of beta-catenin promoter activity in the cancer cells of the invasion front. In addition, the promoter activity was five-fold higher in the interior of the tumour than in cells growing in cell culture. In vitro studies revealed binding of TCF-4 to the beta-catenin promoter and reduced promoter activity by over-expression of dominant negative TCF-4, or beta-catenin knock-down and increased activity by beta-catenin over-expression, indicating that beta-catenin acts as co-transcription factor of its own promoter. In 55% (7/13) of clinical specimens, beta-catenin mRNA was markedly elevated in the cancer cells of the invasion front. Elevation of mRNA was paralleled by increased nuclear and cytoplasmic beta-catenin protein concentrations. These data indicate that transcriptional regulation contributes to the dynamic changes of beta-catenin levels upon the confrontation of tumour cells with the host microenvironment., (2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.)

In situ immunohistochemical staining of tumor-infiltrating immune cells in large cohorts of human colorectal cancers has recently supported the hypothesis that the adaptive immune response influences the behavior of human tumors. Tumor-infiltrating immune cells therefore represent a valuable prognostic marker for patients with colorectal cancer, with a high density of immune cells being associated with a good outcome independently of other established prognostic markers. The aim of the present study was to investigate the correlation between infiltrates of immune cells, in either the primary tumor or (where available) the corresponding liver metastases, with the response to chemotherapy in patients with metastatic colorectal cancer. The analysis consisted of 32 samples from 22 patients with metastasized colorectal cancer, including ten pairs of primary tumors and corresponding liver metastases. In primary tumors the ratio of stained immune cells in the epithelial portion of the tumor as compared to the total number of immune cells staining for CD3, CD8 and Granzyme B showed a relationship to the response to chemotherapy and the time to progression under chemotherapy. The primary tumors showed marked intra-tumoral heterogeneity with respect to immune cell densities. Infiltrate densities differed significantly between corresponding primary tumors and liver metastases, a variability that was also observed at the invasive margin of liver metastases. This suggests that immune infiltrates at the invasive margin of liver metastases could be predictive with respect to response to treatment. This is currently being evaluated in a larger patient cohort.

Background: Invasion-related genes over-expressed by tumor cells as well as by reacting host cells represent promising drug targets for anti-cancer therapy. Such candidate genes need to be validated in appropriate animal models., Results: This study examined the suitability of a murine model (CT26/Balb/C) of colorectal liver metastasis to represent clinical liver metastasis specimens using a global gene expression approach. Cross-species similarity was examined between pure liver, liver invasion, tumor invasion and pure tumor compartments through overlap of up-regulated genes and gene ontology (GO)-based biological themes on the level of single GO-terms and of condensed GO-term families. Three out of four GO-term families were conserved in a compartment-specific way between the species: secondary metabolism (liver), invasion (invasion front), and immune response (invasion front and liver). Among the individual GO-terms over-represented in the invasion compartments in both species were "extracellular matrix", "cell motility", "cell adhesion" and "antigen presentation" indicating that typical invasion related processes are operating in both species. This was reflected on the single gene level as well, as cross-species overlap of potential target genes over-expressed in the combined invasion front compartments reached up to 36.5%. Generally, histopathology and gene expression correlated well as the highest single gene overlap was found to be 44% in syn-compartmental comparisons (liver versus liver) whereas cross-compartmental overlaps were much lower (e.g. liver versus tumor: 9.7%). However, single gene overlap was surprisingly high in some cross-compartmental comparisons (e.g. human liver invasion compartment and murine tumor invasion compartment: 9.0%) despite little histolopathologic similarity indicating that invasion relevant genes are not necessarily confined to histologically defined compartments., Conclusion: In summary, cross-species comparison on a global gene expression scale suggests the validity of an animal model representing the human situation. The actual yield of potential target genes depends on several variables including the animal model, choice of inclusion criteria, inherent species differences and histologic assessment.

Background: Matrix metalloproteinases (MMPs) and their inhibitors, the tissue inhibitors of metalloproteinases (TIMPs), have been implicated in invasion and metastasis. The distribution of MMPs and TIMPs in the invasion front of liver metastases from colorectal cancer were investigated in order to understand their potential role in invasiveness., Materials and Methods: Freshly frozen material of colorectal metastases of the liver was microdissected into four separate compartments, namely pure liver, liver invasion, tumour invasion and pure tumour. RNA was isolated and analyzed on Affymetrix microarrays. Expression of TIMP-1 was confirmed by quantitative polymerase chain reaction in 10 colorectal liver metastases. Cellular localisation of TIMP-1 was examined by immunohistochemistry., Results: Affymetrix microarray data revealed that several MMP and TIMP genes including MMP-2, -3, -7, -9, -11, -12, -14, -15, -16, -19 and -24, and TIMP-1, -2 and -3 were generally up-regulated in both invasion front compartments. Among these genes, TIMP-1 showed the highest expression. The qPCR results indicated an average 15-fold upregulation of TIMP-1 in the liver invasive front and an average 13-fold up-regulation in the tumor invasive front, each compared to normal liver tissue. Immunohistochemistry revealed expression of TIMP-1 in tumour epithelia as well as in host tissue cells, including fibroblastic cells., Conclusion: Our data indicate that tumour invasion in colorectal liver metastasis is associated with increased TIMP-1 RNA and protein levels in both tumour and host cells.

Hepatocyte growth factor (HGF)-MET signalling in cancer biology has been well characterized in multiple organ systems. Numerous investigations have described an up-regulation of c-met mRNA in human colorectal adenomas and carcinomas. However, a quantitative immunohistochemical analysis of MET and HGF protein levels in tumor tissues has not been reported previously. Formalin-fixed and paraffin-embedded tissues from 41 colorectal adenomas and 49 colorectal carcinomas were characterized by immunofluorescent staining using HGF- and MET-specific antibodies. The immunoreactivity was evaluated by confocal laser scanning microscopy, computer-based image analysis and appropriate statistical tests. Normal colorectal mucosa, adenomas and carcinomas exhibited comparable levels of MET and HGF proteins. MET expression in carcinomas, although statistically not significant, demonstrated a tendency to correlate with the grade of differentiation. Correlations of MET and HGF with other clinico-pathological variables including the extent of the mucinous component and the pTNM stage were not observed. The ratio of HGF in carcinoma vs. non-neoplastic tissue was significantly different between high and low carcinoma stage. Alterations of absolute levels of MET and HGF protein during the colorectal adenoma-carcinoma sequence were not significant. The presumed role of MET-HGF interactions in large bowel carcinogenesis may therefore be a result of or depend upon other regulatory factors involved in MET-mediated signalling pathways.

Several pathways of fatty acid metabolism have been shown to be associated with the pathogenesis of colorectal cancer. Fatty acid acyl-CoA thioesters are formed from free fatty acids and coenzyme A by the activity of acyl-CoA synthetases (ACSs). Whilst an increase in ACS4 expression has been associated with colorectal carcinogenesis, little is known about possible pathogenetic functions of other ACS isoforms, such as ACS5, in tumourigenesis. In the present study, gene expression, protein synthesis, and enzymatic activity of ACS5 in sporadic colorectal adenocarcinomas, adenomas, and established cell lines were analysed using RT-PCR, western blot analysis, immunofluorescence, and an enzymatic assay. Enhanced expression of ACS5 mRNA and protein as well as enzymatic activity was found in adenomas and in 11 (73%; group 1) of 15 colorectal adenocarcinomas investigated, while a decrease of ACS5 was seen in four tumours (27%; group 2). However, basal ACS5 enzymatic activity was increased as a percentage of the total activity of ACSs in both groups, arguing for an absolute (group 1) or relative (group 2) increase in ACS5 enzymatic activity in all adenocarcinomas investigated. These findings are reflected by in vitro analysis of three established colorectal adenocarcinoma cell lines, in which activity of ACS5 occurred. The results suggest the involvement of ACS5 in the early genesis of colorectal cancer, most likely by modification of the transport and pool formation of long-chain acyl-CoA thioesters, as recently demonstrated for other isoforms of the ACS family., (Copyright (c) 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.)