Microsatellite instability (MSI-H) is associated with a high immunoscore but not with PD-L1 expression or increased survival in patients (pts.) with metastatic colorectal cancer (mCRC) treated with oxaliplatin (ox) and fluoropyrimidine (FP) with and without bevacizumab (bev): a pooled analysis of the AIO KRK 0207 and RO91 trials.

INTRODUCTION: In a retrospective analysis of two randomized phase III trials in mCRC patients treated first line with oxaliplatin, fluoropyrimidine with and without Bevacizumab (the AIO KRK 0207 and R091 trials) we evaluated the association of high microsatellite instability (MSI-H), immunoscore (IS) and PD-L1 expression in relation to overall survival (OS). METHODS: In total, 550 samples were analysed. Immunohistochemical analysis of the MMR proteins and additionally fragment length analysis was performed, molecular examinations via allele-discriminating PCR in combination with DNA sequencing. Furthermore PD-L1 and IS were assessed. RESULTS: MSI-H tumors were more frequent in right sided tumors (13.66% vs. 4.14%) and were correlated with mutant BRAF (p = 0.0032), but not with KRAS nor NRAS mutations (MT). 3.1% samples were found to be PD-L1 positive, there was no correlation of PDL1 expression with MSI-H status, but in a subgroup analysis of MSI-H tumors the percentage of PD-L1 positive tumors was higher than in MSS tumors (9.75% vs. 2.55%). 8.5% of samples showed a positive IS, MSI-H was associated with a high IS. The mean IS of the pooled population was 0.57 (SD 0.97), while the IS of MSI-H tumors was significantly higher (mean of 2.4; SD 1.4; p =< 0.0001). DISCUSSION: Regarding OS in correlation with MSI-H, PD-L1 and IS status we did not find a significant difference. However, PD-L1 positive mCRC tended to exhibit a longer OS compared to PD-L1 negative cancers (28.9 vs. 22.1 months).

High microsatellite instability (MSI-H) is associated with distinct clinical and molecular characteristics and an improved survival in early Colon cancer (CC); real world data from the AIO molecular registry Colopredict Plus.

Colorectal cancer is one of the leading malignancies and still accounts for almost 25 000 deaths in Germany each year. Although there is accumulating data on the molecular basis, treatment and clinical outcome of patients within clinical trials evidence from the real-world setting is mostly lacking. We started the molecular registry trial Colopredict Plus in 2013 to collect clinical and molecular data from a real-world cohort of patients with early colon cancer stage II and III in 70 German colon cancer centers focusing on the prognostic impact of high microsatellite instability. In this interim report, we characterize a clinical cohort of 2615 patients, of whom 1787 tissue probes were analyzed. Microsatellite status was assessed using immunhistochemistry and fragment length analysis, with a concordance of 91.4 %. These established histopathological methods are sensitive and cost-effective. The median age was 72 years, significantly higher compared to clinical trial populations, with a median Charlson Comorbidity Index of 3. The stage-dependent incidence of microsatellite instability was 23.7 % and was associated with female gender, BRAF-mutation, UICC stage II and localization in the right colon. Survival calculated in disease free, relapse free and overall survival significantly differed between MSI-H and MSS, in favor of MSI-H patients. Multivariate age-adjusted analyses of relapse-free survival, disease-free survival, and overall survival highlighted microsatellite instability as a robust and positive prognostic marker for early colon cancer independent of age.

Pure Large Nested Variant of Urothelial Carcinoma (LNUC) Is the Prototype of an FGFR3 Mutated Aggressive Urothelial Carcinoma with Luminal-Papillary Phenotype.

Since 2016, large nested urothelial carcinoma (LNUC) has been included within the WHO classification of urothelial tumors. Limited reports with mainly small case series have confirmed the malignant behavior of LNUC despite its bland morphological appearance. We evaluated, for the first time, markers for new immunooncological or targeted therapies including FGFR3 mutational status and PD-L1 status, the frequency of TERT-promoter mutations and the molecular subtype in a cohort of 25 LNUC using SNaPshot analysis and immunohistochemistry. Of the 25 cases, 17 were pure LNUC, with 13 showing an additional exophytic papillary/papillary-like component. Seven mixed LNUCs presented areas of classical nested variant urothelial carcinoma (NVUC) and one showed a component of conventional urothelial carcinoma. Of the 17 evaluable pure LNUCs, 16 were FGFR3-mutated with identical mutations in their concomitant papillary/papillary-like components. An FGFR3 mutation was found in 1/7 evaluable mixed LNUCs combined with NVUC. TERT-promoter mutations were detected in 86.7% pure and 83.3% mixed tumors. Immunohistochemistry revealed a luminal phenotype; PD-L1 was negative in the majority of tumor cells and tumor-associated immune cells. Pure LNUC is a prime example of a luminal, FGFR3-mutated, mostly PD-L1-negative tumor. In contrast, FGFR3 mutations seem to be rare in mixed LNUC, which may indicate a different pathway of tumor development.

18F-FDG PET-MR enterography in predicting histological active disease using the Nancy index in ulcerative colitis: a randomized controlled trial.

PURPOSE: To evaluate the diagnostic performance of PET-MR enterography in detecting histological active inflammation in patients with ulcerative colitis and the impact of bowel purgation on diagnostic accuracies of PET-MR parameters. METHODS: Fifty patients were enrolled in this randomized controlled trial (clinicaltrials.gov [NCT03781284]). Forty patients were randomized in two study arms, in which bowel purgation was performed either before or after PET-MR enterography. All patients underwent ileocolonoscopy with mucosal biopsies after PET-MR within 24 h. Diagnostic performance of MR morphological parameters (MRmorph), diffusion-weighted imaging (DWI), and PET in detecting histological inflammation determined by the Nancy index was compared with each other and between study arms. Correlation between PET and histological inflammatory severity was calculated. RESULTS: In study arm without previous bowel purgation, SUVmax ratio of bowel segment (relative to SUVmax of the liver) facilitated the highest specificity and diagnostic accuracy compared with MRmorph and DWI. Bowel cleansing led to markedly increased metabolic activity of bowel segments, resulting in significantly reduced specificity of PET compared with study arm without purgation (0.808 vs. 0.966, p = 0.007, respectively). Inter-observer concordance for assessing MRmorph was clearly increased after bowel cleansing (Cohen's κ, 0.847 vs. 0.665; p = 0.013, respectively), though diagnostic performance of MRmorph was not significantly improved. Our findings suggested that the change of metabolic status was mainly associated with the grade of neutrophil infiltrate and less dependent on chronic infiltrate. CONCLUSION: PET-MR enterography was an excellent non-invasive diagnostic method in the assessment of histological active inflammation in ulcerative colitis without the need of previous bowel purgation. TRIAL REGISTRATION: https://clinicaltrials.gov/ct2/show/NCT03781284.

Assessing Histological Inflammatory Activity in Patients With Ulcerative Colitis: A Diagnostic Accuracy Study Testing Fecal Biomarkers Lactoferrin and Calprotectin.

Background and Aims: Histological remission has arisen as the optimal treatment outcome in ulcerative colitis (UC). The aim of this retrospective study was to explore the diagnostic performance of the noninvasive fecal biomarkers calprotectin (FC) and lactoferrin (FL) compared to the histological indices Nancy Index (NI) and Riley Index (RI). Methods: This study is a retrospective diagnostic accuracy study based on secondary analysis of patient data from 2002 to 2017 extracted from medical registries of our clinics in Essen-Mitte, Germany. Patients with UC underwent a colonoscopy, with biopsies taken from the rectum and the sigmoid scored by 2 experienced pathologists according to NI and RI and provided a stool sample within 7 days pre- or post-colonoscopy. Diagnostic accuracy of recommended cutoffs for FC (>50 µg/g) and FL (≥7.25 µg/g) were tested against our reference standard (NI ≥2) in terms of specificity, sensitivity, positive predictive value, negative predictive value, and accuracy (effectiveness). Results: The number of patients with UC recruited was n = 226, aged 45.2 (SD 13.3). Histological indices were highly correlated (r = 0.980, P < 0.001). Fecal biomarkers correlated moderately with NI (FC: r = 0.383, P < 0.001; FL: r = 0.420, P < 0.001) and RI (FC: r = 0.395, P < 0.001; FL: r = 0.424, P < 0.001). Fecal biomarker concentrations were increased in patients with active histological disease (NI ≥2), median [IQR], FC 69.72 [20.07-254.38], FL 18.59 [6.06-44.42], compared to those with inactive disease (NI ≤1), FC 12.35 [3.89 - 32.16], FL 3.14 [0.75-11.05], z = -6.60, P < 0.001. Fecal biomarker concentrations differed significantly across NI grades 0-4 (FC: H4 = 45.2; FL: H4 = 47.5, both P < 0.001). Patients with grade 0 had significantly lower concentrations of fecal biomarkers than those with grade 3 (median; FC 10.94 vs 72.22; FL 2.30 vs 29.10; both P < 0.001) or grade 4 (FC 10.94 vs 67.00; FL 2.30 vs 27.64; both P < 0.001), as well as grade 2 for FC only (10.94 vs 56.22, P = 0.001). Concentrations were also lower in patients with grade 1 compared to those with grade 3 (FC 17.49 vs 72.22; FL 4.24 vs. 29.10; both P ≤ 0.001) or grade 4 (FC 17.49 vs 67.00; FL 4.24 vs 27.64; both P < 0.001).Receiver operating characteristics area under the curve showed moderate diagnostic accuracy for both FC 0.76 (95% confidence interval [CI] 0.70-0.83) and FL 0.73 (95% CI 0.66-0.80). Optimized cutoffs for both FC (≥34.29) and FL (≥5.85 µg/g) had slightly improved accuracy, compared with the manufacturer's cutoffs (FC: 69.9% vs 65.9%; FL: 71.7% vs 69.0%). Conclusions: Fecal biomarkers calprotectin and lactoferrin correlate with histological disease activity and differentiate between patients in histological remission from those with evidence of moderate to severe disease activity. Their noninvasiveness, in addition to being inexpensive, supports their use in the clinical monitoring of patients with UC.

Amphiregulin (AREG) and Epiregulin (EREG) Gene Expression as Predictor for Overall Survival (OS) in Oxaliplatin/Fluoropyrimidine Plus Bevacizumab Treated mCRC Patients-Analysis of the Phase III AIO KRK-0207 Trial.

Background: The EGFR (epithelial growth factor receptor) ligands amphiregulin (AREG) and epiregulin (EREG) have been considered as predictors for EGFR-antibody efficacy. The effect of AREG and EREG expression levels in primary tumor samples on the outcome of bevacizumab-treated patients is unknown. Patients and Methods: Formalin-fixed paraffin-embedded (FFPE) tumor samples from surgically removed primaries of the AIO KRK-0207 trial have been tested for AREG and EREG expression. The AIO KRK-0207 trial was a randomized phase-3 study to investigate the best maintenance strategy after oxaliplatin/fluoropyrimidine plus bevacizumab induction treatment in patients with mCRC. Association of AREG and EREG levels with outcome parameters were investigated, taking into account RAS and BRAF mutations. Results: A total of 331 tumor samples had measurable AREG and EREG tissue levels. In the total cohort using continuous expression levels, higher logAREG and logEREG levels were associated with a significant longer overall survival (OS) (HR 0.80; p = 0.003 and HR 0.78; p = 0.001, respectively). The subgroup of BRAF mutant tumors displayed significantly lower AREG and EREG levels compared to wild-type tumors. The prognostic effect of AREG and EREG expression was limited to the double wild-type subpopulation, whereas in the RAS mutant and BRAF mutant subgroups no prognostic effect was detected. Conclusion: Low logAREG and logEREG levels are associated with a shorter OS in oxaliplatin/fluoropyrimidine plus bevacizumab treated patients. As low AREG and EREG level are associated with BRAF mutations, the prognostic value of EREG and AREG levels is limited to the RAS and BRAF wild-type subpopulation.

Quantum Cascade Laser-Based Infrared Microscopy for Label-Free and Automated Cancer Classification in Tissue Sections.

A feasibility study using a quantum cascade laser-based infrared microscope for the rapid and label-free classification of colorectal cancer tissues is presented. Infrared imaging is a reliable, robust, automated, and operator-independent tissue classification method that has been used for differential classification of tissue thin sections identifying tumorous regions. However, long acquisition time by the so far used FT-IR-based microscopes hampered the clinical translation of this technique. Here, the used quantum cascade laser-based microscope provides now infrared images for precise tissue classification within few minutes. We analyzed 110 patients with UICC-Stage II and III colorectal cancer, showing 96% sensitivity and 100% specificity of this label-free method as compared to histopathology, the gold standard in routine clinical diagnostics. The main hurdle for the clinical translation of IR-Imaging is overcome now by the short acquisition time for high quality diagnostic images, which is in the same time range as frozen sections by pathologists.