Correct staging of patients with colorectal cancer is of utmost importance for the prediction of operability. Although computed tomography (CT) has a good overall performance, estimation of peritoneal cancer spread is a known weakness, a problem that cannot always be overcome by Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT); especially in infiltrative and miliary disease spread. Due to its high spatial and contrast resolution magnetic resonance imaging (MRI) with diffusion-weighted imaging (DWI) might have a better performance. Our aim was to evaluate the added value of whole-body diffusion-weighted MRI (WB-DWI/MRI) to CT for prediction of peritoneal cancer spread and operability assessment in colorectal cancer patients with clinically suspected peritoneal carcinomatosis (PC). This institutional review board approved retrospective study included sixty colorectal cancer patients who underwent WB-DWI/MRI in addition to CT for clinically suspected peritoneal metastases. WB-DWI/MRI and CT were assessed for detecting PC following the peritoneal cancer index (PCI), determination of PCI-score categorized as PC < 12, PCI = 12–15 and PCI > 15, detection of nodal and distant metastases and estimation of overall operability. Histopathology after surgery and biopsy and/or 6 months follow-up were used as reference standard. For detection of PC, CT had 43.2% sensitivity, 95.6% specificity, 84.5% positive predictive value (PPV) and 75.2% negative predictive value (NPV). WB-DWI/MRI had 97.8% sensitivity, 93.2% specificity, 88.9% PPV and 98.7% NPV. WB-DWI/MRI enabled better detection of inoperable distant metastases (all 12 patients) than CT (2/12 patients) and significantly improved prediction of PCI category [WB-DWI/MRI PCI < 12: 37/39 patients (94.9%); PCI = 12–15: 4/4 patients (100%); PCI > 15: 16/17 patients (94.1%) versus CT PCI < 12: 38/39 patients (97.4%); PCI = 12–15: 0/4 patients (0%); PCI > 15: 2/17 patients (11.8%); p < 0.0001)]. WB-DWI/MRI improved prediction of inoperability over CT with 90.6% sensitivity compared to 25% (p < 0.0001). WB-DWI/MRI significantly outperformed CT for estimation of spread of PC, overall staging and prediction of operability. Pending validation in larger prospective trials, WB-DWI/MRI could be used to guide surgical planning and minimize unnecessary exploratory laparotomies.

We aimed to identify biomarkers that might be used to predict responses of patients with inflammatory bowel diseases (IBD) to vedolizumab therapy. We obtained biopsies from inflamed colon of patients with IBD who began treatment with vedolizumab (n = 31) or tumor necrosis factor (TNF) antagonists (n = 20) and performed RNA-sequencing analyses. We compared gene expression patterns between patients who did and did not enter endoscopic remission (absence of ulcerations at month 6 for patients with Crohn's disease or Mayo endoscopic subscore ≤1 at week 14 for patients with ulcerative colitis) and performed pathway analysis and cell deconvolution for training (n = 20) and validation (n = 11) datasets. Colon biopsies were also analyzed by immunohistochemistry. We validated a baseline gene expression pattern associated with endoscopic remission after vedolizumab therapy using 3 independent datasets (n = 66). We identified significant differences in expression levels of 44 genes between patients who entered remission after vedolizumab and those who did not; we found significant increases in leukocyte migration in colon tissues from patients who did not enter remission (P < .006). Deconvolution methods identified a significant enrichment of monocytes (P = .005), M1-macrophages (P = .05), and CD4+ T cells (P = .008) in colon tissues from patients who did not enter remission, whereas colon tissues from patients in remission had higher numbers of naïve B cells before treatment (P = .05). Baseline expression levels of PIWIL1, MAATS1, RGS13, and DCHS2 identified patients who did vs did not enter remission with 80% accuracy in the training set and 100% accuracy in validation dataset 1. We validated these findings in the 3 independent datasets by microarray, RNA sequencing and quantitative PCR analysis (P = .003). Expression levels of these 4 genes did not associate with response to anti-TNF agents. We confirmed the presence of proteins encoded by mRNAs using immunohistochemistry. We identified 4 genes whose baseline expression levels in colon tissues of patients with IBD associate with endoscopic remission after vedolizumab, but not anti-TNF, treatment. We validated this signature in 4 independent datasets and also at the protein level. Studies of these genes might provide insights into the mechanisms of action of vedolizumab.

Background & Aims Ustekinumab induces and maintains histologic improvement in patients with ulcerative colitis (UC). The clinical relevance of this endpoint alone, and in combination with endoscopic improvement, is unknown. Methods Histologic disease activity were evaluated in 2630 colonic biopsy samples from patients with UC treated in the UNIFI phase 3 UC clinical studies of ustekinumab. We evaluated associations between histologic improvement (defined as the composite of neutrophil infiltration in less than 5% of crypts and no crypt destruction, erosions, ulcerations, or granulation tissue) and clinical endpoints at the end of induction (week 8 and 16) and maintenance (week 44) periods. We assessed the validity of a combined histologic and endoscopic (Mayo endoscopy subscore, 0 or 1) improvement endpoint which we called histo-endoscopic mucosal healing (or histo-endoscopic mucosal improvement). Results Histologic improvement was significantly (P<.0001) associated with clinical remission, lower mean disease activity scores, and greater improvement in disease activity at the end of induction and maintenance studies. Ustekinumab induced and maintained significantly higher rates of histologic improvement at induction week 8 and maintenance week 44 than placebo when more stringent definitions of histologic improvement were used. Histologic improvement and endoscopic improvement following induction were associated with 10%-20% higher rates of histo-endoscopic mucosal healing, clinical remission, and corticosteroid-free remission at week 44 (all P<.05) in patients who received ustekinumab maintenance therapy. At week 44, 61% of patients (56/92) with histo-endoscopic mucosal healing after induction therapy achieved clinical remission, vs 39% of patients (9/23, P=.0983) and 34% of patients (24/71, P=.0009) with endoscopic or histologic improvement alone after induction, respectively. Conclusion Data from the UNIFI program of ustekinumab in patient with UC treated with ustekinumab indicated the achievement of histo-endoscopic mucosal healing after induction therapy is associated with lower disease activity at the end of maintenance therapy than either histologic or endoscopic improvement alone. ClinicalTrials.gov number: NCT02407236.

Although ustekinumab is an effective therapy for moderate to severe Crohn's disease (CD), its effects on the microscopic manifestations of CD are unknown. We evaluated the effects of ustekinumab on histologic CD activity in an analysis of data from 251 participants in phase 3 induction and maintenance studies. Two endoscopic biopsy samples were collected at weeks 0, 8, and 44 from the ileum, splenic flexure, and rectum (18 biopsy samples from each patient). Histologic activity was assessed based on global histology activity scores (GHASs). At week 8, the mean GHAS was significantly reduced after ustekinumab induction treatment (from 10.4 ± 7.0 to 7.1 ± 5.9; P < .001) but not in patients who received placebo (from 9.2 ± 6.4 to 7.8 ± 6.2). At week 44 in the randomized maintenance therapy population, the mean GHAS remained reduced from week 8 in patients who received subcutaneous ustekinumab (90 mg every 8 weeks; from 7.4 ± 7.7 to 6.1 ± 4.7) but not every 12 weeks (from 5.3 ± 3.9 to 8.7 ± 4.1) or placebo (from 9.2 ± 3.8 to 10.9 ± 7.1). In the pooled (randomized and nonrandomized) maintenance therapy population, histologic improvement continued in patients given ustekinumab every 8 weeks (from 7.1 ± 6.2 to 5.2 ± 4.2; P < .0001) but not in those given ustekinumab every 12 weeks (from 6.1 ± 5.7 to 7.2 ± 5.1) or placebo (from 8.2 ± 4.2 to 8.9 ± 6.8). A significantly greater proportion of patients achieved histologic response (≥50% decrease in GHAS from baseline) at week 44 if they received ustekinumab every 8 weeks (50% in the randomized maintenance population and 54% in the pooled maintenance population) compared with every 12 weeks (17% and 39% in the randomized and pooled populations, respectively) or placebo (0% and 22% in the randomized and pooled populations, respectively) (P = .0137 for every 8 weeks vs placebo and P = .3529 for every 12 weeks vs placebo in the randomized population; P = .0168 for every 8 weeks vs placebo and P = .3069 for every 12 weeks vs placebo in the pooled population). Regional and overall mean GHASs correlated with the simple endoscopic score for CD (r = .6255, P < .0001). Multivariate analysis found an association between histologic improvement and endoscopic or histologic burden at baseline. In an analysis of data from participants in phase 3 induction and maintenance trials, we found histologic improvement in a greater proportion of patients given ustekinumab vs placebo. The largest improvements occurred in patients who received ustekinumab maintenance therapy every 8 weeks. ClinicalTrials.gov nos. NCT01369329, NCT01369342, and NCT01369355.

INTRODUCTION: Magnetic resonance enterography (MRE) is useful for detecting bowel strictures, whereas a number of imaging biomarkers may reflect severity of fibrosis burden in Crohn's disease (CD). This study aimed to verify the association of MRE metrics with histologic fibrosis independent of inflammation. METHODS: This prospective European multicenter study performed MRE imaging on 60 patients with CD with bowel strictures before surgical resection. Locations of 61 histological samples were annotated on MRE examinations, followed by central readings using the Chiorean score and measurement of delayed gain of enhancement (DGE), magnetization transfer ratio, T2-weighted MRI sequences (T2R), apparent diffusion coefficient (ADC), and the magnetic resonance index of activity (MaRIA). Correlations of histology and MRE metrics were assessed. Least Absolute Shrinkage and Selection Operator and receiver operator characteristic (ROC) curve analyses were used to select composite MRE scores predictive of histology and to estimate their predictive value. RESULTS: ADC and MaRIA correlated with fibrosis (R = −0.71, P < 0.0001, and 0.59, P < 0.001) and more moderately with inflammation (R = −0.35, P < 0.01, and R = 0.53, P < 0.001). Lower or no correlations of fibrosis or inflammation were found with DGE, magnetization transfer ratio, or T2R. Least Absolute Shrinkage and Selection Operator and ROC identified a composite score of MaRIA, ADC, and DGE as a very good predictor of histologic fibrosis (ROC area under the curve = 0.910). MaRIA alone was the best predictor of histologic inflammation with excellent performance in identifying active histologic inflammation (ROC area under the curve = 0.966). Discussion: MRE-based scores for histologic fibrosis and inflammation may assist in the characterization of CD stenosis and enable development of fibrosis-targeted therapies and clinical treatment of stenotic patients.