The p53-signaling pathway and colorectal cancer: Interactions between downstream p53 target genes and miRNAs.

INTRODUCTION: We examined expression of genes in the p53-signaling pathway. We determine if genes that have significantly different expression in carcinoma tissue compared to normal mucosa also have significantly differentially expressed miRNAs. We utilize a sample of 217 CRC cases. METHODS: We focused on fold change (FC) > 1.50 or <0.67 for genes and miRNAs, that were statistically significant after adjustment for multiple comparisons. We evaluated the linear association between the differential expression of miRNA and mRNA. miRNA:mRNA seed-region matches also were determined. RESULTS: Eleven dysregulated genes were associated with 37 dysregulated miRNAs; all were down-stream from the TP53 gene. MiR-150-5p (HR = 0.82) and miR-196b-5p (HR 0.73) significantly reduced the likelihood of dying from CRC when miRNA expression increased in rectal tumors. CONCLUSIONS: Our data suggest that activation of p53 from cellular stress, could target downstream genes that in turn could influence cell cycle arrest, apoptosis, and angiogenesis through mRNA:miRNA interactions.

Clinical and Molecular Features of Post-Colonoscopy Colorectal Cancers.

BACKGROUND & AIMS: Post-colonoscopy colorectal cancers (PCCRCs) may arise from missed lesions or due to molecular features of tumors that allow them to grow rapidly. We aimed to compare clinical, pathology, and molecular features of PCCRCs (those detected within 6-60 months of colonoscopy) and detected CRCs (those detected within 6 months of a colonoscopy). METHODS: Within a population-based cross-sectional study of incident CRC cases in Utah (from 1995 through 2009), we identified PCCRCs (those cancers that developed within 5 years of a colonoscopy) and matched the patients by age, sex, and hospital site to patients with detected CRC. Archived specimens were retrieved and tested for microsatellite instability (MSI), CpG island methylation, and mutations in KRAS and BRAF. There were 2659 cases of CRC diagnosed within the study window; 6% of these (n = 159) were defined as PCCRCs; 84 of these cases had tissue available and were matched to 84 subjects with detected CRC. RESULTS: Higher proportions of PCCRCs than detected CRCs formed in the proximal colon (64% vs 44%; P = .016) and were of an early stage (86% vs 69%; P = .040). MSI was observed in 32% of PCCRCs compared with 13% of detected CRCs (P = .005). The other molecular features were found in similar proportions of PCCRCs and detected CRCs. In a multivariable logistic regression, MSI (odds ratio, 4.20; 95% CI, 1.58-11.14) was associated with PCCRC. There was no difference in 5-year survival between patients with PCCRCs vs detected CRCs. CONCLUSION: In this population-based cross-sectional study of incident CRC cases in Utah, we found PCCRCs to be more likely to arise in the proximal colon and demonstrate MSI, so PCCRCs and detected CRC appear to have different features or processes of tumorigenesis. Additional studies are needed to determine if post-colonoscopy cancers arise through a specific genetic pathway.

Mutation analysis of adenomas and carcinomas of the colon: Early and late drivers.

Colorectal cancer (CRC) accounts for about 8% of all new cancer cases diagnosed in the US. We used whole exome sequence data from triplet samples (colon carcinoma, colon adenoma, and normal tissue) from 18 individuals to assess gene mutation rates. Of the 2 204 genes that were mutated, APC, TTN, TP53, KRAS, OBSCN, SOX9, PCDH17, SIGLEC10, MYH6, and BRD9 were consistent with genes being an early driver of carcinogenesis, in that they were mutated in multiple adenomas and multiple carcinomas. Fifty-two genes were mutated in ≥12.5% of microsatellite stable (MSS) carcinomas but not in any of the adenomas, in line with the profile of a late driver event involved in tumor progression. Thirty-eight genes were sequenced in a larger independent set of 148 carcinoma/normal tissue pairs to obtain more precise mutation frequencies. Eight of the genes, APC, TP53, ATM, CSMD3, LRP1B, RYR2, BIRC6, and MUC17, contained mutations in >20% of the carcinomas. Interestingly, mutations in four genes in addition to APC that are associated with dysregulation of Wnt signaling, were all classified as early driver events. Most of the genes that are commonly associated with colon cancer, including APC, TP53, and KRAS, were all classified as being early driver genes being mutated in both adenomas and carcinomas. Classifying genes as potential early and late driver events points to candidate genes that may help dissect pathways involved in both tumor initiation and progression.

MicroRNA-transcription factor interactions and their combined effect on target gene expression in colon cancer cases.

Transcription factors (TFs) and microRNAs (miRNAs) regulate gene expression: TFs by influencing messenger RNA (mRNA) transcription and miRNAs by influencing mRNA translation and transcript degradation. Additionally, miRNAs and TFs alter each other's expression, making it difficult to ascertain the effect either one has on target gene (TG) expression. In this investigation, we use a two-way interaction model with the TF and miRNA as independent variables to investigate whether miRNAs and TFs work together to influence TG expression levels in colon cancer subjects. We used known TF binding sites and validated miRNA targets to determine potential miRNA-TF-TG interactions, restricting interactions to those with a TF previously associated with altered risk of colorectal cancer death. We analyzed interactions using normal colonic mucosa expression as well as differential expression, which is measured as colonic carcinoma expression minus normal colonic mucosa expression. We analyzed 3518 miRNA-TF-TG triplets using normal mucosa expression and 617 triplets using differential expression. Normal colonic RNA-Seq data were available for 168 individuals; of these, 159 also had carcinoma RNA-Seq data. Thirteen unique miRNA-TF-TG interactions, comprising six miRNAs, four TFs, and 11 TGs, were statistically significant after adjustment for multiple comparisons in normal colonic mucosa, and 14 unique miRNA-TF-TG interactions, comprising two miRNAs, two TFs, and 13 TGs, were found for carcinoma-normal differential expression. Our results show that TG expression is influenced by both miRNAs as well as TFs, and the influence of one regulator impacts the effect of the other on the shared TG expression.

Dysregulated genes and miRNAs in the apoptosis pathway in colorectal cancer patients.

Apoptosis is genetically regulated and involves intrinsic and extrinsic pathways. We examined 133 genes within these pathways to identify whether they are expressed differently in colorectal carcinoma (CRC) and normal tissue (N = 217) and if they are associated with similar differential miRNA expression. Gene expression data (RNA-Seq) and miRNA expression data (Agilent Human miRNA Microarray V19.0) were generated. We focused on dysregulated genes with a fold change (FC) of > 1.50 or < 0.67, that were significant after adjustment for multiple comparisons. miRNA:mRNA seed-region matches were determined. Twenty-three genes were significantly downregulated (FC < 0.67) and 18 were significantly upregulated (FC > 1.50). Of these 41 genes, 11 were significantly associated with miRNA differential expression. BIRC5 had the greatest number of miRNA associations (14) and the most miRNAs with a seed-region match (10). Four of these matches, miR-145-5p, miR-150-5p, miR-195-5p, and miR-650, had a negative beta coefficient. CSF2RB was associated with ten total miRNAs (five with a seed-region match, and one miRNA, miR-92a-3p, with a negative beta coefficient). Of the three miRNAs associated with CTSS, miR-20b-5p, and miR-501-3p, had a seed-region match and a negative beta coefficient between miRNA:mRNA pairs. Several miRNAs that were associated with dysregulated gene expression, seed-region matches, and negative beta coefficients also were associated with CRC-specific survival. Our data suggest that miRNAs could influence several apoptosis-related genes. BIRC5, CTSS, and CSF2R all had seed-region matches with miRNAs that would favor apoptosis. Our study identifies several miRNA associated with apoptosis-related genes, that if validated, could be important therapeutic targets.

The PI3K/AKT signaling pathway: Associations of miRNAs with dysregulated gene expression in colorectal cancer.

The PI3K/AKT-signaling pathway is one of the most frequently activated signal-transduction pathways in cancer. We examined how dysregulated gene expression is associated with miRNA expression in this pathway in colorectal cancer (CRC). We used data from 217 CRC cases to evaluate differential pathway gene expression between paired carcinoma and normal mucosa and identify miRNAs that are associated with these genes. Gene expression data from RNA-Seq and miRNA expression data from Agilent Human miRNA Microarray V19.0 were analyzed. We focused on genes most associated with CRC (fold change (FC) of >1.5 or <0.67) that were statistically significant after adjustment for multiple comparisons. Of the 304 genes evaluated, 76 had a FC of <0.67, and 57 had a FC of >1.50; 47 of these genes were associated with miRNA differential expression. There were 145 mRNA:miRNA seed-region matches of which 26 were inversely associated suggesting a greater likelihood of a direct association. Most miRNA:mRNA associations were with factors that stimulated the pathway. For instance, both IL6R and PDGFRA had inverse seed-region matches with seven miRNAs, suggesting that these miRNAs have a direct effect on these genes and may be key elements in activation of the pathway. Other miRNA:mRNA associations with similar impact on the pathway were miR-203a with ITGA4, miR-6071 with ITGAV, and miR-375 with THBS2, all genes involved in extracellular matrix function that activate PI3Ks. Gene expression in the PI3K/Akt-signaling pathway is dysregulated in CRC. MiRNAs were associated with many of these dysregulated genes either directly or in an indirect manner.

Infrequently expressed miRNAs in colorectal cancer tissue and tumor molecular phenotype.

This corrects the article DOI: 10.1038/modpathol.2017.38.

The TGFß-signaling pathway and colorectal cancer: associations between dysregulated genes and miRNAs.

BACKGROUND: The TGFß-signaling pathway plays an important role in the pathogenesis of colorectal cancer (CRC). Loss of function of several genes within this pathway, such as bone morphogenetic proteins (BMPs) have been seen as key events in CRC progression. METHODS: In this study we comprehensively evaluate differential gene expression (RNASeq) of 81 genes in the TGFß-signaling pathway and evaluate how dysregulated genes are associated with miRNA expression (Agilent Human miRNA Microarray V19.0). We utilize paired carcinoma and normal tissue from 217 CRC cases. We evaluate the associations between differentially expressed genes and miRNAs and sex, age, disease stage, and survival months. RESULTS: Thirteen genes were significantly downregulated and 14 were significantly upregulated after considering fold change (FC) of > 1.50 or < 0.67 and multiple comparison adjustment. Bone morphogenetic protein genes BMP5, BMP6, and BMP2 and growth differentiation factor GDF7 were downregulated. BMP4, BMP7, INHBA (Inhibin beta A), TGFBR1, TGFB2, TGIF1, TGIF2, and TFDP1 were upregulated. In general, genes with the greatest dysregulation, such as BMP5 (FC 0.17, BMP6 (FC 0.25), BMP2 (FC 0.32), CDKN2B (FC 0.32), MYC (FC 3.70), BMP7 (FC 4.17), and INHBA (FC 9.34) showed dysregulation in the majority of the population (84.3, 77.4, 81.1, 80.2, 82.0, 51.2, and 75.1% respectively). Four genes, TGFBR2, ID4, ID1, and PITX2, were un-associated or slightly upregulated in microsatellite-stable (MSS) tumors while downregulated in microsatellite-unstable (MSI) tumors. Eight dysregulated genes were associated with miRNA differential expression. E2F5 and THBS1 were associated with one or two miRNAs; RBL1, TGFBR1, TGIF2, and INHBA were associated with seven or more miRNAs with multiple seed-region matches. Evaluation of the joint effects of mRNA:miRNA identified interactions that were stronger in more advanced disease stages and varied by survival months. CONCLUSION: These data support an interaction between miRNAs and genes in the TGFß-signaling pathway in association with CRC risk. These interactions are associated with unique clinical characteristics that may provide targets for further investigations.

Variables affecting penetrance of gastric and duodenal phenotype in familial adenomatous polyposis patients.

BACKGROUND: Patients with familial adenomatous polyposis (FAP) frequently undergo colectomy to reduce the 70 to 90% lifetime risk of colorectal cancer. After risk-reducing colectomy, duodenal cancer and complications from duodenal surgeries are the main cause of morbidity. Our objective was to prospectively describe the duodenal and gastric polyp phenotype in a cohort of 150 FAP patients undergoing pre-screening for a chemoprevention trial and analyze variables that may affect recommendations for surveillance. METHODS: Individuals with a diagnosis of FAP underwent prospective esophagogastroduodenoscopy using a uniform system of mapping of size and number of duodenal polyps for a 10 cm segment. Gastric polyps were recorded as the total number. RESULTS: The distribution of the count and sum diameter of duodenal polyps were statistically different in two genotype groups, those with APC mutations associated with classic FAP had a greater count (median 17) and sum diameter of polyps (median 32 mm) than those with APC mutations associated with attenuated FAP (median count 4 and median sum diameter of 7 mm) (p < 0.0001). The number of gastric polyps did not differ based on genotype (p = 0.67) but advancing age correlated with severity of gastric polyposis (p = 0.019). Spigelman (modified) staging of II or greater was found in 88% of classic FAP patients and 48% attenuated FAP patients. Examples of severe and mild upper GI phenotype are observed in patients with identical APC mutations, showing that the APC mutation location is not absolutely predictive of an upper GI phenotype. CONCLUSIONS: Most FAP patients have duodenal and gastric polyps which become more prevalent and advanced with age. Standard upper endoscopic surveillance is recommended based on personal history independent of APC mutation location. TRIAL REGISTRATION: NCT 01187901 registered August 24, 2010, prospective to enrollment.

The co-regulatory networks of tumor suppressor genes, oncogenes, and miRNAs in colorectal cancer.

Tumor suppressor genes (TSGs) and oncogenes (OG) are involved in carcinogenesis. MiRNAs also contribute to cellular pathways leading to cancer. We use data from 217 colorectal cancer (CRC) cases to evaluate differences in TSGs and OGs expression between paired CRC and normal mucosa and evaluate how TSGs and OGs are associated with miRNAs. Gene expression data from RNA-Seq and miRNA expression data from Agilent Human miRNA Microarray V19.0 were used. We focus on genes most strongly associated with CRC (fold change (FC) of ≥1.5 or ≤0.67) that were statistically significant after adjustment for multiple comparisons. Of the 74 TSGs evaluated, 22 were associated with carcinoma/normal mucosa differential expression. Ten TSGs were up-regulated (FAM123B, RB1, TP53, RUNX1, MSH2, BRCA1, BRCA2, SOX9, NPM1, and RNF43); six TSGs were down-regulated (PAX5, IZKF1, GATA3, PRDM1, TET2, and CYLD); four were associated with MSI tumors (MLH1, PTCH1, and CEBPA down-regulated and MSH6 up-regulated); and two were associated with MSS tumors (PHF6 and ASXL1 up-regulated). Thirteen of these TSGs were associated with 44 miRNAs. Twenty-seven of the 59 OGs evaluated were dysregulated: 14 down-regulated (KLF4, BCL2, SSETBP1, FGFR2, TSHR, MPL, KIT, PDGFRA, GNA11, GATA2, FGFR3, AR, CSF1R, and JAK3), seven up-regulated (DNMT1, EZH2, PTPN11, SKP2, CCND1, MET, and MYC); three down-regulated for MSI (FLT3, CARD11, and ALK); two up-regulated for MSI (IDH2 and HRAS); and one up-regulated with MSS tumors (CTNNB1). These findings suggest possible co-regulatory function between TSGs, OGs, and miRNAs, involving both direct and indirect associations that operate through feedback and feedforward loops.

The miRNA landscape of colorectal polyps.

The genomic landscape of adenomas and polyps may help define disease pathways. Expression of miRNAs in adenomas and polyps may importantly contribute to these pathways. We evaluated miRNA expression in 293 polyp-normal colorectal mucosa pairs. Polyps were classified as either adenomatous polyp (AD), hyperplastic polyp (HP), or sessile serrated polyp (SSP). We compared these miRNA expression profiles in polyps to miRNA expression in microsatellite unstable (MSI) and stable (MSS) tumors. A False Discovery Rate of 0.05 based on Benjamini and Hochberg was used to adjust for multiple comparisons. There were 70 miRNAs with differential expression by polyp type with a fold change <0.75 or >1.34 after adjusting for multiple comparisons. The major differences in miRNA expression were observed between AD and SSP and AD and HP, with few differences in expression noted for SSP and HP. AD polyps were more likely to be upregulated from normal colonic mucosa, while SSP and HP were more likely to be downregulated from normal colonic mucosa. MiRNA expression in the SSP and HP tumors almost uniformly go in opposite directions from the MSS tumor miRNA expression and was mixed with MSI tumors. We conclude that different types of polyps have unique miRNA expression profiles. © 2017 Wiley Periodicals, Inc.

A Clinicopathologic Evaluation of Incidental Fundic Gland Polyps With Dysplasia: Implications for Clinical Management.

OBJECTIVES: Fundic gland polyps (FGPs) can rarely exhibit dysplasia of the surface epithelium. Based on retrospective data, FGPs with dysplasia (FGPDs) are thought to be a strong marker for familial adenomatous polyposis (FAP), although sporadic, non-syndromic FGPDs also occur. Owing to the significant syndromic association, diagnosis of an apparently sporadic FGPD may prompt clinical evaluation for FAP, especially its attenuated variant. We sought to evaluate the positive predictive value of incidental FGPDs for FAP. We also characterized the clinicopathologic features of incidental FGPDs to advance clinical management. METHODS: Incidental FGPDs were identified from 2004 to 2015 in patients without FAP at biopsy. All clinical follow-up data were reviewed, and germline analysis for APC and MUTYH mutations was performed in consenting patients. RESULTS: We identified 25 incidental FGPDs in patients not known to have FAP (11.6% of FGPDs, 1.0% of all FGPs). Four patients had a family history of gastric polyps or gastrointestinal cancers. Clinical management included completion polypectomy and gastric endoscopic surveillance (44%), endoscopic surveillance alone (32%), no follow-up (24%), colonoscopy referral (12%), and genetic counseling (4%). Colonoscopies on record revealed 0-7 cumulative adenomas. Follow-up averaged 4.4 years (range 0.3-10.6). No clinical evidence of FAP, gastric cancer, death, or surgery occurred. None of the 11 patients consenting to germline APC and MUTYH testing had genomic alterations. CONCLUSIONS: Incidental FGPDs in this series were all found to be sporadic (25/25) by endoscopic, clinical, and molecular findings, and thus FGPDs were not harbingers of FAP. As isolated findings, FGPDs do not appear to warrant follow-up genetic counseling or testing.

Transcription factor-microRNA associations and their impact on colorectal cancer survival.

MicroRNAs (miRNAs) and Transcription Factors (TFs) both influence messenger RNA (mRNA) expression, disrupting biological pathways involved in carcinogenesis and prognosis. As many miRNAs target multiple mRNAs, thus influencing a multitude of biological pathways, deciphering which miRNAs are important for cancer development and survival is difficult. In this study, we (i) determine associations between TF and survival (N = 168 colon cancer cases); (ii) identify miRNAs associated with TFs related to survival; and (iii) determine if factors derived from TF-specific miRNA principal component analysis (PCA) influence survival. Cox Proportional hazard models were run for each PCA factor to determine Hazard Ratios (HR) and 95% Confidence Intervals (CI) adjusting for age, center, and AJCC stage. Thirty TFs improved survival when differential expression increased; 27 of these were associated significantly with normal colonic mucosa expression of 65 unique miRNAs when an FDR q-value of <0.05 was applied. Five factors, comprising 21 miRNAs, altered survival in rectal cancer subjects; four of these five factors improved survival and one factor reduced survival. One factor comprising four miRNAs reduced survival in colon cancer subjects. In summary, our data suggest that expression of TFs and their related miRNAs influence survival after diagnosis with colorectal cancer.

Infrequently expressed miRNAs in colorectal cancer tissue and tumor molecular phenotype.

We have previously shown that commonly expressed miRNAs influenced tumor molecular phenotype in colorectal cancer. We hypothesize that infrequently expressed miRNAs, when showing higher levels of expression, help to define tumor molecular phenotype. In this study, we examine 304 miRNAs expressed in at least 30 individuals, but in <50% of the population and with a mean level of expression above 1.0 relative florescent unit. We examine associations in 1893 individuals who have the tumor molecular phenotype data as well as miRNA expression levels for both carcinoma and normal colorectal tissue. We compare miRNAs uniquely associated with tumor molecular phenotype to the RNAseq data to identify genes associated with these miRNAs. This information is used to further identify unique pathways associated with tumor molecular phenotypes of TP53-mutated, KRAS-mutated, CpG island methylator phenotype and microsatellite instability tumors. Thirty-seven miRNAs were uniquely associated with TP53-mutated tumors; 30 of these miRNAs had higher level of expression in TP53-mutated tumors, while seven had lower levels of expression. Of the 34 miRNAs associated with CpG island methylator phenotype-high tumors, 16 were more likely to have a CpG island methylator phenotype-high tumor and 19 were less likely to be CpG island methylator phenotype-high. For microsatellite instability, 13 of the 22 infrequently expressed miRNAs were significantly less likely to be expressed in microsatellite unstable tumors. KRAS-mutated tumors were not associated with any miRNAs after adjustment for multiple comparisons. Of the dysregulated miRNAs, 17 were more likely to be TP53-mutated tumors while simultaneously being less likely to be CpG island methylator phenotype-high and/or microsatellite instability tumors. Genes regulated by these miRNAs were involved in numerous functions and pathways that influence cancer risk and progression. In summary, some infrequently expressed miRNAs, when expressed at higher levels, appear to have significant biological meaning in terms of tumor molecular phenotype and gene expression profiles.

Feasibility of Large-Scale Identification of Sessile Serrated Polyp Patients Using Electronic Records: A Utah Study.

BACKGROUND/AIMS: The serrated pathway accounts for 15-25% of sporadic colorectal cancer (CRC). In our study, we sought to accurately characterize sessile serrated polyps (SSP) in a population by electronically interrogating colonoscopy patients' endoscopy and pathology reports using a rules-based text search of pre-defined SSP-related terms. To this aim, we compared a sample of putative SSP and hyperplastic polyps (HP) using our algorithm to a determination of SSP or HP by pathologist and molecular examination to determine the feasibility of large-scale identification of SSP in electronic medical records. METHODS: In 23,990 endoscopy reports from colonoscopies with pathology performed at a University of Utah Healthcare facility in 2000-2012, we identified serrated lesions and categorized each as putative SSP or HP using a text search algorithm. We obtained 93 tissue samples for histologic and molecular analysis. RESULTS: Serrated polyps were categorized as putative SSP (N = 920) and putative HP (N = 7159) by text search algorithm. Histologic examination of 93 samples identified 37 SSP, 11 probable SSP, and 45 HP. Of 26 putative SSP, 25 were SSP/probable SSP (96%) by histology. Of 67 putative HP, 44 were HP (66%) by histology. Reducing size criterion from ≥1 to ≥5 mm in the search algorithm caused improved sensitivity (77.1%) without decline in specificity (97.8%). CONCLUSIONS: A simple rules-based search to identify SSP provides "proof of principle" that SSP can be identified in a large electronic record set. Pilot data indicate defining large, right-sided polyps as ≥5 mm provides adequate sensitivity to detect SSP from electronic records while maintaining high specificity.

MicroRNA profiles in colorectal carcinomas, adenomas and normal colonic mucosa: variations in miRNA expression and disease progression.

MiRNAs are small, non-protein-coding RNA molecules that regulate gene expression either by post-transcriptionally suppressing mRNA translation or by mRNA degradation. We examine differentially expressed miRNAs in colorectal carcinomas, adenomas and normal colonic mucosa. Data come from population-based studies of colorectal cancer conducted in Utah and the Kaiser Permanente Medical Care Program. A total of 1893 carcinoma/normal-paired samples and 290 adenoma tissue samples were run on the Agilent Human miRNA Microarray V19.0 which contained 2006 miRNAs. We tested for significant differences in miRNA expression between paired carcinoma/adenoma/normal colonic tissue samples. Fewer than 600 miRNAs were expressed in >80% of people for colonic tissue; of these 86.5% were statistically differentially expressed between carcinoma and normal colonic mucosa using a false discovery rate of 0.05. Roughly half of these differentially expressed miRNAs showed a progression in levels of expression from normal to adenoma to carcinoma tissue. Other miRNAs appeared to be altered at the normal to adenoma stage, while others were only altered at the adenoma to carcinoma stage or only at the normal to carcinoma stage. Evaluation of the Agilent platform showed a high degree of repeatability (r = 0.98) and reasonable agreement with the NanoString platform. Our data suggest that miRNAs are highly dysregulated in colorectal tissue among individuals with colorectal cancer; the pattern of disruption varies by miRNA as tissue progresses from normal to adenoma to carcinoma.

Effect of Sulindac and Erlotinib vs Placebo on Duodenal Neoplasia in Familial Adenomatous Polyposis: A Randomized Clinical Trial.

IMPORTANCE: Patients with familial adenomatous polyposis (FAP) are at markedly increased risk for duodenal polyps and cancer. Surgical and endoscopic management of duodenal neoplasia is difficult and chemoprevention has not been successful. OBJECTIVE: To evaluate the effect of a combination of sulindac and erlotinib on duodenal adenoma regression in patients with FAP. DESIGN, SETTING, AND PARTICIPANTS: Double-blind, randomized, placebo-controlled trial, enrolling 92 participants with FAP, conducted from July 2010 through June 2014 at Huntsman Cancer Institute in Salt Lake City, Utah. INTERVENTIONS: Participants with FAP were randomized to sulindac (150 mg) twice daily and erlotinib (75 mg) daily (n = 46) vs placebo (n = 46) for 6 months. MAIN OUTCOMES AND MEASURES: The total number and diameter of polyps in the proximal duodenum were mapped at baseline and 6 months. The primary outcome was change in total polyp burden at 6 months. Polyp burden was calculated as the sum of the diameters of polyps. The secondary outcomes were change in total duodenal polyp count, change in duodenal polyp burden or count stratified by genotype and initial polyp burden, and percentage of change from baseline in duodenal polyp burden. RESULTS: Ninety-two participants (mean age, 41 years [range, 24-55]; women, 56 [61%]) were randomized when the trial was stopped by the external data and safety monitoring board because the second preplanned interim analysis met the prespecified stopping rule for superiority. Grade 1 and 2 adverse events were more common in the sulindac-erlotinib group, with an acne-like rash observed in 87% of participants receiving treatment and 20% of participants receiving placebo (P < .001). Only 2 participants experienced grade 3 adverse events. [table: see text]. CONCLUSIONS AND RELEVANCE: Among participants with FAP, the use of sulindac and erlotinib compared with placebo resulted in a lower duodenal polyp burden after 6 months. Adverse events may limit the use of these medications at the doses used in this study. Further research is necessary to evaluate these preliminary findings in a larger study population with longer follow-up to determine whether the observed effects will result in improved clinical outcomes. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT 01187901.

An evaluation and replication of miRNAs with disease stage and colorectal cancer-specific mortality.

MicroRNAs (miRNAs) have been implicated in colorectal cancer (CRC) development and associated with prognostic indicators such as disease stage and survival. Prognostic associations are often based on few individuals and imprecise. In this study, we utilize population-based data from 1,141 CRC cases to replicate previously reported associations between 121 miRNAs and disease stage and survival. The Agilent Human miRNA Microarray V19.0 was used to generate miRNA data following a stringent quality control protocol. Assessment of survival was done using Cox Proportional Hazard models adjusting for age, disease stage and tumor molecular phenotype. Five miRNAs were associated with more advanced disease stage; hsa-miR-145-5p and hsa-miR-31-5p showed increased expression with more advanced tumor stage, while hsa-miR-200b-3p, hsa-miR-215 and hsa-miR-451a had decreased expression with more advanced tumors. Thirteen miRNAs were associated with CRC mortality among individuals diagnosed with colon cancer while 14 were associated with CRC mortality after a diagnosis with rectal cancer. Strongest associations were observed for those miRNAs that were expressed in a small subset of tumors. Most notable associations were for hsa-miR-145-3p [hazard ratio (HR) 2.94, 95% confidence interval (CI) 1.54, 5.61], and hsa-miR-9-3p (HR 10.28, 95% CI 1.31, 80.84) with colon cancer and hsa-miR-335-5p (HR 0.17, 95% CI 0.05, 0.54) for rectal cancer. hsa-miR-374a-5p, hsa-miR-570-3p and hsa-miR-18a-5p significantly reduced the hazard of dying for all cases, regardless of tumor site. Our findings illustrate the need for a large sample to evaluate the association of miRNAs with survival and disease stage in order to determine associations by tumor site.

Evaluation of colorectal cancers for Lynch syndrome: practical molecular diagnostics for surgical pathologists.

Lynch syndrome is the most common inherited colorectal cancer syndrome, accounting for 2-4% of all colorectal cancer cases. This review focuses on the tissue workup of Lynch syndrome, including methods to determine whether or not a tumor is mismatch repair deficient, and whether a mismatch repair-deficient tumor is sporadic or Lynch syndrome-associated. Strategies for determining which tumors to test and how best to implement a Lynch syndrome screening program are also discussed, as well as potential developments in the future.

ACMG technical standards and guidelines for genetic testing for inherited colorectal cancer (Lynch syndrome, familial adenomatous polyposis, and MYH-associated polyposis).

Lynch syndrome, familial adenomatous polyposis, and Mut Y homolog (MYH)-associated polyposis are three major known types of inherited colorectal cancer, which accounts for up to 5% of all colon cancer cases. Lynch syndrome is most frequently caused by mutations in the mismatch repair genes MLH1, MSH2, MSH6, and PMS2 and is inherited in an autosomal dominant manner. Familial adenomatous polyposis is manifested as colonic polyposis caused by mutations in the APC gene and is also inherited in an autosomal dominant manner. Finally, MYH-associated polyposis is caused by mutations in the MUTYH gene and is inherited in an autosomal recessive manner but may or may not be associated with polyps. There are variants of both familial adenomatous polyposis (Gardner syndrome--with extracolonic features--and Turcot syndrome, which features medulloblastoma) and Lynch syndrome (Muir-Torre syndrome features sebaceous skin carcinomas, and Turcot syndrome features glioblastomas). Although a clinical diagnosis of familial adenomatous polyposis can be made using colonoscopy, genetic testing is needed to inform at-risk relatives. Because of the overlapping phenotypes between attenuated familial adenomatous polyposis, MYH-associated polyposis, and Lynch syndrome, genetic testing is needed to distinguish among these conditions. This distinction is important, especially for women with Lynch syndrome, who are at increased risk for gynecological cancers. Clinical testing for these genes has progressed rapidly in the past few years with advances in technologies and the lower cost of reagents, especially for sequencing. To assist clinical laboratories in developing and validating testing for this group of inherited colorectal cancers, the American College of Medical Genetics and Genomics has developed the following technical standards and guidelines. An algorithm for testing is also proposed.