Algorithm Training and Testing for a Nonendoscopic Barrett's Esophagus Detection Test in Prospective Multicenter Cohorts.

BACKGROUND & AIMS: Endoscopic Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC) detection is invasive and expensive. Nonendoscopic BE/EAC detection tools are guideline-endorsed alternatives. We previously described a 5-methylated DNA marker (MDM) panel assayed on encapsulated sponge cell collection device (CCD) specimens. We aimed to train a new algorithm using a 3-MDM panel and test its performance in an independent cohort. METHODS: Algorithm training and test samples were from 2 prospective multicenter cohorts. All BE cases had esophageal intestinal metaplasia (with or without dysplasia/EAC); control subjects had no endoscopic evidence of BE. The CCD procedure was followed by endoscopy. From CCD cell lysates, DNA was extracted, bisulfite treated, and MDMs were blindly assayed. The algorithm was set and locked using cross-validated logistic regression (training set) and its performance was assessed in an independent test set. RESULTS: Training (N = 352) and test (N = 125) set clinical characteristics were comparable. The final panel included 3 MDMs (NDRG4, VAV3, ZNF682). Overall sensitivity was 82% (95% CI, 68%-94%) at 90% (79%-98%) specificity and 88% (78%-94%) sensitivity at 84% (70%-93%) specificity in training and test sets, respectively. Sensitivity was 90% and 68% for all long- and short-segment BE, respectively. Sensitivity for BE with high-grade dysplasia and EAC was 100% in training and test sets. Overall sensitivity for nondysplastic BE was 82%. Areas under the receiver operating characteristic curves for BE detection were 0.92 and 0.94 in the training and test sets, respectively. CONCLUSIONS: A locked 3-MDM panel algorithm for BE/EAC detection using a nonendoscopic CCD demonstrated excellent sensitivity for high-risk BE cases in independent validation samples. (Clinical trials.gov: NCT02560623, NCT03060642.).

Multitarget Stool DNA Testing Has High Positive Predictive Value for Colorectal Neoplasia on the Second Round of Testing.

BACKGROUND & AIMS: Multitarget stool DNA (mt-sDNA) testing is a stool-based screening test for colorectal cancer (CRC). In a single instance of testing, the pivotal Food and Drug Administration-approval study (NCT01397747) found that 16% of mt-sDNA tests were positive, and the positive predictive value (PPV) for CRC or advanced precursor lesions (APL) was 27.3%. We aimed to examine real-world longitudinal performance by determining the test-positive rate and PPV of mt-sDNA on the second round of testing. METHODS: Colonoscopy and pathology reports were reviewed retrospectively for patients with a negative mt-sDNA on the first round of screening and a positive mt-sDNA on the second round. The test-positivity rate and PPV for CRC, APL, and any colorectal neoplasia were calculated for the second mt-sDNA and compared with baseline PPVs from a previously published cohort of patients from our institution who tested positive on the first round of screening. RESULTS: A total of 2758 patients completed a second test at a median of 3.2 years after the first test. Of these, 422 (15%) had a positive second mt-sDNA. The PPV was 0.25% for CRC, 24% for APL, and 67% for any colorectal neoplasia. There was no significant difference in PPV on the second mt-sDNA test compared with the first round (24% vs 28% for APL; P = .12). CONCLUSIONS: mt-sDNA test positive rate and PPV were similar between the first and second rounds of screening. These observations confirm the utility of a second round of mt-sDNA screening and may inform estimates of mt-sDNA effectiveness for CRC screening.

Detection of endometrial cancer using tampon-based collection and methylated DNA markers.

OBJECTIVE: Alterations in DNA methylation are early events in endometrial cancer (EC) development and may have utility in EC detection via tampon-collected vaginal fluid. METHODS: For discovery, DNA from frozen EC, benign endometrium (BE), and benign cervicovaginal (BCV) tissues underwent reduced representation bisulfite sequencing (RRBS) to identify differentially methylated regions (DMRs). Candidate DMRs were selected based on receiver operating characteristic (ROC) discrimination, methylation level fold-change between cancers and controls, and absence of background CpG methylation. Methylated DNA marker (MDM) validation was performed using qMSP on DNA from independent EC and BE FFPE tissue sets. Women ≥45 years of age with abnormal uterine bleeding (AUB) or postmenopausal bleeding (PMB) or any age with biopsy-proven EC self-collected vaginal fluid using a tampon prior to clinically indicated endometrial sampling or hysterectomy. Vaginal fluid DNA was assayed by qMSP for EC-associated MDMs. Random forest modeling analysis was performed to generate predictive probability of underlying disease; results were 500-fold in-silico cross-validated. RESULTS: Thirty-three candidate MDMs met performance criteria in tissue. For the tampon pilot, 100 EC cases were frequency matched by menopausal status and tampon collection date to 92 BE controls. A 28-MDM panel highly discriminated between EC and BE (96% (95%CI 89-99%) specificity; 76% (66-84%) sensitivity (AUC 0.88). In PBS/EDTA tampon buffer, the panel yielded 96% (95% CI 87-99%) specificity and 82% (70-91%) sensitivity (AUC 0.91). CONCLUSION: Next generation methylome sequencing, stringent filtering criteria, and independent validation yielded excellent candidate MDMs for EC. EC-associated MDMs performed with promisingly high sensitivity and specificity in tampon-collected vaginal fluid; PBS-based tampon buffer with added EDTA improved sensitivity. Larger tampon-based EC MDM testing studies are warranted.

Neoplasia Diagnosis After Multi-target Stool DNA Is Enhanced Among Lowest Baseline Detectors.

BACKGROUND AND AIMS: Variation in colorectal neoplasia detection limits the effectiveness of screening colonoscopy. By evaluating neoplasia detection rates of individual colonoscopists, we aimed to quantify the effects of pre-procedural knowledge of a positive (+) multi-target stool DNA (mt-sDNA) on colonoscopy quality metrics. METHODS: We retrospectively identified physicians who performed a high volume of + mt-sDNA colonoscopies; colorectal neoplasia at post-mt-sDNA colonoscopy was recorded. These colonoscopists were stratified into quartiles based on baseline adenoma detection rates. Baseline colonoscopy adenoma detection rates and sessile serrated lesion detection rates were compared to post-mt-sDNA colonoscopy neoplasia diagnosis rates among each quartile. Withdrawal times were measured from negative exams. RESULTS: During the study period (2014-17) the highest quartile of physicians by volume of post-mt-sDNA colonoscopies were evaluated. Among thirty-five gastroenterologists, their median screening colonoscopy adenoma detection rate was 32% (IQR, 28-39%) and serrated lesion detection rate was 13% (8-15%). After + mt-sDNA, adenoma diagnosis increased to 47% (36-56%) and serrated lesion diagnosis increased to 31% (17-42%) (both p < 0.0001). Median withdrawal time increased from 10 (7-13) to 12 (10-17) minutes (p < 0.0001) and was proportionate across quartiles. After + mt-sDNA, lower baseline detectors had disproportionately higher rates of adenoma diagnosis in female versus male patients (p = 0.048) and higher serrated neoplasia diagnosis rates among all patients (p = 0.0092). CONCLUSIONS: Knowledge of + mt-sDNA enriches neoplasia diagnosis compared to average risk screening exams. Adenomatous and serrated lesion diagnosis was magnified among those with lower adenoma detection rates. Awareness of the mt-sDNA result may increase physician attention during colonoscopy. Pre-procedure knowledge of a positive mt-sDNA test improves neoplasia diagnosis rates among colonoscopists with lower baseline adenoma detection rates, independent of withdrawal time.

Tissue methylated DNA markers for sporadic pancreatic cancer are strongly associated with familial and genetically predisposed pancreatic cancer.

High-risk individuals (HRIs) with familial and genetic predisposition to pancreatic ductal adenocarcinoma (PDAC) are eligible for screening. There is no accurate biomarker for detecting early-stage PDAC. We previously demonstrated that a panel of methylated DNA markers (MDMs) accurately detect sporadic PDAC. In this study we compared the distribution of MDMs in DNA extracted from tissue of PDAC cases who carry germline mutations and non-carriers with family history, with control tissue and demonstrate high discrimination like that seen in sporadic PDAC. These results provide scientific rationale for examining plasma MDMs in HRIs with the goal of developing a minimally-invasive early detection test.

Methylated DNA markers for plasma detection of ovarian cancer: Discovery, validation, and clinical feasibility.

OBJECTIVE: Aberrant DNA methylation is an early event in carcinogenesis which could be leveraged to detect ovarian cancer (OC) in plasma. METHODS: DNA from frozen OC tissues, benign fallopian tube epithelium (FTE), and buffy coats from cancer-free women underwent reduced representation bisulfite sequencing (RRBS) to identify OC MDMs. Candidate MDM selection was based on receiver operating characteristic (ROC) discrimination, methylation fold change, and low background methylation among controls. Blinded biological validation was performed using methylated specific PCR on DNA extracted from independent OC and FTE FFPE tissues. MDMs were tested using Target Enrichment Long-probe Quantitative Amplified Signal (TELQAS) assays in pre-treatment plasma from women newly diagnosed with OC and population-sampled healthy women. A random forest modeling analysis was performed to generate predictive probability of disease; results were 500-fold in silico cross-validated. RESULTS: Thirty-three MDMs showed marked methylation fold changes (10 to >1000) across all OC subtypes vs FTE. Eleven MDMs (GPRIN1, CDO1, SRC, SIM2, AGRN, FAIM2, CELF2, RIPPLY3, GYPC, CAPN2, BCAT1) were tested on plasma from 91 women with OC (73 (80%) high-grade serous (HGS)) and 91 without OC; the cross-validated 11-MDM panel highly discriminated OC from controls (96% (95% CI, 89-99%) specificity; 79% (69-87%) sensitivity, and AUC 0.91 (0.86-0.96)). Among the 5 stage I/II HGS OCs included, all were correctly identified. CONCLUSIONS: Whole methylome sequencing, stringent filtering criteria, and biological validation yielded candidate MDMs for OC that performed with high sensitivity and specificity in plasma. Larger plasma-based OC MDM studies, including testing of pre-diagnostic specimens, are warranted.

Validation of a methylated DNA marker panel for the nonendoscopic detection of Barrett's esophagus in a multisite case-control study.

BACKGROUND AND AIMS: We previously identified a 5 methylated DNA marker (MDM) panel for the detection of nonendoscopic Barrett's esophagus (BE). In this study, we aimed to recalibrate the performance of the 5 MDM panel using a simplified assay in a training cohort, validate the panel in an independent test cohort, and explore the accuracy of an MDM panel with only 3 markers. METHODS: Participants were recruited from 3 medical centers. The sponge on a string device (EsophaCap; CapNostics, Concord, NC, USA) was swallowed and withdrawn, followed by endoscopy, in BE cases and control subjects. A 5 MDM panel was blindly assayed using a simplified assay. Random forest modeling analysis was performed, in silico cross-validated in the training set, and then locked down, before test set analysis. RESULTS: The training set had 199 patients: 110 BE cases and 89 control subjects, and the test set had 89 patients: 60 BE cases and 29 control subjects. Sensitivity of the 5 MDM panel for BE diagnosis was 93% at 90% specificity in the training set and 93% at 93% specificity in the test set. Areas under the receiver operating characteristic curves were .96 and .97 in the training and test sets, respectively. Model accuracy was not influenced by age, sex, or smoking history. Multiple 3 MDM panels achieved similar accuracy. CONCLUSIONS: A 5 MDM panel for BE is highly accurate in training and test sets in a blinded multisite case-control analysis using a simplified assay. This panel may be reduced to only 3 MDMs in the future. (Clinical trial registration number: NCT02560623.).

Low Incidence of Aerodigestive Cancers in Patients With Negative Results From Colonoscopies, Regardless of Findings From Multitarget Stool DNA Tests.

BACKGROUND & AIMS: We aimed to compare the incidence of aerodigestive cancers in persons with negative results from colonoscopies and positive vs negative results from multitarget stool DNA tests for colorectal cancer and vs expected incidence. METHODS: We performed a retrospective cohort study of 1216 subjects with comprehensive patient records and/or cancer registry data from 3 medical centers in North America. Subjects had no neoplasia or only nonadvanced adenomas, based on screening colonoscopy, and either negative results (concordant with colonoscopy, n = 1011) or positive results (discordant colonoscopy, n = 205) from the multitarget stool DNA test. Outcomes included aerodigestive cancers in discordant vs concordant groups and comparison of observed aerodigestive cancer incidence between the groups and compared with expected incidence for the population, based on the Surveillance, Epidemiology, and End Results (SEER) data. RESULTS: Median follow-up times were comparable between subjects in the discordant (5.3 y; interquartile range, 3.5-5.8 y) and concordant (5.4 y; interquartile range, 3.7-5.8 y) groups. Aerodigestive cancers developed in 5 subjects in the discordant group vs 11 subjects in the concordant group (crude risk ratio, 2.3; 95% CI, 0.8-6.6; adjusted risk ratio, 2.2; 95% CI, 0.8-6.2; P = .151). The incidence of aerodigestive cancer was lower in the concordant group than the expected incidence based on SEER data (risk ratio, 0.4; 95% CI, 0.2-0.6; P = .0008). The incidence of aerodigestive cancer was not significantly greater in the population in the discordant group than the expected incidence based on SEER data (risk ratio, 0.8; 95% CI, 0.3-1.9; P = .599). CONCLUSIONS: In a retrospective study with a median follow-up time of 5.4 years, incident aerodigestive cancers were uncommon among subjects with negative findings from colonoscopies, regardless of discordant or concordant results from multitarget stool DNA tests. Patients with negative results from high-quality colonoscopies therefore should not undergo further testing.

Methylated DNA in Pancreatic Juice Distinguishes Patients With Pancreatic Cancer From Controls.

BACKGROUND & AIMS: Precursors of pancreatic cancer arise in the ductal epithelium; markers exfoliated into pancreatic juice might be used to detect high-grade dysplasia (HGD) and cancer. Specific methylated DNA sequences in pancreatic tissue have been associated with adenocarcinoma. We analyzed these methylated DNA markers (MDMs) in pancreatic juice samples from patients with pancreatic ductal adenocarcinomas (PDACs) or intraductal papillary mucinous neoplasms (IPMNs) with HGD (cases), and assessed their ability to discriminate these patients from individuals without dysplasia or with IPMNs with low-grade dysplasia (controls). METHODS: We obtained pancreatic juice samples from 38 patients (35 with biopsy-proven PDAC or pancreatic cystic lesions with invasive cancer and 3 with HGD) and 73 controls (32 with normal pancreas and 41 with benign disease), collected endoscopically from the duodenum after secretin administration from February 2015 through November 2016 at 3 medical centers. Samples were analyzed for the presence of 14 MDMs (in the genes NDRG4, BMP3, TBX15, C13orf18, PRKCB, CLEC11A, CD1D, ELMO1, IGF2BP1, RYR2, ADCY1, FER1L4, EMX1, and LRRC4), by quantitative allele-specific real-time target and signal amplification. We performed area under the receiver operating characteristic curve analyses to determine the ability of each marker, and panels of markers, to distinguish patients with HGD and cancer from controls. MDMs were combined to form a panel for detection using recursive partition trees. RESULTS: We identified a group of 3 MDMs (at C13orf18, FER1L4, and BMP3) in pancreatic juice that distinguished cases from controls with an area under the receiver operating characteristic value of 0.90 (95% CI, 0.83-0.97). Using a specificity cut-off value of 86%, this group of MDMs distinguished patients with any stage of pancreatic cancer from controls with 83% sensitivity (95% CI, 66%-93%) and identified patients with stage I or II PDAC or IPMN with HGD with 80% sensitivity (95% CI, 56%-95%). CONCLUSIONS: We identified a group of 3 MDMs in pancreatic juice that identify patients with pancreatic cancer with an area under the receiver operating characteristic value of 0.90, including patients with early stage disease or advanced precancer. These DNA methylation patterns might be included in algorithms for early detection of pancreatic cancer, especially in high-risk cohorts. Further optimization and clinical studies are needed.

Multitarget Stool DNA Screening in Clinical Practice: High Positive Predictive Value for Colorectal Neoplasia Regardless of Exposure to Previous Colonoscopy.

OBJECTIVES: Multitarget stool DNA (MT-sDNA) testing has grown as a noninvasive screening modality for colorectal cancer (CRC), but real-world clinical data are limited in the post-FDA approval setting. The effect of previous colonoscopy on MT-sDNA performance is not known. We aimed to evaluate findings of colorectal neoplasia (CRN) at diagnostic colonoscopy in patients with positive MT-sDNA testing, stratified by patient exposure to previous colonoscopy. METHODS: We identified consecutive patients completing MT-sDNA testing over a 39-month period and reviewed the records of those with positive tests for neoplastic findings at diagnostic colonoscopy. MT-sDNA test positivity rate, adherence to diagnostic colonoscopy, and the positive predictive value (PPV) of MT-sDNA for any CRN and neoplastic subtypes were calculated. RESULTS: Of 16,469 MT-sDNA tests completed, testing returned positive in 2,326 (14.1%) patients. After exclusion of patients at increased risk for CRC, 1,801 patients remained, 1,558 (87%) of whom underwent diagnostic colonoscopy; 918 of 1,558 (59%) of these patients had undergone previous colonoscopy, whereas 640 (41%) had not. Any CRN was found in 1,046 of 1,558 patients (PPV = 67%). More neoplastic lesions were found in patients without previous colonoscopy (73%); however, the rates remained high among those who had undergone previous colonoscopy (63%, P < 0.0001). The large majority (79%) of patients had right-sided neoplasia. DISCUSSION: MT-sDNA has a high PPV for any CRN regardless of exposure to previous colonoscopy. Right-sided CRN was found at colonoscopy in most patients with positive MT-sDNA testing, representing a potential advantage over other currently available screening modalities for CRC.

Accurate Nonendoscopic Detection of Barrett's Esophagus by Methylated DNA Markers: A Multisite Case Control Study.

INTRODUCTION: Nonendoscopic Barrett's esophagus (BE) screening may help improve esophageal adenocarcinoma outcomes. We previously demonstrated promising accuracy of methylated DNA markers (MDMs) for the nonendoscopic diagnosis of BE using samples obtained from a capsule sponge-on-string (SOS) device. We aimed to assess the accuracy of these MDMs in an independent cohort using a commercial grade assay. METHODS: BE cases had ≥ 1 cm of circumferential BE with intestinal metaplasia; controls had no endoscopic evidence of BE. The SOS device was withdrawn 8 minutes after swallowing, followed by endoscopy (the criterion standard). Highest performing MDMs from a previous study were blindly assessed on extracted bisulfite-converted DNA by target enrichment long-probe quantitative amplified signal (TELQAS) assays. Optimal MDM combinations were selected and analyzed using random forest modeling with in silico cross-validation. RESULTS: Of 295 patients consented, 268 (91%) swallowed the SOS device; 112 cases and 89 controls met the pre-established inclusion criteria. The median BE length was 6 cm (interquartile range 4-9), and 50% had no dysplasia. The cross-validated sensitivity and specificity of a 5 MDM random forest model were 92% (95% confidence interval 85%-96%) and 94% (95% confidence interval 87%-98%), respectively. Model performance was not affected by age, gender, or smoking history but was influenced by the BE segment length. SOS administration was well tolerated (median [interquartile range] tolerability 2 [0, 4] on 10 scale grading), and 95% preferred SOS over endoscopy. DISCUSSION: Using a minimally invasive molecular approach, MDMs assayed from SOS samples show promise as a safe and accurate nonendoscopic test for BE prediction.

Hepatocellular Carcinoma Detection by Plasma Methylated DNA: Discovery, Phase I Pilot, and Phase II Clinical Validation.

Early detection improves hepatocellular carcinoma (HCC) outcomes, but better noninvasive surveillance tools are needed. We aimed to identify and validate methylated DNA markers (MDMs) for HCC detection. Reduced representation bisulfite sequencing was performed on DNA extracted from 18 HCC and 35 control tissues. Candidate MDMs were confirmed by quantitative methylation-specific PCR in DNA from independent tissues (74 HCC, 29 controls). A phase I plasma pilot incorporated quantitative allele-specific real-time target and signal amplification assays on independent plasma-extracted DNA from 21 HCC cases and 30 controls with cirrhosis. A phase II plasma study was then performed in 95 HCC cases, 51 controls with cirrhosis, and 98 healthy controls using target enrichment long-probe quantitative amplified signal (TELQAS) assays. Recursive partitioning identified best MDM combinations. The entire MDM panel was statistically cross-validated by randomly splitting the data 2:1 for training and testing. Random forest (rForest) regression models performed on the training set predicted disease status in the testing set; median areas under the receiver operating characteristics curve (AUCs; and 95% confidence interval [CI]) were reported after 500 iterations. In phase II, a six-marker MDM panel (homeobox A1 [HOXA1], empty spiracles homeobox 1 [EMX1], AK055957, endothelin-converting enzyme 1 [ECE1], phosphofructokinase [PFKP], and C-type lectin domain containing 11A [CLEC11A]) normalized by beta-1,3-galactosyltransferase 6 (B3GALT6) level yielded a best-fit AUC of 0.96 (95% CI, 0.93-0.99) with HCC sensitivity of 95% (88%-98%) at specificity of 92% (86%-96%). The panel detected 3 of 4 (75%) stage 0, 39 of 42 (93%) stage A, 13 of 14 (93%) stage B, 28 of 28 (100%) stage C, and 7 of 7 (100%) stage D HCCs. The AUC value for alpha-fetoprotein (AFP) was 0.80 (0.74-0.87) compared to 0.94 (0.9-0.97) for the cross-validated MDM panel (P < 0.0001). Conclusion: MDMs identified in this study proved to accurately detect HCC by plasma testing. Further optimization and clinical testing of this promising approach are indicated.

Analysis of DNA Methylation at Specific Loci in Stool Samples Detects Colorectal Cancer and High-Grade Dysplasia in Patients With Inflammatory Bowel Disease.

BACKGROUND & AIMS: Patients with inflammatory bowel diseases (IBDs), including ulcerative colitis and Crohn's disease, are at increased risk for colorectal cancer (CRC). Analyses of DNA methylation patterns in stool samples have been reported to detect CRC in patients with IBD. We sought to validate these findings in larger cohorts and assess the accuracy of analysis of DNA methylation patterns in stool for detection of CRC and high-grade dysplasia (HGD) normalized to methylation level at ZDHHC1. METHODS: We obtained buffered, frozen stool samples from a US case-control study and from 2 European surveillance cohorts (referral or population based) of patients with chronic ulcerative colitis (n = 248), Crohn's disease (n = 82), indeterminate colitis (n = 2), or IBD with primary sclerosing cholangitis (n = 38). Stool samples were collected before bowel preparation for colonoscopy or at least 1 week after colonoscopy. Among the study samples, stools from individuals with IBD but without neoplasia were used as controls (n = 291). DNA was isolated from stool, exposed to bisulfite, and then assayed by multiplex quantitative allele-specific real-time target and signal amplification. We analyzed methylation levels of BMP3, NDRG4, VAV3, and SFMBT2 relative to the methylation level of ZDHHC1, and compared these between patients with CRC or HGD and controls. RESULTS: Levels of methylation at BMP3 and VAV3, relative to ZDHHC1 methylation, identified patients with CRC and HGD with an area under the curve value of 0.91 (95% CI, 0.77-1.00). Methylation levels at specific promotor regions of these genes identified 11 of the 12 patients with CRC and HGD, with 92% sensitivity (95% CI, 60%-100%) and 90% specificity (95% CI, 86%-93%). The proportion of false-positive results did not differ significantly among the case-control, referral cohort, and population cohort studies (P = .60) when the 90% specificity cut-off from the whole sample set was applied. CONCLUSIONS: In an analysis of stool samples from 3 independent studies of 332 patients with IBD, we associated levels of methylation at 2 genes (BMP3 and VAV3), relative to level of methylation at ZDHHC1, with detection of CRC and HGD. These methylation patterns identified patients with CRC and HGD with more than 90% specificity, and might be used in CRC surveillance.

Novel Methylated DNA Markers Discriminate Advanced Neoplasia in Pancreatic Cysts: Marker Discovery, Tissue Validation, and Cyst Fluid Testing.

OBJECTIVES: Pancreatic cystic lesions (PCLs) may be precancerous. Those likely to harbor high-grade dysplasia (HGD) or pancreatic cancer (PC) are targets for surgical resection. Current algorithms to predict advanced neoplasia (HGD/PC) in PCLs lack diagnostic accuracy. In pancreatic tissue and cyst fluid (CF) from PCLs, we sought to identify and validate novel methylated DNA markers (MDMs) that discriminate HGD/PC from low-grade dysplasia (LGD) or no dysplasia (ND). METHODS: From an unbiased whole-methylome discovery approach using predefined selection criteria followed by multistep validation on case (HGD or PC) and control (ND or LGD) tissues, we identified discriminant MDMs. Top candidate MDMs were then assayed by quantitative methylation-specific polymerase chain reaction on archival CF from surgically resected PCLs. RESULTS: Of 25 discriminant MDMs identified in tissue, 13 were selected for validation in 134 CF samples (21 cases [8 HGD, 13 PC], 113 controls [45 ND, 68 LGD]). A tree-based algorithm using 2 CF-MDMs (TBX15, BMP3) achieved sensitivity and specificity above 90%. Discrimination was significantly better by this CF-MDM panel than by mutant KRAS or carcinoembryonic antigen, with areas under the receiver operating characteristic curve of 0.93 (95% confidence interval: 0.86-0.99), 0.71 (0.57-0.85), and 0.72 (0.60-0.84), respectively. Cutoffs for the MDM panel applied to an independent CF validation set (31 cases, 56 controls) yielded similarly high discrimination, areas under the receiver operating characteristic curve = 0.86 (95% confidence interval: 0.77-0.94, P = 0.2). DISCUSSION: Novel MDMs discovered and validated in tissue accurately identify PCLs harboring HGD/PC. A panel of 2 MDMs assayed in CF yielded results with potential to enhance current risk prediction algorithms. Prospective studies are indicated to optimize and further evaluate CF-MDMs for clinical use.

A Comprehensive Approach to Sequence-oriented IsomiR annotation (CASMIR): demonstration with IsomiR profiling in colorectal neoplasia.

BACKGROUND: MicroRNA (miRNA) profiling is an important step in studying biological associations and identifying marker candidates. miRNA exists in isoforms, called isomiRs, which may exhibit distinct properties. With conventional profiling methods, limitations in assay and analysis platforms may compromise isomiR interrogation. RESULTS: We introduce a comprehensive approach to sequence-oriented isomiR annotation (CASMIR) to allow unbiased identification of global isomiRs from small RNA sequencing data. In this approach, small RNA reads are maintained as independent sequences instead of being summarized under miRNA names. IsomiR features are identified through step-wise local alignment against canonical forms and precursor sequences. Through customizing the reference database, CASMIR is applicable to isomiR annotation across species. To demonstrate its application, we investigated isomiR profiles in normal and neoplastic human colorectal epithelia. We also ran miRDeep2, a popular miRNA analysis algorithm to validate isomiRs annotated by CASMIR. With CASMIR, specific and biologically relevant isomiR patterns could be identified. We note that specific isomiRs are often more abundant than their canonical forms. We identify isomiRs that are commonly up-regulated in both colorectal cancer and advanced adenoma, and illustrate advantages in targeting isomiRs as potential biomarkers over canonical forms. CONCLUSIONS: Studying miRNAs at the isomiR level could reveal new insight into miRNA biology and inform assay design for specific isomiRs. CASMIR facilitates comprehensive annotation of isomiR features in small RNA sequencing data for isomiR profiling and differential expression analysis.

Highly Discriminant Methylated DNA Markers for the Non-endoscopic Detection of Barrett's Esophagus.

BACKGROUND: Minimally invasive methods have been described to detect Barrett's esophagus (BE), but are limited by subjectivity and suboptimal accuracy. We identified methylated DNA markers (MDMs) for BE in tissue and assessed their accuracy on whole esophagus brushings and capsule sponge samples. METHODS: Step 1: Unbiased whole methylome sequencing was performed on DNA from BE and normal squamous esophagus (SE) tissue. Discriminant MDM candidates were validated on an independent patient cohort (62 BE cases, 30 controls) by quantitative methylation specific PCR (qMSP). Step 2: Selected MDMs were further evaluated on whole esophageal brushings (49 BE cases, 36 controls). 35 previously sequenced esophageal adenocarcinoma (EAC) MDMs were also evaluated. Step 3: 20 BE cases and 20 controls were randomized to swallow capsules sponges (25 mm, 10 pores or 20 pores per inch (ppi)) followed endoscopy. DNA yield, tolerability, and mucosal injury were compared. Best MDM assays were performed on this cohort. RESULTS: Step 1: 19 MDMs with areas under the ROC curve (AUCs) >0.85 were carried forward. Step 2: On whole esophageal brushings, 80% of individual MDM candidates showed high accuracy for BE (AUCs 0.84-0.94). Step 3: The capsule sponge was swallowed and withdrawn in 98% of subjects. Tolerability was superior with the 10 ppi sponge with minimal mucosal injury and abundant DNA yield. A 2-marker panel (VAV3 + ZNF682) yielded excellent BE discrimination (AUC = 1). CONCLUSIONS: Identified MDMs discriminate BE with high accuracy. BE detection appears safe and feasible with a capsule sponge. Corroboration in larger studies is warranted. ClinicalTrials.gov number NCT02560623.

Multitarget stool DNA test: clinical performance and impact on yield and quality of colonoscopy for colorectal cancer screening.

BACKGROUND AND AIMS: Multitarget stool DNA (MT-sDNA) testing is now approved by the U.S. Food and Drug Administration for average-risk colorectal cancer screening. Trials leading to its approval used blinded colonoscopy as the reference standard. In the postapproval screen setting, the clinical performance and impact of MT-sDNA testing on unblinded colonoscopy has not been described. We measured the impact that knowledge of a positive MT-sDNA test result has on colonoscopy yield and quality. METHODS: The unblinded group comprised all patients with positive MT-sDNA results on screening from September 1, 2014 to September 30, 2015 at a single tertiary center. Off-label test patients were excluded. The blinded group included all MT-sDNA-positive participants in a preapproval screening study from the same center. Detailed colonoscopy findings and withdrawal times were recorded. RESULTS: There were 172 MT-sDNA-positive patients in the unblinded group and 72 in the blinded group. More total adenomatous/sessile serrated polyps (70% vs 53%, P = .013) and advanced neoplasms (28% vs 21%, P = .27) were detected in unblinded than in blinded groups. Median numbers of polyps detected were 2 (IQR, 1-4) and 1 (IQR, 0-2) in unblinded and blinded groups, respectively (P = .0007). Among polyps detected, flat or slightly raised lesions in the right side of the colon were proportionately more frequent with unblinded (40%) than with blinded examinations (9%) (P = .0017). Median withdrawal time was 19 minutes (IQR, 13-29) in the unblinded group compared with 13 minutes (IQR, 10-20) in the blinded group (P = .0001). CONCLUSIONS: Knowledge of a positive MT-sDNA result appears to have a beneficial impact on the diagnostic yield and quality of subsequent colonoscopy.

Germline genetic variation in JAK2 as a prognostic marker in castration-resistant prostate cancer.

OBJECTIVES: To evaluate the prognostic significance of germline variation in candidate genes in patients with castration-resistant prostate cancer (CRPC). METHODS: Germline DNA was extracted from peripheral blood mononuclear cells of patients with CRPC enrolled in a clinically annotated registry. Fourteen candidate genes implicated in either initiation or progression of prostate cancer were tagged using single nucleotide polymorphisms (SNPs) from HapMap with a minor allele frequency of >5%. The primary endpoint was overall survival (OS), defined as time from development of CRPC to death. Principal component analysis was used for gene levels tests of significance. For SNP-level results the per allele hazard ratios (HRs) and 95% confidence intervals (CIs) under the additive allele model were estimated using Cox regression, adjusted for age at CRPC and Gleason score (GS). RESULTS: A total of 240 patients with CRPC were genotyped (14 genes; 84 SNPs). The median (range) age of the cohort was 69 (43-93) years. The GS distribution was 55% with GS ≥8, 32% with GS = 7 and 13% with GS <7 or unknown. The median (interquartile range) time from castration resistance to death for the cohort was 2.67 (1.6-4.07) years (144 deaths). At the gene level, a single gene, JAK2 was associated with OS (P < 0.01), and 11 of 18 JAK2 SNPs were individually associated with OS after adjustment for age and GS. A multivariate model consisting of age, GS, rs2149556 (HR 0.67; 95% CI 0.38-1.18) and rs4372063 (HR 2.17; 95% CI 1.25-3.76) was constructed to predict survival in patients with CRPC (concordance of 0.69, P < 3.2 × 10-9 ). CONCLUSIONS: Germline variation in the JAK2 gene was associated with survival in patients with CRPC and warrants further validation as a potential prognostic biomarker.

Novel Approach to Fecal Occult Blood Testing by Assay of Erythrocyte-Specific microRNA Markers.

BACKGROUND: Fecal occult blood testing (FOBT) has historically relied on methods to detect hemoglobin with no fundamental innovations in decades. AIM: To examine microRNA (miRNA) as a new marker class for FOBT. METHODS: Candidate miRNA markers were identified by small RNA sequencing of human whole blood compared to colorectal epithelia. Markers were tested in human blood cell subsets and blood from non-human species. We assessed assay linearity in blood spiking and marker stability in stool over incubation experiments. Levels of candidate erythrocyte markers were explored in stools from colorectal cancer (CRC) cases and controls. RESULTS: Based on small RNA sequencing and validation RT-qPCR, expression level of each of the top blood-enriched markers (hsa-miR-144-3p, 144-5p, 451a, 486-5p, 363-3p, 20b-5p) could perfectly discriminate blood from colorectal epithelia. All six markers arose from and showed specificity to human erythrocytes. Marker levels increased linearly with erythrocyte concentration in saline or stool and demonstrated a broader dynamic range than did immunochemical test for hemoglobin. Degradation of markers occurred in stool but was reduced with preservative buffers. Erythrocyte marker candidates for stool testing were selected in an exploratory set of stools (20 CRC, 40 normal). Candidates were then further tested in a feasibility set (29 CRC, 31 advanced adenoma, and 115 normal); a miRNA panel (hsa-miR-451a, 144-5p, and 200b-3p as normalizer) yielded an AUC of 0.89 (95% CI 0.82-0.95, P < .0001) for CRC. CONCLUSIONS: A novel miRNA-based approach accurately quantifies fecal blood levels over a broad, clinically relevant range.

Endoscopic overestimation of colorectal polyp size.

BACKGROUND AND AIMS: Polyp size ≥ 1 cm triggers more frequent colonoscopic surveillance, yet size is typically based on subjective endoscopic estimates. We sought to compare contemporary assessments of polyp size by endoscopic estimation and pathology measurement. METHODS: Colonoscopy and pathology reports were reviewed from the 2012 medical records at a large institution. Only polyps resected in toto with both endoscopic estimates and pathology measurements were included. Pathology measurements were considered the criterion standard. Factors affecting endoscopic miscall rates were assessed by multivariate analyses. RESULTS: From 6067 polyps resected, both endoscopic and pathology sizes were available on 1528. Distribution of polyp size appraised by endoscopy but not by pathology revealed modal clustering, particularly around 1 cm. Among 99 polyps endoscopically called 1 cm, 72% were <1 cm on pathology. Of all 222 polyps estimated as ≥ 1 cm on endoscopy, 46% were <1 cm on pathology; of 1306 polyps estimated as <1 cm, 3.9% were ≥ 1 cm on pathology. By histology, 39% of adenomatous, 59% of sessile serrated, and 73% of hyperplastic polyps were overcalled; P = .008. By configuration, 34% of pedunculated, 49% of sessile, and 61% of flat polyps were overcalled; P = .014. Endoscopic overestimation was more common in women (54%) than in men (40%) (P = .03) and with proximal (56%) than distal (40%) sites; P = .02. Miscall rates were unaffected by endoscopist covariates. CONCLUSIONS: Substantial discordance exists between endoscopic and pathology-based assessments of polyp size. Almost half of polyps called advanced on endoscopic estimates of size ≥ 1 cm fell below this threshold on actual pathology measurements.