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781 Sensitive DNA Marker Panel for Detection of Pancreatic Cancer by Assay in Pancreatic Juice
AGA Abstracts
Ectopic expression of Spdef in tumors caused by treatment with azoxymethane (AOM) and dextran sodium sulfate (DSS), or spontaneously formed in ApcMin/+ mice was sufficient to drive cell cycle exit of tumor cells in both mouse models. Furthermore, loss of Spdef lead to a significant increase in colonic tumor number from both mouse models (AOM+DSS and ApcMin/+ ), defining Spdef as a tumor suppressor in the colon. Importantly, our previous study indicates that SPDEF expression is often silenced in human colon cancer and this SPDEF silencing in colon cancer is tightly correlated to ATOH1 silencing, suggesting SPDEF as a mediator of ATOH1's function in intestinal homeostasis and tumorigenesis. Therefore, we hypothesize that Spdef is a key effector of Notch-Atoh1 effects in intestinal tumors. Here, we assess the requirement of Spdef for Atoh1-directed growth inhibition in colonic tumors, and extend the analysis to elucidate the sufficiency of Spdef to promote cell cycle exit and goblet cell differentiation in Atoh1-null colonic tumors that mimic human colon cancer. Method: All analysis was performed in transgenic mice. The sufficiency of Spdef was tested by re-expressing Spdef in colonic tumors that lack Atoh1. The requirement of Spdef was tested by inducing Atoh1 expression through inhibition of the Notch activity in tumors that lack Spdef. Progenitor cell proliferation, Lgr5+ stem cell population and differentiation were immunohistologically assessed. Results: In Atoh1-null tumors, proliferation and Lgr5+ stem cell population was significantly reduced upon expression of SPDEF without induction of goblet cell markers. In response to Atoh1 induction by Notch inhibitor treatment, cell proliferation was inhibited and goblet cell differentiation was induced in colonic tumors; this response was prevented in Spdef-/- mice. In contrast, Lgr5+ stem cell population was similarly reduced in tumors from both control and Spdef-/- mice. Conclusions: SPDEF mediates the effect on tumor cell proliferation of Atoh1 induced by Notch inhibitors. The sufficiency and requirement for Spdef in promoting cell cycle exit in intestinal tumors suggest Spdef as a potential therapeutic target for colon cancer. Future studies will investigate the Notch-Atoh1 independent mechanisms to activate expression of SPDEF, which can be utilized as a colon cancer therapy.
*Specificity cutoffs based on reference control (CON) data. **Top 7 individual methylated DNA markers shown. ***Except for ADCY1, the Panel had significantly higher AUC than individual methylated DNA markers (p<0.05). 782
781
Risk of Incident Colorectal Cancer Diagnosis After Colonoscopy: A Population-Based Study in Utah N. Jewel Samadder, Karen Curtin, Lisa Pappas, Kenneth M. Boucher, Dawn Provenzale, Geraldine P. Mineau, Ken Smith, Alison Fraser, Anita Y. Kinney, Randall W. Burt
Sensitive DNA Marker Panel for Detection of Pancreatic Cancer by Assay in Pancreatic Juice Massimo Raimondo, Tracy C. Yab, Douglas W. Mahoney, William R. Taylor, John B. Kisiel, Hatim Allawi, Graham P. Lidgard, David A. Ahlquist
Introduction: Colorectal cancer (CRC) is the third most common cause of cancer in the US. Colonoscopy is widely recommended for CRC screening in the USA but evidence of effectiveness is limited. Most studies on the effectiveness of colonoscopy are from countries with healthcare systems different from those in the US. In the US, studies have been done in Veterans, and in Medicare or HMO samples that may not reflect the general population. Aim: To examine if exposure to colonoscopy decreases the risk of incident CRC in Utah. Methods: We performed a population-based case-control study of the association of colonoscopy and CRC. We used 3 data sources. The Utah Cancer Registry tracks all incident cancer cases diagnosed in the state. The Utah Department of Health records information on all colonoscopy procedures performed in the state between 1996 and 2010. The Utah Population Database is linked to both and includes demographic information and length of residence in Utah. Cases were patients aged 54 to 90 years, diagnosed with CRC between 1 January 2000 and 31 December 2010. The CRC diagnosis date was set as the reference date for ascertaining exposure to colonoscopy. Each case patient was matched to 4 controls for age and gender with no history of CRC. All cases and controls lived in Utah from 1996 to at least the date of the matched case's CRC diagnosis. We detected exposure to colonoscopy from 1 January 1996 to an index date 6 months before case patients received a diagnosis of CRC. We measured the odds of exposure to colonoscopy in case patients and controls and used conditional logistic regression to calculate odds ratios (OR) for exposure that estimate the association between colonoscopy and CRC. Analysis was repeated, stratified by sex, age, cancer site and stage of cancer. Results: 4,137 case patients and 16,548 controls were identified with 577 (14%) case patients and 4851 (29%) controls having received colonoscopy (Table 1). Exposure to colonoscopy decreased colon cancer diagnosis in all groups with an OR of 0.39 (95% CI: 0.35-0.43) for any CRC, 0.62 (CI: 0.53-0.73) for proximal colon cancer, 0.29 (CI: 0.24-0.34) for distal colon cancer and 0.30 (CI: 0.250.35) for rectal cancer (Table 2). This finding was consistent for gender, age groups and cancer stages (Table 2). Discussion: Colonoscopy is associated with a large reduction in risk of new-onset CRC in men and women. This reduction in risk for CRC was greatest for the distal colon and rectum with a more modest reduction for proximal colon cancer. This is the largest population-based study in the US to examine the association between colonoscopy and CRC reduction throughout an entire state (academic, managed care, private practice). These results are more likely to be generalizeable than those from healthcare systems outside the US or restricted populations. Table 1: Demographic and Clinical Characteristics of Case Patients and Control Patients
Background: Pancreatic juice analysis represents a minimally-invasive approach to detection of pancreatic cancer (PC) and precancer. We have found that specific methylated DNA markers in pancreatic juice discriminate PC from chronic pancreatitis (CP) and normal pancreas (Gastroenterology 2013;144:S-90), but new markers and marker combinations remain unexplored. Aim: Assess the value of recently discovered methylated DNA markers and mutant KRAS assayed alone and combined in pancreatic juice to discriminate PC from chronic pancreatitis (CP) and reference controls (CON). Methods: We studied 167 patients (85 PC, 30 CP, 23 premalignant intraductal mucinous neoplasm (IPMN), 29 CON) who had undergone secretin stimulated pancreatic juice collection during EUS. Diagnoses were histologically based for PC, radiographically for CP, and histologically or radiographically for IPMN. Specificity was based on CON, which included patients with risk factors for PC, abnormal blood tests, or GI symptoms but radiographically-normal pancreas. Juice samples archived at -80°C were blindly batch assayed. Candidate methylated DNA markers were selected by whole methylome sequencing in prior tissue studies and preliminary pancreatic juice testing. On DNA extracted from 200 μL pancreatic juice, gene methylation was determined after bisulfite treatment by quantitative allele-specific real-time target and signal amplification (QuARTS) for assay of ADCY1, CD1D, BMP3, PRKCB, KCNK12, C13ORF18, IKZF1, CLEC11A, TWIST1, NDRG4, ELMO, and 55957. Mutant KRAS mutations (7 total) and β-actin (a marker for total human DNA) were also assayed by QuARTS. From quantitative data, a simple algorithm was followed to achieve optimal discrimination by a panel combining all markers. Results: Respectively for PC, CP, IPMN, and CON: median age was 67 (IQR 60-77), 66 (55-77), 66 (60-76) and 70 (62-77); men comprised 52, 53, 49, and 72%. At respective specificity cutoffs of 90% and 95%: the combined marker panel achieved highest PC sensitivities, 88% and 77%; ADCY1, the most sensitive single marker, detected 84% and 71%. Other single markers detected PC but to variable extents (table). Overall discrimination by area under ROC curve was higher by panel than by any single marker (p<0.05), except ADCY1 (table). At 90% specificity, panel detected 44% of all IPMNs and 75% (3/4) of subset with high grade dysplasia. Positivity rates were substantially lower in CP than in PC for all markers in table (p<0.0001). At 100% specificity, the panel was positive in 58% PC, 17% IPMN, and 13% CP. Conclusions: A panel of novel methylated DNA markers and mutant KRAS assayed from pancreatic juice achieves high sensitivity for PC. With technical optimization and inclusion of fully normal controls, discrimination may be further improved. Corroboration and extension of our findings are clearly indicated. Marker Positivity Rates in Pancreatic Juice of Patients with Pancreatic Cancer (PC), Intraductal Papillary Mucinous Neoplasm (IPMN), and Chronic Pancreatitis (CP)
Table 2: Association between receipt of colonoscopy and colorectal cancer, 2000-2010
AGA Abstracts
S-132
Ectopic expression of Spdef in tumors caused by treatment with azoxymethane (AOM) and dextran sodium sulfate (DSS), or spontaneously formed in ApcMin/+ mice was sufficient to drive cell cycle exit of tumor cells in both mouse models. Furthermore, loss of Spdef lead to a significant increase in colonic tumor number from both mouse models (AOM+DSS and ApcMin/+ ), defining Spdef as a tumor suppressor in the colon. Importantly, our previous study indicates that SPDEF expression is often silenced in human colon cancer and this SPDEF silencing in colon cancer is tightly correlated to ATOH1 silencing, suggesting SPDEF as a mediator of ATOH1's function in intestinal homeostasis and tumorigenesis. Therefore, we hypothesize that Spdef is a key effector of Notch-Atoh1 effects in intestinal tumors. Here, we assess the requirement of Spdef for Atoh1-directed growth inhibition in colonic tumors, and extend the analysis to elucidate the sufficiency of Spdef to promote cell cycle exit and goblet cell differentiation in Atoh1-null colonic tumors that mimic human colon cancer. Method: All analysis was performed in transgenic mice. The sufficiency of Spdef was tested by re-expressing Spdef in colonic tumors that lack Atoh1. The requirement of Spdef was tested by inducing Atoh1 expression through inhibition of the Notch activity in tumors that lack Spdef. Progenitor cell proliferation, Lgr5+ stem cell population and differentiation were immunohistologically assessed. Results: In Atoh1-null tumors, proliferation and Lgr5+ stem cell population was significantly reduced upon expression of SPDEF without induction of goblet cell markers. In response to Atoh1 induction by Notch inhibitor treatment, cell proliferation was inhibited and goblet cell differentiation was induced in colonic tumors; this response was prevented in Spdef-/- mice. In contrast, Lgr5+ stem cell population was similarly reduced in tumors from both control and Spdef-/- mice. Conclusions: SPDEF mediates the effect on tumor cell proliferation of Atoh1 induced by Notch inhibitors. The sufficiency and requirement for Spdef in promoting cell cycle exit in intestinal tumors suggest Spdef as a potential therapeutic target for colon cancer. Future studies will investigate the Notch-Atoh1 independent mechanisms to activate expression of SPDEF, which can be utilized as a colon cancer therapy.
*Specificity cutoffs based on reference control (CON) data. **Top 7 individual methylated DNA markers shown. ***Except for ADCY1, the Panel had significantly higher AUC than individual methylated DNA markers (p<0.05). 782
781
Risk of Incident Colorectal Cancer Diagnosis After Colonoscopy: A Population-Based Study in Utah N. Jewel Samadder, Karen Curtin, Lisa Pappas, Kenneth M. Boucher, Dawn Provenzale, Geraldine P. Mineau, Ken Smith, Alison Fraser, Anita Y. Kinney, Randall W. Burt
Sensitive DNA Marker Panel for Detection of Pancreatic Cancer by Assay in Pancreatic Juice Massimo Raimondo, Tracy C. Yab, Douglas W. Mahoney, William R. Taylor, John B. Kisiel, Hatim Allawi, Graham P. Lidgard, David A. Ahlquist
Introduction: Colorectal cancer (CRC) is the third most common cause of cancer in the US. Colonoscopy is widely recommended for CRC screening in the USA but evidence of effectiveness is limited. Most studies on the effectiveness of colonoscopy are from countries with healthcare systems different from those in the US. In the US, studies have been done in Veterans, and in Medicare or HMO samples that may not reflect the general population. Aim: To examine if exposure to colonoscopy decreases the risk of incident CRC in Utah. Methods: We performed a population-based case-control study of the association of colonoscopy and CRC. We used 3 data sources. The Utah Cancer Registry tracks all incident cancer cases diagnosed in the state. The Utah Department of Health records information on all colonoscopy procedures performed in the state between 1996 and 2010. The Utah Population Database is linked to both and includes demographic information and length of residence in Utah. Cases were patients aged 54 to 90 years, diagnosed with CRC between 1 January 2000 and 31 December 2010. The CRC diagnosis date was set as the reference date for ascertaining exposure to colonoscopy. Each case patient was matched to 4 controls for age and gender with no history of CRC. All cases and controls lived in Utah from 1996 to at least the date of the matched case's CRC diagnosis. We detected exposure to colonoscopy from 1 January 1996 to an index date 6 months before case patients received a diagnosis of CRC. We measured the odds of exposure to colonoscopy in case patients and controls and used conditional logistic regression to calculate odds ratios (OR) for exposure that estimate the association between colonoscopy and CRC. Analysis was repeated, stratified by sex, age, cancer site and stage of cancer. Results: 4,137 case patients and 16,548 controls were identified with 577 (14%) case patients and 4851 (29%) controls having received colonoscopy (Table 1). Exposure to colonoscopy decreased colon cancer diagnosis in all groups with an OR of 0.39 (95% CI: 0.35-0.43) for any CRC, 0.62 (CI: 0.53-0.73) for proximal colon cancer, 0.29 (CI: 0.24-0.34) for distal colon cancer and 0.30 (CI: 0.250.35) for rectal cancer (Table 2). This finding was consistent for gender, age groups and cancer stages (Table 2). Discussion: Colonoscopy is associated with a large reduction in risk of new-onset CRC in men and women. This reduction in risk for CRC was greatest for the distal colon and rectum with a more modest reduction for proximal colon cancer. This is the largest population-based study in the US to examine the association between colonoscopy and CRC reduction throughout an entire state (academic, managed care, private practice). These results are more likely to be generalizeable than those from healthcare systems outside the US or restricted populations. Table 1: Demographic and Clinical Characteristics of Case Patients and Control Patients
Background: Pancreatic juice analysis represents a minimally-invasive approach to detection of pancreatic cancer (PC) and precancer. We have found that specific methylated DNA markers in pancreatic juice discriminate PC from chronic pancreatitis (CP) and normal pancreas (Gastroenterology 2013;144:S-90), but new markers and marker combinations remain unexplored. Aim: Assess the value of recently discovered methylated DNA markers and mutant KRAS assayed alone and combined in pancreatic juice to discriminate PC from chronic pancreatitis (CP) and reference controls (CON). Methods: We studied 167 patients (85 PC, 30 CP, 23 premalignant intraductal mucinous neoplasm (IPMN), 29 CON) who had undergone secretin stimulated pancreatic juice collection during EUS. Diagnoses were histologically based for PC, radiographically for CP, and histologically or radiographically for IPMN. Specificity was based on CON, which included patients with risk factors for PC, abnormal blood tests, or GI symptoms but radiographically-normal pancreas. Juice samples archived at -80°C were blindly batch assayed. Candidate methylated DNA markers were selected by whole methylome sequencing in prior tissue studies and preliminary pancreatic juice testing. On DNA extracted from 200 μL pancreatic juice, gene methylation was determined after bisulfite treatment by quantitative allele-specific real-time target and signal amplification (QuARTS) for assay of ADCY1, CD1D, BMP3, PRKCB, KCNK12, C13ORF18, IKZF1, CLEC11A, TWIST1, NDRG4, ELMO, and 55957. Mutant KRAS mutations (7 total) and β-actin (a marker for total human DNA) were also assayed by QuARTS. From quantitative data, a simple algorithm was followed to achieve optimal discrimination by a panel combining all markers. Results: Respectively for PC, CP, IPMN, and CON: median age was 67 (IQR 60-77), 66 (55-77), 66 (60-76) and 70 (62-77); men comprised 52, 53, 49, and 72%. At respective specificity cutoffs of 90% and 95%: the combined marker panel achieved highest PC sensitivities, 88% and 77%; ADCY1, the most sensitive single marker, detected 84% and 71%. Other single markers detected PC but to variable extents (table). Overall discrimination by area under ROC curve was higher by panel than by any single marker (p<0.05), except ADCY1 (table). At 90% specificity, panel detected 44% of all IPMNs and 75% (3/4) of subset with high grade dysplasia. Positivity rates were substantially lower in CP than in PC for all markers in table (p<0.0001). At 100% specificity, the panel was positive in 58% PC, 17% IPMN, and 13% CP. Conclusions: A panel of novel methylated DNA markers and mutant KRAS assayed from pancreatic juice achieves high sensitivity for PC. With technical optimization and inclusion of fully normal controls, discrimination may be further improved. Corroboration and extension of our findings are clearly indicated. Marker Positivity Rates in Pancreatic Juice of Patients with Pancreatic Cancer (PC), Intraductal Papillary Mucinous Neoplasm (IPMN), and Chronic Pancreatitis (CP)
Table 2: Association between receipt of colonoscopy and colorectal cancer, 2000-2010
AGA Abstracts
S-132