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Sa2043 Inherent Single Nucleotide Variants in the TBX21 Gene As Novel Prognostic Markers in Patients With Pancreatic Ductal Adenocarcinoma
AGA Abstracts
metastatic PC patients. SOMAmer® reagents are a unique class of DNA aptamers that bind their protein targets with high selectivity and a median limit of detection of 40fM. We have reported that a plasma SOMApanel can detect resectable PC in a multi-center case-control study. Methods: Chart reviews were performed for the 100 PC patients from our site used in the prior study to determine their time to disease progression (PFS) through September 2014. Pre-treatment plasma samples collected between 2008 and 2010 were analyzed for CA 19-9 and a SOMAscanTM assay consisting of 1045 known proteins. Univariate Cox models were used for identifying biomarkers related to time to progression compared to patients who have not progressed. Short PFS was defined as those with documented progression less than one year from PC diagnosis or unrecognized metastatic disease found at surgery. Long PFS was defined as progression greater than one year. The top 10 proteins identified in this analysis were then compared to 42 Stage IV patients. Statistical p-values were calculated with log likelihood ratio test of Cox regression and corrected for multiple comparisons using q-values calculated with the Benjamin and Hochberg method. Results: Nine of 43 patients who had resection for pancreatic cancer were excluded due to noncancer cause of death in the first year or loss to follow up. Thirty-four patients were eligible for progression analysis: 14 with short PFS including 2 individuals with unrecognized metastatic disease and 7 with no disease progression with a minimum 4 year's follow-up. As shown in the Figure, two of the 10 top performing prognostic proteins that had higher levels correlating with shorter PFS times were present at similar levels in baseline samples from subjects presenting with Stage IV PC. CA 19-9 was not prognostic in these samples. Conclusions: This study demonstrates the potential utility of identifying biomarkers that predict the presence of unrecognized metastatic disease defined as the detection of metastases at or the rapid recurrence following attempted curative resection of a PC. Future studies are planned to validate the results. If successful, this could lead to a test that identifies a subset of PC patients who can avoid the morbidity and health care costs associated with a major pancreatic resection.
Sa2044 Investigation of Novel Multivariate Index Based on the Plasma Free Amino Acid Profile for Detection of Pancreatic Cancer Nobuyasu Fukutake, Makoto Ueno, Nobuyoshi Hiraoka, Kazuaki Shimada, Koichi Shiraishi, Nobuhiro Saruki, Toshifumi Ito, Minoru Yamakado, Nobukazu Ono, Akira Imaizumi, Shinya Kikuchi, Hiroshi Yamamoto, Kazuhiro Katayama Background: The incidence of pancreatic cancer (PC) has increased worldwide. Most patients are diagnosed with advanced stages and survive less than 12 months because of the difficulty of early detection. To improve this poor prognosis, more accurate screening and diagnostic methods are required. Recently, plasma free amino acid (PFAA) profiles have been investigated in different types of cancer. It has been reported that the PFAA index can discriminate between patients with these cancers and healthy subjects. In this study, we developed and confirmed a multivariate index composed of a few PFAAs for the detection of PC. Methods: This was a multicenter study in Japan between 2007 and 2014. Fasting plasma samples were obtained from 360 patients with PC, 28 with chronic pancreatitis (CP), and 8372 healthy control (HC) subjects without apparent cancers who underwent comprehensive medical examinations. The patients with PC and HC subjects were allocated to the training set (120 patients with PC and 600 HC subjects) or the validation set (240 patients with PC and 7772 HC subjects). All 28 patients with CP were included in the validation set. PFAA concentrations were measured by liquid chromatography-mass spectrometry. Multivariate logistic regression analysis, using PFAA concentrations as variables, was performed to construct the optimal index in order to discriminate between patients with PC and HC subjects in the training set. Subsequently, receiver operating characteristic (ROC) analysis was performed in the validation set to evaluate the PFAA index. Results: In the training set, there was a significant difference in most of the PFAA concentrations between patients with PC and HC subjects. Especially, serine concentrations were higher and tryptophan and histidine concentrations were lower than those in HC subjects. The resulting index consisted of the following six amino acids as variables: serine, asparagine, alanine, isoleucine, histidine, and tryptophan. In the validation set, the area under the ROC curve of the PFAA index was 0.86 (95%CI, 0.84-0.89) for all patients with PC versus HC subjects, 0.81 (95%CI, 0.750.86) for patients with PC in stage IIA and IIB versus HC subjects, and 0.87 (95%CI, 0.800.93) for all patients with PC versus patients with CP. Moreover, the values of the PFAA index did not correlate with CA19-9 and elastase-1. Conclusions: The novel PFAA index which we developed in this study could be a potential biomarker for the detection of PC. The PFAA index and CA19-9, when used concurrently, may complement each other in order to more accurately detect PC, although further studies are required to determine clinical implications of this index especially at early stages. Sa2045 Impact of TP53 Codon 72 and MDM2 SNP 309 Polymorphisms in Pancreatic Ductal Adenocarcinoma Yasuki Hori, Katsuyuki Miyabe, Michihiro Yoshida, Takahiro Nakazawa, Kazuki Hayashi, Itaru Naitoh, Shuya Shimizu, Hiromu Kondo, Yuji Nishi, Shuichiro Umemura, Akihisa Kato, Takashi Joh
Sa2043 Inherent Single Nucleotide Variants in the TBX21 Gene As Novel Prognostic Markers in Patients With Pancreatic Ductal Adenocarcinoma Tomokazu Fuji, Yuzo Umeda, Takeshi Nagasaka, Fumitaka Taniguchi, Yuko Takehara, Takashi Kawai, Keisuke Kimura, Toshiaki Toshima, Takahito Yagi, Ajay Goel, Toshiyoshi Fujiwara
Single-nucleotide polymorphisms (SNPs) of TP53 (codon 72, rs1042522) and MDM2 promoter (SNP 309, rs2279744) have been associated with risk for various human cancers. However, studies analyzing these polymorphisms in pancreatic ductal adenocarcinoma (PDAC) are lacking. We investigated TP53 codon 72 and MDM2 SNP 309 polymorphisms in 32 patients with PDAC, 16 patients with chronic pancreatitis (CP), and 32 normal controls, using formalin-fixed paraffin-embedded tissue. We also examined TP53 and MDM2 protein immunohistochemistry (IHC) to assess the involvement of these differences in malignant transformation and disease progression. TP53 Pro/Pro genotype was significantly more frequent in PDAC patients than in controls (65.6 vs. 15.6%, p < 0.001) and no significant difference was found between CP patients (37.5%) and controls. In MDM2 SNP 309, there were no significant differences among the three groups. Based on the Kaplan-Meier analysis, overall survival was significantly shorter in MDM2 G/G genotypes compared with other genotypes (G/T and T/T) (359 vs. 911 days, p = 0.016) whereas no significant differences in TP53 genotypes were observed (638 vs. 752 days, p = 0.471). Although TP53 IHC was frequent in PDAC patients (53.1%), TP53 and MDM2 protein expression was not correlated with polymorphisms. Our study demonstrated TP53 codon 72 polymorphism is potentially a genetic predisposing factor while MDM2 SNP 309 polymorphism might be useful in predicting survival outcome.
Background: Pancreatic ductal adenocarcinoma (PDAC) is an intractable malignancy, with a high prevalence for liver metastasis and dissemination. Generally, it is believed that inherent immune response of each patient is a critical determinant for mounting a defense response and in dictating prognostic outcomes in human cancers, in particular, in a malignancy such as PDAC that is associated with poor outcomes. The transcription factor T-bet (TBX21) critically regulates differentiation of Th0 to Th1/Th2 helper T-cells. Previous studies have reported that functional single nucleotide variants (SNV) in codon 33 activate T-bet function, and may lead to increased differential ratios between Th1/Th2 cells. In contrast, SNVs at nucleotide position -1993 from the transcriptional start site (TSS) lead to decreased T-bet expression. We hypothesized that inherent polymorphisms within the TBX21 gene may alter immune response and help explain the disparity in observed outcomes in postoperative patients with PDAC. Methods: We analyzed matched tumor and normal tissues obtained from a cohort of 77 PDAC patients who underwent R0/1 pancreactectomy. SNVs at nt. -1993 and codon 33 within the TBX21 gene were identified by Sanger sequencing. Expression status of T-bet was assessed by immunohistochemistry, and the staining was scored as follows: High, with 6 or more T-bet positive lymphocytes/HPF; Low, with 1-5/HPF; None, with 0/HPF, tumor infiltrating lymphocytes with T-bet expression (TILT-bet). Results: In this cohort, the 2- and 3-year recurrence free survivals were 21% and 11.5%, respectively. The most frequent recurrence sites were peritoneum (n=41), followed by liver (n=24) and the other organs (n=8). The SNVs at nt. -1993 and codon 33 within the TBX21 gene were classified into the three groups: H33Q variant (n=13, 17%), T-1993C variant (n=17, 22%), and wild-type (n=47, 61%). The high grade infiltration of T-bet positive lymphocytes (TILTbet High) were frequently observed in H33Q variant (n=8, 62%), followed by T-1993C variant (n=6, 35%), and wild-type (n=8, 17%, p=0.02). None or Low TILT-bet expression pattern was frequently observed in PDAC patients with liver metastasis (n=22, 92%), with other organs (n=6, 75%), and to the peritoneum (n=25, 62%, p=0.028). With regards to the SNV at codon 33, H33Q variant showed a low frequency of liver metastasis, and lead to a better outcome compared with T-1993 variant (median OS; 27 vs 13 months, p=0.067). Conclusions: These are novel findings that for the first time describes that inherent SNVs in the TBX21 gene could be novel prognostic biomarkers with important clinical implications in PDAC patients; particularly in patients with recurrent disease to the liver.
AGA Abstracts
Sa2046 Vascular Enhancement Pattern of Mass in Computed Tomography May Predict Chemo-Responsiveness in Advanced Pancreatic Cancer Shin Il Kim, Seok Jeong, Don Haeng Lee, Hyun Jong Choi, Jong Ho Moon, Chang-Il Kwon, Yong Woon Shin Background/Aims: Chemo-responsiveness in pancreatic cancer with liver metastases may be different among the patients. The purpose of this study is to assess vascular enhancement of pancreatic ductal adenocarcinoma with liver metastasis and to analyze the correlation between enhancement and chemo-responsiveness. Patients and methods: From January 2007 to May 2013, 58 patients with advanced pancreatic adenocarcinoma were selected in three institutions. Chemo-responsiveness of all patients was assessed with CT before and after receiving at least 3 cycles of gemcitabine-based chemotherapy. Hounsefield unit (HU) was measured in pancreatic mass and the largest metastatic liver mass using region of interest (ROI). HU difference between arterial and pre-contrast phase (Delta value) could reflect vascular enhancement. According to chemo-responsiveness, the patients were divided into 2 group, Responder group (Partial response and stable disease) and Non-responder group (Progressive disease). Results: Total 58 patients (28 men and 30 women; median age 64 years; range 41-84 years) were included in the study. 41 patients belonged to pancreatic responder group (70.7%) and 17 patients belonged to pancreas non-responder group (29.3%). Mean delta value (SD) in pancreas responder group and non-responder group was
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metastatic PC patients. SOMAmer® reagents are a unique class of DNA aptamers that bind their protein targets with high selectivity and a median limit of detection of 40fM. We have reported that a plasma SOMApanel can detect resectable PC in a multi-center case-control study. Methods: Chart reviews were performed for the 100 PC patients from our site used in the prior study to determine their time to disease progression (PFS) through September 2014. Pre-treatment plasma samples collected between 2008 and 2010 were analyzed for CA 19-9 and a SOMAscanTM assay consisting of 1045 known proteins. Univariate Cox models were used for identifying biomarkers related to time to progression compared to patients who have not progressed. Short PFS was defined as those with documented progression less than one year from PC diagnosis or unrecognized metastatic disease found at surgery. Long PFS was defined as progression greater than one year. The top 10 proteins identified in this analysis were then compared to 42 Stage IV patients. Statistical p-values were calculated with log likelihood ratio test of Cox regression and corrected for multiple comparisons using q-values calculated with the Benjamin and Hochberg method. Results: Nine of 43 patients who had resection for pancreatic cancer were excluded due to noncancer cause of death in the first year or loss to follow up. Thirty-four patients were eligible for progression analysis: 14 with short PFS including 2 individuals with unrecognized metastatic disease and 7 with no disease progression with a minimum 4 year's follow-up. As shown in the Figure, two of the 10 top performing prognostic proteins that had higher levels correlating with shorter PFS times were present at similar levels in baseline samples from subjects presenting with Stage IV PC. CA 19-9 was not prognostic in these samples. Conclusions: This study demonstrates the potential utility of identifying biomarkers that predict the presence of unrecognized metastatic disease defined as the detection of metastases at or the rapid recurrence following attempted curative resection of a PC. Future studies are planned to validate the results. If successful, this could lead to a test that identifies a subset of PC patients who can avoid the morbidity and health care costs associated with a major pancreatic resection.
Sa2044 Investigation of Novel Multivariate Index Based on the Plasma Free Amino Acid Profile for Detection of Pancreatic Cancer Nobuyasu Fukutake, Makoto Ueno, Nobuyoshi Hiraoka, Kazuaki Shimada, Koichi Shiraishi, Nobuhiro Saruki, Toshifumi Ito, Minoru Yamakado, Nobukazu Ono, Akira Imaizumi, Shinya Kikuchi, Hiroshi Yamamoto, Kazuhiro Katayama Background: The incidence of pancreatic cancer (PC) has increased worldwide. Most patients are diagnosed with advanced stages and survive less than 12 months because of the difficulty of early detection. To improve this poor prognosis, more accurate screening and diagnostic methods are required. Recently, plasma free amino acid (PFAA) profiles have been investigated in different types of cancer. It has been reported that the PFAA index can discriminate between patients with these cancers and healthy subjects. In this study, we developed and confirmed a multivariate index composed of a few PFAAs for the detection of PC. Methods: This was a multicenter study in Japan between 2007 and 2014. Fasting plasma samples were obtained from 360 patients with PC, 28 with chronic pancreatitis (CP), and 8372 healthy control (HC) subjects without apparent cancers who underwent comprehensive medical examinations. The patients with PC and HC subjects were allocated to the training set (120 patients with PC and 600 HC subjects) or the validation set (240 patients with PC and 7772 HC subjects). All 28 patients with CP were included in the validation set. PFAA concentrations were measured by liquid chromatography-mass spectrometry. Multivariate logistic regression analysis, using PFAA concentrations as variables, was performed to construct the optimal index in order to discriminate between patients with PC and HC subjects in the training set. Subsequently, receiver operating characteristic (ROC) analysis was performed in the validation set to evaluate the PFAA index. Results: In the training set, there was a significant difference in most of the PFAA concentrations between patients with PC and HC subjects. Especially, serine concentrations were higher and tryptophan and histidine concentrations were lower than those in HC subjects. The resulting index consisted of the following six amino acids as variables: serine, asparagine, alanine, isoleucine, histidine, and tryptophan. In the validation set, the area under the ROC curve of the PFAA index was 0.86 (95%CI, 0.84-0.89) for all patients with PC versus HC subjects, 0.81 (95%CI, 0.750.86) for patients with PC in stage IIA and IIB versus HC subjects, and 0.87 (95%CI, 0.800.93) for all patients with PC versus patients with CP. Moreover, the values of the PFAA index did not correlate with CA19-9 and elastase-1. Conclusions: The novel PFAA index which we developed in this study could be a potential biomarker for the detection of PC. The PFAA index and CA19-9, when used concurrently, may complement each other in order to more accurately detect PC, although further studies are required to determine clinical implications of this index especially at early stages. Sa2045 Impact of TP53 Codon 72 and MDM2 SNP 309 Polymorphisms in Pancreatic Ductal Adenocarcinoma Yasuki Hori, Katsuyuki Miyabe, Michihiro Yoshida, Takahiro Nakazawa, Kazuki Hayashi, Itaru Naitoh, Shuya Shimizu, Hiromu Kondo, Yuji Nishi, Shuichiro Umemura, Akihisa Kato, Takashi Joh
Sa2043 Inherent Single Nucleotide Variants in the TBX21 Gene As Novel Prognostic Markers in Patients With Pancreatic Ductal Adenocarcinoma Tomokazu Fuji, Yuzo Umeda, Takeshi Nagasaka, Fumitaka Taniguchi, Yuko Takehara, Takashi Kawai, Keisuke Kimura, Toshiaki Toshima, Takahito Yagi, Ajay Goel, Toshiyoshi Fujiwara
Single-nucleotide polymorphisms (SNPs) of TP53 (codon 72, rs1042522) and MDM2 promoter (SNP 309, rs2279744) have been associated with risk for various human cancers. However, studies analyzing these polymorphisms in pancreatic ductal adenocarcinoma (PDAC) are lacking. We investigated TP53 codon 72 and MDM2 SNP 309 polymorphisms in 32 patients with PDAC, 16 patients with chronic pancreatitis (CP), and 32 normal controls, using formalin-fixed paraffin-embedded tissue. We also examined TP53 and MDM2 protein immunohistochemistry (IHC) to assess the involvement of these differences in malignant transformation and disease progression. TP53 Pro/Pro genotype was significantly more frequent in PDAC patients than in controls (65.6 vs. 15.6%, p < 0.001) and no significant difference was found between CP patients (37.5%) and controls. In MDM2 SNP 309, there were no significant differences among the three groups. Based on the Kaplan-Meier analysis, overall survival was significantly shorter in MDM2 G/G genotypes compared with other genotypes (G/T and T/T) (359 vs. 911 days, p = 0.016) whereas no significant differences in TP53 genotypes were observed (638 vs. 752 days, p = 0.471). Although TP53 IHC was frequent in PDAC patients (53.1%), TP53 and MDM2 protein expression was not correlated with polymorphisms. Our study demonstrated TP53 codon 72 polymorphism is potentially a genetic predisposing factor while MDM2 SNP 309 polymorphism might be useful in predicting survival outcome.
Background: Pancreatic ductal adenocarcinoma (PDAC) is an intractable malignancy, with a high prevalence for liver metastasis and dissemination. Generally, it is believed that inherent immune response of each patient is a critical determinant for mounting a defense response and in dictating prognostic outcomes in human cancers, in particular, in a malignancy such as PDAC that is associated with poor outcomes. The transcription factor T-bet (TBX21) critically regulates differentiation of Th0 to Th1/Th2 helper T-cells. Previous studies have reported that functional single nucleotide variants (SNV) in codon 33 activate T-bet function, and may lead to increased differential ratios between Th1/Th2 cells. In contrast, SNVs at nucleotide position -1993 from the transcriptional start site (TSS) lead to decreased T-bet expression. We hypothesized that inherent polymorphisms within the TBX21 gene may alter immune response and help explain the disparity in observed outcomes in postoperative patients with PDAC. Methods: We analyzed matched tumor and normal tissues obtained from a cohort of 77 PDAC patients who underwent R0/1 pancreactectomy. SNVs at nt. -1993 and codon 33 within the TBX21 gene were identified by Sanger sequencing. Expression status of T-bet was assessed by immunohistochemistry, and the staining was scored as follows: High, with 6 or more T-bet positive lymphocytes/HPF; Low, with 1-5/HPF; None, with 0/HPF, tumor infiltrating lymphocytes with T-bet expression (TILT-bet). Results: In this cohort, the 2- and 3-year recurrence free survivals were 21% and 11.5%, respectively. The most frequent recurrence sites were peritoneum (n=41), followed by liver (n=24) and the other organs (n=8). The SNVs at nt. -1993 and codon 33 within the TBX21 gene were classified into the three groups: H33Q variant (n=13, 17%), T-1993C variant (n=17, 22%), and wild-type (n=47, 61%). The high grade infiltration of T-bet positive lymphocytes (TILTbet High) were frequently observed in H33Q variant (n=8, 62%), followed by T-1993C variant (n=6, 35%), and wild-type (n=8, 17%, p=0.02). None or Low TILT-bet expression pattern was frequently observed in PDAC patients with liver metastasis (n=22, 92%), with other organs (n=6, 75%), and to the peritoneum (n=25, 62%, p=0.028). With regards to the SNV at codon 33, H33Q variant showed a low frequency of liver metastasis, and lead to a better outcome compared with T-1993 variant (median OS; 27 vs 13 months, p=0.067). Conclusions: These are novel findings that for the first time describes that inherent SNVs in the TBX21 gene could be novel prognostic biomarkers with important clinical implications in PDAC patients; particularly in patients with recurrent disease to the liver.
AGA Abstracts
Sa2046 Vascular Enhancement Pattern of Mass in Computed Tomography May Predict Chemo-Responsiveness in Advanced Pancreatic Cancer Shin Il Kim, Seok Jeong, Don Haeng Lee, Hyun Jong Choi, Jong Ho Moon, Chang-Il Kwon, Yong Woon Shin Background/Aims: Chemo-responsiveness in pancreatic cancer with liver metastases may be different among the patients. The purpose of this study is to assess vascular enhancement of pancreatic ductal adenocarcinoma with liver metastasis and to analyze the correlation between enhancement and chemo-responsiveness. Patients and methods: From January 2007 to May 2013, 58 patients with advanced pancreatic adenocarcinoma were selected in three institutions. Chemo-responsiveness of all patients was assessed with CT before and after receiving at least 3 cycles of gemcitabine-based chemotherapy. Hounsefield unit (HU) was measured in pancreatic mass and the largest metastatic liver mass using region of interest (ROI). HU difference between arterial and pre-contrast phase (Delta value) could reflect vascular enhancement. According to chemo-responsiveness, the patients were divided into 2 group, Responder group (Partial response and stable disease) and Non-responder group (Progressive disease). Results: Total 58 patients (28 men and 30 women; median age 64 years; range 41-84 years) were included in the study. 41 patients belonged to pancreatic responder group (70.7%) and 17 patients belonged to pancreas non-responder group (29.3%). Mean delta value (SD) in pancreas responder group and non-responder group was
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