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Sa1942 MicroRNA Expression in Unresectable Pancreatic Cancer As a Prognostic Marker in EUS-FNA Cytology Specimens
and 27.0%, NEFM; 10.2% and 8.0%, and NKX6-1; 49.8% and 47.2%, respectively. The methylation levels of EMX1 and NEFM significantly decreased after H. pylori eradication (P=0.014 and 0.020, respectively, by one-sided paired t-test). Individually, the methylation levels of EMX1, NEFM, and NKX6-1, decreased after H. pylori eradication in 15, 15, and 11 subjects, respectively. On the other hands, the methylation levels did not decrease in 7, 7, and 11 subjects, respectively, 16 months after the eradication. Conclusion: The methylation levels of EMX1 and NEFM significantly decreased after H. pylori eradication. Individually, the methylation levels of the two genes did not decrease in about one third of subjects with successful H. pylori eradication. These results suggest that the irreversible methylation levels of two genes might sensitively reflect "Point of No Return". Therefore, EMX1 and NEFM could be the candidate markers to identify the high-risk group for gastric cancer developing after H. pylori eradication. Sa1942 MicroRNA Expression in Unresectable Pancreatic Cancer As a Prognostic Marker in EUS-FNA Cytology Specimens Kwang Hyun Chung, Ji Kon Ryu, Jin Myung Park, Jae Min Lee, Sang Hyub Lee, YongTae Kim Background: Deregulated microRNA (miRNAs) expression is widespread in pancreatic cancer and some of them are expected to correlate with clinicopathological factor or treatment response and prognosis. Aim of this study was to investigate expression profile of wellestablished miRNAs in pancreatic cancer and its correlation with clinicopathological factor and prognosis. Method: Forty-nine samples of unresectable pancreatic ductal adenocarcinoma were obtained by endoscopic ultrasound guided fine needle aspiration. MiRNAs were extracted and miR-21, miR-10b and miR-17-5p expressions were analyzed by real-time polymerase chain reaction. The results were normalized by internal control (U6) and clinicopathological factor and prognosis were compared retrospectively between high and low 2ΔCt group of each miRNA. Results: Mean 2- ΔCt value of miR-21, miR-10b and miR-175p were 942.70, 0.834 and 40.71, respectively. High expression group and low expression group were divided by the Mean 2- ΔCt value of each miRNA. Pancreatic cancer status (T, N and M stage) were not different between high and low expression group. Chemotherapy responsiveness of low miRNA expression group seemed to be better than high miRNA expression group but it was not significant. High expression group of miR-21 showed significantly shorter median progression free survival than low expression group (130 days vs. 177 days, P = 0.036). Conclusions: High expression of miR-21 is related with shorter progression free survival and poor prognosis in unresectable pancreatic cancer. Sa1943 Histopathologic Grading Using Poorly-Differentiated Clusters Predicts Outcome in Colorectal Carcinoma Hector H. Li-Chang, Bojana Mitrovic, Kelly Handley, Richard Gray, Naziheh Assarzadegan, Gordon Hutchins, Philip Quirke, Robert H. Riddell, Richard Kirsch
Figure 1
Background: Tumour grade is an independent prognostic factor in colorectal cancer (CRC), and is considered when deciding on the administration of adjuvant treatment. However, current grading schemes may overlook the significance of small but clinically significant high-grade components. The grading of CRC through the quantification of poorly-differentiated clusters (PDCs) has been proposed as being superior to conventional grading schemes in terms of both reproducibility and prognostic power. However, its impact on response to chemotherapy has not been studied. Methods: A pathologist, blinded to outcome and case information, used PDC quantification to grade whole-slide digital hematoxylin and eosin images of 770 CRC cases from the QUick And Simple And Reliable (QUASAR) trial. The latter is the largest reported randomized study of observation versus adjuvant chemotherapy in patients with resected stage II colon cancer, and demonstrated that adjuvant 5-FU/ leucovorin treatment benefits a small but significant population of stage II patients. PDCs were defined as groups of 5 or more tumour cells that lacked gland formation. Tumors were graded as follows: Grade 1: <5 PDCs; Grade 2: 5-9 PDCs and Grade 3: >9 PDCs in any high-power (400x) microscopic field at the leading edge of the tumor. Grading based on PDCs was compared to other clinicopathologic features, including outcome. Results: PDC grades amongst the 770 CRC cases were as follows: Grade 1 (n=399), Grade 2(n=149) and grade 3 (n=102). No differences in T-stage amongst the 3 PDC grades were noted. A trend towards more frequent lymph node metastases was present amongst those subjects with PDC grade 3 tumors. PDC grade 3 tumors were significantly associated with proximal location (p = 0.03), vascular invasion (p = 0.01), microsatellite instability (p = 0.001), and wild-type KRAS status (p = 0.02). PDC grades of 2 and 3 were significantly associated with the presence of high-grade tumor budding (p < 0.0001). Log-rank tests showed that PDC grade was prognostically significant for both the risk of recurrence (p = 0.01) and mortality (p = 0.03) with a follow-up period of 10 years.. Subgroup analysis showed no differences in MORTALITY OR 2-year recurrence rates within individual PDC grades between those receiving and not receiving chemotherapy Conclusions: Grading via the quantification of PDCs is prognostically valid in CRC patients, but does not predict response to adjuvant 5FU with leucovorin. The use of this grading method may improve the prognostic power of histopathologic examination, and warrants further study.
Figure 2 Sa1941 The Candidate Molecular Markers for Evaluating the Risk of Gastric Cancer After Helicobacter pylori Eradication Sohachi Nanjo, Takayuki Ando, Shuichi Terao, Toshiro Sugiyama Background: Aberrant DNA methylation in gastric mucosa is induced by Helicobacter pylori (H. pylori), and plays a pivotal role for development of pre-malignant lesions. Although aberrant DNA methylation generally decreases after H. pylori eradication, the methylation level in the stomach with long-term H. pylori infection do not normalize to that in noninfected stomach, even if H. pylori is eradicated. Thus, aberrantly methylated genes might be useful markers, so-called "Point of No Return" markers, to identify high-risk individuals for gastric cancer developing after H. pylori eradication. From this point of view, we have previously identified and reported candidate markers (Nanjo et al. Gastric Cancer. 15:3828, 2012). In the present study, we aimed to evaluate the proper markers in the candidates in clinical follow-up after eradication. Method: Forty-four gastric mucosae at lesser curvature of the middle body were obtained from 22 subjects with H. pylori infection before and 16 months after H. pylori eradication. H. pylori infection was analyzed by serum IgG titer, urea breath test, and Giemsa staining for the diagnosis. Success of H. pylori eradication was confirmed by urea breath test. Methylation levels of EMX1, NEFM, and NKX6-1, which are risk markers previously reported among subjects with gastric cancer (Nanjo et al. Gastric Cancer), were measured in the biopsy specimens by quantified methylation-specific PCR. Result: Mean methylation levels before and after H. pylori eradication were EMX1; 33.0%
S-335
AGA Abstracts
AGA Abstracts
extracellularly cleaved to generate mature NGF in epithelium of the lung, nasal mucosa, skin, gastrointestinal and genitourinary tracts, cardiac, smooth and skeletal muscle and immune cells (lymphocytes, mast cells and eosinophils). Dysregulation of NGF expression and signalling have been described in allergy, asthma, inflammation in the gut, chronic constipation, coronary artery disease and some cancers. In prostate cancer NGF stimulates tumour cell growth and metastasis and may drive nerve sprouting and infiltration. Inhibiting NGF by using blocking antibodies has a significant analgesic effect and is proposed to decrease metastatic cancer pain. Aim: ProNGF expression has not been previously described in tumours of the gastrointestinal tract. Materials and Methods: The expression of proNGF was examined by immunocytochemistry of esophageal squamous cancer (SCC) (15 cases), gastric adenocarcinoma (10 cases) and colorectal adenocarcinoma (12 cases) and corresponding normal adjacent tissues in the gut in tumour microarrays (Figure 1). Sections were scored for site of cytoplasmic staining in esophagus and cancer grade. Results: All gut epithelial tissue expressed pro-NGF. In normal oesophageal squamous epithelium expression site was diffuse, superficial or basal (Figure 2), in squamous carcinoma, staining was intense and diffuse. In adenocarcinomas (stomach and colon) staining was diffuse, and in intestinal metaplasia (IM) in the stomach, staining was more intense compared to adjacent gastric epithelium. There was no significant difference in intensity of staining by grade of cancer. Conclusions: There is significant expression of pro-NGF in squamous oesophageal and gastrointestinal columnar epithelium in both normal tissue and cancer. Pro-NGF may be therefore be a target of interest in biomarker exploration and therapeutic development for inhibition of cancer growth and cancer pain.
Figure 1
Background: Tumour grade is an independent prognostic factor in colorectal cancer (CRC), and is considered when deciding on the administration of adjuvant treatment. However, current grading schemes may overlook the significance of small but clinically significant high-grade components. The grading of CRC through the quantification of poorly-differentiated clusters (PDCs) has been proposed as being superior to conventional grading schemes in terms of both reproducibility and prognostic power. However, its impact on response to chemotherapy has not been studied. Methods: A pathologist, blinded to outcome and case information, used PDC quantification to grade whole-slide digital hematoxylin and eosin images of 770 CRC cases from the QUick And Simple And Reliable (QUASAR) trial. The latter is the largest reported randomized study of observation versus adjuvant chemotherapy in patients with resected stage II colon cancer, and demonstrated that adjuvant 5-FU/ leucovorin treatment benefits a small but significant population of stage II patients. PDCs were defined as groups of 5 or more tumour cells that lacked gland formation. Tumors were graded as follows: Grade 1: <5 PDCs; Grade 2: 5-9 PDCs and Grade 3: >9 PDCs in any high-power (400x) microscopic field at the leading edge of the tumor. Grading based on PDCs was compared to other clinicopathologic features, including outcome. Results: PDC grades amongst the 770 CRC cases were as follows: Grade 1 (n=399), Grade 2(n=149) and grade 3 (n=102). No differences in T-stage amongst the 3 PDC grades were noted. A trend towards more frequent lymph node metastases was present amongst those subjects with PDC grade 3 tumors. PDC grade 3 tumors were significantly associated with proximal location (p = 0.03), vascular invasion (p = 0.01), microsatellite instability (p = 0.001), and wild-type KRAS status (p = 0.02). PDC grades of 2 and 3 were significantly associated with the presence of high-grade tumor budding (p < 0.0001). Log-rank tests showed that PDC grade was prognostically significant for both the risk of recurrence (p = 0.01) and mortality (p = 0.03) with a follow-up period of 10 years.. Subgroup analysis showed no differences in MORTALITY OR 2-year recurrence rates within individual PDC grades between those receiving and not receiving chemotherapy Conclusions: Grading via the quantification of PDCs is prognostically valid in CRC patients, but does not predict response to adjuvant 5FU with leucovorin. The use of this grading method may improve the prognostic power of histopathologic examination, and warrants further study.
Figure 2 Sa1941 The Candidate Molecular Markers for Evaluating the Risk of Gastric Cancer After Helicobacter pylori Eradication Sohachi Nanjo, Takayuki Ando, Shuichi Terao, Toshiro Sugiyama Background: Aberrant DNA methylation in gastric mucosa is induced by Helicobacter pylori (H. pylori), and plays a pivotal role for development of pre-malignant lesions. Although aberrant DNA methylation generally decreases after H. pylori eradication, the methylation level in the stomach with long-term H. pylori infection do not normalize to that in noninfected stomach, even if H. pylori is eradicated. Thus, aberrantly methylated genes might be useful markers, so-called "Point of No Return" markers, to identify high-risk individuals for gastric cancer developing after H. pylori eradication. From this point of view, we have previously identified and reported candidate markers (Nanjo et al. Gastric Cancer. 15:3828, 2012). In the present study, we aimed to evaluate the proper markers in the candidates in clinical follow-up after eradication. Method: Forty-four gastric mucosae at lesser curvature of the middle body were obtained from 22 subjects with H. pylori infection before and 16 months after H. pylori eradication. H. pylori infection was analyzed by serum IgG titer, urea breath test, and Giemsa staining for the diagnosis. Success of H. pylori eradication was confirmed by urea breath test. Methylation levels of EMX1, NEFM, and NKX6-1, which are risk markers previously reported among subjects with gastric cancer (Nanjo et al. Gastric Cancer), were measured in the biopsy specimens by quantified methylation-specific PCR. Result: Mean methylation levels before and after H. pylori eradication were EMX1; 33.0%
S-335
AGA Abstracts
AGA Abstracts
extracellularly cleaved to generate mature NGF in epithelium of the lung, nasal mucosa, skin, gastrointestinal and genitourinary tracts, cardiac, smooth and skeletal muscle and immune cells (lymphocytes, mast cells and eosinophils). Dysregulation of NGF expression and signalling have been described in allergy, asthma, inflammation in the gut, chronic constipation, coronary artery disease and some cancers. In prostate cancer NGF stimulates tumour cell growth and metastasis and may drive nerve sprouting and infiltration. Inhibiting NGF by using blocking antibodies has a significant analgesic effect and is proposed to decrease metastatic cancer pain. Aim: ProNGF expression has not been previously described in tumours of the gastrointestinal tract. Materials and Methods: The expression of proNGF was examined by immunocytochemistry of esophageal squamous cancer (SCC) (15 cases), gastric adenocarcinoma (10 cases) and colorectal adenocarcinoma (12 cases) and corresponding normal adjacent tissues in the gut in tumour microarrays (Figure 1). Sections were scored for site of cytoplasmic staining in esophagus and cancer grade. Results: All gut epithelial tissue expressed pro-NGF. In normal oesophageal squamous epithelium expression site was diffuse, superficial or basal (Figure 2), in squamous carcinoma, staining was intense and diffuse. In adenocarcinomas (stomach and colon) staining was diffuse, and in intestinal metaplasia (IM) in the stomach, staining was more intense compared to adjacent gastric epithelium. There was no significant difference in intensity of staining by grade of cancer. Conclusions: There is significant expression of pro-NGF in squamous oesophageal and gastrointestinal columnar epithelium in both normal tissue and cancer. Pro-NGF may be therefore be a target of interest in biomarker exploration and therapeutic development for inhibition of cancer growth and cancer pain.