Hepaticocholecystojejunostomy as effective palliative biliary bypass for unresectable pancreatic cancer.

BACKGROUND/AIMS: The majority of patients with pancreatic cancer present with far advanced disease and jaundice. With the advancement of endoscopic interventional techniques, the role of surgical bypass has declined. However, surgical bypass is still considered to be appropriate in patients who are able to tolerate surgery. We performed hepaticocholecystojejunostomy consecutively as a palliative surgical biliary bypass for the purpose of long-term palliation. The aim of this study was to analyze the results of our palliative surgical biliary bypass, hepaticocholecystojejunostomy. METHODOLOGY: Between January 2001 through December 2009, 69 patients received palliative surgical biliary bypass (bypass group) and 33 patients received endoscopic biliary stenting (stent group) for unresectable pancreatic cancers. Mortality, morbidity and survival between the two groups were compared. RESULTS: There was no in-hospital death in the bypass group, but 2 patients (6%) in the stent group died in the hospital (p = 0.04). The surgical morbidity rate was 15% in the bypass group, while 20 patients (61%) in the stent group developed complications, mainly due to stent blockage. There was no significant difference in overall survival between the two groups. Among patients who underwent systemic chemotherapy but did not present with jaundice at the time of diagnosis, those who underwent prophylactic surgical biliary bypass before chemotherapy showed better survival than those who underwent systemic chemotherapy preceding biliary bypass or biliary stenting after occurrence of jaundice (p = 0.01). CONCLUSIONS: Hepaticocholecystojejunostomy resulted in negligible mortality, low morbidity and effective long-term palliation. Prophylactic surgical biliary bypass with gastrointestinal bypass might be a good treatment option for non-jaundiced patients undergoing chemotherapy for unresectable pancreatic cancer.

Combination therapy of portal vein resection and adjuvant gemcitabine improved prognosis of advanced pancreatic cancer.

BACKGROUND/AIMS: Although adjuvant chemotherapy (AC) using gemcitabine improves the prognosis of patients with resectable pancreatic cancer, the effect of gemcitabine AC on the prognosis of patients with borderline resectable pancreatic cancer is not clear. METHODOLOGY: We analyzed the prognosis of patients with pancreatic cancer who underwent curative pancreatoduodenectomy or total pancreatectomy in combination with portal/superior mesenteric vein resection (PVR) [PVR (+) group] or without PVR [PVR(-) group]. RESULTS: MST of the PVR (+) group was significantly shorter than that of the PVR(-) group (p=0.017). In contrast, when we focused on the patients with gemcitabine AC, there was no significant difference in MST between the PVR (+) and the PVR (-) groups (p=0.247). Furthermore, we compared MST of two subgroups in the PVR (+) group depending on gemcitabine AC status. In the PVR (+) group, MST of the patients with gemcitabine AC was significantly longer than that without gemcitabine AC (p=0.003). This was also true for the patients with pancreatic cancer which had histologically proven invasion to portal/superior mesenteric vein (PV/SMV) (p=0.001). CONCLUSIONS: The prognosis of patients with pancreatic cancer invading PV/SMV can be improved by combination therapy with PVR and gemcitabine adjuvant chemotherapy.

Claudin-4 expression predicts survival in pancreatic ductal adenocarcinoma.

BACKGROUND: Identification of prognostic markers would be useful in the clinical management of patients with pancreatic ductal adenocarcinoma (PDAC). The clinical relevance of claudin-4 (CLDN4), recently identified as overexpressed in PDAC, is unknown. METHODS: Using quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR), we analyzed CLDN4 mRNA expression in a panel of 9 pancreatic cancer cell lines and formalin-fixed paraffin-embedded (FFPE) tissues from 100 patients with PDAC. The CLDN4 expression levels were then correlated with clinicopathological variables and patient outcome. We also performed immunohistochemical analysis in 20 FFPE samples of PDAC to investigate the expression of CLDN4 protein. RESULTS: Increased expression of CLDN4 was confirmed in all the pancreatic cancer cell lines tested compared with normal ductal epithelial cells and fibroblasts. We found that low expression of CLDN4 was significantly associated with shorter survival in patients with PDAC (hazard ratio; 1.362, 95% confidence interval; 1.011-1.873, P = 0.0419). Patients with high CLDN4 expression survived longer for a median of 63.0 months, compared with 14.7 months in patients with low CLDN4 expression (P = 0.0067). In immunohistochemical analysis, the level of CLDN4 mRNA expression was significantly correlated with the expression of CLDN4 protein (P = 0.0168). CONCLUSION: Increased expression of CLDN4 mRNA predicts better prognosis in PDAC.

Liver-intestine cadherin expression is associated with intestinal differentiation and carcinogenesis in intraductal papillary mucinous neoplasm.

OBJECTIVES: Intraductal papillary mucinous neoplasms (IPMN) are classified into four phenotypes according to the WHO classification. Recently, intestinal-type IPMN has been suggested to grow with a distinct carcinogenetic pathway. Like mucin 2, oligomeric mucus/gel forming (MUC2) and caudal-related homeobox 2 (CDX2), liver-intestine cadherin (LI cadherin) is an intestine-specific marker. We aimed to investigate the roles of LI cadherin expression in IPMN. METHODS: We examined LI cadherin expression in 135 cases of IPMN by immunohistochemical staining and the quantitative real-time reverse-transcription polymerase chain reaction. RESULTS: LI cadherin protein and mRNA levels were significantly higher in intestinal-type IPMN than in nonintestinal-type IPMN (protein level, p < 0.001; mRNA level, p = 0.0312). A positive correlation was found between protein and mRNA of LI cadherin (p = 0.0037). The positivity rates of LI cadherin expression were significantly higher in CDX2-positive cases than in CDX2-negative cases (p < 0.001). In 41 intestinal-type IPMNs, LI cadherin-positive rates tended to increase gradually, from IPMN with low-grade dysplasia (IPMN-L) to IPMN with an associated invasive carcinoma (IPMN-IC) [IPMN-L vs. IPMN with high-grade dysplasia (IPMN-H); p = 0.0357, IPMN-L vs. IPMN-IC; p = 0.0230] and positively correlated with the Ki-67 labeling index (p = 0.0408), whereas this tendency was not recognized in nonintestinal-type IPMNs. CONCLUSIONS: LI cadherin is associated with an intestinal phenotype and an 'intestinal pathway' of carcinogenesis in IPMN.

Insig2 is overexpressed in pancreatic cancer and its expression is induced by hypoxia.

A hypoxic microenvironment is a characteristic feature of pancreatic cancer, and induces the expressions of various genes involved in malignant behaviors. Insulin-induced gene 2 (Insig2) has recently been shown to be correlated with cellular invasion in colon cancer. However, there have been no reports regarding its expression in pancreatic cancer. In this study, we evaluated Insig2 mRNA expression and the biological function of Insig2 in pancreatic cancer. We measured Insig2 mRNA expression in cultured pancreatic cancer cell lines and invasive ductal carcinoma (IDC) cells, normal pancreatic epithelial cells, and pancreatic intraepithelial neoplasia cells obtained by laser-capture microdissection. We also investigated the effects of Insig2-targeting siRNAs on the cell proliferation and cell invasion of pancreatic cancer cell lines. All pancreatic cancer cell lines expressed Insig2 mRNA. The PANC-1 and MIA PaCa-2 pancreatic cancer cell lines showed >2-fold higher Insig2 mRNA expression levels under hypoxic conditions (1% O2) than under normoxic conditions (21% O2 ). Cell proliferation was significantly decreased in SUIT-2 cells and cell invasion was significantly decreased in SUIT-2, Capan-2, and CFPAC-1 cells after transfection of the Insig2-targeting siRNAs. In analyses of microdissected cells, cells from IDC tissues expressed significantly higher levels of Insig2 mRNA than normal pancreatic cells (P < 0.001) and pancreatic intraepithelial neoplasia cells (P = 0.082). In analyses of IDC cells, the levels of Insig2 mRNA expression were significantly higher in late-stage patients than in early-stage patients. The present data suggest that Insig2 is associated with the malignant potential of pancreatic cancer under hypoxic conditions.

CD10+ pancreatic stellate cells enhance the progression of pancreatic cancer.

BACKGROUND & AIMS: Pancreatic stellate cells (PSCs) promote the progression of pancreatic cancer by producing extracellular matrix and soluble factors. However, the functional heterogeneity of PSCs has not been identified until now. Detailed characterization of the PSCs in human pancreatic cancer would provide a set of potential targets for stroma-directed therapy. METHODS: We isolated PSCs from fresh pancreatic ductal adenocarcinoma tissue and sorted them by flow cytometry according to cell surface expression of CD10, which is a stromal prognostic marker for various tumors. We analyzed the functional differences between CD10(+) PSCs and CD10(-) PSCs. RESULTS: Immunohistochemical analysis showed that the frequency of CD10 expression by PSCs was markedly higher in tumor tissue than in normal tissue (33.7% vs 0%, respectively, P = .028). In pancreatic ductal adenocarcinoma, CD10 expression by PSCs was associated with positive nodal metastases (P = .011) and a shorter survival time (P < .001). In vitro coculture experiments showed that CD10(+) PSCs promoted the invasiveness of pancreatic cancer cell lines, SUIT-2 and Panc-1 cells more intensively than CD10(-) PSCs. CD10(+) PSCs significantly increased the tumor growth and invasiveness of SUIT-2 cells in a murine cotransplantation model. CD10(+) PSCs secreted higher levels of matrix metalloproteinase 3 than CD10(-) PSCs, and knockdown of matrix metalloproteinase 3 in cocultured PSCs reduced the invasion of SUIT-2 and Panc-1 cells. CONCLUSIONS: CD10(+) PSCs enhance the progression of pancreatic cancer cells. CD10(+) PSCs may be a candidate for selective therapeutic targeting in the treatment of pancreatic cancer.

MicroRNA expression as a predictive marker for gemcitabine response after surgical resection of pancreatic cancer.

BACKGROUND: To improve the prognosis of patients after resection of pancreatic cancer, the most appropriate and efficient treatment should be provided to specific subsets of patients. Our aim was to identify promising microRNAs as markers to predict responses to gemcitabine in patients with resected pancreatic cancer. METHODS: Two gemcitabine-resistant pancreatic cancer cell lines were established, and global microRNA expression analyses was performed by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Eleven miRNAs were selected as putative predictive markers and analyzed by means of macrodissected formalin-fixed, paraffin-embedded samples obtained from 90 patients with or without gemcitabine treatment after resection of pancreatic cancer. RESULTS: We identified 24 microRNAs whose expression was altered in gemcitabine-resistant cells. qRT-PCR analyses showed that patients with high miR-142-5p and miR-204 expression had significantly longer survival times than those with low miR-142-5p (P = 0.0077) and miR-204 (P = 0.0054) expression in the gemcitabine-treated group. This was not seen in the nontreated group. Multivariate analyses showed that miR-142-5p expression was an independent prognostic marker only in patients treated with gemcitabine (P = 0.034). CONCLUSIONS: miR-142-5p is a promising predictive marker for gemcitabine response in patients with resected pancreatic cancer.

MicroRNA, hsa-miR-200c, is an independent prognostic factor in pancreatic cancer and its upregulation inhibits pancreatic cancer invasion but increases cell proliferation.

BACKGROUND: Recently, the microRNA-200 family was reported to affect cancer biology by regulating epithelial to mesenchymal transition (EMT). Especially, the expression of miR-200c has been shown to be associated with upregulating the expression of E-cadherin, a gene known to be involved in pancreatic cancer behavior. However, the significance of miR-200c in pancreatic cancer is unknown. METHODS: In the present study, we investigated the relationship between E-cadherin and miR-200c expression in a panel of 14 pancreatic cancer cell lines and in macro-dissected formalin-fixed paraffin-embedded (FFPE) tissue samples obtained from 99 patients who underwent pancreatectomy for pancreatic cancer. We also investigated the effects of miR-200c on the proliferation and invasion of pancreatic cancer cells. RESULTS: We found that patients with high levels of miR-200c expression had significantly better survival rates than those with low levels of miR-200c expression. We also found a remarkably strong correlation between the levels of miR-200c and E-cadherin expression. CONCLUSIONS: These data indicate that miR-200c may play a role in the pancreatic cancer biology and may be a novel marker for the prognosis of pancreatic cancer.

MicroRNA-203 expression as a new prognostic marker of pancreatic adenocarcinoma.

BACKGROUND: Detection of aberrant microRNA (miR) expression may contribute to diagnosis and prognosis of various cancers. The aim of this study is to evaluate the correlation between miR-203 expression and prognosis of patients with pancreatic adenocarcinoma after curative resection. METHODS: A total of 113 formalin-fixed paraffin-embedded tissue samples of pancreatic adenocarcinoma, 20 samples of chronic pancreatitis, and 8 samples of normal pancreas were obtained. We investigated the association of miR-203 expression measured by quantitative reverse-transcription polymerase chain reaction assays with clinicopathological parameters and survival times. RESULTS: miR-203 was overexpressed in pancreatic adenocarcinoma samples compared with chronic pancreatitis (P < 0.001) and normal pancreas (P = 0.001) samples. An association between miR-203 expression and clinicopathological factors of pancreatic adenocarcinoma was not observed. On univariate analysis, the high-miR-203 group and the subgroup (20%) of cases with the highest miR-203 overexpression had significantly shorter survival time (P = 0.048 and P = 0.024, respectively). Multivariate analysis revealed that miR-203 expression was an independent predictor of poor prognosis in cases with no residual tumor (relative risk 2.298, P = 0.027). CONCLUSIONS: miR-203 expression is a new prognostic marker in pancreatic adenocarcinoma patients.

Treatment of arteriovenous shunts after renal transplantation.

PURPOSE: Immunosuppressive drugs have improved the results of renal transplantation dramatically in recent years; however, there is still no consensus on the treatment of arteriovenous (A-V) shunts after successful transplantation. We evaluated the treatment of A-V shunts after transplantation. METHODS: We reviewed all patients who underwent shunt closure at our hospital between 2005 and 2007 assessing surgical methods, operative time, blood loss, and complications. RESULTS: Fifty-two patients underwent shunt closure, as a simple transection in 5 patients, resection of the anastomotic site in 16, resection and reconstruction of the artery in 26, and graftectomy in 5. Graftectomy was associated with copious blood loss and a long operative time. The most frequent complication was phlebitis, but there were no nerve complications. CONCLUSIONS: An A-V shunt after renal transplantation may result in an aneurysm, severe venous dilatation, pain, bloating of the arm, infection, and cardiac problems. Thus, after successful transplantation, shunt closure should be performed to prevent these complications and to improve quality of life.

MicroRNA-10b is overexpressed in pancreatic cancer, promotes its invasiveness, and correlates with a poor prognosis.

BACKGROUND: MicroRNAs (miRNAs) have been gaining attention as new, key molecules that contribute to carcinogenesis. In pancreatic cancer, previous profiling analyses of miRNA expression have shown that several miRNAs are differently expressed in normal and cancerous tissues. Several pancreatic cancer-specific miRNAs differed, however, in each analysis. METHODS: We investigated the miRNA expression profiles of the pancreatic cancer cell lines CAPAN-1 and CFPAC1 and an immortalized human normal pancreatic ductal epithelial cell line (HPDE) using a high-throughput, TaqMan, qRT-PCR array analysis. We also analyzed the expression levels of this miRNA in microdissected (n = 15) and formalin-fixed, paraffin-embedded (FFPE) (n = 115) samples from pancreatic cancers by quantitative RT-PCR. Finally, we investigated the effects of this miRNA on the invasiveness of pancreatic cancer cells. RESULTS: Based on the microarray analysis, miR-372, miR-146a, miR-204, miR-10a, and miR-10b showed particularly large differences (>10-fold changes) between both pancreatic cell lines and HPDE cells. Thirteen of the 15 pancreatic cancer cell lines showed 2.1- to 36.4-fold (median, 15.3-fold) greater levels of miR-10b than HPDE cells. Microdissection analysis revealed that miR-10b exhibited greater expression levels in pancreatic cancer cells (n = 5) than in normal pancreatic ductal cells (n = 10) (P < .020). Analysis of FFPE samples showed that high miR-10b expression was associated with a lesser overall survival (P = .014). Furthermore, miR-10b correlated with the invasiveness of pancreatic cancer cells (P < .01). CONCLUSION: miR-10b is overexpressed in pancreatic cancer and may be involved in the invasiveness in pancreatic cancer cells, thereby leading to a poor prognosis.

Invasive carcinoma derived from intestinal-type intraductal papillary mucinous neoplasm is associated with minimal invasion, colloid carcinoma, and less invasive behavior, leading to a better prognosis.

OBJECTIVES: Although intestinal-type intraductal papillary mucinous carcinoma (IPMC) is reported to have a better prognosis, few studies have addressed its invasive pattern. The meaning of "minimal invasion" (MI) in IPMC also remains unclear. We investigated the prognosis of intraductal papillary mucinous neoplasm (IPMN) focusing on MI and subtypes. METHODS: We evaluated 71 patients with IPMC among a total of 179 patients with resected IPMN. RESULTS: Although 2 of 10 MI-IPMC patients had lymph node metastasis, there were no disease-specific deaths among the MI-IPMC patients. Minimally invasive IPMCs were more frequently observed in intestinal-type IPMC (23/33 cases) than in non-intestinal-type IPMCs (16/38 cases; P = 0.019). Among 32 patients with massively invasive IPMC, the prognosis was significantly better for patients with intestinal-type IPMC than for patients with non-intestinal-type IPMC (P = 0.013). When confined to massively invasive IPMC, tubular invasion (P < 0.001) and lymphatic (P = 0.001) or serosal (P = 0.021) invasion were less frequently observed in intestinal-type IPMC than in non-intestinal-type IPMC. CONCLUSIONS: Invasive carcinoma derived from intestinal-type IPMN is associated with MI, colloid carcinoma, and less invasive behavior.

High EGFR mRNA expression is a prognostic factor for reduced survival in pancreatic cancer after gemcitabine-based adjuvant chemotherapy.

Pancreatic ductal adenocarcinoma (PDAC) still presents a major therapeutic challenge and a phase III clinical trial has revealed that the combination of gemcitabine and a human epidermal growth factor receptor type I (HER1/EGFR) targeting agent presented a significant benefit compared to treatment with gemcitabine alone. The aim of this study was to investigate EGFR mRNA expression in resected PDAC tissues and its correlation with patient prognosis. We obtained formalin-fixed paraffin-embedded (FFPE) tissue samples from 88 patients with PDAC who underwent pancreatectomy, and measured EGFR mRNA levels by quantitative real-time reverse transcription-polymerase chain reaction. The high-level EGFR group had significantly shorter disease-free-survival (p=0.029) and overall-survival (p=0.014) as shown by univariate analyses, although these did not reach statistical significance, as shown by multivariate analyses. However, we found that high EGFR expression was an independent prognostic factor in patients receiving gemcitabine-based adjuvant chemotherapy (p=0.023). Furthermore, we measured EGFR mRNA levels in 20 endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) cytological specimens. Altered EGFR levels were distinguishable in microdissected neoplastic cells from EUS-FNA cytological specimens compared to those in whole cell pellets. In conclusion, quantitative analysis of EGFR mRNA expression using FFPE tissue samples and microdissected neoplastic cells from EUS-FNA cytological specimens could be useful in predicting prognosis and sensitivity to gemcitabine in PDAC patients.

Characterization of CD24 expression in intraductal papillary mucinous neoplasms and ductal carcinoma of the pancreas.

CD24 is a molecule involved in cell adhesion and tumor metastasis. The aims of this study were (1) to evaluate the association between CD24 expression and the progression of intraductal papillary mucinous neoplasms of the pancreas and (2) to investigate the association between CD24 expression in pancreatic cancer and the prognosis of patients who underwent curative pancreatectomy. Immunohistochemical analysis of CD24 was performed for 95 intraductal papillary mucinous neoplasms of the pancreas and 83 pancreatic cancers. We investigated the association between CD24 expression and the histologic grade of intraductal papillary mucinous neoplasms of the pancreas, the clinicopathologic parameters of pancreatic cancers, and the survival time of pancreatic cancer patients who underwent pancreatectomy. The positive rates of CD24 expression in intraductal papillary mucinous adenoma, borderline intraductal papillary mucinous neoplasm, noninvasive intraductal papillary mucinous carcinoma, and invasive intraductal papillary mucinous carcinoma were 5 (20%) of 24, 12 (48%) of 25, 10 (43%) of 23, and 15 (65%) of 23, respectively. The CD24-positive rates were significantly higher in borderline intraductal papillary mucinous neoplasm and intraductal papillary mucinous carcinoma compared with intraductal papillary mucinous adenoma (P = .046 and P = .007, respectively). The staining scores, which were determined from the percentage of stained cells and the staining intensity, were significantly higher in invasive intraductal papillary mucinous carcinoma than in noninvasive intraductal papillary mucinous carcinoma (P = .043). In the pancreatic cancers, higher tumor stage (P = .007), nodal metastasis (P = .021), and higher-grade tumors (P < .001) were more frequent in the CD24-positive group compared with the CD24-negative group. CD24 expression was associated with shorter survival in univariate analysis (P = .028) However, based on the multivariate analysis, the CD24 expression was not associated with survival. In conclusion, CD24 is involved in the progression of intraductal papillary mucinous neoplasms of the pancreas and in the malignant behavior of pancreatic cancers.

alpha-Smooth Muscle Actin Expressing Stroma Promotes an Aggressive Tumor Biology in Pancreatic Ductal Adenocarcinoma.

OBJECTIVES: Pancreatic ductal adenocarcinoma (PDAC) is often characterized by a prominent desmoplastic stroma that is induced partially by alpha-smooth muscle actin (SMA)-expressing activated pancreatic stellate cells (PSCs). This study aimed to investigate the significance of alpha-SMA expression in PDAC and the correlation between alpha-SMA mRNA levels and the patient prognosis. METHODS: We obtained formalin-fixed, paraffin-embedded tissue samples from 109 patients with PDAC, who underwent pancreatectomy at our institution from 1992 to 2007. We measured alpha-SMA mRNA levels by quantitative real-time reverse transcription-polymerase chain reaction and investigated the association of alpha-SMA mRNA expression with clinicopathologic parameters and survival time. We also assessed the influence of activated PSCs on malignant behaviors of pancreatic cancer cells using in vitro experiments. RESULTS: alpha-SMA immunoreactivity was detected exclusively in the stroma of PDAC. The group with high alpha-SMA expression showed a significantly shorter survival, as shown by univariate analysis (P = 0.005) and multivariate analysis (P < 0.0001). alpha-SMA-expressing activated PSCs enhanced the invasiveness, proliferation, and colony formation of pancreatic cancer cells. CONCLUSIONS: Quantitative analysis of alpha-SMA mRNA expression using formalin-fixed, paraffin-embedded tissue samples was useful to predict the prognosis of patients with PDAC. Activated PSCs may regulate the malignant behavior of pancreatic cancer cells.

Gene expression levels as predictive markers of outcome in pancreatic cancer after gemcitabine-based adjuvant chemotherapy.

BACKGROUND AND AIMS: The standard palliative chemotherapy for pancreatic ductal adenocarcinoma (PDAC) is gemcitabine-based chemotherapy; however, PDAC still presents a major therapeutic challenge. The aims of this study were to investigate the expression pattern of genes involved in gemcitabine sensitivity in resected PDAC tissues and to determine correlations of gene expression with treatment outcome. MATERIALS AND METHODS: We obtained formalin-fixed paraffin-embedded (FFPE) tissue samples from 70 patients with PDAC. Of the 70 patients, 40 received gemcitabine-based adjuvant chemotherapy (AC). We measured hENT1, dCK, CDA, RRM1, and RRM2 messenger RNA (mRNA) levels by quantitative real-time reverse transcription-polymerase chain reaction and determined the combined score (GEM score), based on the expression levels of hENT1, dCK, RRM1, and RRM2, to investigate the association with survival time. By determining the expression levels of these genes in endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) cytologic specimens, we investigated the feasibility of individualized chemotherapy. RESULTS: High dCK (P = .0067), low RRM2 (P = .003), and high GEM score (P = .0003) groups had a significantly longer disease-free survival in the gemcitabine-treated group. A low GEM score (<2) was an independent predictive marker for poor outcome to gemcitabine-based AC as shown by multivariate analysis (P = .0081). Altered expression levels of these genes were distinguishable in microdissected neoplastic cells from EUS-FNA cytologic specimens. CONCLUSIONS: Quantitative analyses of hENT1, dCK, RRM1, and RRM2 mRNA levels using FFPE tissue samples and microdissected neoplastic cells from EUS-FNA cytologic specimens may be useful in predicting the gemcitabine sensitivity of patients with PDAC.

LMO2 is a novel predictive marker for a better prognosis in pancreatic cancer.

PURPOSE: LIM domain only 2 (LMO2) has been identified as a novel oncogene associated with carcinogenesis and better prognosis in several malignant tumors. We investigate the involvement of LMO2 in pancreatic cancer. EXPERIMENTAL DESIGN: We evaluated LMO2 expression in cultured cells, bulk tissues, and microdissected cells from pancreatic cancers by quantitative reverse transcription-polymerase chain reaction and immunohistochemistry. RESULTS: Of 164 pancreatic cancers, 98 (60%) were positive for LMO2 expression. LMO2 was more frequently detected in high-grade pancreatic intraepithelial neoplasia (PanIN) lesions (PanIN-2 and -3) than in low-grade PanIN lesions (PanIN-1A and -1B; P < .001) and was not detected in normal pancreatic ductal epithelium. The LMO2 messenger RNA levels were significantly higher in invasive ductal carcinoma cells than in normal pancreatic cells as evaluated by quantitative reverse transcription-polymerase chain reaction analyses of microdissected cells (P = .036). We also found higher incidence of LMO2 expression in histologic grade G1/G2 cancers than in grade G3 cancers (P < .001). The median survival time of LMO2-positive patients was significantly longer than that of LMO2-negative patients (P < .001), and multivariate analyses revealed that high LMO2 expression was an independent predictor of longer survival (risk ratio, 0.432, P < .001). Even among patients with a positive operative margin, LMO2-positive patients had a significant survival benefit compared with LMO2-negative patients. We further performed a large cohort study (n = 113) to examine the LMO2 messenger RNA levels in formalin-fixed paraffin-embedded samples and found similar results. CONCLUSIONS: LMO2 is a promising marker for predicting a better prognosis in pancreatic cancer.