Long-term survival and prognostic indicators in small (<or=2 cm) pancreatic cancer

Artificial Intelligence and Early Detection of Pancreatic Cancer: 2020 Summative Review

ABSTRACT

Despite considerable research efforts, pancreatic cancer is associated with a dire prognosis and a 5-year survival rate of only 10%. Early symptoms of the disease are mostly nonspecific. The premise of improved survival through early detection is that more individuals will benefit from potentially curative treatment. Artificial intelligence (AI) methodology has emerged as a successful tool for risk stratification and identification in general health care. In response to the maturity of AI, Kenner Family Research Fund conducted the 2020 AI and Early Detection of Pancreatic Cancer Virtual Summit (www.pdac-virtualsummit.org) in conjunction with the American Pancreatic Association, with a focus on the potential of AI to advance early detection efforts in this disease. This comprehensive presummit article was prepared based on information provided by each of the interdisciplinary participants on one of the 5 following topics: Progress, Problems, and Prospects for Early Detection; AI and Machine Learning; AI and Pancreatic Cancer-Current Efforts; Collaborative Opportunities; and Moving Forward-Reflections from Government, Industry, and Advocacy. The outcome from the robust Summit conversations, to be presented in a future white paper, indicate that significant progress must be the result of strategic collaboration among investigators and institutions from multidisciplinary backgrounds, supported by committed funders.

Systemic Proteome Alterations Linked to Early Stage Pancreatic Cancer in Diabetic Patients

BACKGROUND

Diabetes is a risk factor associated with pancreatic ductal adenocarcinoma (PDAC), and new adult-onset diabetes can be an early sign of pancreatic malignancy. Development of blood-based biomarkers to identify diabetic patients who warrant imaging tests for cancer detection may represent a realistic approach to facilitate earlier diagnosis of PDAC in a risk population.

METHODS

A spectral library-based proteomic platform was applied to interrogate biomarker candidates in plasma samples from clinically well-defined diabetic cohorts with and without PDAC. Random forest algorithm was used for prediction model building and receiver operating characteristic (ROC) curve analysis was applied to evaluate the prediction probability of potential biomarker panels.

RESULTS

Several biomarker panels were cross-validated in the context of detection of PDAC within a diabetic background. In combination with carbohydrate antigen 19-9 (CA19-9), the panel, which consisted of apolipoprotein A-IV (APOA4), monocyte differentiation antigen CD14 (CD14), tetranectin (CLEC3B), gelsolin (GSN), histidine-rich glycoprotein (HRG), inter-alpha-trypsin inhibitor heavy chain H3 (ITIH3), plasma kallikrein (KLKB1), leucine-rich alpha-2-glycoprotein (LRG1), pigment epithelium-derived factor (SERPINF1), plasma protease C1 inhibitor (SERPING1), and metalloproteinase inhibitor 1 (TIMP1), demonstrated an area under curve (AUC) of 0.85 and a two-fold increase in detection accuracy compared to CA19-9 alone. The study further evaluated the correlations of protein candidates and their influences on the performance of biomarker panels.

CONCLUSIONS

Proteomics-based multiplex biomarker panels improved the detection accuracy for diagnosis of early stage PDAC in diabetic patients.

Identification of Cystic Lesions by Secondary Screening of Familial Pancreatic Cancer (FPC) Kindreds Is Not Associated with the Stratified Risk of Cancer

OBJECTIVES

Intraductal papillary mucinous neoplasms (IPMNs) are associated with risk of pancreatic ductal adenocarcinoma (PDAC). It is unclear if an IPMN in individuals at high risk of PDAC should be considered as a positive screening result or as an incidental finding. Stratified familial pancreatic cancer (FPC) populations were used to determine if IPMN risk is linked to familial risk of PDAC.

METHODS

This is a cohort study of 321 individuals from 258 kindreds suspected of being FPC and undergoing secondary screening for PDAC through the European Registry of Hereditary Pancreatitis and Familial Pancreatic Cancer (EUROPAC). Computerised tomography, endoscopic ultrasound of the pancreas and magnetic resonance imaging were used. The risk of being a carrier of a dominant mutation predisposing to pancreatic cancer was stratified into three even categories (low, medium and high) based on: Mendelian probability, the number of PDAC cases and the number of people at risk in a kindred.

RESULTS

There was a median (interquartile range (IQR)) follow-up of 2 (0-5) years and a median (IQR) number of investigations per participant of 4 (2-6). One PDAC, two low-grade neuroendocrine tumours and 41 cystic lesions were identified, including 23 IPMN (22 branch-duct (BD)). The PDAC case occurred in the top 10% of risk, and the BD-IPMN cases were evenly distributed amongst risk categories: low (6/107), medium (10/107) and high (6/107) (P = 0.63).

CONCLUSIONS

The risk of finding BD-IPMN was independent of genetic predisposition and so they should be managed according to guidelines for incidental finding of IPMN.

Prognostic stratification of resected pancreatic ductal adenocarcinoma: Past, present, and future

Pancreatic ductal adenocarcinoma (PDAC) is the digestive cancer with the poorest prognosis, with a 5-year overall survival rate of 7%. Complete surgical resection followed by adjuvant chemotherapy is the only treatment with curative intent. However, many patients with an apparently localized disease who may undergo primary tumor resection already have micro-metastatic disease and will promptly develop metastases. Considering the significant rate of morbidity and mortality upon pancreatic surgery, the pre-operative identification of patients with an aggressive disease is therefore a major clinical issue. Although tumor size, differentiation, margins, and lymph node invasion are the main "classical" prognostic factors, they are not sufficient to fully predict early disease recurrence. In the last decade, multi-omics high-throughput analyses have provided a new insight into PDAC biology and have led to the description of multiple molecular subtypes, with a significant prognostic value for most of them, but that have not yet been transposed to routine clinical practice, mainly due to poor availability of tumor tissue material prior to surgical resection. In this review, we provide an overview of the current status of clinico-pathological and molecular biomarkers (tumor and blood) to predict early recurrence, and their implications for clinical practice and future research development.

Histologic Tumor Grade and Preoperative Bilary Drainage are the Unique Independent Prognostic Factors of Survival in Pancreatic Ductal Adenocarcinoma Patients After Pancreaticoduodenectomy

BACKGROUND AND AIM

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal types of cancer; most patients die during the first 6 months after diagnosis. With a 5% 5-year survival rate, is the fourth leading cause of cancer death in developed countries. In this regard, several clinical, histopathologic and biological characteristics of the disease favoring long-term survival after pancreaticoduodenectomy have been reported to be significant prognostic factors. Despite the availability of this information, there is no consensus about the different prognostic factors reported in the literature, probably due to variations in patient selection, methods, and sample size studied. The aim of this study was to identify the clinical and pathologic features associated to prognosis of the disease after pancreaticoduodenectomy.

MATERIALS AND METHODS

The clinical and pathologic data from 78 patients who underwent a potentially curative resection for PDAC at our institution between 2003 and 2014 were analyzed retrospectively.

RESULTS

Overall, high-grade PDAC cases showed larger tumor size (P=0.009) and a higher frequency of deaths in association with a nonsignificantly shortened patient overall survival (median of 12.5 vs. 21.7 mo; P=0.065) as compared with low-grade PDAC patients. High histologic grade (P=0.013), preoperative drainage on the main bile duct (P=0.014) and absence of adjuvant therapy (P=0.035) were associated with a significantly poorer outcome. Overall survival multivariate analysis showed histologic grade (P=0.019) and bile duct preoperative drainage (P=0.016) as the sole independent variables predicting an adverse outcome.

CONCLUSIONS

Our results indicate that histologic tumor grade and preoperative biliary drainage are the only significant independent prognostic factors in PDAC patients after pancreatectomy.

Aggressive venous invasion in the area of carcinoma correlates with liver metastasis as an index of metastasis for invasive ductal carcinoma of the pancreas

BACKGROUND

Invasive ductal carcinoma of the pancreas (IDCP) predominantly causes death through liver metastasis (LM) and peritoneal dissemination with local recurrence. However, whether its venous invasion is from the enlarged carcinoma accompanied by tumor growth, or from a distinct carcinoma group, for which venous invasion is facilitated by proximity to the origin, is unclear. We analyzed the correlation between LM and venous invasion in patients with small IDCP tumors.

METHODS

Of 388 patients who were diagnosed with IDCP, 20 (5.2%) had tumors with diameters <2 cm. The follow-up period of the 20 patients with smaller tumors was 1-24 years.

RESULTS

The small-tumor group (n = 20) included 11 men and 9 women, aged 51-80 years. Five died of liver metastasis (LM group, n = 5) and 15 patients (non-LM group, n = 15) were either alive without recurrence (n = 11) or died of peritonitis carcinomatosa following local recurrence, subarachnoid hemorrhage, primary lung cancer, or old age (n = 1 for each cause of death). The LM and non-LM groups did not significantly differ in numbers of venous invasion by the carcinoma in IDCP and non-IDCP area of the pancreas. However, median numbers of invaded veins in the area of IDCP and percentage of invaded vein/total number of vein in IDCP area were significantly higher in the LM group.

CONCLUSION

Among patients with small IDCP tumors, the LM group showed more aggressive venous invasion by IDPC. Patients in whom ≥60% of veins were invaded by IDCP should be prepared for LM.

Relationship between tumour size and outcome in pancreatic ductal adenocarcinoma

BACKGROUND

The size of pancreatic ductal adenocarcinoma (PDAC) at diagnosis is an indicator of outcome. Previous studies have focused mostly on patients with resectable disease. The aim of this study was to investigate the relationship between tumour size and risk of metastasis and death in a large PDAC cohort, including all stages.

METHODS

Patients diagnosed with PDAC between 1988 and 2013 were identified from the Surveillance, Epidemiology, and End Results (SEER) database. Tumour size was defined as the maximum dimension of the tumour as provided by the registry. Metastatic spread was assessed, and survival was calculated according to size of the primary tumour using the Kaplan-Meier method. Cox proportional regression modelling was used to adjust for known confounders.

RESULTS

Some 58 728 patients were included. There were 187 patients (0·3 per cent) with a tumour size of 0·5 cm or less, in whom the rate of distant metastasis was 30·6 per cent. The probability of tumour dissemination was associated with tumour size at the time of diagnosis. The association between survival and tumour size was linear for patients with localized tumours, but stochastic in patients with regional and distant stages. In patients with resected tumours, increasing tumour size was associated with worse tumour-specific survival, whereas size was not associated with survival in patients with unresected tumours. In the adjusted Cox regression analysis, the death rate increased by 4·1 per cent for each additional 1-cm increase in tumour size.

CONCLUSION

Pancreatic cancer has a high metastatic capacity even in small tumours. The prognostic impact of tumour size is restricted to patients with localized disease.

CT Imaging Biomarkers Predict Clinical Outcomes After Pancreatic Cancer Surgery

This study aimed to determine whether changes in contrast-enhanced computed tomography (CT) parameters could predict postsurgery overall and progression-free survival (PFS) in pancreatic cancer patients. Seventy-nine patients with a final pathological diagnosis of pancreatic adenocarcinoma were included in this study from June 2008 to August 2012. Dynamic contrast-enhanced (DCE) CT of tumors was obtained before curative-intent surgery. Absolute enhancement change (AEC) and relative enhancement change (REC) were evaluated on DCE-CT. PFS and overall survival (OS) were compared based on CT enhancement patterns. The markers of fibrogenic alpha-smooth muscle antigen (α-SMA) and periostin in tumor specimens were evaluated by immunohistochemical staining. The χ test was performed to determine whether CT enhancement patterns were associated with α-SMA-periostin expression levels (recorded as positive or negative). Lower REC (<0.9) was associated with shorter PFS (HR 0.51, 95% CI: 0.31-0.89) and OS (HR 0.44, 95% CI: 0.25-0.78). The α-SMA and periostin expression level were negatively correlated with REC (both P = 0). Among several CT enhancement parameters, REC was the best predictor of patient postsurgery survival. Low REC was associated with a short progression-free time and poor survival. The pathological studies suggested that REC might be a reflection of cancer fibrogenic potential.

Expression and Significances of MTSS1 in Pancreatic Cancer

Thus far, expression of metastasis suppressor 1 (MTSS1), its clinicopathologic and prognostic significances in pancreatic cancer (PC) remain unknown. Expression of MTSS1 was detected by Western blotting in PC cell lines, and by tissue microarray-based immunohistochemical staining in paired tumor and non-tumor samples from 242 patients with PC. Furthermore, the correlations between MTSS1 expression and clinicopathologic variables as well as overall survival were evaluated. In PC cell lines, MTSS1 was differentially expressed. In addition, MTSS1 expression was significantly lower in tumor than in non-tumor tissues (P < 0.001 in both McNemar and Mann-Whitney U tests). High tumoral expression of MTSS1 was closely associated with absence of lymph node metastasis (P = 0.023). Univariate analysis found that high MTSS1 expression in tumor tissues was a strong predictor of favorable overall survival in the whole cohort (P < 0.001). Besides, its impacts on prognosis were also observed in nine out of fourteen subgroups. Finally, MTSS1 expression was identified as an independent prognostic marker in the whole cohort (P = 0.031) as well as in six subgroups (P < 0.05), as shown by multivariate Cox regression test. Down-regulation of MTSS1 expression is evident in PC, and is associated with lymph node metastasis and poor prognosis.

Nuclear translocation of fibroblast growth factor receptor 3 and its significance in pancreatic cancer

Nuclear translocation of fibroblast growth factor receptor 3 (FGFR3) was previously observed in some kinds of cancer. However, whether the phenomenon occurs in pancreatic cancer (PC), a malignancy with very dismal prognosis, remains unknown. In the present study, FGFR3 expression was firstly detected by Western blot and immunohistochemical staining in specimens of PC. Then, its correlations with clinicopathologic features and patient survival were evaluated. It was shown that FGFR3 was highly expressed in all the nuclear extracts, but in only one out of four whole tissue lysates, of tumor tissues, in contrast to those of non-tumor ones. Using immunohistochemistry, nuclear expression of FGFR3 was found to mainly locate in tumor cells, and was significantly associated with N stage. Furthermore, high FGFR3 nuclear expression was revealed to be associated with poor overall and disease-free survival in univariate analysis. For overall survival in the whole cohort and disease-free survival in patients with curative resection, high nuclear expression of FGFR3 was significant or marginally significant in multivariate analysis. However, its cytoplasmic expression was not related to clinical, pathologic variables and prognosis. These data suggest that nuclear translocation of FGFR3 is frequent and carries clinicopathologic as well as prognostic significances in PC.

Clinical and pathological features of five-year survivors after pancreatectomy for pancreatic adenocarcinoma

BACKGROUND

Clinical factors determining short-term survival after pancreatectomy have been well studied, but factors predicting long-term survival with curative resection are poorly understood in pancreatic carcinoma. Our objective was to identify clinical and pathological features of five-year disease-free survivors after surgical resection of pancreatic adenocarcinoma.

METHODS

The clinical and pathological data from 147 patients who underwent a potentially curative resection for pancreatic adenocarcinoma at our institution between 1988 and 2012 were retrospectively analyzed.

RESULTS

Of 147 patients, 18 survived for more than five years after surgery without disease recurrence. A univariate analyses demonstrated that: two or fewer lymph node metastases (P=0.014), a preoperative serum carbohydrate antigen 19-9 (CA19-9) level of 40 U/mL or less (P=0.0018), an absence of intrapancreatic nerve invasion (P=0.028), and undergoing an R0 resection (P=0.011) were significantly associated with five-year survival. A logistic regression model identified the following independent cancer-related predictors of five-year survivors: having two or fewer lymph node metastases (odds ratio (OR): 6.02; 95% confidence interval (CI): 1.08 to 112.98; P=0.0385), a preoperative serum CA19-9 level of 40 U/mL or less (OR: 5.02; 95% CI: 1.68 to 16.48; P=0.0036), and undergoing an R0 resection (OR: 3.63; 95% CI: 1.12 to 14.28; P=0.0316).

CONCLUSIONS

We conclude that number of lymph node metastases being two or less, a preoperative serum CA19-9 level of 40 U/mL or less, and undergoing an R0 resection may be independent predictive factors to identify actual five-year survivors after pancreatectomy for pancreatic adenocarcinoma.

Survival effect of tumor size and extrapancreatic extension in surgically resected pancreatic cancer: proposal for improved T classification

The T classification for pancreatic cancer of the American Joint Committee on Cancer may be inaccurate owing to lack of consideration of tumor size in cases of extension beyond the pancreas. To examine the accuracy of American Joint Committee on Cancer staging and to determine the prognostic implication of combined tumor size and extrapancreatic extension, 6145 cases of pancreatic ductal adenocarcinomas from the Surveillance, Epidemiology, and End Results database were categorized according to tumor size and extension as follows: group 1 (G1, ≤2 cm and limited to the pancreas), G2 (>2 cm and limited to the pancreas), G3 (≤2 cm with extrapancreatic extension), and G4 (>2 cm with extrapancreatic extension). The median survival of G1, G2, G3, and G4 were 23, 15, 19, and 14 months, respectively (P < .001), and the survival time in G3 was closer to that of G2 than G4. To test the classification system for accuracy of prognosis, G3 was merged with G2. The survival discrimination of this new grouping was greater (overall comparison, P < .001; G1 versus G2 + G3, P < .001; G2 + G3 versus G4, P < .001; χ(2) = 92.043) than that of the current T-classification scheme (overall comparison, P < .001; G1 versus G2, P < .001; G2 versus G3 + G4, P = .048; χ(2) = 60.424). To better discriminate survival, patients with a tumor less than or equal to 2 cm extending beyond the pancreas should be downstaged from the current class T3 to class T2.

Pancreatic head carcinoma and vascular endothelial growth factor (VEGF-A) concentration in portal blood: its association with cancer grade, tumor size and probably poor prognosis

INTRODUCTION

Vascular endothelial growth factor (VEGF) is overexpressed in pancreatic cancer. Although VEGF has been shown to be a probable marker for poor prognosis, the VEGF concentration in portal blood has not yet been clinically reported in pancreatic ductal adenocarcinoma (PDAC). The aim of the study was to measure VEGF-A portal blood concentration in patients with PDAC and to evaluate its performance as a prognostic marker.

MATERIAL AND METHODS

Thirty-six consecutive patients out of 57 operated on for pancreatic head lesion with pathologically verified diagnosis of PDAC were enrolled in this study. We evaluated the VEGF concentration in portal blood samples obtained intraoperatively and associated their values with tumor size, stage, grade and survival.

RESULTS

The portal VEGF-A concentration was associated with tumor grade (G1: 80.52 ±43.05 vs. G2: 185.39 ±134.98, p = 0.006, G2: 185.39 ±134.98 vs. G3: 356.46 ±229.12, p = 0.08), and there was a positive correlation with tumor size (r = 0.42, p < 0.05). In the multivariate regression analysis high levels of VEGF-A were not correlated with poor survival (HR = 5.22, 95% CI = -0.6457 to 3.9513, p = 0.19).

CONCLUSIONS

The portal VEGF-A concentration is associated with tumor grade and size. The correlation of portal VEGF-A with poor survival is not clear and needs further investigation.

In vivo SPECT imaging with 111In-DOTA-c(RGDfK) to detect early pancreatic cancer in a hamster pancreatic carcinogenesis model

Early detection of pancreatic cancer is key to overcoming its poor prognosis. α(v)β(3)-integrin is often overexpressed in pancreatic tumor cells, whereas it is scarcely expressed in normal pancreatic cells. In this study, we investigated the usefulness of SPECT imaging with (111)In-1,4,7,10-tetraazacylododecane-N,N',N″,N'''-tetraacetic acid-cyclo-(Arg-Gly-Asp-d-Phe-Lys) [(111)In-DOTA-c(RGDfK)], an imaging probe of α(v)β(3)-integrin, for the early detection of pancreatic cancer in a hamster pancreatic carcinogenesis model.

METHODS

Hamsters were subcutaneously injected with the pancreatic duct carcinogen N-nitrosobis(2-oxopropyl)amine to induce pancreatic cancer. N-nitrosobis(2-oxopropyl)amine-treated hamsters underwent in vivo SPECT with (111)In-DOTA-c(RGDfK). After imaging, the tumor-to-normal pancreatic tissue radioactivity ratios in excised pancreatic samples were measured with autoradiography (ARG) and compared with the immunopathologic findings for α(v)β(3)-integrin. In a mouse model in which inflammation was induced with turpentine, the uptake of (111)In-DOTA-c(RGDfK) in inflammatory regions was evaluated with ARG and compared with that of (18)F-FDG.

RESULTS

(111)In-DOTA-c(RGDfK) was clearly visualized in pancreatic cancer lesions as small as 3 mm in diameter. ARG analysis revealed high tumor-to-normal pancreatic tissue radioactivity ratios (4.6 ± 1.0 [mean ± SD] in adenocarcinoma and 3.3 ± 1.4 in atypical hyperplasia). The uptake of (111)In-DOTA-c(RGDfK) strongly correlated with α(v)β(3)-integrin expression. In the inflammatory model, inflammation-to-muscle ratios for (18)F-FDG and (111)In-DOTA-c(RGDfK) were 8.37 ± 4.37 and 1.98 ± 0.60, respectively. These results imply that (111)In-DOTA-c(RGDfK) has a lower rate of false-positive tumor detection than (18)F-FDG.

CONCLUSION

Our findings suggest that SPECT with (111)In-DOTA-c(RGDfK) has great potential for the early and accurate detection of pancreatic cancer.

Protein kinase Ciota is required for pancreatic cancer cell transformed growth and tumorigenesis

Pancreatic cancer is the fourth leading cause of cancer deaths in the United States, with an overall 5-year survival rate of <5%. Pancreatic ductal adenocarcinoma (PDAC), the most common form of pancreatic cancer, is highly resistant to conventional chemotherapies, underscoring the critical need for new molecular targets for pancreatic cancer chemotherapy. The KRAS proto-oncogene is mutated in >90% of PDAC. Protein kinase Ciota (PKCiota) is required for the oncogenic Ras-mediated transformed growth of lung cancer and intestinal epithelial cells. However, little is known about the role of PKCiota in pancreatic cancer. In this study, we evaluated the expression of PKCiota in human pancreatic cancer and the requirement for PKCiota for the transformed growth and tumorigenicity of PDAC cells. We find that PKCiota is significantly overexpressed in human pancreatic cancer, and high PKCiota expression correlates with poor patient survival. Inhibition of PKCiota expression blocks PDAC cell transformed growth in vitro and tumorigenicity in vivo. Inhibition of PKCiota expression in pancreatic tumors also significantly reduces tumor angiogenesis and metastasis. Analysis of downstream PKCiota effectors implicates the Rac1-MEK/ERK1/2 signaling axis in PKCiota-mediated transformed growth and cellular invasion. Taken together, our data show a required role for PKCiota in the transformed growth of pancreatic cancer cells and reveal a novel role for PKCiota in pancreatic cancer cell metastasis and angiogenesis in vivo. Our results strongly indicate that PKCiota will be an effective target for pancreatic cancer therapy.

SMAD4 gene mutations are associated with poor prognosis in pancreatic cancer

PURPOSE

Recently, the majority of protein coding genes were sequenced in a collection of pancreatic cancers, providing an unprecedented opportunity to identify genetic markers of prognosis for patients with adenocarcinoma of the pancreas.

EXPERIMENTAL DESIGN

We previously sequenced more than 750 million base pairs of DNA from 23,219 transcripts in a series of 24 adenocarcinomas of the pancreas. In addition, 39 genes that were mutated in more than one of these 24 cancers were sequenced in a separate panel of 90 well-characterized adenocarcinomas of the pancreas. Of these 114 patients, 89 underwent pancreaticoduodenectomy, and the somatic mutations in these cancers were correlated with patient outcome.

RESULTS

When adjusted for age, lymph node status, margin status, and tumor size, SMAD4 gene inactivation was significantly associated with shorter overall survival (hazard ratio, 1.92; 95% confidence interval, 1.20-3.05; P = 0.006). Patients with SMAD4 gene inactivation survived a median of 11.5 months, compared with 14.2 months for patients without SMAD4 inactivation. By contrast, mutations in CDKN2A or TP53 or the presence of multiple (> or =4) mutations or homozygous deletions among the 39 most frequently mutated genes were not associated with survival.

CONCLUSIONS

SMAD4 gene inactivation is associated with poorer prognosis in patients with surgically resected adenocarcinoma of the pancreas.

LIM only 4 is overexpressed in late stage pancreas cancer

Background

LIM-only 4 (LMO4), a member of the LIM-only (LMO) subfamily of LIM domain-containing transcription factors, was initially reported to have an oncogenic role in breast cancer. We hypothesized that LMO4 may be related to pancreatic carcinogenesis as it is in breast carcinogenesis. If so, this could result in a better understanding of tumorigenesis in pancreatic cancer.

Methods

We measured LMO4 mRNA levels in cultured cells, pancreatic bulk tissues and microdissected target cells (normal ductal cells; pancreatic intraepithelial neoplasia-1B [PanIN-1B] cells; PanIN-2 cells; invasive ductal carcinoma [IDC] cells; intraductal papillary-mucinous adenoma [IPMA] cells; IPM borderline [IPMB] cells; and invasive and non-invasive IPM carcinoma [IPMC]) by quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR).

Results

9 of 14 pancreatic cancer cell lines expressed higher levels of LMO4 mRNA than did the human pancreatic ductal epithelial cell line (HPDE). In bulk tissue samples, expression of LMO4 was higher in pancreatic carcinoma than in intraductal papillary-mucinous neoplasm (IPMN) or non-neoplastic pancreas (p < 0.0001 for both). We carried out microdissection-based analyses. IDC cells expressed significantly higher levels of LMO4 than did normal ductal epithelia or PanIN-1B cells (p < 0.001 for both) or PanIN-2 cells (p = 0.014). IPMC cells expressed significantly higher levels of LMO4 than did normal ductal epithelia (p < 0.001), IPMA (p < 0.001) and IPMB cells (p = 0.003).

Conclusion

Pancreatic carcinomas (both IDC and IPMC) expressed significantly higher levels of LMO4 mRNA than did normal ductal epithelia, PanIN-1B, PanIN-2, IPMA and IPMB. These results suggested that LMO4 is overexpressed at late stages in carcinogenesis of pancreatic cancer.