Early Pancreatic Ductal Adenocarcinoma Research Articles

Thrombospondin-2 as a diagnostic biomarker for distal cholangiocarcinoma and pancreatic ductal adenocarcinoma

PurposeDistal cholangiocarcinoma and pancreatic ductal adenocarcinoma are malignancies with poor prognoses that can be difficult to distinguish preoperatively. Thrombospondin-2 has been proposed as a novel diagnostic biomarker for early pancreatic ductal adenocarcinoma. The aim of the present study was to evaluate thrombospondin-2 as a diagnostic and prognostic biomarker in combination with current biomarker CA 19-9 for distal cholangiocarcinoma and pancreatic ductal adenocarcinoma.MethodsThrombospondin-2 was measured in prospectively collected serum samples from patients who underwent surgery with a histopathological diagnosis of distal cholangiocarcinoma (N = 51), pancreatic ductal adenocarcinoma (N = 52) and benign pancreatic diseases (N = 27) as well as healthy blood donors (N = 52) using an enzyme-linked immunosorbent assay.ResultsThrombospondin-2 levels (ng/ml) were similar in distal cholangiocarcinoma 55 (41–77) and pancreatic ductal adenocarcinoma 48 (35–80) (P = 0.221). Thrombospondin-2 + CA 19-9 had an area under the curve of 0.92 (95% CI 0.88–0.97) in differentiating distal cholangiocarcinoma and pancreatic ductal adenocarcinoma from healthy donors which was superior to CA 19-9 alone (P < 0.001). The diagnostic value of adding thrombospondin-2 to CA 19-9 was larger in early disease stages. Thrombospondin-2 did not provide additional value to CA 19-9 in differentiating the benign disease group; however, heterogeneity was notable in the benign cohort. Three of five patients with autoimmune pancreatitis patients had greatly elevated thrombospondin-2 levels. Thrombospondin-2 levels had no correlation with prognoses.ConclusionsSerum thrombospondin-2 in combination with CA 19-9 has potential as a biomarker for distal cholangiocarcinoma and pancreatic cancer.

Abstract 2884: Wnt11 dictates the patterns and latency of pulmonary micrometastatic disease in pancreatic cancer

Abstract Introduction: Pancreatic ductal adenocarcinoma (PDAC) is a systemic disease characterized by early metastasis involving numerous pro-metastatic pathways. However, dominant drivers of early PDAC cell dissemination and metastasis remain poorly defined. The non-canonical Wnt-PCP pathway has been shown to promote cancer cell motility predominantly through Wnt ligand-mediated activation of frizzled receptors that result in cytoskeleton rearrangements. As one of these Wnt ligands, Wnt11, has been previously implicated in metastasis, we tested if Wnt11 significantly affects PDAC metastasis in vivo. Methods: LSL-KrasG12D/+, p53wmR172H/+, and p48-Cre alleles were crossed with and without a conditional Wnt11fl allele to generate cohorts of Wnt11 wildtype and knockout mice in the well-established KPC PDAC mouse model (KPwmC, n = 22; KPwmC-Wnt11fl/fl, n = 37). Both cohorts included mice with a conditional LSL-ROSA26-tdTomato reporter to identify and enumerate distant metastases. Mice were sacrificed when euthanasia criteria were met, and metastases were visualized via full organ fluorescence microscopy to identify tdTomato(+) signals. Liver and lung metastases were enumerated and measured through automated color range selection and manual counting. Metastases were classified by diameter as micrometastases (&amp;lt;100 uM), intermediate metastases (100-499 uM), or macrometastases (≥500 uM). Results: Primary pancreatic tumors from KPwmC and KPwmC-Wnt11fl/fl mice were similar in histologic appearance without gross alterations in peritumoral stroma. There were no differences in median overall survival between KPwmC and KPwmC-Wnt11fl/fl mice (185 vs. 193 days, p = 0.92). Pulmonary micrometastatic disease in mice &amp;lt;170 days at euthanasia was significantly lower in KPwmC-Wnt11fl/fl mice relative to KPwmC mice (mean number of metastases 88.8 vs. 1780, respectively; p = 0.009). Moreover, while pulmonary metastases in KPwmC mice were diffuse and miliary, the lungs of KPwmC-Wnt11fl/fl mice contained only scant, scattered metastases. No significant differences were observed in the mean number of intermediate-sized (0.5 vs. 27.4, p = 0.17) or macrometastases (0.0 vs 1.6, p = 0.13). Differences in metastatic tumor size or burden were not observed in liver metastases between each cohort. Conclusions: Wnt11 affects the pattern and latency of early metastasis to the lung but does not affect any stage of hepatic metastasis. The role of Wnt11 in PDAC metastasis is context dependent and may be related to factors inherent in the pre-metastatic niche. Citation Format: Eileen C. Donovan, Bingbing Dai, Jenying Deng, Christian M. Siangco, Xinqun Li, Erika Y. Faraoni, Sylvia M. Evans, Michael P. Kim. Wnt11 dictates the patterns and latency of pulmonary micrometastatic disease in pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2884.

PGC1α-Mediated Metabolic Reprogramming Drives the Stemness of Pancreatic Precursor Lesions.

Metabolic reprogramming and cancer stem cells drive the aggressiveness of pancreatic ductal adenocarcinoma (PDAC). However, the metabolic and stemness programs of pancreatic precursor lesions (PPL), considered early PDAC development events, have not been thoroughly explored. Meta-analyses using gene expression profile data from NCBI Gene Expression Omnibus and IHC on tissue microarrays (TMA) were performed. The following animal and cellular models were used: cerulean-induced KrasG12D; Pdx1 Cre (KC) acinar-to-ductal metaplasia (ADM) mice, KrasG12D; Smad4Loss; Pdx-1 Cre (KCSmad4-) intraductal papillary mucinous neoplasm (IPMN) mice, LGKC1 cell line derived from the doxycycline-inducible Gnas IPMN model, and human IPMN organoids. Flow cytometry, Seahorse extracellular flux analyzer, qRT-PCR, and sphere assay were used to analyze metabolic and stemness features. SR18292 was used to inhibit PGC1α, and short hairpin RNA was used to knockdown (KD) PGC1α. The meta-analysis revealed a significant upregulation of specific stemness genes in ADM-mediated pancreatic intraepithelial neoplasms (PanIN) and IPMN. Meta- and TMA analyses followed by in vitro and in vivo validation revealed that ADM/PanIN exhibit increased PGC1α and oxidative phosphorylation (OXPhos) but reduced CPT1A. IPMN showed elevated PGC1α, fatty acid β-oxidation (FAO) gene expression, and FAO-OXPhos. PGC1α was co-overexpressed with its coactivator NRF1 in ADM/PanINs and with PPARγ in IPMN. PGC1α KD or SR18292 inhibited the specific metabolic and stemness features of PPLs and repressed IPMN organoid growth. ADM/PanINs and IPMNs show specific stemness signatures with unique metabolisms. Inhibition of PGC1α using SR18292 diminishes the specific stemness by targeting FAO-independent and FAO-dependent OXPhos of ADM/PanINs and IPMNs, respectively.

REG3A/REG3B promotes acinar to ductal metaplasia through binding to EXTL3 and activating the RAS-RAF-MEK-ERK signaling pathway

Persistent acinar to ductal metaplasia (ADM) is a recently recognized precursor of pancreatic ductal adenocarcinoma (PDAC). Here we show that the ADM area of human pancreas tissue adjacent to PDAC expresses significantly higher levels of regenerating protein 3A (REG3A). Exogenous REG3A and its mouse homolog REG3B induce ADM in the 3D culture of primary human and murine acinar cells, respectively. Both Reg3b transgenic mice and REG3B-treated mice with caerulein-induced pancreatitis develop and sustain ADM. Two out of five Reg3b transgenic mice with caerulein-induced pancreatitis show progression from ADM to pancreatic intraepithelial neoplasia (PanIN). Both in vitro and in vivo ADM models demonstrate activation of the RAS-RAF-MEK-ERK signaling pathway. Exostosin-like glycosyltransferase 3 (EXTL3) functions as the receptor for REG3B and mediates the activation of downstream signaling proteins. Our data indicates that REG3A/REG3B promotes persistent ADM through binding to EXTL3 and activating the RAS-RAF-MEK-ERK signaling pathway. Targeting REG3A/REG3B, its receptor EXTL3, or other downstream molecules could interrupt the ADM process and prevent early PDAC carcinogenesis.

Whether early stage pancreatic ductal adenocarcinoma patients could benefit from the post-operation chemotherapy regimens: a SEER-based propensity score matching study.

To investigate whether chemotherapy could prolong the postoperative survival time in patients with early stages pancreatic ductal adenocarcinoma (PDAC). A total of 5280 stage ⅠA -ⅡB PDAC patients diagnosed from 2010 to 2015 were selected from surveillance，epidemiology，and end results (SEER) database. Propensity score matching (PSM) analysis was adopted to reduce the baseline differences between the groups. Univariate survival analysis was conducted with the Kaplan-Meier method. Multivariate survival analysis was performed with the Cox proportional hazards model. Univariate and multivariate survival analyses showed that age, differentiation, stage, chemotherapy were independent risk factors for the survival of PDAC patients. After PSM, it is found that adjuvant chemotherapy could prolong the median overall survival time (mOS) for stage ⅠB, ⅡA and ⅡB patients. However, for stage ⅠA patients, there were no significant differences in 3-year survival rate and mOS between patients with chemotherapy (=283) and without chemotherapy (=229) (57.4% vs 55.6%, vs all >0.05). Further analyses show that among 101 patients with well differentiated PDAC and 294 patients with moderately differentiated PDAC, there were no significant differences in survival rate and mOS between patients with and without chemotherapy (all >0.05). Among 117 patients with low-differentiated + undifferentiated PDAC, 3-year survival rate and mOS in patients with chemotherapy were significantly better than those without chemotherapy (48.5% vs 34.1%, vs all <0.05). Chemotherapy regimen used currently is not beneficial for patients with moderately and well differentiated stage ⅠA PDAC, but it is an independent prognostic factor for low-differentiated + undifferentiated PDAC patients.

Body composition measurements and overall survival in patients with resectable pancreatic adenocarcinoma receiving neoadjuvant chemotherapy: Analysis from SWOG S1505.

4131 Background: Sarcopenia and sarcopenic obesity have been associated with overall survival (OS) in patients (pts) with borderline resectable and advanced pancreatic ductal adenocarcinoma (PDA), but little is known about the effect of body composition on OS in pts with resectable PDA. We examined the relationship between skeletal muscle and adipose tissue measurements on baseline computed tomography (CT) and OS of pts with resectable PDA in a secondary analysis of SWOG S1505 (NCT02562716). Methods: SWOG S1505 enrolled pts with resectable PDA who were randomized to receive neoadjuvant FOLFIRINOX or gemcitabine-nab paclitaxel, followed by surgical resection. Baseline axial CT images at the L3 level were analyzed with externally validated software and measurements were recorded for skeletal muscle area (SMA), density (SMD) and index (SMI); visceral adipose tissue area (VATA) and density (VATD); and subcutaneous adipose tissue area (SATA) and density (SATD). Sarcopenia was defined as SMI &lt; 52 cm2/m2 for men and &lt; 39 cm2/m2 for women; sarcopenic obesity was defined as sarcopenia and a body mass index (BMI) &gt;30 kg/m2. The relationships between CT metrics and OS were analyzed using Cox regression models, with 95% CI. Statistical significance was defined as p &lt; 0.05. Results: Of 98 pts with available baseline abdominal CT, 8 were excluded for scan quality, resulting in 90 evaluable cases: 51 men (57%), 39 women (43%); mean age, 63.2 years, SD 8.5; mean BMI, 29.3 kg/m2, SD 6.4; 80 (89%) White, 6 (7%) Black, and 4 (4%) unknown. Sarcopenia was present in 32 (36%) and sarcopenic obesity in 10 (11%) patients. Univariable analyses for the variables of interest indicated VATA (HR 1.24; 0.97-1.60; p = 0.09) and SMD (HR 0.75; 0.57-0.98; p = 0.04) were associated with OS. Analyses adjusted for sex, race, age, BMI, performance score, contrast use, sarcopenia, and sarcopenic obesity showed VATA was associated with OS (HR 1.58; 1.0-2.51; p = 0.05). No significant difference in median OS was observed between pts with vs. without sarcopenia (OS 23.6 [19.3-NA] vs. 27.9 months [18.6-NA], respectively). Pts with vs. without sarcopenic obesity had lower median OS: 18.6 (14.7-NA) vs. 25.1 (10.5-46.0) months, respectively, but this difference was not statistically significant (HR 1.90, 95%CI 0.81-4.47, p = 0.14). Conclusions: This is one of the first studies to systematically evaluate body composition parameters in a prospective trial of patients with resectable PDA who received neoadjuvant chemotherapy. We found that visceral fat (VATA) is a prognostic marker in this population, but that sarcopenia may not be predictive in early PDA. Further studies to define the impact of longitudinal changes in body composition on individual outcomes may provide greater precision in predicting OS for subsets of pts with pancreatic cancer. Clinical trial information: NCT02562716.

Prediction of early recurrence of pancreatic ductal adenocarcinoma after resection.

BackgroundEven after curative resection, pancreatic ductal adenocarcinoma (PDAC) patients suffer a high rate of recurrence. There is an unmet need to predict which patients will experience early recurrence after resection in order to adjust treatment strategies.MethodsData of patients with resectable PDAC undergoing surgical resection between January 2005 and September 2018 were reviewed to stratify for early recurrence defined as occurring within 6 months of resection. Preoperative data including demographics, tumor markers, blood immune-inflammatory factors and clinicopathological data were examined. We employed Elastic Net, a sparse modeling method, to construct models predicting early recurrence using these multiple preoperative factors. As a result, seven preoperative factors were selected: age, duke pancreatic monoclonal antigen type 2 value, neutrophil:lymphocyte ratio, systemic immune-inflammation index, tumor size, lymph node metastasis and is peripancreatic invasion. Repeated 10-fold cross-validations were performed, and area under the receiver operating characteristic curve (AUC) and decision curve analysis were used to evaluate the usefulness of the models.ResultsA total of 136 patients was included in the final analysis, of which 35 (34%) experienced early recurrence. Using Elastic Net, we found that 7 of 14 preoperative factors were useful for the predictive model. The mean AUC of all models constructed in the repeated validation was superior to the standard marker CA 19–9 (0.718 vs 0.657), whereas the AUC of the model constructed from the entire patient cohort was 0.767. Decision curve analysis showed that the models had a higher mean net benefit across the majority of the range of reasonable threshold probabilities.ConclusionA model using multiple preoperative factors can improve prediction of early resectable PDAC recurrence.

Prognostic value and potential molecular mechanism of the like-Sm gene family in early-stage pancreatic ductal adenocarcinoma.

BackgroundThe purpose of this study was to investigate the prognostic significance of like-Sm (LSM) genes in early pancreatic ductal adenocarcinoma (PDAC) and explore the potential molecular mechanism. The protein product of the LSM1 gene is also known as CASM and YJL124C, while that of the LSM4 gene is known as GRP and YER112W.MethodsData from 112 patients attached to the Whipple surgery were collected from the TCGA database of clinical characteristics and survival data. The Kaplan-Meier method and the multivariate Cox proportional risk regression model were used to analyze the impact of LSM genes on outcomes in these 112 patients. We performed gene-gene interaction (GGI) and protein-protein interaction (PPI) analysis to probe interactions between LSM family genes. Bioinformatics techniques were applied to study the potential early-stage molecular mechanisms of LSM genes. Previously, only a few studies have explored the role and potential mechanisms of LSM1 in pancreatic tumor transformation, revealing possible links to transforming growth factor-β, altering the expression of MMP1, uPAR, and SerpinB5 to enhance invasion and metastasis in pancreatic cancer, and facilitating mRNA decapping and degradation. Gene set enrichment analysis (GSEA) also proved that LSM genes are associated with RNA splicing, RNA synthesis, and RNA decomposition, and they may indirectly cause carcinogenesis through other genes such as myc.ResultsThe results showed that LSM1 (adjusted P=0.004) and LSM4 (adjusted P=0.034) were associated with the prognosis of patients with PDAC, and patients with high expression levels of LSM1 (adjusted HR =2.338) or LSM4 (adjusted HR =1.803) tended to experience bad outcomes.ConclusionsOur study revealed that LSM1 and LSM4 might be used as prognostic biomarkers in early PDAC.

Upregulated MicroRNA-483-3p is an Early Event in Pancreatic Ductal Adenocarcinoma (PDAC) and as a Powerful Liquid Biopsy Biomarker in PDAC.

BackgroundThere is an urgent need for the development of effective noninvasive biomarkers for early pancreatic cancer diagnosis. MicroRNAs (miRNAs) are promising candidates that can be identified in peripheral blood and can act as “liquid biopsy” biomarkers. miR-483-3p is overexpressed in the tumor tissue of pancreatic duct adenocarcinoma, but its potential as noninvasive biomarker remains unknown.MethodsWe conducted locked nucleic acid in situ hybridization (LNA-ISH) for miR-483-3p in archival tissues of 107 patients with PDAC. We also used immunohistochemistry to evaluate SMAD4 expression, the putative miR-483-3p target gene. miR-483-3p expression level was also assessed using quantitative real-time PCR (qRT-PCR) in serum and serum exosome samples from 63 patients with PDAC and 22 healthy individuals.ResultsLNA-ISH showed that miR-483-3p was overexpressed in PDAC and PanIN tissues compared to normal pancreatic duct cells. miR-483-3p expression levels correlated with increases in PanIN lesion grade. miR-483-3p expression negatively correlated with Smad4 expression (γ=−0.770, p<0.0001) in PDAC and PanIN tissues. Circulating miR-483-3p levels were significantly elevated in the serum and serum exosomes of PDAC patients compared to healthy controls (p<0.0001 and p<0.01, respectively). Specifically, serum miR-483-3p levels were able to distinguish patients with early stage (≤2cm) PDAC from healthy controls with an AUC of 0.83 [95% CI, 0.70–0.96]. Higher serum exosomal miR-483-3p levels predicted worse survival in PDAC patients and serum exosomal miR-483-3p also proved to be an independent prognostic factor for PDAC (hazard ratio = 3.307; 95% CI=1.104 to 9.903; p=0.033). In vitro studies also showed that miR-483-3p promoted pancreatic cancer cell migration and invasion.ConclusionmiR-483-3p overexpression occurs early in PDAC development and is present in premalignant PanIN lesions. Serum miR-483-3p may act as an early PDAC diagnostic biomarker and serum exosomal miR-483-3p may be a PDAC prognostic biomarker.

Abstract LT013: Endocrine-exocrine signaling is a driver of obesity-associated pancreatic ductal adenocarcinoma

Abstract Obesity is a major modifiable host risk factor for pancreatic ductal adenocarcinoma (PDAC), the third leading cause of cancer death in the United States and a major cause of morbidity and mortality worldwide. Despite the rapid rise in the prevalence of obesity, surprisingly little is known about how it drives tumor progression. Therefore, deciphering these mechanisms is not only a societal imperative but also represents a key untapped target to develop novel strategies for PDAC prevention and therapy. Motivated by this gap in knowledge, we developed a rapid and reversible autochthonous mouse model of obesity-associated PDAC that recapitulates the genetic and histologic features of the human disease. We showed that obesity accelerates pancreatic tumorigenesis, while genetic or dietary weight loss intercepts tumor development, consistent with a causal and reversible role for obesity in early PDAC progression. By analyzing human and murine biospecimens, we defined obesity-driven microenvironmental alterations that foster tumorigenesis rather than new driver mutations, including significant inflammation, fibrosis, and islet adaptation. Specifically, we identified aberrant pancreatic beta cell expression of the hormone cholecystokinin (CCK) in response to obesity and showed that islet CCK itself promotes oncogenic Kras-driven pancreatic cancer. We further observed that CCK expression and tumor progression correlated with hyperglycemia, beta cell dysfunction, and reduced insulin secretion, suggesting that islet adaptations apart from insulin may drive tumorigenesis in obesity. By performing single-cell RNA-sequencing of islets from genetic and diet-induced obesity models, we have further nominated molecular mechanisms of CCK induction in beta cells and are testing their functional role in PDAC progression. Together, our findings argue that PDAC development is driven by local obesity-associated alterations in the tumor microenvironment, implicate a previously unappreciated endocrine-exocrine signaling axis beyond insulin in this process, and highlight the possibility of targeting the endocrine pancreas as a novel approach to intercept pancreatic exocrine tumorigenesis. Citation Format: Cathy Garcia, Jaffarguriqbal Singh, Lauren Lawres, Sherry Agabiti, Daniel B. Burkhardt, Alexander Tong, Rebecca Cardone, Richard G. Kibbey, Smita Krishnaswamy, Mandar D. Muzumdar. Endocrine-exocrine signaling is a driver of obesity-associated pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the AACR Virtual Special Conference on the Evolving Tumor Microenvironment in Cancer Progression: Mechanisms and Emerging Therapeutic Opportunities; in association with the Tumor Microenvironment (TME) Working Group; 2021 Jan 11-12. Philadelphia (PA): AACR; Cancer Res 2021;81(5 Suppl):Abstract nr LT013.

Kras mutation rate precisely orchestrates ductal derived pancreatic intraepithelial neoplasia and pancreatic cancer

AbstractPancreatic ductal adenocarcinoma (PDAC) is the third leading cause of cancer-related death in the United States. Despite the high prevalence of Kras mutations in pancreatic cancer patients, murine models expressing the oncogenic mutant Kras (Krasmut) in mature pancreatic cells develop PDAC at a low frequency. Independent of cell of origin, a second genetic hit (loss of tumor suppressor TP53 or PTEN) is important for development of PDAC in mice. We hypothesized ectopic expression and elevated levels of oncogenic mutant Kras would promote PanIN arising in pancreatic ducts. To test our hypothesis, the significance of elevating levels of K-Ras and Ras activity has been explored by expression of a CAG driven LGSL-KrasG12V allele (cKras) in pancreatic ducts, which promotes ectopic Kras expression. We predicted expression of cKras in pancreatic ducts would generate neoplasia and PDAC. To test our hypothesis, we employed tamoxifen dependent CreERT2 mediated recombination. Hnf1b:CreERT2;KrasG12V (cKrasHnf1b/+) mice received 1 (Low), 5 (Mod) or 10 (High) mg per 20 g body weight to recombine cKras in low (cKrasLow), moderate (cKrasMod), and high (cKrasHigh) percentages of pancreatic ducts. Our histologic analysis revealed poorly differentiated aggressive tumors in cKrasHigh mice. cKrasMod mice had grades of Pancreatic Intraepithelial Neoplasia (PanIN), recapitulating early and advanced PanIN observed in human PDAC. Proteomics analysis revealed significant differences in PTEN/AKT and MAPK pathways between wild type, cKrasLow, cKrasMod, and cKrasHigh mice. In conclusion, in this study, we provide evidence that ectopic expression of oncogenic mutant K-Ras in pancreatic ducts generates early and late PanIN as well as PDAC. This Ras rheostat model provides evidence that AKT signaling is an important early driver of invasive ductal derived PDAC. SummaryIn this study, the authors provide evidence that ectopic expression of oncogenic mutant Kras in pancreatic ducts generates early and late (PanIN) and pancreatic ductal adenocarcinoma (PDAC) . They characterized this Ras rheostat model which reveals elevated Kras mutation frequency and loss of PTEN are important drivers of PanIN and invasive ductal derived PDAC.

Characterization of undiagnosed pancreatic ductal adenocarcinoma on CT scans.

380 Background: Pancreatic ductal adenocarcinoma (PDAC) is the third leading cause of cancer-related deaths. At present, the best 5-year survival is 25% for resectable PDAC. For small (1 cm) stage 1 PDAC, resection has resulted in much better survival. The goal of this study was to evaluate the appearance and location of early undiagnosed PDAC on computed tomography scans (CT) prior to diagnosis with the goal of minimizing missing early PDAC. We also categorize the errors as either perceptive or cognitive. Methods: PDAC cases were retrospectively reviewed from 1/1/2012 through 12/31/2018 from our tumor registry, identifying 81 cases with paired CT scans both at the time of and prior to diagnosis. Among these, 31 contained imaging features considered diagnostic or suspicious for early PDAC(38%). These “errors” were classified by radiologic features and as well as by location. In addition, errors were classified into “perceptive errors" when the first study was read as normal, and as “cognitive errors” when the report noted an abnormality but failed to note suspicion for malignancy. Results: Among the 31 undiagnosed PDAC, 18 had features of an identifiable mass (58%), 9 had pancreatic ductal dilatation (29%), and 4 had evidence of perivascular soft tissue (13%). 44% of undiagnosed tumors were located in the head-neck, 39% in the body, and 17% in the tail. Perceptive errors were found in 58% and 42% were cognitive. No significant differences were seen between perceptive and cognitive errors based on suspicious features. Conclusions: Radiologic findings of early PDAC was retrospectively evident in more than one third of cases in which prior imaging was performed. These findings are most often masses or ductal dilatation. Location of these undiagnosed tumors were distributed throughout the gland. This study identifies the radiologic features of undiagnosed PDAC which may provide an opportunity for future prospective studies and improved technology which may improve early detection of pancreatic cancer.

Opportunity costs of undergoing surgical resection and perioperative chemotherapy for pancreatic adenocarcinoma.

398 Background: Treatment of early stage pancreatic ductal adenocarcinoma (PDAC) includes surgical resection and either neoadjuvant or adjuvant chemotherapy. Due to the intensity of treatment and perioperative morbidity rates of pancreatic resection, patients may spend a significant portion of their survival time in receipt of clinical care. However, time spent in receipt of care has not been previously described in patients with early stage PDAC. The primary aim of this study was to determine the total time spent in receipt of surgical and perioperative chemotherapy in patients with resectable PDAC. Methods: A retrospective cohort study was performed of patients diagnosed with PDAC who underwent curative-intent resection at a single institution tertiary care center between January 2015 and October 2019. Patients who died within 30 days of surgery were excluded. Total care time, including all relevant clinician visits, laboratory, radiologic and procedural studies, and treatment visits, was abstracted from the primary medical record. Care time included estimated travel time based on patient address. Care time was divided into preoperative, surgical, and systemic therapy phases of care. Time spent in surgical care included the hospital length of stay, postoperative follow-up visits, and admissions for postoperative complications. Results: A total of 86 patients were identified. Median total preoperative care time was 29 hours (IQR 11-135; 0.4% of survival time, range 0% - 72.7%). Median total time spent in surgical care was 216 hours (IQR 164-371; 2% of survival time, range 0.3% - 68.4%). Among the patients who received systemic chemotherapy care within the same institutional health system (N = 41), median total time spent in receipt of systemic therapy was 447 hours (IQR 194-647; 3% of survival time, range 0.1% - 55.4%). 10.5% of patients (N = 9) spent more than 10% of total survival time in surgical care and 5.8% (N = 5) patients spent more than 10% of survival time in receipt of systemic care. Median cumulative travel time for patients was 19 hours (IQR 10.2-37.6). Conclusions: For the majority of patients undergoing resection for PDAC, time spent in receipt of surgical care does not appear to represent a substantial time burden relative to survival time. However, for a subset of patients, the time burden is considerable. Further research to determine predictors of increased time spent in receipt of multimodality cancer care is warranted to better inform patient and surgeon communication and decision-making.

Circulating tumor DNA methylation as markers for early detection of pancreatic ductal adenocarcinoma (PDAC).

395 Background: PDAC is a cancer of high mortality and low survival. Its early detection is critical due to symptoms often occur only at advanced stages. However there is no reliable screening tool to identify high-risk patients. ctDNA methylation has recently emerged as a promising new target to differentiate PDAC plasma from normal plasma for its early detection. Methods: Reduced representation bisulfite sequencing libraries were made in 46 PDAC tissues, 30 para-PDAC tissues and 20 PDAC plasmas to screen PDAC-specific markers, which was done by quantifying and comparing methylation levels of genomic regions and individual CpG sites between those groups. Markers were validated in plasma samples from 84 PDAC patients and 64 normal controls to propose a blood classifier. The best-performing markers were developed into a targeted sequencing panel, which was tested on a larger collection of plasma samples from patients of a variety of pancreatic diseases to build and validate a PDAC-predicting model. Results: We profiled genome-wide methylation patterns of tissues samples to identify 171 PDAC-specific markers. We reiterated training and cross-validating PDAC classification models using SVM method, and achieved an average sensitivity of 86% and specificity of 88%. To prove the feasibility of a non-invasive detection in plasma, a targeted methylation assay using those markers was tested on PDAC and normal plasmas, and yielded an average sensitivity of 68.4% and a specificity of 85.8%. We refined the panel by selecting the most discriminatory markers and built the version II of the panel, which was named PANcreatic Cancer Detection Assay, or PANDA, for a more efficient target capture, which was validated in an independent cohort of plasma samples that included 94 PDAC cases, 25 chronic pancreatitis (CP) cases and 80 normal samples from multiple centers. The PANDA achieved an AUC of 0.906 when classifying PDAC from normal, and an AUC of 0.882 when separating PDAC from CPs, both of which are more accurate than CA19-9, the conventional blood marker for PDAC. We further integrated test subjects’ age and their CA19-9 level as features into the PANDA model, which further elevated their AUC to 0.882 and 0.933 when classifying PDAC plasma from either CP plasma or normal plasma, respectively. Conclusions: We have developed PANDA, an NGS based target assay covering PDAC-specific DNA methylation targets by screening and validation on PDAC tissues and plasmas. Combined with age and CA19-9 blood level, PANDA has shown encouraging results to classify PDAC plasma from non-malignant diseases, demonstrating its potential to be optimized into non-invasive diagnostics for blood-based early PDAC screening.

Plasma protein biomarkers for early detection of pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis, mainly due to late diagnosis at advanced tumor stages. In this study, we aimed to identify plasma protein biomarkers for early detection of PDAC. Totally, 135 PDAC patients (early PDAC, Stage I/II, n = 71; advanced PDAC, Stage III/IV, n = 64), 13 benign lesions/chronic pancreatitis patients and 72 healthy individuals, with corresponding plasma samples from a case-control study in Sweden were included. A proximity extension assay was used to detect 92 cancer-related proteins, and an enzyme-linked immunosorbent assay/electrochemiluminescence immunoassay was used to detect CA19-9. Predictive features were selected from these 93 candidate proteins and three covariates in the Swedish participants, and then validated in Spanish participants, including 37 early PDAC patients, 38 advanced PDAC patients, 19 chronic pancreatitis patients and 36 healthy controls. A panel of eight proteins discriminating early PDAC from healthy individuals was identified, and the cross-validated area under the curves (AUCs) were 0.85 (95% confidence interval, 95% CI, 0.78-0.91) and 0.81 (95% CI, 0.70-0.92) in the Swedish and Spanish participants, respectively. Another eight-protein panel was predictive for classifying advanced PDAC from healthy controls in two populations, with cross-validated AUCs of 0.89 (95% CI, 0.83-0.95) and 0.90 (95% CI, 0.83-0.98), respectively. In conclusion, eight protein biomarkers were identified and externally validated, potentially allowing early detection of PDAC patients if validated in additional prospective studies.

UXT antisense RNA 1 sever as a novel prognostic long non-coding RNA in early stage pancreatic ductal adenocarcinoma patients after receiving pancreaticoduodenectomy.

Objective: The principal objective of this project was to investigate the prognostic value of UXT antisense RNA 1 (UXT-AS1) in pancreatic ductal adenocarcinoma (PDAC), as well as its biological function mechanisms and the screening of targeted drugs using The Cancer Genome Atlas (TCGA) PDAC genome-wide RNA sequencing (RNA-seq) dataset.Methods: We used TCGA 112 early stage PDAC patients to screen the prognostic value of UXT-AS1. Biological functions and mechanisms of UXT-AS1 were investigated by co-expression analysis, differentially expressed genes (DEGs) and gene set enrichment analysis, while targeted drug screening was investigated by connectivity Map (CMap).Results: By analyzing the dataset from TCGA cohort, we found that UXT-AS1 was significantly up-regulated in pancreatic cancer tissues. Multivariate survival analysis demonstrated that PDAC patients with high UXT-AS1 expression had an unfavourable prognosis (adjusted P=0.033, HR=1.830, 95%CI=1.051-3.188). Genome-wide co-expression analysis and gene set enrichment analysis suggested that UXT-AS1 may act as a pivotal part in PDAC by participating in nuclear factor kappa beta, regulation of tumor necrosis factor, cell adhesion, T cell receptor signaling pathway, and numerous immune-related biological processes and signaling pathways. Functional enrichment analysis of DEGs between high- and low-UXT-AS1 expression groups suggested that these DEGs were significant enriched in B cell receptor complex, response to drug chemical carcinogenesis and drug metabolism-cytochrome P450. CMap analysis revealed that quipazine and terazosin may be targeted drugs for UXT-AS1 in PDAC.Conclusion: Our current study has identified UXT-AS1 as a novel biomarker for the prognosis of early stage PDAC. We also clarified its biological functional mechanisms and identified two targeted drugs of UXT-AS1 in PDAC.

Developing a Multi-analyte Biomarker Panel to Detect Pancreatic Adenocarcinoma

Purpose: Outcomes from Pancreatic Ductal Adenocarcinoma (PDAC) remain poor despite advances in peri-operative care and neoadjuvant/adjuvant oncological strategies. A lack of reliable diagnostic tests in early disease mean that PDAC is now the 6th most common cause of cancer death in the UK, despite being the 10th most prevalent cancer. We sought to examine a selection of plasma biomarkers in the hope of identifying a reliable panel to detect early PDAC. Method: A feasibility study was designed and approved by the relevant local ethics and research committees. Blood was collected from consenting participants. Participants were divided into 4 groups (early cancer, advanced cancer, benign pancreatic disease, control). Plasma concentrations of Ca19-9, Thrombospondin-2 (THBS2) and Chitinase-3-like protein 1 (YKL-40) were quantified using a Sandwich ELISA technique from each of the above groups. Results: To date, 88 participants have been recruited (28 PDAC, 30 benign pancreatic pathologies, 30 control). Mean plasma Ca19-9 concentration was the only marker to be significantly different between the 2 cancer and 2 non-cancer groups (104.34U/ml vs 32.19U/ml, p = <0.001). However, when early cancers were compared to just the control group, mean values of all 3 plasma markers were significantly raised in the early cancer group. THBS2 (48.87ng/ml vs 25.65 ng/ml, p = 0.049), YKL-40 (142.80ng/ml vs 80.73ng/ml, p = 0.001) and Ca19-9 (97.16U/ml vs 28.65U/ml, p = <0.001). Conclusion: Preliminary results show that plasma concentrations of THBS2 and YKL-40 are elevated in patients with early PDAC compared to controls. This may allow the development of a biomarker panel to detect early pancreatic cancer.

A novel prognostic factor TIPE2 inhibits cell proliferation and promotes apoptosis in pancreatic ductal adenocarcinoma (PDAC).

Background: Tumor necrosis factor (TNF)-alpha-induced protein 8-like 2 (TIPE2 or TNFAIP8L2) is a newly discovered negative immune regulator. Studies have shown that TIPE2 causes significant malignant biological effects and is differentially expressed in various malignant tumors. However, the expression and roles of TIPE2 in pancreatic ductal adenocarcinoma (PDAC) are largely unknown.Materials and Methods: The expression of TIPE2 in PDAC tissues was assessed by immunohistochemistry, qPCR and western blot analysis and related clinicopathological parameters including survival time were analyzed. After overexpression of TIPE2, cell proliferation and apoptosis analysis were conducted, and the associated underlying molecular mechanism was also explored.Results: In the present study, TIPE2 was upregulated in early PDAC tissues, and TIPE2 expression decreased as the tumor progressed (P<0.001). TIPE2 expression was negatively associated with tumor size, TNM stage and metastasis of lymph nodes. Furthermore, as an independent risk factor, TIPE2 could be used to predict the survival of patients with PDAC (P=0.035). TIPE2 overexpression significantly suppressed the viability, proliferation and induced apoptosis of PDAC cells by inhibiting survivin and increasing the activity of caspase3/7.Conclusions: For the first time, this study demonstrated that TIPE2 is an independent prognostic factor in PDAC. TIPE2 inhibited the proliferation and induced apoptosis via regulating survivin/caspase3/7 signaling pathway. These results indicated that TIPE2 is a potential biomarker for predicting the prognosis of PDAC patients and plays a pivotal role in the progression of PDAC.

Synergistic Analysis of Protein Corona and Haemoglobin Levels Detects Pancreatic Cancer.

Simple SummaryPancreatic ductal adenocarcinoma (PDAC) is often diagnosed at an advanced stage and is burdened by poor prognosis. Its early diagnosis is rare because the disease is frequently asymptomatic for a long time. Our research aims to identify a useful and simple diagnostic tool for early PDAC detection. The combination of user-friendly, nanotechnology-based tools and standard blood tests showed high accuracy in discriminating PDAC patients from healthy subjects. If confirmed in large-cohort studies, these findings could represent an innovative and non-invasive method with a potential impact in clinical practice in early detection of PDAC.Simultaneous detection of multiple analytes from a single biological sample is gaining more attention in the development of more reliable and point-of-care diagnostic devices. We developed a multiplexed strategy that combined outcomes of clinical biomarkers with analysis of the protein corona that forms around graphene oxide sheets upon exposure to patient’s plasma. As a paradigmatic case study, we selected pancreatic ductal adenocarcinoma (PDAC), mainly because of the absence of effective detection strategies that resulted in an extremely low five-year survival rate after diagnosis (<10%). Association of protein corona analysis and haemoglobin levels discriminated PDAC patients from healthy volunteers in up to 90% of cases. If further confirmed in larger-cohort studies, this approach may be used in the detection of PDAC.

Single-Cell RNA-Seq Reveals Dynamic Change in Tumor Microenvironment During Pancreatic Ductal Adenocarcinoma Malignant Progression

Background: Pancreatic ductal adenocarcinoma (PDAC) is most aggressive among all gastrointestinal tumors. The complex intra-tumor heterogeneity and special tumor microenvironment in PDAC bring great challenges for developing effective treatment strategies. We aimed to delineate dynamic changes of tumor microenvironment components during PDAC malignant progression utilizing single-cell RNA sequencing. Methods: A total of 11 samples (4 PDAC I, 4 PDAC II, 3 PDAC III) were used to construct expression matrix. After identifying distinct cell clusters, subcluster analysis for each cluster was performed. New cancer associated fibroblasts (CAFs) subset was validated by weighted gene co-expression network analysis, RNA in situ hybridization and immunofluorescence. Findings: We found that ductal cells were not dominant component while tumor infiltrating immune cells and pancreatic stellate cells gradually accumulated during tumor development. We defined several new Treg and exhausted T cell signature genes, including DUSP4, FANK1 and LAIR2. The analysis of TCGA datasets showed that patients with high expression of DUSP4 had significantly worse prognosis. In addition, we identified a new CAFs subset (complement-secreting CAFs, csCAFs), which specifically expresses complement system components, and constructed csCAFs-related module by weighted gene co-expression network analysis. The csCAFs were located in the tissue stroma adjacent to malignant ductal cells only in early PDAC. Interpretation: We systematically explored PDAC heterogeneity and identified csCAFs as a new CAFs subset special to PDAC, which is valuable for understanding the crosstalk inside tumor. Funding Statement: This study was supported by The Natural Science Foundation of China (NO.81572339, 81672353, 81871954) and the Youth Clinical Research Project of Peking University First Hospital (2018CR28). Declaration of Interests: We declare there are no any competing financial interests in relation to this work. Ethics Approval Statement: According to the article (GSA: https://bigd.big.ac.cn/gsa under accession number CRA00116064), all patient samples were obtained from the department of general surgery of Peking Union Medical College Hospital (PUMCH) and patients had signed the informed consent. This study was approved by Ethics Committee.