Ductal Adenocarcinoma of the Pancreas

Role of microRNAs in response to cadmium chloride in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the most fatal and aggressive malignancies with a 5-year survival rate less than 9%. Early detection is particularly difficult due to the lack of symptoms even in advanced stages. microRNAs (miRs/miRNAs) are small (~ 18-24 nucleotides), endogenous, non-coding RNAs, which are involved in the pathogenesis of several malignancies including PDAC. Alterations of miR expressions can lead to apoptosis, angiogenesis, and metastasis. The role of environmental pollutants such as cadmium (Cd) in PDAC has been suggested but not fully understood. This study underlines the role of miRs (miR-221, miR-155, miR-126) in response to cadmium chloride (CdCl2) in vitro. Lethal concentration (LC50) values for CdCl2 resulted in a toxicity series of AsPC-1 > HPNE > BxPC-3 > Panc-1 = Panc-10.5. Following the treatment with CdCl2, miR-221 and miR-155 were significantly overexpressed, whereas miR-126 was downregulated. An increase in epithelial-mesenchymal transition (EMT) via the dysregulation of mesenchymal markers such as Wnt-11, E-cadherin, Snail, and Zeb1 was also observed. Hence, this study has provided evidence to suggest that the environmental pollutant Cd can have a significant role in the development of PDAC, suggesting a significant correlation between miRs and Cd exposure during PDAC progression. Further studies are needed to investigate the precise role of miRs in PDAC progression as well as the role of Cd and other environmental pollutants.

Overcoming the Tumor Microenvironmental Barriers of Pancreatic Ductal Adenocarcinomas for Achieving Better Treatment Outcomes

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive disease with the lowest survival rate among all solid tumors. The lethality of PDAC arises from late detection and propensity of the tumor to metastasize and develop resistance against chemo and radiation therapy. A highly complex tumor microenvironment composed of dense stroma, immune cells, fibroblast, and disorganized blood vessels, is the main obstacle to current PDAC therapy. Despite the tremendous success of immune checkpoint inhibitors (ICIs) in cancers, PDAC remains one of the poorest responders of ICIs therapy. The immunologically "cold" phenotype of PDAC is attributed to the low mutational burden, high infiltration of myeloid-derived suppressor cells and T-regs, contributing to a significant immunotherapy resistance mechanism. Thus, the development of innovative strategies for turning immunologically "cold" tumor into "hot" ones is an unmet need to improve the outcome of PDAC ICIs therapies. Other smart strategies, such as nanomedicines, sonic Hedgehog inhibitor, or smoothened inhibitor, are discussed to enhance chemotherapeutic agents' efficiency by disrupting the PDAC stroma. This review highlights the current challenges and various preclinical and clinical strategies to overcome current PDAC therapy difficulties, thus significantly advancing PDAC research knowledge.

Non-Invasive Biomarkers for Earlier Detection of Pancreatic Cancer-A Comprehensive Review

Simple Summary

Pancreatic ductal adenocarcinoma (PDAC), which represents approximately 90% of all pancreatic cancers, is an extremely aggressive and lethal disease. It is considered a silent killer due to a largely asymptomatic course and late clinical presentation. Earlier detection of the disease would likely have a great impact on changing the currently poor survival figures for this malignancy. In this comprehensive review, we assessed over 4000 reports on non-invasive PDAC biomarkers in the last decade. Applying the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool, we selected and reviewed in more detail 49 relevant studies reporting on the most promising candidate biomarkers. In addition, we also highlight the present challenges and complexities of translating novel biomarkers into clinical use.

Abstract

Pancreatic ductal adenocarcinoma (PDAC) carries a deadly diagnosis, due in large part to delayed presentation when the disease is already at an advanced stage. CA19-9 is currently the most commonly utilized biomarker for PDAC; however, it lacks the necessary accuracy to detect precursor lesions or stage I PDAC. Novel biomarkers that could detect this malignancy with improved sensitivity (SN) and specificity (SP) would likely result in more curative resections and more effective therapeutic interventions, changing thus the present dismal survival figures. The aim of this study was to systematically and comprehensively review the scientific literature on non-invasive biomarkers in biofluids such as blood, urine and saliva that were attempting earlier PDAC detection. The search performed covered a period of 10 years (January 2010—August 2020). Data were extracted using keywords search in the three databases: MEDLINE, Web of Science and Embase. The Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool was applied for study selection based on establishing the risk of bias and applicability concerns in Patient Selection, Index test (biomarker assay) and Reference Standard (standard-of-care diagnostic test). Out of initially over 4000 published reports, 49 relevant studies were selected and reviewed in more detail. In addition, we discuss the present challenges and complexities in the path of translating the discovered biomarkers into the clinical setting. Our systematic review highlighted several promising biomarkers that could, either alone or in combination with CA19-9, potentially improve earlier detection of PDAC. Overall, reviewed biomarker studies should aim to improve methodological and reporting quality, and novel candidate biomarkers should be investigated further in order to demonstrate their clinical usefulness. However, challenges and complexities in the path of translating the discovered biomarkers from the research laboratory to the clinical setting remain and would have to be addressed before a more realistic breakthrough in earlier detection of PDAC is achieved.

Beneficial Diets and Pancreatic Cancer: Molecular Mechanisms and Clinical Practice

Pancreatic cancer (PC) is a malignant tumor with high invasiveness, easy metastatic ability, and chemoresistance. Patients with PC have an extremely low survival rate due to the difficulty in early diagnosis. It is estimated that nearly 90% of PC cases are caused by environmental risk factors. Approximately 50% of PC cases are induced by an unhealthy diet, which can be avoided. Given this large attribution to diet, numerous studies have assessed the relationship between various dietary factors and PC. This article reviews three beneficial diets: a ketogenic diet (KD), a Mediterranean diet (MD), and a low-sugar diet. Their composition and impact mechanism are summarized and discussed. The associations between these three diets and PC were analyzed, and we aimed to provide more help and new insights for the prevention and treatment of PC.

Addition of analysis of KRAS mutation or immunohistochemistry with MUC1 and carcinoembryonic antigen improves the diagnostic performance of fine needle aspiration cytology for the diagnosis of pancreatic carcinoma

BACKGROUND

Pancreatic adenocarcinoma (PAC) is a health problem because of high lethality, increasing incidence and the absence of an early diagnosis. Biopsy by fine needle aspiration guided by endoscopic ultrasound has allowed obtaining tissue for cytopathological analysis, but there are several problems with their interpretation. We aimed to compare the diagnostic performance of the cytopathological analysis with the addition of either an immunohistochemical (IHC) panel or the KRAS mutation for the diagnosis of PAC.

METHODS

We evaluated 62 pancreatic lesions by fine needle aspiration guided by endoscopic ultrasound, applying an IHC panel with mucin (MUC)-1, MUC4, carcinoembryonic antigen (CEA) and p53. All cases also had a KRAS mutation determination. Three cytopathologists blinded to clinical data and the KRAS status reviewed the cytology independently. We calculated diagnostic performances for the cytology alone, cytology+IHC and cytology+KRAS to show the best method to diagnose PAC.

RESULTS

From 62 samples, 50 (80.6%) were PAC and 12 benign lesions. The cytopathological analysis correctly interpreted 26 malignant and 12 non-neoplastic cases (sensitivity 52%, specificity 100% and diagnostic accuracy 61.3%). The KRAS mutation was present in 88% of PAC. The cytology+ KRAS mutation increased the sensitivity by 10% and the diagnostic accuracy by 8%. The sensitivity increased by 2% adding either MUC1 or CEA to the cytology, and the diagnostic accuracy by 10 or 18%, respectively.

CONCLUSION

The addition of IHC either with CEA or MUC1 improved the diagnostic performance of the cytology alone to diagnose PAC. The cytology + IHC evaluation was superior to the cytology + KRAS mutation to diagnose PAC.