Histopathologic assessment of pancreatic cancer: Does one size fit all?

Prognostic utility of TME-associated genes in pancreatic cancer

Background: Pancreatic cancer (PC) is a deadly disease. The tumor microenvironment (TME) participates in PC oncogenesis. This study focuses on the assessment of the prognostic and treatment utility of TME-associated genes in PC. Methods: After obtaining the differentially expressed TME-related genes, univariate and multivariate Cox analyses and least absolute shrinkage and selection operator (LASSO) were performed to identify genes related to prognosis, and a risk model was established to evaluate risk scores, based on The Cancer Genome Atlas (TCGA) data set, and it was validated by external data sets from the Gene Expression Omnibus (GEO) and Clinical Proteomic Tumor Analysis Consortium (CPTAC). Multiomics analyses were adopted to explore the potential mechanisms, discover novel treatment targets, and assess the sensitivities of immunotherapy and chemotherapy. Results: Five TME-associated genes, namely, FERMT1, CARD9, IL20RB, MET, and MMP3, were identified and a risk score formula constructed. Next, their mRNA expressions were verified in cancer and normal pancreatic cells. Multiple algorithms confirmed that the risk model displayed a reliable ability of prognosis prediction and was an independent prognostic factor, indicating that high-risk patients had poor outcomes. Immunocyte infiltration, gene set enrichment analysis (GSEA), and single-cell analysis all showed a strong relationship between immune mechanism and low-risk samples. The risk score could predict the sensitivity of immunotherapy and some chemotherapy regimens, which included oxaliplatin and irinotecan. Various latent treatment targets (LAG3, TIGIT, and ARID1A) were addressed by mutation landscape based on the risk model. Conclusion: The risk model based on TME-related genes can reflect the prognosis of PC patients and functions as a novel set of biomarkers for PC therapy.

Survival and Prognostic Factors in Patients With Pancreatic Colloid Carcinoma Compared With Pancreatic Ductal Adenocarcinoma

OBJECTIVES

Colloid carcinoma (CC) is a rare subtype of pancreatic carcinoma. The aims of the study are to characterize the clinicopathological features and to evaluate the overall survival (OS) of patients with CC.

METHODS

Patients diagnosed with pancreatic CC and pancreatic ductal adenocarcinoma (PDAC) between 2004 and 2016 were identified from the National Cancer Database using International Classification of Disease-O-3 morphology (8480/3 and 8140/3) and topography (C25) codes. Kaplan-Meier analysis and Cox proportional hazards models were used to analyze OS.

RESULTS

Fifty-six thousand eight hundred forty-six patients were identified. A total of 2430 patients (4.3%) were diagnosed with pancreatic CC. Males constituted 52.8% of CC and 52.2% of PDAC. Colloid carcinoma presented with pathological stage I disease more often (16.7% vs 5.9%) and stage IV disease less often (42.1% vs 52.4%) than PDAC (P < 0.001). Stage I CC received chemotherapy (36.0% vs 59.4%) and neoadjuvant chemotherapy (4.4% vs 14.2%) less often compared with PDAC (P < 0.001). Statistically significant improved OS was seen among stage I, II, and IV CC compared with PDAC.

CONCLUSIONS

Pancreatic CC presented as stage I disease more often compared with PDAC. Neoadjuvant chemotherapy was administered more often in stage I PDAC compared with CC. Colloid carcinoma had improved OS compared with PDAC among all stages except stage III.

Oxidative Stress Markers Are Associated with a Poor Prognosis in Patients with Pancreatic Cancer

Pancreatic cancer is a malignancy of rising prevalence, especially in developed countries where dietary patterns and sedentariness favor its onset. This malady ranks seventh in cancer-related deaths in the world, although it is expected to rank second in the coming years, behind lung cancer. The low survival rate is due to the asymptomatic course of the early stages, which in many cases leads to metastases when becoming evident in advanced stages. In this context, molecular pathology is on the way towards finding new approaches with biomarkers that allow a better prognosis and monitoring of patients. So the present study aims to evaluate a series of molecular biomarkers, PARP1, NOX1, NOX2, eNOS and iNOS, as promising candidates for prognosis and survival by using immunohistochemistry. The analysis performed in 41 patients with pancreatic cancer showed a correlation between a high expression of all these components with a low survival rate, with high statistical power for all. In addition, a 60-month longitudinal surveillance program was managed, accompanied by several clinical parameters. The derivative Kaplan–Meier curves indicated a low cumulative survival rate as well. Ultimately, our research emphasized the value of these molecules as survival-associated biomarkers in pancreatic cancer, offering new gates for clinical management.

Autophagy Contributes to Metabolic Reprogramming and Therapeutic Resistance in Pancreatic Tumors

Metabolic reprogramming is a feature of cancers for which recent research has been particularly active, providing numerous insights into the mechanisms involved. It occurs across the entire cancer process, from development to resistance to therapies. Established tumors exhibit dependencies for metabolic pathways, constituting vulnerabilities that can be targeted in the clinic. This knowledge is of particular importance for cancers that are refractory to any therapeutic approach, such as Pancreatic Ductal Adenocarcinoma (PDAC). One of the metabolic pathways dysregulated in PDAC is autophagy, a survival process that feeds the tumor with recycled intracellular components, through both cell-autonomous (in tumor cells) and nonautonomous (from the local and distant environment) mechanisms. Autophagy is elevated in established PDAC tumors, contributing to aberrant proliferation and growth even in a nutrient-poor context. Critical elements link autophagy to PDAC including genetic alterations, mitochondrial metabolism, the tumor microenvironment (TME), and the immune system. Moreover, high autophagic activity in PDAC is markedly related to resistance to current therapies. In this context, combining autophagy inhibition with standard chemotherapy, and/or drugs targeting other vulnerabilities such as metabolic pathways or the immune response, is an ongoing clinical strategy for which there is still much to do through translational and multidisciplinary research.

Clinical Analysis of Acinar Cell Carcinoma of the Pancreas: A Single-Center Experience of 45 Consecutive Cases

Backgrounds:

Acinar cell carcinoma of the pancreas is a rare malignancy, and its features remain unclear. We aimed to analyze the clinical characteristics, treatment and prognosis of acinar cell carcinoma with our institutional case series.

Methods:

Patients diagnosed with acinar cell carcinoma in our hospital between 2005 and 2019 were reviewed. Investigations on clinicopathological features, treatment details and long-term survival were performed.

Results:

A total of 45 pathologically confirmed acinar cell carcinomas were identified. The median age at diagnosis was 58 years with a male-to-female ratio of 3.1:1. There were 24 (53.3%) localized, 5 (11.1%) locally advanced and 16 (35.6%) metastatic cases, with a pancreatic head-to-body/tail ratio of 1:1.4 for all the primary lesions. In the localized group, there were 10 pancreatoduodenectomy, 12 distal pancreatectomy, 1 total pancreatectomy, and 1 distal pancreatectomy combined with proximal gastrectomy. Among the locally advanced and metastatic cases, 13 patients received chemotherapy, 1 received concurrent radiochemotherapy, 1 underwent synchronous resection of primary tumor and liver metastasis, 1 underwent palliative operation, 1 underwent exploratory laparotomy, and 4 required no treatment. The median overall survival of this series was 18.9 months with a 5-year survival rate of 19.6%. Moreover, the resected acinar cell carcinoma patients were associated with prolonged survival compared with the unresected cases (36.6 vs. 8.5 months, P < 0.001).

Conclusions:

Surgical resection could improve the long-term survival of acinar cell carcinoma patients, which might also improve the prognosis of selected metastatic cases. Large-scale studies are needed to further clarify the biological behavior and clinical features, and to seek the optimal treatments.

Morphologic Variants of Pancreatic Neuroendocrine Tumors: Clinicopathologic Analysis and Prognostic Stratification

Better prognostication/stratification of pancreatic neuroendocrine tumors (PanNETs) is needed. In this detailed morpheomic study of 163 resected PanNETs, 11 unusual variants, some of which were not previously recognized, and others scarcely documented in the literature, were identified, and their pathologic characteristics were further analyzed. By behavior and clinicopathologic associations, these variants could be grouped into three prognostically different categories. I. More aggressive (20%). Included in this group were the variants that in average showed higher grade and stage and adverse outcome including oncocytic, plasmacytoid, lipid-rich and previously unrecognized hepatoid variants, which often had a more diffuse/broad-band growth pattern, with some also displaying discohesiveness. They were characterized by abundant cytoplasm and often had prominent nucleoli (as seen in metabolically active cells), thus the provisional name "metabolic cell phenotype." Because of their diversion from classical neuroendocrine cytomorphology, these variants created challenges on original diagnostic workup, particularly hepatoid examples, which revealed Arginase 1/Hep Par-1 expression in 50%. II. Less aggressive (10%). These cases either showed signs of maturation, including nested growth, paraganglioid pattern (which was previously unrecognized), and organoid PanNETs such as "ductulo-insular" growth, or showed symplastic/degenerative changes, and despite their paradoxically disconcerting histology, were more benevolent in behavior. III. Undetermined. There were other variants including mammary tubulolobular-like, pseudoglandular, peliotic, and sclerotic PanNETs, which although diagnostically challenging, their biologic significance could not be determined because of rarity or heterogeneous characteristics. Prognostic associations: Features that were significantly different in the more aggressive group than the less aggressive group were median size (5.0 vs 1.6 cm, p < 0.001), percentage of pT3+T4 cases (72% vs 12%, p < 0.001), Ki67 index (5.3% vs 2.3%, p = 0.001), % G2 and G3 cases (77% vs 27%, p < 0.001), and rate of lymph node and distant metastasis (96% vs 27%, p < 0.001). In stepwise logistic regression model using the 3 established prognosticators of T stage, size, and grade along with morphology, only aggressive-morphology (metabolic cell phenotype) was found to be associated with metastatic behavior with an odds ratio of 5.9 with 95% confidence interval (C.I.) 1.688 to 22.945 and p value 0.007. In conclusion, PanNETs display various morphologic patterns that are not only challenging and important diagnostically but appear to have biologic significance. Tumors with more diffuse growth of cells with nucleoli and abundant cytoplasm and/or discohesion (oncocytic, hepatoid, lipid-rich, plasmacytoid PanNETs), provisionally termed "metabolic cell phenotype," show aggressive characteristics and are an independent determinant of adverse outcome and thus may require closer post-surgical follow-up, whereas variants with more degenerative or mature features (ductuloinsular, pleomorphic, paraganglioma-like) appear to be more benevolent despite their more atypical and worrisome morphology.

Cystic Lesions of the Pancreas: Differential Diagnosis and Cytologic-Histologic Correlation

CONTEXT.—

Pancreatic cystic lesions (PCLs) are very common, and their detection is increasing with the advances in imaging techniques. Because of the major implications for management, distinguishing between neoplastic and nonneoplastic PCLs is critical. Neoplastic cysts with potential to progress into cancer include mucinous PCLs (intraductal papillary mucinous neoplasms and mucinous cystic neoplasms) and nonmucinous cysts (solid pseudopapillary tumors, serous cystic neoplasms, and neuroendocrine tumors with cystic degeneration). Nonneoplastic cysts with no risk of malignant transformation include pseudocysts, retention cysts, lymphoepithelial cysts, cystic pancreatic lymphangioma, and duplication cyst/ciliated foregut cysts. The role of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) cytology with cyst fluid analysis in the diagnosis of PCLs has evolved during the last decade; however, a definitive diagnosis on cytologic specimens is hampered by the sparse cellularity and can be challenging. EUS-FNA can play an important role to differentiate low-risk from high-risk pancreatic cysts and to distinguish between patients with cysts who need clinical follow-up versus those who require surgery.

OBJECTIVE.—

To provide an integrative approach to diagnose pancreatic cystic lesions using EUS-FNA cytology and cyst fluid analysis, along with clinical, radiologic, histologic, genetic, and molecular characteristics.

DATA SOURCES.—

The review and analysis of the latest literature describing pancreatic cystic lesions.

CONCLUSIONS.—

Accurate diagnosis of PCLs requires a multidisciplinary and multimodal team approach, including the integration of clinical findings, imaging, cytology, cyst fluid analysis, and molecular testing.

Molecular subtypes of pancreatic cancer

Cancers that appear morphologically similar often have dramatically different clinical features, respond variably to therapy and have a range of outcomes. Compelling evidence now demonstrates that differences in the molecular pathology of otherwise indistinguishable cancers substantially impact the clinical characteristics of the disease. Molecular subtypes now guide preclinical and clinical therapeutic development and treatment in many cancer types. The ability to predict optimal therapeutic strategies ahead of treatment improves overall patient outcomes, minimizing treatment-related morbidity and cost. Although clinical decision making based on histopathological criteria underpinned by robust data is well established in many cancer types, subtypes of pancreatic cancer do not currently inform treatment decisions. However, accumulating molecular data are defining subgroups in pancreatic cancer with distinct biology and potential subtype-specific therapeutic vulnerabilities, providing the opportunity to define a de novo clinically applicable molecular taxonomy. This Review summarizes current knowledge concerning the molecular subtyping of pancreatic cancer and explores future strategies for using a molecular taxonomy to guide therapeutic development and ultimately routine therapy with the overall goal of improving outcomes for this disease.

Pancreatic Neuroendocrine Tumors Complicated by Sinistral Portal Hypertension: Insights into Pathogenesis

Purpose: To investigate the association between pancreatic neuroendocrine tumors (panNETs) and sinistral portal hypertension (SPH) and provide insights into the pathogenesis.

Methods: A retrospective review of panNETs was conducted from our institution for 12 years. Medical imaging findings were analyzed to determine any association with splenic vein thrombosis (SVT) at diagnosis. The cases were further selected based on the criteria for SPH, namely, (1) presence of SVT, (2) gastric varices, (3) patent portal vein, and (4) normal liver function tests.

Results: There were 61 patients with panNETs and 8 (8/61) had SVT and gastric varices at diagnosis. Four (4/8) met the strict criteria for SPH while the other four had more conventional portal hypertension. The four with SPH had large tumors located in the tail with splenic vein invasion and three of four presented with bleeding gastric varices. All four patients underwent surgical resection. Mean follow-up was 8.5 years and the hematemesis never recurred. The other four patients (four of eight) with gastric varices had unresectable disease and all died after a mean survival of 29 months.

Conclusion: PanNETs appear to be more commonly associated with SVT and SPH compared with other tumors. This could be related to their relatively indolent nature and their intrinsic vascularity. From a surgical viewpoint, the decision to operate depends on many factors including but not limited to the size/stage, grade, and functionality of the tumor and comorbidities. These considerations notwithstanding, the association between panNETs and SPH suggests that there is benefit in timely resection of panNETs located in the tail.

p53 and p16Ink4a/p19Arf Loss Promotes Different Pancreatic Tumor Types from PyMT-Expressing Progenitor Cells

In human studies and mouse models, the contributions of p53 and p16^Ink4a/p19^Arf loss are well established in pancreatic ductal adenocarcinoma (PDAC). Although loss of functional p53 pathway and loss of Ink4a/Arf in human pancreatic acinar cell carcinoma (PACC) and pancreatic neuroendocrine tumor (PanNET) are identified, their direct roles in tumorigenesis of PACC and PanNET remain to be determined. Using transgenic mouse models expressing the viral oncogene polyoma middle T antigen (PyMT), we demonstrate that p53 loss in pancreatic Pdx1+ progenitor cells results in aggressive PACC, whereas Ink4a/Arf loss results in PanNETs. Concurrent loss of p53 and Ink4a/Arf resembles loss of p53 alone, suggesting that Ink4a/Arf loss has no additive effect to PACC progression. Our results show that specific tumor suppressor genotypes provocatively influence the tumor biological phenotypes in pancreatic progenitor cells. Additionally, in a mouse model of β-cell hyperplasia, we demonstrate that p53 and Ink4a/Arf play cooperative roles in constraining the progression of PanNETs.

Clinical significance of pancreatic circulating tumor cells using combined negative enrichment and immunostaining-fluorescence in situ hybridization

BACKGROUND

Circulating tumor cells (CTCs) hold great potential in both clinical application and basic research for the managements of cancer. However, it remains to be an enormous challenge to obtain efficient detection of pancreatic CTCs. New detection platforms for the detection of pancreatic CTCs are urgently required.

METHODS

In the present study, we applied a newly-developed platform integrated subtraction enrichment and immunostaining-fluorescence in situ hybridization (SE-iFISH) to analyze clinical significance of pancreatic CTCs. Immunostaining of CK, CD45, DAPI and FISH with the centromere of chromosome 8 (CEP8) were utilized to identify CTCs. Cells with features of CK+/CD45-/DAPI+/CEP8 = 2, CK+/CD45-/DAPI+/CEP8 > 2, CK-/CD45-/DAPI+/CEP8 > 2 were defined as pancreatic CTCs. The Kaplan-Meier method and Cox proportional hazards model were used to analyze the relationship of CTC level and other clinicopathological factors with pancreatic cancer clinical outcomes.

RESULTS

CTC count in pancreatic cancer was higher than healthy individuals (median, 3 vs. 0 per 7.5 ml; P < 0.001). SE-iFISH platform yielded a sensitivity of 88% and specificity of 90% in pancreatic cancer at the cutoff value of 2 cells/7.5 ml. Pancreatic cancer patients with lower CTC count (<3/7.5 ml) had substantially better overall survival (OS) compared with these with higher CTC count (≥3/7.5 ml) (15.2 vs. 10.2 months, P = 0.023). Multivariate analysis indicated that higher CTC count was a strong indicator for worse OS (HR = 4.547, P = 0.016).

CONCLUSION

Our current data showed that CTCs could be detected in pancreatic cancer patients in various stages, whether localized, locally advanced and metastatic. Besides, CTCs have shown the potential implication in predicting prognosis of pancreatic cancer.

Reduced expression of caspase-8 and cleaved caspase-3 in pancreatic ductal adenocarcinoma cells

Pancreatic ductal adenocarcinoma (PDAC) is a rare neoplasm that affects the gastrointestinal system, and is characterized by a high mortality rate. It has been demonstrated that apoptosis has a significant role in the regulation of cancer cells. Therefore, the aim of the present study was to immunohistochemically assess the expression of proteins belonging to the caspase family, namely caspase-8, pro-caspase-3 and cleaved (active) caspase-3 in pancreatic cancer. The study group consisted of 29 patients exhibiting PDAC. Protein expression was evaluated by immunohistochemical methods. The expression of caspase-8 in normal cells was negative in 17.2% of cases and positive in 82.8% of cases. All cases demonstrated pro-caspase-3 expression in normal pancreatic cells, compared with 93.1% of cancer cells. Staining for activated caspase-3 was positive in 27 normal tissue cases, compared with positivity in only 10 cancer cases. Caspase-8 expression positively correlated with cleaved caspase-3 expression in the cytoplasm of cancer cells (P<0.002). Caspase-3 expression was identified to correlate with inflammatory peritumoral infiltration (P<0.015). No correlation was observed between caspase expression and any other clinicopathological parameters. The results of the present study demonstrated aberrant initiation of cancer cell apoptosis in PDAC via a decrease in caspase-8 expression, which may lead to disorders in the activation of effector caspase-3.

Multimodal approach and long-term survival in a patient with recurrent metastatic acinar cell carcinoma of the pancreas: A case report

Pancreatic acinar cell carcinoma is an uncommon neoplasm of the exocrine pancreas associated with a poor prognosis, especially when found to be metastatic. Since there are a lack of large studies and prospective, randomized data, no consensus treatment guidelines are available. Here, we report a case of a patient with recurrent metastatic acinar cell carcinoma involving the liver who had presented initially with pancreatic panniculitis. She received chemotherapy with capecitabine and oxaliplatin prior to resection of her primary tumor and liver metastases, after which she experienced a 30 months recurrence-free survival. Upon relapse, she was treated with a combination of capecitabine and oxaliplatin followed by maintenance capecitabine. Now, more than seven years after initial diagnosis, the patient remains stable without evidence of active disease. This case highlights the possibility of therapeutic success even for a patient initially deemed unresectable due to a poor performance status who responded to fluoropyrimidine-based therapy.

Colloid (mucinous non-cystic) carcinoma of the pancreas: A case report

Colloid carcinoma (CC) of the pancreas, also known as mucinous non-cystic carcinoma, is a rare histological variant of pancreatic cancer. The present study reports the case of a 65-year-old male with a pancreatic head tumor 4.6×3.1 cm in size. The tumor had not invaded the superior mesenteric or celiac arteries. Laboratory data showed elevated alkaline phosphatase, γ-gluytamyl transpeptidase and cancer antigen 19-9 (CA19-9) levels. The patient underwent a pancreaticoduodenectomy (PD), and the pathology revealed CC extending to the submucosa of the duodenum, with mild atypical hyperplasia of the pancreatic duct. The patient was negative for circulating tumor cells, indicating a good prognosis. The CA19-9 concentration decreased to within the normal range following surgery. The present study reports a rare case of CC of the pancreas presenting with obstructive jaundice, in which a PD procedure was performed. Primary surgical treatment with curative intent is the optimal management and this subtype of pancreatic cancer is associated with a better prognosis compared with pancreatic ductal adenocarcinoma.

The genetic classification of pancreatic neoplasia

Cancer is caused by the accumulation of inherited and/or acquired alterations in specific genes. The recent decline in the cost of DNA sequencing has allowed tumor sequencing to be conducted on a large scale, which, in turn, has led to an unprecedented understanding of the genetic events that drive neoplasia. This understanding, when integrated with meticulous histologic analyses and with clinical findings, has direct clinical implications. The recent sequencing of all of the major types of cystic and noncystic neoplasms of the pancreas has revealed opportunities for molecular diagnoses and for personalized treatment. This review summarizes the results from these recent studies focusing on the clinical relevance of genomic data.

[Update of the S3 guidelines for pancreatic cancer. What is new for pathologists?]

The S3 guidelines for pancreatic cancer were revised in 2013. Besides the oncological and palliative therapy modalities and surgical therapy, the guidelines for pathologists in topic 3 were updated. The modifications essentially concern the histopathological assessment of surgical specimens and in particular the circumferential resection margin and the R classification. In addition, the current recommendations were amended by recommendations concerning the pathohistological records, which should include the lymph node ratio in the future.

Role of Fine-Needle Aspiration in the Surgical Management of Pancreatic Neuroendocrine Tumors: Utility and Limitations in Light of the New World Health Organization Classification

Context.—Pancreatic neuroendocrine tumors (Panc-NETs) are rare and tend to get overshadowed by their more prevalent and aggressive ductal adenocarcinoma counterparts. The biological behavior of PancNETs is unpredictable, and thus management is controversial. However, the new World Health Organization classification has significantly contributed to the prognostic stratification of these patients. Concurrently, there have been advances in surgical techniques for benign or low-grade pancreatic tumors. These procedures include minimally invasive and parenchyma-sparing operations such as laparoscopy and enucleation.

Objective.—To report on the utility and limitations of fine-needle aspiration in the preoperative evaluation and management of PancNETs.

Design.—This was a retrospective review of our institutional tumor database from 2002 to 2012. There were 25 cases of PancNETs that were localized and staged by medical imaging and diagnosed by fine-needle aspiration.

Results.—Fourteen patients underwent laparotomy, with some requiring only limited surgery; 4 had laparoscopic resections; 4 were serially observed without surgical intervention; and another 3 were inoperable. After a mean follow-up of 37 months, more than half of the patients had no evidence of disease, including most of those who underwent minimally invasive surgery.

Conclusions.—Fine-needle aspiration is a useful diagnostic adjunct to medical imaging in the preoperative evaluation and management of PancNETs. However, there are limitations with regard to grading PancNETs using this technique.

Molecular genetics of pancreatic neoplasms and their morphologic correlates: an update on recent advances and potential diagnostic applications

OBJECTIVES

To summarize the most clinically and biologically relevant advances in molecular/genetic characteristics of various pancreatic neoplasms, with morphologic correlation.

METHODS

Whole-exome sequencing of numerous benign and malignant pancreatic tumors, along with the plethora of highly sensitive molecular studies now available for analyzing these tumors, provide mounting evidence to support the long-held belief that cancer is essentially a genetic disease. These genetic discoveries have not only helped to confirm the age-old, morphology-based classifications of pancreatic neoplasia but have shed new light on their mechanisms. Many of these molecular discoveries are currently being used in preoperative diagnosis.

RESULTS

Mutations in KRAS, P16/CDKN2A, TP53, and SMAD4/DPC4 are commonly seen in ductal neoplasia but not in nonductal tumors; ductal adenocarcinomas with SMAD4/DPC4 loss are associated with widespread metastasis and poor prognosis. GNAS and RNF43 mutations have been discovered in most intraductal pancreatic mucinous neoplasms, providing critical molecular fingerprints for their diagnosis. Mutation in DAXX/ATRX is only seen in pancreatic neuroendocrine tumors, making it a useful potential marker in distinguishing these tumors from mimics.

CONCLUSIONS

When combined with morphologic observations, molecular studies will increase our understanding of the pathogenesis and morphomolecular signatures associated with specific neoplasms and provide new horizons for precision medicine and targeted therapies.

The anti-tumor effect of HDAC inhibition in a human pancreas cancer model is significantly improved by the simultaneous inhibition of cyclooxygenase 2

Pancreatic ductal adenocarcinoma is the fourth leading cause of cancer death worldwide, with no satisfactory treatment to date. In this study, we tested whether the combined inhibition of cyclooxygenase-2 (COX-2) and class I histone deacetylase (HDAC) may results in a better control of pancreatic ductal adenocarcinoma. The impact of the concomitant HDAC and COX-2 inhibition on cell growth, apoptosis and cell cycle was assessed first in vitro on human pancreas BxPC-3, PANC-1 or CFPAC-1 cells treated with chemical inhibitors (SAHA, MS-275 and celecoxib) or HDAC1/2/3/7 siRNA. To test the potential antitumoral activity of this combination in vivo, we have developed and characterized, a refined chick chorioallantoic membrane tumor model that histologically and proteomically mimics human pancreatic ductal adenocarcinoma. The combination of HDAC1/3 and COX-2 inhibition significantly impaired proliferation of BxPC-3 cells in vitro and stalled entirely the BxPC-3 cells tumor growth onto the chorioallantoic membrane in vivo. The combination was more effective than either drug used alone. Consistently, we showed that both HDAC1 and HDAC3 inhibition induced the expression of COX-2 via the NF-kB pathway. Our data demonstrate, for the first time in a Pancreatic Ductal Adenocarcinoma (PDAC) model, a significant action of HDAC and COX-2 inhibitors on cancer cell growth, which sets the basis for the development of potentially effective new combinatory therapies for pancreatic ductal adenocarcinoma patients.