YAP/BRD4-controlled ROR1 promotes tumor-initiating cells and hyperproliferation in pancreatic cancer.

Tumor-initiating cells are major drivers of chemoresistance and attractive targets for cancer therapy, however, their identity in human pancreatic ductal adenocarcinoma (PDAC) and the key molecules underlying their traits remain poorly understood. Here, we show that a cellular subpopulation with partial epithelial-mesenchymal transition (EMT)-like signature marked by high expression of receptor tyrosine kinase-like orphan receptor 1 (ROR1) is the origin of heterogeneous tumor cells in PDAC. We demonstrate that ROR1 depletion suppresses tumor growth, recurrence after chemotherapy, and metastasis. Mechanistically, ROR1 induces the expression of Aurora kinase B (AURKB) by activating E2F through c-Myc to enhance PDAC proliferation. Furthermore, epigenomic analyses reveal that ROR1 is transcriptionally dependent on YAP/BRD4 binding at the enhancer region, and targeting this pathway reduces ROR1 expression and prevents PDAC growth. Collectively, our findings reveal a critical role for ROR1high cells as tumor-initiating cells and the functional importance of ROR1 in PDAC progression, thereby highlighting its therapeutic targetability.

Organoids for Functional Precision Medicine in Advanced Pancreatic Cancer.

BACKGROUND & AIMS: Patient-derived organoids (PDOs) are promising tumor avatars that could enable ex vivo drug tests to personalize patients' treatments in the frame of functional precision oncology. However, clinical evidence remains scarce. This study aims to evaluate whether PDOs can be implemented in clinical practice to benefit patients with advanced refractory pancreatic ductal adenocarcinoma (PDAC). METHODS: During 2021 to 2022, 87 patients were prospectively enrolled in an institutional review board-approved protocol. Inclusion criteria were histologically confirmed PDAC with the tumor site accessible. A panel of 25 approved antitumor therapies (chemogram) was tested and compared to patient responses to assess PDO predictive values and map the drug sensitivity landscape in PDAC. RESULTS: Fifty-four PDOs were generated from 87 pretreated patients (take-on rate, 62%). The main PDO mutations were KRAS (96%), TP53 (88%), and CDKN2A/B (22%), with a 91% concordance rate with their tumor of origin. The mean turnaround time to chemogram was 6.8 weeks. In 91% of cases, ≥1 hit was identified (gemcitabine (n = 20 of 54), docetaxel (n = 18 of 54), and vinorelbine (n = 17 of 54), with a median of 3 hits/patient (range, 0-12). Our cohort included 34 evaluable patients with full clinical follow-up. We report a chemogram sensitivity of 83.3% and specificity of 92.9%. The overall response rate and progression-free survival were higher when patients received a hit treatment as compared to patients who received a nonhit drug (as part of routine management). Finally, we leveraged our PDO collection as a platform for drug validation and combo identification. We tested anti-KRASG12D (MRTX1133), alone or combined, and identified a specific synergy with anti-EGFR therapies in KRASG12D variants. CONCLUSIONS: We report the largest prospective study aiming at implementing PDO-based functional precision oncology and identify very robust predictive values in this clinical setting. In a clinically relevant turnaround time, we identify putative hits for 91% of patients, providing unexpected potential survival benefits in this very aggressive indication. Although this remains to be confirmed in interventional precision oncology trials, PDO collection already provides powerful opportunities for drugs and combinatorial treatment development.

Endoplasmic reticulum stress regulators exhibit different prognostic, therapeutic and immune landscapes in pancreatic adenocarcinoma.

Endoplasmic reticulum stress (ERS) and unfolded protein response are the critical processes of tumour biology. However, the roles of ERS regulatory genes in pancreatic adenocarcinoma (PAAD) remain elusive. A novel ERS-related risk signature was constructed using the Lasso regression analysis. Its prognostic value, immune effect, metabolic influence, mutational feature and therapeutic correlation were comprehensively analysed through multiple bioinformatic approaches. The biofunctions of KDELR3 and YWHAZ in pancreatic cancer (PC) cells were also investigated through colony formation, Transwell assays, flow cytometric detection and a xenograft model. The upstream miRNA regulatory mechanism of KDELR3 was predicted and validated. ERS risk score was identified as an independent prognostic factor and could improve traditional prognostic model. Meanwhile, it was closely associated with metabolic reprogramming and tumour immune. High ERS risk enhanced glycolysis process and nucleotide metabolism, but was unfavourable for anti-tumour immune response. Moreover, ERS risk score could act as a potential biomarker for predicting the efficacy of ICBs. Overexpression of KDELR3 and YWHAZ stimulated the proliferation, migration and invasion of SW1990 and BxPC-3 cells. Silencing KDELR3 suppressed tumour growth in a xenograft model. miR-137 could weaken the malignant potentials of PC cells through inhibiting KDELR3 (5'-AGCAAUAA-3'). ERS risk score greatly contributed to PAAD clinical assessment. KDELR3 and YWHAZ possessed cancer-promoting capacities, showing promise as a novel treatment target.

Activation of the PI3K/AKT signaling pathway by ARNTL2 enhances cellular glycolysis and sensitizes pancreatic adenocarcinoma to erlotinib.

BACKGROUND: Pancreatic adenocarcinoma (PC) is an aggressive malignancy with limited treatment options. The poor prognosis primarily stems from late-stage diagnosis and when the disease has become therapeutically challenging. There is an urgent need to identify specific biomarkers for cancer subtyping and early detection to enhance both morbidity and mortality outcomes. The addition of the EGFR tyrosine kinase inhibitor (TKI), erlotinib, to gemcitabine chemotherapy for the first-line treatment of patients with advanced pancreatic cancer slightly improved outcomes. However, restricted clinical benefits may be linked to the absence of well-characterized criteria for stratification and dependable biomarkers for the prediction of treatment effectiveness. METHODS AND RESULTS: We examined the levels of various cancer hallmarks and identified glycolysis as the primary risk factor for overall survival in PC. Subsequently, we developed a glycolysis-related score (GRS) model to accurately distinguish PC patients with high GRS. Through in silico screening of 4398 compounds, we discovered that erlotinib had the strongest therapeutic benefits for high-GRS PC patients. Furthermore, we identified ARNTL2 as a novel prognostic biomarker and a predictive factor for erlotinib treatment responsiveness in patients with PC. Inhibition of ARNTL2 expression reduced the therapeutic efficacy, whereas increased expression of ARNTL2 improved PC cell sensitivity to erlotinib. Validation in vivo using patient-derived xenografts (PDX-PC) with varying ARNTL2 expression levels demonstrated that erlotinib monotherapy effectively halted tumor progression in PDX-PC models with high ARNTL2 expression. In contrast, PDX-PC models lacking ARNTL2 did not respond favorably to erlotinib treatment. Mechanistically, we demonstrated that the ARNTL2/E2F1 axis-mediated cellular glycolysis sensitizes PC cells to erlotinib treatment by activating the PI3K/AKT signaling pathway. CONCLUSIONS: Our investigations have identified ARNTL2 as a novel prognostic biomarker and predictive indicator of sensitivity. These results will help to identify erlotinib-responsive cases of PC and improve treatment outcomes. These findings contribute to the advancement of precision oncology, enabling more accurate and targeted therapeutic interventions.

Clinical and molecular features of early onset pancreatic adenocarcinoma.

Pancreatic adenocarcinoma (PDAC) is a major health burden and may become the second cause of death by cancer in developed countries. The incidence of early-onset pancreatic cancer (EOPC, defined by an age at diagnosis <50 years old) is increasing. Here, we conducted a study of all PDAC patients followed at our institution. Patients were classified as EOPC or non-early onset (nEOPC, >50). Eight hundred and seventy eight patients were included, of which 113 EOPC, exhibiting a comparable performance status. EOPC were more often diagnosed at the metastatic stage (70.0% vs 58.3%) and liver metastases were more prevalent at diagnosis (60.2% vs. 43.9%). The median overall survival (OS) from diagnosis was 18.1 months, similar between EOPC and nEOPC. Among patients who underwent surgery, recurrence-free survival was similar between age groups. Among metastatic patients, first line progression free survival was similar but EOPC received more treatment lines (72.3% vs. 58.1% received ≥2 lines). Regarding molecular alterations, the mean tumor mutational burden (TMB) was lower in EOPC (1.42 vs. 2.95 mut/Mb). The prevalence of KRAS and BRCA1/2 mutations was similar, but EOPC displayed fewer alterations in CNKN2A/B. Fifty eight patients (18.6%) had actionable alterations (ESCAT I-III) and 31 of them received molecularly matched treatments. On the transcriptomic level, despite its clinical aggressiveness, EOPC was less likely to display a basal-like phenotype. To conclude, EOPC were diagnosed more frequently at the metastatic stage. OS and 1st line PFS were similar to nEOPC. EOPC displayed specific molecular features, such as a lower TMB and fewer alterations in CDKN2A/B.

Clinical outcomes of liposomal irinotecan in patients with advanced pancreatic cancer previously treated with conventional irinotecan: A meta-analysis of real-world evidence.

BACKGROUND: Pivotal clinical trials supported survival benefits of liposomal irinotecan (nal-IRI) plus fluorouracil/leucovorin in patients with pancreatic ductal adenocarcinoma (PDAC) who previously received gemcitabine-based therapy. There are concerns about the benefits of nal-IRI in patients who received FOLFIRINOX (combined fluorouracil, leucovorin, IRI, and oxaliplatin) because of potential cross-resistance to IRI. The objective of this meta-analysis was to characterize the impact of the previous receipt of IRI on the outcomes of nal-IRI regimens in patients with advanced PDAC. METHODS: Real-world studies evaluating the outcomes of nal-IRI in patients who had prior IRI exposure published up to April 2023 were searched using electronic databases. The meta-analysis was conducted using a random effects model to estimate pooled hazard ratios (HRs) and 95% confidence intervals (CIs). RESULTS: Eight studies (n = 1368 patients) were included. The pooled median progression-free survival (PFS) was 2.02 months (95% CI, 1.43-2.57 months), and the median overall survival (OS) was 4.26 months (95% CI, 3.03-5.39 months). Patients with prior IRI exposure had PFS (HR, 1.17; 95% CI, 0.94-1.47; p = .17) and OS (HR, 1.16; 95% CI, 0.95-1.42; p = .16) comparable to patients without prior IRI exposure. Likewise, patients who had progressive disease on conventional IRI had PFS (HR, 1.50; 95% CI, 0.73-3.08; p = .24) and OS (HR, 1.70; 95% CI, 0.68-4.27; p = .26) with nal-IRI comparable to patients who had no progressive disease. CONCLUSIONS: Prior IRI exposure does not affect the survival outcomes of nal-IRI regimens in patients who have advanced PDAC. The selection of later lines of chemotherapy regimens should be based on the differential safety profile, patient status, the cost of treatment, and health-related quality of life.

Association of personalized and tumor-informed ctDNA with patient survival outcomes in pancreatic adenocarcinoma.

INTRODUCTION: Personalized and tumor-informed circulating tumor DNA (ctDNA) testing is feasible and allows for molecular residual disease (MRD) identification in patients with pancreatic ductal adenocarcinoma (PDAC). METHODS: In this retrospective analysis of commercial cases from multiple US institutions, personalized, tumor-informed, whole-exome sequenced, and germline-controlled ctDNA levels were quantified and analyzed in patients with PDAC. Plasma samples (n = 1329) from 299 clinically validated patients were collected at diagnosis, perioperatively (MRD-window; within 2-12 weeks after surgery, before therapy), and during surveillance (>12 weeks post-surgery if no ACT or starting 4 weeks post-ACT) from November 2019 to March 2023. RESULTS: Of the initially diagnosed patients with stages I-III PDAC who went for resection, the median follow-up time from surgery was 13 months (range 0.1-214). Positive ctDNA detection rates were 29% (29/100) and 29.6% (45/152) during the MRD and surveillance windows, respectively. Positive ctDNA detection was significantly associated with shorter DFS within the MRD window (median DFS of 6.37 months for ctDNA-positive vs 33.31 months for ctDNA-negative patients; HR: 5.45, P < .0001) as well as during the surveillance period (median DFS: 11.40 months for ctDNA-positive vs NR for ctDNA-negative; HR: 12.38, P < .0001). Additionally, DFS was significantly better with KRAS wildtype status followed by KRASG12R (HR: 0.99, P = .97), KRASG12D (HR: 1.42, P = .194), and worse with KRASG12V (HR: 2.19, P = .002) status. In multivariate analysis, ctDNA detection at surveillance was found to be the most significant prognostic factor for recurrence (HR: 24.28, P < .001). CONCLUSIONS: Perioperative tumor-informed ctDNA detection in PDAC is feasible across all stages and is associated with patient survival outcomes.

IL-2 promotes expansion and intratumoral accumulation of tumor infiltrating dendritic cells in pancreatic cancer.

This study aims to investigate the diagnostic potential of IL-2 for PDAC and develop a method to improve the dendritic cell (DC) based vaccine against PDAC. The gene expression data and clinical characteristics information for 178 patients with PDAC were obtained from The Cancer Genome Atlas (TCGA). DCs were isolated from Human peripheral blood mononuclear cells (PBMCs) and were cultured in 4 different conditions. DCs were pulsed by tumor cell lysates or KRAS G12D1 - 23 peptide, and then used to activate T cells. The mixture of DCs and T cells were administered to xenograft mouse model through the tail vein. The infiltration of DCs and T cells were detected by immunohistochemistry. The generation of KRAS G12D mutation specific cytotoxic T cells was determined by in vitro killing assay. We observed that PDAC patients with higher IL-2 mRNA levels exhibited improved overall survival and increased infiltration of CD8 + T cells, NK cells, naïve B cells, and resting myeloid DCs in the tumor microenvironment. IL-2 alone did not enhance DC proliferation, antigen uptake, or apoptosis inhibition unless co-cultured with PBMCs. DCs co-cultured with PBMCs in IL-2-containing medium demonstrated the strongest tumor repression effect in vitro and in vivo. Compared to DCs obtained through the traditional method (cultured in medium containing GM-CSF and IL-4), DCs cultured with PBMCs, and IL-2 exhibited increased tumor infiltration capacity, potentially facilitating sustained T cell immunity. DCs cultured in the PBMCs-IL-2 condition could promote the generation of cytotoxic T cells targeting tumor cells carrying KRAS G12D mutation.

Machine learning-based identification of biomarkers and drugs in immunologically cold and hot pancreatic adenocarcinomas.

BACKGROUND: Pancreatic adenocarcinomas (PAADs) often exhibit a "cold" or immunosuppressive tumor milieu, which is associated with resistance to immune checkpoint blockade therapy; however, the underlying mechanisms are incompletely understood. Here, we aimed to improve our understanding of the molecular mechanisms occurring in the tumor microenvironment and to identify biomarkers, therapeutic targets, and potential drugs to improve PAAD treatment. METHODS: Patients were categorized according to immunologically hot or cold PAAD subtypes with distinct disease outcomes. Cox regression and weighted correlation network analysis were performed to construct a novel gene signature, referred to as 'Downregulated in hot tumors, Prognostic, and Immune-Related Genes' (DPIRGs), which was used to develop prognostic models for PAAD via machine learning (ML). The role of DPIRGs in PAAD was comprehensively analyzed, and biomarker genes able to distinguish PAAD immune subtypes and predict prognosis were identified by ML. The expression of biomarkers was verified using public single-cell transcriptomic and proteomic resources. Drug candidates for turning cold tumors hot and corresponding target proteins were identified via molecular docking studies. RESULTS: Using the DPIRG signature as input data, a combination of survival random forest and partial least squares regression Cox was selected from 137 ML combinations to construct an optimized PAAD prognostic model. The effects and molecular mechanisms of DPIRGs were investigated by analysis of genetic/epigenetic alterations, immune infiltration, pathway enrichment, and miRNA regulation. Biomarkers and potential therapeutic targets, including PLEC, TRPV1, and ITGB4, among others, were identified, and the cell type-specific expression of the biomarkers was validated. Drug candidates, including thalidomide, SB-431542, and bleomycin A2, were identified based on their ability to modulate DPIRG expression favorably. CONCLUSIONS: By combining multiple ML algorithms, we developed a novel prognostic model with excellent performance in PAAD cohorts. ML also proved to be powerful for identifying biomarkers and potential targets for improved PAAD patient stratification and immunotherapy.

Insights into gemcitabine resistance in pancreatic cancer: association with metabolic reprogramming and TP53 pathogenicity in patient derived xenografts.

BACKGROUND: With poor prognosis and high mortality, pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies. Standard of care therapies for PDAC have included gemcitabine for the past three decades, although resistance often develops within weeks of chemotherapy initiation through an array of possible mechanisms. METHODS: We reanalyzed publicly available RNA-seq gene expression profiles of 28 PDAC patient-derived xenograft (PDX) models before and after a 21-day gemcitabine treatment using our validated analysis pipeline to identify molecular markers of intrinsic and acquired resistance. RESULTS: Using normalized RNA-seq quantification measurements, we first identified oxidative phosphorylation and interferon alpha pathways as the two most enriched cancer hallmark gene sets in the baseline gene expression profile associated with intrinsic gemcitabine resistance and sensitivity, respectively. Furthermore, we discovered strong correlations between drug-induced expression changes in glycolysis and oxidative phosphorylation genes and response to gemcitabine, which suggests that these pathways may be associated with acquired gemcitabine resistance mechanisms. Thus, we developed prediction models using baseline gene expression profiles in those pathways and validated them in another dataset of 12 PDAC models from Novartis. We also developed prediction models based on drug-induced expression changes in genes from the Molecular Signatures Database (MSigDB)'s curated 50 cancer hallmark gene sets. Finally, pathogenic TP53 mutations correlated with treatment resistance. CONCLUSION: Our results demonstrate that concurrent upregulation of both glycolysis and oxidative phosphorylation pathways occurs in vivo in PDAC PDXs following gemcitabine treatment and that pathogenic TP53 status had association with gemcitabine resistance in these models. Our findings may elucidate the molecular basis for gemcitabine resistance and provide insights for effective drug combination in PDAC chemotherapy.

Circ_0002395 promotes aerobic glycolysis and proliferation in pancreatic adenocarcinoma cells via miR-548c-3p/PDK1 axis.

Circular RNAs (circRNAs) showing unusual expressions have been discovered in pancreatic adenocarcinoma (PAAD). However, the functions and underlying mechanisms of these circRNAs still remain largely unclear. Our current study discovered a notable increase in the expression of circRNA hsa_circ_0002395 (circ_0002395) in both PAAD tissues and cell lines. This up-regulation of circ_0002395 was found to be associated with larger tumor sizes and lymph node metastasis. Furthermore, our findings showed that circ_0002395 facilitated aerobic glycolysis and cell proliferation in PAAD cells by regulating the miR-548c-3p/PDK1 axis. Mechanistically, we identified circ_0002395 as a competing endogenous RNA (ceRNA) that sponged miR-548c-3p, thereby promoting PDK1 expression and aerobic glycolysis, and ultimately resulting in the enhancement of cell proliferation. Our findings found that circ_0002395 promoted proliferation of PAAD cells by enhancing PDK1 expression and aerobic glycolysis by sponging miR-548c-3p.

Impact on Survival of Early Versus Late Initiation of Adjuvant Chemotherapy After Pancreatic Adenocarcinoma Surgery: A Target Trial Emulation.

BACKGROUND: We examined the impact of early (0-4 weeks after discharge) versus late (> 4-8 weeks after discharge) initiation of adjuvant chemotherapy on pancreatic adenocarcinoma survival. METHODS: We used Danish population-based healthcare registries to emulate a hypothetical target trial using the clone-censor-weight approach. All eligible patients were cloned with one clone assigned to 'early initiation' and one clone assigned to 'late initiation'. Clones were censored when the assigned treatment was no longer compatible with the actual treatment. Informative censoring was addressed using inverse probability of censoring weighting. RESULTS: We included 1491 patients in a hypothetical target trial, of whom 32.3% initiated chemotherapy within 0-4 weeks and 38.3% between > 4 and 8 weeks after discharge for pancreatic adenocarcinoma surgery; 206 (13.8%) initiated chemotherapy after > 8 weeks, and 232 (15.6%) did not initiate chemotherapy. Median overall survival was 30.4 and 29.9 months in late and early initiators, respectively. The absolute differences in OS, comparing late with early initiators, were 3.2% (95% confidence interval [CI] - 1.5%, 7.9%), - 0.7% (95% CI - 7.2%, 5.8%), and 3.2% (95% CI - 2.8%, 9.3%) at 1, 3, and 5 years, respectively. Late initiators had a higher increase in albumin levels as well as higher pretreatment albumin values. CONCLUSIONS: Postponement of adjuvant chemotherapy up to 8 weeks after discharge from pancreatic adenocarcinoma surgery is safe and may allow more patients to receive adjuvant therapy due to better recovery.

To Revise or Not Revise? Isolated Margin Positivity in Localized Pancreatic Ductal Adenocarcinoma.

BACKGROUND: The study determined the proportion of patients with pancreatic adenocarcinoma (PDAC) who had margin-positive disease and no other adverse pathologic findings (APF) using institutional and administrative datasets. METHODS: Patients with clinical stage I or II PDAC in the National Cancer Database (NCDB 2010-2020) and those who underwent pancreatectomy at the authors' institution (2010-2021) were identified. Isolated margin positivity (IMP) was defined as a positive surgical margin with no APF (negative nodes, no lymphovascular/perineural invasion). RESULTS: The study included 225 patients from the authors' institution and 23,598 patients from the NCDB. The margin-positive rates were 21.8% and 20.3%, and the IMP rates were 0.4% and 0.5%, respectively. In the institutional cohort, 68.4% of the patients had recurrence, and most of the patients (65.6%) had distant recurrences. The median recurrence-free survival (RFS) was 63.3 months for no APF, not reached for IMP, 14.8 months for negative margins & 1 APF, 20.3 months for positive margins & 2 APFs, and 12.9 months with all APF positive. The patients in the NCDB with IMP had a lower median OS than the patients with no APF (20.5 vs 390 months), but a higher median OS than those with margin positivity plus 1 APF (20.5 vs 18.0 months) or all those with APF positivity (20.5 vs 15.4 months). Based on institutional rates of IMP, any margin positivity, neck margin positivity (NMP), and no APF, the fraction of patients who might benefit from neck margin revision was 1 in 100,000, and those likely to benefit from any margin revision was 1 in 18,500. In the NCDB, those estimated to derive potential benefit from margin revision was 1 in 25,000. CONCLUSIONS: Isolated margin positivity in resected PDAC is rare, and most patients experience distant recurrence. Revision of IMP appears unlikely to confer benefit to most patients.

Serum CEA as a Prognostic Marker for Overall Survival in Patients with Localized Pancreatic Adenocarcinoma and Non-Elevated CA19-9 Levels Treated with FOLFIRINOX as Initial Treatment: A TAPS Consortium Study.

INTRODUCTION: About 25% of patients with localized pancreatic adenocarcinoma have non-elevated serum carbohydrate antigen (CA) 19-9 levels at baseline, hampering evaluation of response to preoperative treatment. Serum carcinoembryonic antigen (CEA) is a potential alternative. METHODS: This retrospective cohort study from five referral centers included consecutive patients with localized pancreatic adenocarcinoma (2012-2019), treated with one or more cycles of (m)FOLFIRINOX, and non-elevated CA19-9 levels (i.e., < 37 U/mL) at baseline. Cox regression analyses were performed to assess prognostic factors for overall survival (OS), including CEA level at baseline, restaging, and dynamics. RESULTS: Overall, 277 patients were included in this study. CEA at baseline was elevated (≥5 ng/mL) in 53 patients (33%) and normalized following preoperative therapy in 14 patients (26%). In patients with elevated CEA at baseline, median OS in patients with CEA normalization following preoperative therapy was 33 months versus 19 months in patients without CEA normalization (p = 0.088). At time of baseline, only elevated CEA was independently associated with (worse) OS (hazard ratio [HR] 1.44, 95% confidence interval [CI] 1.04-1.98). At time of restaging, elevated CEA at baseline was still the only independent predictor for (worse) OS (HR 1.44, 95% CI 1.04-1.98), whereas elevated CEA at restaging (HR 1.16, 95% CI 0.77-1.77) was not. CONCLUSIONS: Serum CEA was elevated in one-third of patients with localized pancreatic adenocarcinoma having non-elevated CA19-9 at baseline. At both time of baseline and time of restaging, elevated serum CEA measured at baseline was the only predictor for (worse) OS. Therefore, serum CEA may be a useful tool for decision making at both initial staging and time of restaging in patients with non-elevated CA19-9.

Quantitative proteomic analysis of HER2 protein expression in PDAC tumors.

Metastatic pancreatic adenocarcinoma (PDAC) is the third leading cause of cancer-related death in the United States, with a 5-year survival rate of only 11%, necessitating identification of novel treatment paradigms. Tumor tissue specimens from patients with PDAC, breast cancer, and other solid tumor malignancies were collected and tumor cells were enriched using laser microdissection (LMD). Reverse phase protein array (RPPA) analysis was performed on enriched tumor cell lysates to quantify a 32-protein/phosphoprotein biomarker panel comprising known anticancer drug targets and/or cancer-related total and phosphorylated proteins, including HER2Total, HER2Y1248, and HER3Y1289. RPPA analysis revealed significant levels of HER2Total in PDAC patients at abundances comparable to HER2-positive (IHC 3+) and HER2-low (IHC 1+ /2+ , FISH-) breast cancer tissues, for which HER2 screening is routinely performed. These data support a critical unmet need for routine clinical evaluation of HER2 expression in PDAC patients and examination of the utility of HER2-directed antibody-drug conjugates in these patients.

Pancreatic adenocarcinoma third line systemic treatments: a retrospective cohort study.

BACKGROUND: Chemotherapy for metastatic pancreatic adenocarcinoma (PDAC) primarily relies on FOLFIRINOX (LV5FU- irinotecan - Oxaliplatine) and Gemcitabine - Nab-Paclitaxel in the first-line setting. However, second-lines remain less well-defined and there is limited data regarding third-line treatments. The objective of our study was to determine the proportion of patients advancing to third line chemotherapy, to outline the various third-line chemotherapy regimens used in routine practice and to evaluate their respective efficacy. METHODS: A retrospective single-center cohort from 2010-2022 compiled baseline characteristics, treatment outcomes and survival of PDAC patients who received at least one chemotherapy line in a French tertiary-center. Overall survivals (OS) were analyzed using a Cox multivariable model. RESULTS: In total, 676 patients were included, with a median follow-up time of 69.4 months, (Interquartile Range (IQR) = 72.1). Of these, 251 patients (37%) that proceeded to 3rd-line chemotherapy. The median PFS in 3rd line was 2.03 months, [CI95%: 1.83, 2.36]. The median 3rd line overall survival was 5.5 months, [CI95%: 4.8, 6.3]. In multivariable analysis erlotinib-based chemotherapy was found to be deleterious (HR=2.38, [CI95%: 1.30, 4.34], p=0.005) compared to fluoropyrimidine-based chemotherapy in terms of 3rd line overall survival while gemcitabine monotherapy showed a tendency towards negative outcomes. First and 2nd line chemotherapies sequence didn't influence 3rd line outcome. CONCLUSION: In our cohort, one-third of treated patients proceeded to 3rd line chemotherapy resulting in a 5.5 months median 3rd line OS, consistent with treatments at advanced stage. Our results argue against the use of erlotinib and gemcitabine monotherapy.

Impact of previous S-1 treatment on efficacy of liposomal irinotecan plus 5-fluorouracil and leucovorin in patients with metastatic pancreatic cancer.

BACKGROUND/OBJECTIVES: Liposomal irinotecan plus 5-fluorouracil and leucovorin (nal-IRI + 5-FU/LV) provides survival benefits for metastatic pancreatic adenocarcinoma (mPDAC) refractory to gemcitabine-based treatment, mainly gemcitabine plus nab-paclitaxel (GA), in current practice. Gemcitabine plus S-1 (GS) is another commonly administered first-line regimen before nab-paclitaxel reimbursement; however, the efficacy and safety of nal-IRI + 5-FU/LV for mPDAC after failed GS treatment has not been reported and was therefore explored in this study. METHODS: In total, 177 patients with mPDAC received first-line GS or GA treatment, followed by second-line nal-IRI + 5-FU/LV treatment (identified from a multicenter retrospective cohort in Taiwan from 2018 to 2020); 85 and 92 patients were allocated to the GS and GA groups, respectively. Overall survival (OS), time-to-treatment failure (TTF), and adverse events were compared between the two groups. RESULTS: The baseline characteristics of the two groups were generally similar; however, a higher median age (67 versus 62 years, p < 0.001) and fewer liver metastases (52% versus 78%, p < 0.001) were observed in the GS versus GA group. The median OS was 15.0 and 15.9 months in the GS and GA groups, respectively (p = 0.58). The TTF (3.1 versus 2.8 months, p = 0.36) and OS (7.6 versus 6.7 months, p = 0.83) after nal-IRI treatment were similar between the two groups. More patients in the GS group developed mucositis during nal-IRI treatment (15% versus 4%, p = 0.02). CONCLUSIONS: The efficacy of second-line nal-IRI +5-FU/LV treatment was unaffected by prior S-1 exposure. GS followed by nal-IRI treatment is an alternative treatment sequence for patients with mPDAC.

Venous thromboembolism in patients with pancreatic adenocarcinoma: Disease burden and initiation of ambulatory thromboprophylaxis.

BACKGROUND/OBJECTIVES: Ambulatory thromboprophylaxis (AT) in patients with pancreatic adenocarcinoma (PAC) reduces venous thromboembolism (VTE) risk and is recommended for patients receiving systemic chemotherapy. We evaluated VTE rates, severity, timing, and risk factors in PAC patients as well as AT rates and initiation times. METHODS: Patients diagnosed with PAC were included. Data collected included patient demographics, medical history, PAC diagnosis, development of VTE, AT, and bleeding episodes. VTE was defined as a DVT or a PE. Patients were classified as receiving AT for VTE prevention if they received a prescription for outpatient anticoagulation. RESULTS: The cohort included 243 PAC patients. VTE occurred in 24 %. Overall, 52 % developing VTE were hospitalized and 5 % died as a result of the VTE. Of those who developed VTE 50 % were diagnosed within the first 2 months of PAC diagnosis. Univariate predictors of elevated VTE risk included an elevated Onkotev score, metastasis at diagnosis, male gender and not receiving AT. Multivariate predictors of elevated VTE risk included male gender (P = 0.014) and not receiving AT (P = 0.001). Overall, 30 % of patients received AT. The median time from diagnosis to initiation of AT was 43 days. Major bleeding occurred in 5.8 %. Patients receiving AT were not at a significantly increased risk of major bleeding (p = 0.5). Patients with intestinal tumor invasion were at significantly increased risk of major bleeding (P = 0.021). CONCLUSION: VTE risk is significant and morbid in PAC patients. AT rates are low, and initiation is often delayed. Therapeutic endoscopists diagnosing PAC may be helpful in AT initiation.

K-ras gene mutation analysis to diagnosis pancreatic adenocarcinoma from endoscopic ultrasound-guided tissue acquisition; a systematic review and meta-analysis.

BACKGROUND: Endoscopic ultrasound-guided tissue acquisition (EUS-TA) has high sensitivity for the pathological diagnosis of pancreatic masses, but also a high false-negative rate. K-ras gene mutations occur in over 75 % of pancreatic ductal adenocarcinomas (PDAC), and this meta-analysis evaluated the utility of detecting K-ras gene mutations from EUS-TA specimens for the diagnosis of PDAC. METHODS: Relevant studies in PubMed, the Cochrane Library, and Web of Science were systematically searched. Meta-analysis was performed on data from the selected studies using a bivariate model to provide pooled values of sensitivity, specificity, and their 95 % confidence intervals (CIs). RESULTS: This meta-analysis included 1521 patients (from 10 eligible studies) who underwent EUS-TA with K-ras gene mutation analysis for diagnosis of pancreatic solid masses. The pooled estimates of sensitivity and specificity were 76.6 % (95 % CI, 70.9-81.5 %) and 97.0 % (95 % CI, 94.0-98.5 %), respectively, for pathological diagnosis, 75.9 % (95 % CI 69.5-81.4 %) and 95.3 % (95 % CI, 92.3-97.2 %) for K-ras gene mutation analysis, and 88.7 % (95 % CI 87.1-91.7 %) and 94.9 % (95 % CI, 91.5-97.0 %) for pathological diagnosis in combination with K-ras gene mutation analysis. The sensitivity for diagnosis of PDAC was significantly higher for pathological diagnosis in combination with K-ras gene mutation analysis than for pathological diagnosis or K-ras gene mutation analysis alone (both, p < 0.001). There was no difference in specificity between pathological diagnosis in combination with K-ras gene mutation analysis and both either (p = 0.234, 0.945, respectively). CONCLUSIONS: K-ras gene mutation analysis in combination with to pathological diagnosis of EUS-TA increases the accuracy of differential diagnosis of PDAC.

Perineural invasion score system and clinical outcomes in resected pancreatic cancer patients.

BACKGROUND/OBJECTIVES: Perineural invasion (PNI), classified according to its presence or absence in tumor specimens, is recognized as a poor prognostic factor in pancreatic ductal adenocarcinoma (PDAC) patients. Herein, we identified five histological features of PNI and investigated their impact on survival outcomes of PDAC resected patients. METHODS: Five histopathological features of PNI (diameter, number, site, sheath involvement, and mitotic figures within perineural invasion) were combined in an additional final score (ranging from 0 to 8), and clinical data of PDAC patients were retrospectively analyzed. PNI + patients were stratified in two categories according to the median score value (<6 and ≥ 6, respectively). Impact of PNI on disease-free survival (DFS) and overall survival (OS) were analyzed. RESULTS: Forty-five patients were enrolled, of whom 34 with PNI (PNI+) and 11 without PNI (PNI-). The DFS was 11 months vs. not reached (NR) (p = 0.258), while the OS was 19 months vs. NR (p = 0.040) in PNI+ and PNI- patients, respectively. A ≥6 PNI was identified as an independent predictor of worse OS vs. <6 PNI + patients (29 vs. 11 months, p < 0.001) and <6 PNI+ and PNI- patients (43 vs. 11 months, p < 0.001). PNI ≥6 was an independent negative prognostic factor of DFS vs. <6 PNI+ and PNI- patients (13 vs. 6 months, p = 0.022). CONCLUSIONS: We report a PNI scoring system that stratifies surgically-treated PDAC patients in a graded manner that correlates with patient prognosis better than the current dichotomous (presence/absence) definition. However, further and larger studies are needed to support this PNI scoring system.