Survival In Pancreatic Ductal Adenocarcinoma Research Articles

Prognostic impact of osteosarcopenia in patients undergoing pancreatic resection for pancreatic ductal adenocarcinoma.

We investigated the prognostic impact of osteosarcopenia, defined as the combination of osteopenia and sarcopenia, in patients undergoing pancreatic resection for pancreatic ductal adenocarcinoma (PDAC). The relationship of osteosarcopenia with disease-free survival and overall survival was analyzed in 183 patients who underwent elective pancreatic resection for PDAC. Computed tomography was used to measure the pixel density in the midvertebral core of the 11th thoracic vertebra for evaluation of osteopenia and in the psoas muscle area of the 3rd lumbar vertebra for evaluation of sarcopenia. Osteosarcopenia was defined as the simultaneous presence of both osteopenia and sarcopenia. The study employed a retrospective design to examine the relationship between osteosarcopenia and survival outcomes. Osteosarcopenia was identified in 61 (33%) patients. In the univariate analysis, disease-free survival was significantly worse in patients with male sex (p = 0.031), pathological stage ≥ III PDAC (p = 0.001), NLR, ≥ 2.71 (p = 0.041), sarcopenia (p = 0.027), osteopenia (p = 0.001), and osteosarcopenia (p < 0.001), and overall survival was significantly worse in patients with male sex (p = 0.001), pathological stage ≥ III PDAC (p = 0.001), distal pancreatectomy (p = 0.025), sarcopenia (p = 0.003), osteopenia (p < 0.001), and osteosarcopenia (p < 0.001). In the multivariate analysis, the independent predictors of disease-free survival were osteosarcopenia (p < 0.001) and pathological stage ≥ III PDAC (p = 0.002), and the independent predictors of overall survival were osteosarcopenia (p < 0.001), male sex (p = 0.006) and pathological stage ≥ III PDAC (p = 0.001). Osteosarcopenia has an adverse prognostic impact on long-term outcomes in patients undergoing pancreatic resection for PDAC.

ELAPOR1 induces the classical/progenitor subtype and contributes to reduced disease aggressiveness through metabolic reprogramming in pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is a heterogeneous disease with distinct molecular subtypes described as classical/progenitor and basal-like/squamous PDAC. We hypothesized that integrative transcriptome and metabolome approaches can identify candidate genes whose inactivation contributes to the development of the aggressive basal-like/squamous subtype. Using our integrated approach, we identified endosome-lysosome associated apoptosis and autophagy regulator 1 (ELAPOR1/KIAA1324) as a candidate tumor suppressor in both our NCI-UMD-German cohort and additional validation cohorts. Diminished ELAPOR1 expression was linked to high histological grade, advanced disease stage, the basal-like/squamous subtype, and reduced patient survival in PDAC. In vitro experiments demonstrated that ELAPOR1 transgene expression not only inhibited the migration and invasion of PDAC cells but also induced gene expression characteristics associated with the classical/progenitor subtype. Metabolome analysis of patient tumors and PDAC cells revealed a metabolic program associated with both upregulated ELAPOR1 and the classical/progenitor subtype, encompassing upregulated lipogenesis and downregulated amino acid metabolism. 1-Methylnicotinamide, a known oncometabolite derived from S-adenosylmethionine, was inversely associated with ELAPOR1 expression and promoted migration and invasion of PDAC cells in vitro. Taken together, our data suggest that enhanced ELAPOR1 expression promotes transcriptome and metabolome characteristics that are indicative of the classical/progenitor subtype, whereas its reduction associates with basal-like/squamous tumors with increased disease aggressiveness in PDAC patients. These findings position ELAPOR1 as a promising candidate for diagnostic and therapeutic targeting in PDAC.

Rintatolimod in Advanced Pancreatic Cancer Enhances Antitumor Immunity through Dendritic Cell-Mediated T-Cell Responses.

Amid the need for new approaches to improve survival in pancreatic ductal adenocarcinoma (PDAC), immune-based therapies have garnered interest. Rintatolimod, a Toll-like receptor 3 (TLR-3) agonist, is a potential candidate due to its dual impact on restraining PDAC cell functions and boosting the antitumor immune response. This study investigates the effect of TLR-3 activation through rintatolimod on the peripheral immune landscape of patients with advanced PDAC. Paired blood samples of 30 patients with advanced PDAC, collected at baseline and after 12 rintatolimod intravenous infusions, underwent comprehensive transcriptomic NanoString and proteomic flow cytometry profiling. The impact of rintatolimod and immunologic factors on survival outcomes was assessed through univariate Cox proportional hazards models. Rintatolimod treatment enhances peripheral immune activity at the transcriptomic and proteomic levels, particularly involving type 1 conventional dendritic cells (cDC1) and T cells. Post-rintatolimod, the increased peripheral abundance of BTLA+ XCR1+ cDC1s and CD4+SELL+ T cells correlated with improved clinical outcomes. Patients with stable disease exhibited pronouncedDCand T-cell activation gene overexpression. Notably, the expression of immune checkpoints PD-L1 and PD-L2 decreased post-rintatolimod across all patients. However, those with progressive disease showed increased expression of genes encoding IDO1 and PD-1. This study presents compelling evidence of the immune-stimulatory properties linked to TLR-3 activation through rintatolimod. Rintatolimod may break immunologic tolerance by enhancing antitumor immunity through DC-mediated Th-cell responses. Furthermore, our findings lay the groundwork for investigating the potential synergy between TLR-3 activation and immune checkpoint inhibitor therapy to improve therapeutic outcomes. See related commentary by Martínez-Riaño et al., p. 3355.

Neoadjuvant chemotherapy is associated with suppression of the B cell-centered immune landscape in pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is typically diagnosed at advanced stages and associated with early distant metastasis and poor survival. Besides clinical factors, the tumor microenvironment (TME) emerged as a crucial determinant of patient survival and therapy response in many tumors, including PDAC. Thus, the presence of tumor-infiltrating lymphocytes and the formation of tertiary lymphoid structures (TLS) is associated with longer survival in PDAC. Although neoadjuvant therapy (NeoTx) has improved the management of locally advanced tumors, detailed insight into its effect on various TME components is limited. While a remodeling towards a proinflammatory state was reported for PDAC-infiltrating T cells, the effect of NeoTx on B cell subsets, including plasma cells, and TLS formation is widely unclear. We thus investigated the frequency, composition, and spatial distribution of PDAC-infiltrating B cells in primary resected (PR) versus neoadjuvant-treated patients using a novel multiplex immunohistochemistry panel. The NeoTx group displayed significantly lower frequencies of pan B cells, GC B cells, plasmablasts, and plasma cells, accompanied by a reduced abundance of TLS. This finding was supported by bulk RNA-sequencing analysis of an independent fresh frozen tissue cohort, which revealed that major B cell pathways were downregulated in the NeoTx group. We further observed that plasma cells frequently formed aggregates that localized close to TLS and that TLS+ patients displayed significantly higher plasma cell frequencies compared to TLS- patients in the PR group. Additionally, high densities of CD20+ intratumoral B cells were significantly associated with longer overall survival in the PR group. While CD20+ B cells held no prognostic value for NeoTx patients, an increased frequency of proliferating CD20+Ki67+ B cells emerged as an independent prognostic factor for longer survival in the NeoTx group. These results indicate that NeoTx differentially affects PDAC-infiltrating immune cells and may have detrimental effects on the existing B cell landscape and the formation of TLS. Gaining further insight into the underlying molecular mechanisms is crucial to overcome the intrinsic immunotherapy resistance of PDAC and develop novel strategies to improve the long-term outcome of PDAC patients.

Exploring the prognostic value of circular RNAs in pancreatic ductal adenocarcinoma using genome-wide expression profiling

Background/ObjectivesMedian survival of pancreatic ductal adenocarcinoma (PDAC) is around eight months and new prognostic tools are needed. Circular RNAs (circRNAs) have gained interest in different types of cancer. However, only a few studies have evaluated their potential in PDAC. We aimed to identify the most differentially expressed circRNAs in PDAC compared to controls and to explore their potential as prognostic markers. MethodsUsing frozen specimens with PDAC and controls, we performed RNA sequencing and identified 20,440 unique circRNAs. A custom code set of capture- and reporter probes for NanoString nCounter analysis was designed to target 152 circRNAs, based on abundancy, differential expression and a literature study. Expression of these 152 circRNAs was examined in 108 formalin-fixed and paraffin-embedded surgical PDAC specimens and controls. The spatial expression of one of the most promising candidates, ciRS-7 (hsa_circ_0001946), was evaluated by chromogenic in situ hybridization (CISH) using multi-punch tissue microarrays (TMAs) and digital imaging analysis. ResultsBased on circRNA expression profiles, we identified different PDAC subclusters. The 30 most differentially expressed circRNAs showed log2 fold changes from −3.43 to 0.94, where circNRIP1 (hsa_circ_0004771), circMBOAT2 (hsa_circ_0007334) and circRUNX1 (hsa_circ_0002360) held significant prognostic value in multivariate analysis. CiRS-7 was absent in PDAC cells but highly expressed in the tumor microenvironment. ConclusionsWe identified several new circRNAs with biomarker potential in surgically treated PDAC, three of which showed an independent prognostic value. We also found that ciRS-7 is absent in cancer cells but abundant in tumor microenvironment and may hold potential as marker of activated stroma.

Modelling the micro- and macro- environment of pancreatic cancer: from patients to pre-clinical models and back.

Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignancy with very low survival rates. Over the past 50 years, improvements in PDAC survival have significantly lagged behind the progress made in other cancers. PDAC's dismal prognosis is due to typical late-stage diagnosis combined with lack of effective treatments and complex mechanisms of disease. We propose that improvements in survival are partly hindered by the current focus on largely modelling and targeting PDAC as one disease, despite it being heterogeneous. Implementing new disease-representative pre-clinical mouse models that capture this complexity could enable the development of transformative therapies. Specifically, these models should recapitulate human PDAC late-stage biology, heterogeneous genetics, extensive non-malignant stroma, and associated risk factors and comorbidities. In this Perspective, we focus on how pre-clinical mouse models could be improved to exemplify key features of PDAC micro- and macro- environments, which would drive clinically relevant patient stratification, tailored treatments and improved survival.

The inverted U-shaped relationship between epinephrine and pancreatic ductal adenocarcinoma patients' survival with compensation of lymphocyte.

The relationship between epinephrine and cancer can be dose-dependent in invivo study. Whether it is the same in human body still needs verification. We used frozen human pancreatic ductal adenocarcinoma (PDAC) tissues to detect epinephrine content and analyzed its relationship with survival using the K-M method and Cox regression. Disturbance of blood cell count and C-reactive protein and identification of related potent intermediary factors were also analyzed. K-M plot and Cox regression all showed the inverted U-shaped relationship between epinephrine and PDAC survival. Lymphocyte adjustment can increase the HRs of epinephrine for PDAC death by >10%. Epinephrine played an anti-tumor or pro-tumor effect depending on the specific concentration. Circulating lymphocyte count was elevated and might acted as a compensation pathway to reduce the pro-tumor effect of epinephrine to PDAC.

Abstract 6818: Obesity-mediated perineural invasion promotes PDAC tumorigenesis

Abstract Obesity is a modifiable host factor that has been reported to increase the risk of pancreatic ductal adenocarcinoma (PDAC) by ~60% and the mortality by two-fold, however, the exact mechanisms by which obesity enhances PDAC aggressiveness is incompletely understood. Given that nearly 74% of U.S. adults are overweight or obese (US Center for Disease Control), resolving the complex association between obesity and PDAC may unveil new targets for prevention and/or intervention to decrease incidence and improve outcomes. The prevailing notion is that obesity-induced tumor in situ factors (i.e., oxidative, hypoxic, nutrient, and biochemical) play crucial roles in enhancing cancer cell fitness and survival. However, these concepts have yet to lead to the identification of any actionable target in patients, with obesity-related cancer in general and PDAC in particular. Prior studies and our preliminary data show the presence of a distinctive tumor immune profile in PDAC models under conditions of obesity, which encompasses immune suppressive myeloid and type 2 immune cells, namely M2-like tumor-associated macrophages (TAMs), and myeloid-derived suppressor cells (MDSCs), that inhibit effector CD8+ T cell expansion and function enabling PDAC progression. However, the genesis of this ‘type 2 immune cell’ dominant tumor-immune microenvironment (TIME) of obesity-driven PDAC remains to be fully understood. This led us to take a holistic approach utilizing multiple genetically engineered mouse models (GEMMs), pharmacological inhibitors, transcriptomic analysis (RNA-seq, spatial transcriptomic, and scRNA-seq), fresh PDAC patient samples, and imaging technologies (confocal microscopy) to understand the molecular mechanisms. Our novel mechanistic study using some of the above-mentioned tools shows that obesity-driven PDAC has significantly higher perineural invasion (PNI) that enhances PDAC progression. We found that sympathetic nerve terminals (of the PNI) via neurotransmitter release control the expression of integral cytokines that cause a dramatic remodeling of the TIME. Specifically, the PNI-mediated neuro-adrenergic signaling activates β2-adrenergic receptor (β2-AR) on PDAC cells, leading to increased tumor cell production/proliferation and secretion of the ‘alarmins’ IL-33 and IL-1β. Importantly, we showed that mitigation of adrenergic signaling using two separate approaches: (i) pharmacological antagonists of β2-ARs (β-blockers), and (ii) the use of a thermoneutral model leads to substantial abrogation of obesity-mediated tumor progression. These, and other key data raise the provocative question that reducing adrenergic signaling-dependent IL-33 expression and release favor a pro-inflammatory TIME and significantly increase patient survival in obesity-driven PDAC. Citation Format: Shyamananda Singh Mayengbam, Aftab Alam, Sharon Senchanthisai, Irmak Bektas, Prasenjit Dey. Obesity-mediated perineural invasion promotes PDAC tumorigenesis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6818.

Long-term Outcomes following Resection of Adenocarcinoma Arising from Intraductal Papillary Mucinous Neoplasm (A-IPMN) versus Pancreatic Ductal Adenocarcinoma (PDAC): A Propensity-score Matched Analysis.

The aim of the present study was to compare long-term post-resection oncological outcomes between A-IPMN and PDAC. Knowledge of long term oncological outcomes (e.g recurrence and survival data) comparing between adenocarcinoma arising from intraductal papillary mucinous neoplasms (A-IPMN) and pancreatic ductal adenocarcinoma (PDAC) is scarce. Patients undergoing pancreatic resection (2010-2020) for A-IPMN were identified retrospectively from 18 academic pancreatic centres and compared with PDAC patients from the same time-period. Propensity-score matching (PSM) was performed and survival and recurrence were compared between A-IPMN and PDAC. 459 A-IPMN patients (median age,70; M:F,250:209) were compared with 476 PDAC patients (median age,69; M:F,262:214). A-IPMN patients had lower T-stage, lymphovascular invasion (51.4%vs. 75.6%), perineural invasion (55.8%vs. 71.2%), lymph node positivity (47.3vs. 72.3%) and R1 resection (38.6%vs. 56.3%) compared to PDAC(P<0.001). The median survival and time-to-recurrence for A-IPMN versus PDAC were 39.0 versus19.5months (P<0.001) and 33.1 versus 14.8months (P<0.001), respectively (median follow-up,78 vs.73 months). Ten-year overall survival for A-IPMN was 34.6%(27/78) and PDAC was 9%(6/67). A-IPMN had higher rates of peritoneal (23.0 vs. 9.1%, P<0.001) and lung recurrence (27.8% vs. 15.6%, P<0.001) but lower rates of locoregional recurrence (39.7% vs. 57.8%; P<0.001). Matched analysis demonstrated inferior overall survival (P=0.005), inferior disease-free survival (P=0.003) and higher locoregional recurrence (P<0.001) in PDAC compared to A-IPMN but no significant difference in systemic recurrence rates (P=0.695). PDACs have inferior survival and higher recurrence rates compared to A-IPMN in matched cohorts. Locoregional recurrence is higher in PDAC but systemic recurrence rates are comparable and constituted by their own distinctive site-specific recurrence patterns.

Abstract 1583: Neutrophil pro-tumorigenic role in progression and therapy resistance in pancreatic ductal adenocarcinoma

Abstract Pancreatic cancer (PC) continues to be a challenge for today’s therapeutics, with a meager 5-year survival rate of 12%. Due to the pancreas’ location, patients often receive diagnosis late, leaving them with limited treatment options. Often, they fail to respond to chemotherapy regimens or develop resistance to those therapies. Tumor-promoting inflammation is a hallmark of cancer, contributing to tumor cells’ survival and proliferation. Infiltrating leukocytes and pro-inflammatory cytokines released into the tumor microenvironment (TME) often cause this inflammation. My lab has previously linked increases in pancreatic ductal adenocarcinoma (PDAC) progression and chemotherapy resistance to inflammation and the CXCR2 pathway. In the present study, we examined the role of neutrophil recruitment in PDAC progression using patient samples and KRAS-dependent KC and KPC murine models. Our data suggest a positive association between tumor-associated neutrophils (TANs) and PDAC progression. In vitro, we observed neutrophil-PDAC interaction enhancing the survival of both neutrophils and PDAC cell lines. Moreover, this survival was mediated by cellular aggressiveness and therapy resistance. Concerning survival, we saw increased expression of anti-apoptotic genes in the neutrophils upon PDAC cancer cell conditioned media treatment. We also observed modulated expression of immunoregulatory molecules. Our data suggest that increased recruitment of TANs supports PDAC progression and survival, and PDAC cell-neutrophil interaction modulates neutrophil survival and immunoregulatory phenotype. Citation Format: Reegan Sturgeon, Esther Johnson, Caitlin Molczyk, Paran Goel, Parker Tinsley, Lauren Abrahams, Michael Maher, Rakesh K. Singh. Neutrophil pro-tumorigenic role in progression and therapy resistance in pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1583.

Handgrip Strength Predicts Survival in Patients With Pancreatic Cancer.

Pancreatic ductal adenocarcinoma (PDAC) is a common cancer with a poor prognosis and is associated with a high prevalence of cachexia, a metabolic syndrome of muscle wasting due to complex mechanisms. In addition to loss of muscle mass, cancer patients also experience functional deterioration. The aim of this study is to determine whether there is an association between muscle mass and function and clinical outcomes, particularly survival. We performed a prospective cohort study including all patients with PDAC at Monash Health from March 2016 to December 2017. We conducted body composition analysis for myopenia and handgrip strength testing. We constructed Kaplan-Meier curves to estimate whether myopenia and low hand grip strength were associated with poorer survival. Myopenia was not associated with a significant difference in PDAC-specific survival (log-rank P = 0.60). However, low handgrip strength was associated with significantly worse PDAC-specific survival compared with other patients (log-rank hazard ratio, 1.88; 95% confidence interval, 1.15-3.09; P = 0.004). The relationship between survival in PDAC and handgrip strength, but not anatomical muscle mass, suggests that functional testing of strength may be important in prognostication of patients with PDAC, alongside existing tools such as the Eastern Cooperative Oncology Group performance status.

Limited Role of the Apparent Diffusion Coefficient (ADC) for Tumor Grade and Overall Survival in Resectable Pancreatic Ductal Adenocarcinoma.

This study evaluated the relationship between apparent diffusion coefficient (ADC) values in pancreatic ductal adenocarcinoma (PDAC) and tumor grades based on WHO, Adsay, and Kalimuthu classifications, using whole-mount pancreatectomy specimens. If glandular formation plays a key role in the degree of diffusion restriction, diffusion-weighted imaging could facilitate non-invasive grading of PDAC. A freehand region of interest (ROI) was drawn along tumor borders on the preoperative ADC map in each tumor-containing slice. Resection specimens were retrospectively graded according to WHO, Adsay, and Kalimuthu classifications and correlated with overall survival and the 10th percentile of whole-volume ADC values. Findings from 40 patients (23 male, median age 67) showed no correlation between ADC p10 values and WHO differentiation (p = 0.050), Adsay grade (p = 0.955), or Kalimuthu patterns (p = 0.117). There was no association between ADC p10 and overall survival (p = 0.082) and other clinicopathological variables. Survival was significantly lower for poor tumor differentiation (p = 0.046) and non-glandular Kalimuthu patterns (p = 0.016) and there was a trend towards inferior survival for Adsay G3 (p = 0.090) after correction for age, tumor location, and stage. Preoperative ADC measurements for determining PDAC aggressiveness had limited clinical utility, as there was no correlation with histological parameters or overall survival in resectable PDAC.

Development and Validation of Case-Finding Algorithms to Identify Pancreatic Cancer in the Veterans Health Administration.

Survival in pancreatic ductal adenocarcinoma (PDAC) remains poor due to late diagnosis. Electronic Health Records (EHRs) can be used to study this rare disease, but validated algorithms to identify PDAC in the United States EHRs do not currently exist. To develop and validate an algorithm using Veterans Health Administration (VHA) EHR data for the identification of patients with PDAC. We developed two algorithms to identify patients with PDAC in the VHA from 2002 to 2023. The algorithms required diagnosis of exocrine pancreatic cancer in either ≥ 1 or ≥ 2 of the following domains: (i) the VA national cancer registry, (ii) an inpatient encounter, or (iii) an outpatient encounter in an oncology setting. Among individuals identified with ≥ 1 of the above criteria, a random sample of 100 were reviewed by three gastroenterologists to adjudicate PDAC status. We also adjudicated fifty patients not qualifying for either algorithm. These patients died as inpatients and had alkaline phosphatase values within the interquartile range of patients who met ≥ 2 of the above criteria for PDAC. These expert adjudications allowed us to calculate the positive and negative predictive value of the algorithms. Of 10.8 million individuals, 25,533 met ≥ 1 criteria (PPV 83.0%, kappa statistic 0.93) and 13,693 individuals met ≥ 2 criteria (PPV 95.2%, kappa statistic 1.00). The NPV for PDAC was 100%. An algorithm incorporating readily available EHR data elements to identify patients with PDAC achieved excellent PPV and NPV. This algorithm is likely to enable future epidemiologic studies of PDAC.

Prognostic Value of Circulating Cell-Free DNA Concentration and Neutrophil-to-Lymphocyte Ratio in Patients with Pancreatic Ductal Adenocarcinoma: A Prospective Cohort Study.

Circulating cell-free DNA (ccfDNA) quantity correlates with the clinical characteristics and prognosis of various cancer types. We investigated whether ccfDNA levels and the neutrophil-to-lymphocyte ratio (NLR) have prognostic value in patients with pancreatic ductal adenocarcinoma (PDAC). Peripheral blood was collected from 82 patients with PDAC prior to any diagnostic procedure or the administration of chemotherapy. Plasma DNA was isolated, and ccfDNA concentration and NLR were determined. We found that ccfDNA levels were correlated with age and tumor burden. Moreover, higher values of NLR (≥3.31) were linked with worse overall survival (OS) (4 vs. 10 months; log rank p = 0.011), and an elevated ccfDNA concentration (≥25.79 ng/mL) was strongly associated with shorter OS (4 vs. 8 months; log rank p = 0.009). According to the results of the multivariable Cox regression analysis, the baseline concentration of ccfDNA was an independent prognostic factor for OS (HR 0.45, 95% CI 0.21-0.97, p = 0.041). Furthermore, the combination of ccfDNA levels with NLR greatly enhanced the prognostic accuracy of PDAC patients. Our study demonstrates that ccfDNA concentration and NLR are independent predictors of survival in PDAC. Subsequent studies should validate this combination as a prognostic indicator in PDAC patients and assess its utility for guiding therapeutic decisions.

Concurrent inhibition of pBADS99 synergistically improves MEK inhibitor efficacy in KRASG12D-mutant pancreatic ductal adenocarcinoma

Therapeutic targeting of KRAS-mutant pancreatic ductal adenocarcinoma (PDAC) has remained a significant challenge in clinical oncology. Direct targeting of KRAS has proven difficult, and inhibition of the KRAS effectors have shown limited success due to compensatory activation of survival pathways. Being a core downstream effector of the KRAS-driven p44/42 MAPK and PI3K/AKT pathways governing intrinsic apoptosis, BAD phosphorylation emerges as a promising therapeutic target. Herein, a positive association of the pBADS99/BAD ratio with higher disease stage and worse overall survival of PDAC was observed. Homology-directed repair of BAD to BADS99A or small molecule inhibition of BADS99 phosphorylation by NCK significantly reduced PDAC cell viability by promoting cell cycle arrest and apoptosis. NCK also abrogated the growth of preformed colonies of PDAC cells in 3D culture. Furthermore, high-throughput screening with an oncology drug library to identify potential combinations revealed a strong synergistic effect between NCK and MEK inhibitors in PDAC cells harboring either wild-type or mutant-KRAS. Mechanistically, both mutant-KRAS and MEK inhibition increased the phosphorylation of BADS99 in PDAC cells, an effect abrogated by NCK. Combined pBADS99-MEK inhibition demonstrated strong synergy in reducing cell viability, enhancing apoptosis, and achieving xenograft stasis in KRAS-mutant PDAC. In conclusion, the inhibition of BADS99 phosphorylation enhances the efficacy of MEK inhibition, and their combined inhibition represents a mechanistically based and potentially effective therapeutic strategy for the treatment of KRAS-mutant PDAC.

Recurrence and Survival Prediction Models for Receiving Preoperative Chemotherapy Pancreatic Ductal Adenocarcinoma Cancer: A Single-center Retrospective Research

Purpose: Regard preoperative chemotherapy as a holistic sequential treatment modality to identify predictive factors associated with recurrence and survival in pancreatic ductal adenocarcinoma (PDAC) and construct models to provide decision support and treatment selection for the candidate patients. Methods: Retrospect PDAC patients who received preoperative chemotherapy from January 2016 to June 2023 at the Second Affiliated Hospital of Zhejiang University School of Medicine. Run a univariate and multivariate analysis of factors associated with recurrence-free survival (RFS) and overall survival (OS). Scoring systems were developed based on the hazard ratios (HR) of all significant predictors. Kaplan–Meier analyses and log-rank tests were used to calculate RFS and OS. Results: A total of 72 PDAC patients with preoperative chemotherapy were analyzed. After preoperative chemotherapy, 21(29.17%) patients achieved any radiologic downstaging with 68(94.44%) patients achieving negative resection margin status (R0 margins). For carbohydrate antigen 19-9(CA19-9) non-secreting patients, shrinkage rate of length diameter of tumor≥20%(P=0.027), resection margin status(P=0.011) were independent predictors of OS. And for CA19-9 secreting patients, CA19-9 serum level at the end of chemotherapy≥1000(P=0.027) and resection margin status (P=0.012) were independent predictors of OS. Points according HR were allocated to these factors in the proposed scoring system, respectively. Recurrence curves and survival curves with statistically significant differences were also presented for patients grouped according to the scoring systems. For CA19-9 non-secreting patients, the OS of patients with a score from 2 to 2.97 was significantly shorter than that of patients with a score from 4.94 to 5.91 (P=0.009). And for CA19-9 secreting patients, the OS of patients with a score of 2 was significantly shorter than that of patients with a score from 3.75 to 4.99 (P&lt;0.001). Conclusion: Simple scoring models for RFS and OS incorporating CA19-9 serum levels or the tumor shrinkage rate and postoperative pathology may assist clinicians in evaluating prognosis of PDAC patients with preoperative chemotherapy.

Identification and validation of stemness-based and ferroptosis-related molecular clusters in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignancy with an extremely poor prognosis. Cancer stem cells (CSCs) are considered to be responsible for the poor survival, recurrence and therapy resistance of PDAC. Ferroptosis plays a crucial role in the sustain and survival of CSCs. Here, we employed a rigorous evaluation of multiple datasets to identify a novel stemness-based and ferroptosis-related genes (SFRGs) signature to access the potential prognostic application. This work we retrieved RNA-sequencing and clinical annotation data from the TCGA, ICGC, GTEx and GEO database, and acquired 26 stem cell gene sets and 259 ferroptosis genes from StemChecker database and FerrDb database, respectively. Based on consensus clustering and ssGSEA analysis, we identified two expression patterns of CSCs traits (C1 and C2). Then, WGCNA analysis was implemented to screen out hub module genes correlated with stemness. Furthermore, differential expression analysis, Pearson correlation analysis, and the Least absolute shrinkage and selection operator (LASSO) and Cox regression were performed to identify the SFRGs and to construct model. In addition, the differences in prognosis, tumor microenvironment (TME) components and therapy responses were evaluated between two risk groups. Finally, we verified the most influential marker ARNTL2 experimentally by western blot, qRT-PCR, sphere formation assay, mitoscreen assay, intracellular iron concentration determination and MDA determination assays. In conclusion, we developed a stemness-based and ferroptosis-related prognostic model, which could help predict overall survival for PDAC patients. Targeting ferroptosis may be a promising therapeutic strategy to inhibit PDAC progression by suppressing CSCs.

Characterization of the cachexia pathway in pancreatic ductal adenocarcinoma.

699 Background: Cancer cachexia is characterized by progressive weight loss and skeletal muscle degradation, contributing to 33% of pancreatic ductal adenocarcinoma (PDAC) deaths. Targeting myostatin in the myostatin-activin pathway has been shown to reverse cachexia. Here, we present comprehensive clinical and molecular characterization of the myostatin-activin pathway in PDAC. Methods: 9,607 samples of PDAC tested at Caris Life Sciences (Phoenix, AZ) with WTS (Illumina NovaSeq) and NextGen DNA sequencing (NextSeq, 592 Genes and NovaSEQ, WES) were analyzed. Cachexia gene scores (GS) were calculated by averaging the positive z scores of activators and negative z scores of repressors in the myostatin-activin pathway. Activators were ACVR1B, ACVR1C, ACVR2A, ACVR2B, SMAD2, SMAD3, SMAD4, and TGFBR1, while repressors were SMAD1, SMAD5, SMAD6, SMAD7, SMURF1, and SMURF2. The top quartile (Q4) and bottom quartile (Q1) of GS were compared using chi-squared and Fisher-Exact tests. RNA deconvolution analysis with QuantiSEQ estimated cell infiltration in the tumor microenvironment (TME). Differences in overall survival (OS) were analyzed from insurance claims data and calculated from time of tissue collection using Kaplan-Meier estimates. Statistical significance was determined as a P-value adjusted for multiple comparisons ( q&lt;0.05). Results: GS were higher in primary tumors compared to metastases (median: -0.71 vs -0.86, q&lt;0.05). GS was associated with increased PD-L1 IHC expression (Q1 21.2% vs Q4 10.3%, q&lt;0.001), but not TMB-high (1.9% vs 2.1%, q=1) or MSI-H status (1.1% vs 1.3%, q=1). GS correlated with increased expression of immune related genes ( CD274, CD80, IDO1, CD86, PDCD1, LAG3, CTLA4, HAVCR2, and IFNG, q&lt;0.05). However, TME immune cell infiltration did not vary based on cachexia GS. Mutation rates of TP53 (Q1 79.4% vs Q4 73.7%), ARID1A (Q1 11.8% vs Q4 6.9%) and KRAS (Q1 92.7% vs Q4 86.4%) were associated with Q1-GS (all q&lt;0.01), while STK11 mutations (1.1% vs 3.0%, q=0.001) were associated with Q4-GS. Spearman correlation linked cachexia GS with the lipid metabolizing genes UCP2 (rho=0.49) and UCP3 (rho=0.30), as well as the inflammatory markers CCL2/MCP-1(rho=0.34) and IL1B (rho=0.33). Decreased OS was seen with higher tumor expression of the myostatin-activin pathway activator, SMAD3 (6.6 vs 8.5 mo, HR=1.22, CI 1.12-1.33, P&lt;0.001), and lower expression of the repressor SMAD7 (6.9 vs 8.9 mo, HR=0.91, CI 0.79-0.90, P=0.034) in metastatic PDAC. Conclusions: This is the largest molecular and clinical characterization of the myostatin-activin cachexia pathway in PDAC. Our data show that increased activation of the myostatin-activin pathway is associated with immune mediators, lipid metabolism, and inflammatory gene activation. Activators and repressors are significant predictors of survival in PDAC, suggesting possible novel therapeutic targets.

Associations between BMI, morphomics and survival in 528 patients with metastatic pancreatic cancer.

637 Background: Literature describing associations between patient body mass index (BMI) and survival in pancreatic ductal adenocarcinoma (PDA) remains inconsistent. This heterogeneity may be due to studies using pre-diagnosis BMI and including few metastatic patients despite high prevalence at diagnosis. Furthermore, BMI may not adequately reflect other body compositions such as those reflected via morphomic variables (subcutaneous fat, visceral fat, muscle, and fascia) that may have unique associations with survival. In this study, we sought to explore the relationships between detailed body composition in patients with metastatic PDA on both overall survival (OS) and progression-free survival (PFS). Methods: We evaluated data and scans from a phase 3 clinical trial in which 528 patients with metastatic PDA with no prior chemotherapy were randomized to either FOLFIRINOX or modified FOLFIRINOX plus devimistat. No differences in response rate, median PFS or OS were observed. Of the 528 enrolled patients, 377 had baseline CT scans eligible for morphomic evaluation for which Analytic Morphomics was used to measure body composition. For analysis, morphomic variables were summed across the T10-T12 and L1-L4 vertebrae and then divided into tertiles. BMI at diagnosis was evaluated in tertiles and per WHO standards. Cox proportional hazards models and cubic splines were used to evaluate associations between BMI, morphomic variables and PFS, OS. Univariate and multivariate models were evaluated. Kaplan-Meier plots were created to evaluate median survival times between those in the highest and lowest tertiles (R v4.3.1). Results: We did not observe an association between BMI and PDA patient survival: HR (95% CI) comparing BMI ≥30 (obese) to 18.5-24.9 (healthy weight), PFS 0.96 (0.66, 1.39), p-trend=0.80; OS 0.87 (0.64, 1.18), p-trend=0.30. However, multiple morphomic variables were significantly associated with PFS and/or OS in univariate and multivariate models when comparing the highest to lowest tertile. More subcutaneous fat was associated with longer median OS (12.4 vs 10.5 mos, p=0.006; HR (95% CI) 0.41 (0.25-0.68), p-trend=0.001). More dense visceral fat was associated with shorter median PFS (6.0 vs 9.1 mos, p=0.05, HR (95% CI) 1.52 (1.00-2.33), p-trend=0.047). A higher muscle to fascia ratio was associated with longer PFS (9.3 vs 6.5 mos, p=0.03; HR (95% CI) 0.58 (0.38-0.88), p-trend=0.01) and median OS (13.9 vs 10 mos, p=0.005; HR (95% CI) 0.53 (0.38-0.76), p-trend=0.0004). Conclusions: BMI was not associated with PFS or OS in this large prospective study of patients with metastatic PDA receiving chemotherapy. However, morphomic variables including subcutaneous fat area, visceral fat density, and the muscle to fascia ratio were statistically significantly associated with metastatic PDA patient survival.

Abstract C065: Base excision repair pathway regulates transcription-replication conflicts in pancreatic ductal adenocarcinoma

Abstract Oncogenic mutations (such as in KRAS) can dysregulate transcription and replication leading to transcription conflicts (TRCs). Unresolved TRCs can cause lethal DNA damage. Here, we sought to investigate the causal role of oncogenic mutations in regulating TRCs in pancreatic ductal adenocarcinoma (PDAC). Further, we characterize the adaptive pathways that mitigate TRCs for PDAC survival. Human PDAC demonstrated 30-120-fold higher levels of TRC genomic signature compared to breast, colon and lung cancer (p&amp;lt;0.001). Gene expression analysis demonstrated high levels of known TRC resolution factors in human tumors compared to normal tissues. TRCs as measured by RNAPII-PCNA proximity ligation assay were significantly enriched in human PDAC cells (Panc-1, BxPC3, MiaPaca2) compared to immortalized normal HPNE cells (p&amp;lt;0.001). Similarly transcriptomic complexes were enriched in nascent DNA immunoprecipitates from Panc1 cells but not HPNE cells. Ectopic expression of oncogenic KRAS(G12D) in human pancreatic ductal epithelial (HPNE) cells enhanced TRCs, and TRC-related DNA:RNA hybrids (R-loops). Inhibition of KRAS or downstream effectors abrogated TRCs in Panc1 and MiaPaca2 cells. An siRNA screen identified several factors in the base-excision repair (BER) pathway as regulators of TRCs. Sub-lethal exposure to hydrogen peroxide enhanced TRCs, whereas N-acetyl cysteine abrogated TRCs. These findings were validated by a pharmacologic approach using inhibitors of APE1 endonuclease in BER pathway (Methoxyamine and CRT). Mechanistic studies revealed that BER pathway inhibition severely altered RNA polymerase II dynamics at nascent DNA; causing RNAPII trapping and contributing to enhanced TRCs. The ensuing DNA damage activated Chk2-ATR pathway but not Chk1-ATM pathway. Co-treatment with ATR inhibitor (VX970, 10-80nM) and BER inhibitor (methoxyamine, 6-12mM) at clinically relevant doses, synergistically enhanced DNA damage and reduced clonogenic survival in PDAC cells. The study uncovers a novel role of BER pathway defects and oxidative DNA damage in promoting TRCs. Our studies provide mechanistic insights into the regulation of TRCs in PDAC which has implications for genome instability and therapy in PDAC. Citation Format: Fan Meng, Anup K. Singh, Tiane Li, Marc Attiyeh, Fatemeh Kohram, Terence Williams, Yilun Liu, Mustafa Raoof. Base excision repair pathway regulates transcription-replication conflicts in pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr C065.