Hypofractionated radiotherapy concomitant to capecitabine after induction chemotherapy for advanced pancreatic adenocarcinoma.

Background and purpose: To assess feasibility, toxicity and outcome of moderately hypofractionated radiotherapy concomitant to capecitabine after induction chemotherapy for advanced pancreatic cancer. Materials and methods: Patients with advanced pancreatic cancer without distant progression after induction chemotherapy (CHT) were considered. Radiochemotherapy (RCT) consisted of 44.25 Gy in 15 fractions to the tumor and involved lymph-nodes concomitant to capecitabine 1250 mg/m2/day. Feasibility and toxicity were evaluated in all pts. Overall survival (OS), progression free survival (PFS), distant PFS (DPFS) and local PFS (LPFS) were assessed only in stage III patients. Results: 254 patients, 220 stage III, 34 stage IV, were treated. Median follow up was 19 months. Induction CHT consisted of Gemcitabine (35 patients), or drug combination (219 patients); median duration was 6 months.Four patients (1.6 %) did not complete RT (1 early progression, 3 toxicity), median duration of RT was 20 days, 209 patients (82 %) received ≥ 75 % of capecitabine dose.During RCT G3 gastrointestinal toxicity occurred in 3.2% of patients, G3-G4 hematologic toxicity in 5.4% of patients. Subsequently, G3, G4, G5 gastric or duodenal lesions occurred in 10 (4%), 2 (0.8%) and 1 patients (0.4%), respectively.Median PFS, LPFS, and DPFS were 11.9 months (95 % CI:11.4-13), 16 months (95 % CI:14.2-17.3) and 14.0 months (95 % CI:12.6-146.5), respectively.Median OS was 19.5 months (95 % CL:18.1-21.3). One- and two-year survival were 85.2 % and 36 %, respectively. Conclusions: The present schedule of hypofractionated RT after induction CHT is feasible with acceptable toxicity rate and provides an outcome comparable with that achievable with standard doses and fractionation.

Communication, understanding and engagement of patients with pancreatic cancer at time of diagnosis.

BACKGROUND: Objectives: To investigate communication clarity and understanding at the time of pancreatic adenocarcinoma (PDAC) diagnosis and whether they can influence patient engagement and compliance. METHODS: Consecutive PDAC patients were enrolled at the time of diagnosis after obtaining informed consent in a single-center study. The patients completed a validated scale (PHE-s®), and the understanding rate was assessed using standardized tools. Patient compliance was evaluated, and the correlation between the PHE-s®, understanding, and compliance was calculated. RESULTS: Thirty patients were enrolled (15 female) with a mean age 64.4, 13 were metastatic. The mean visit time was 31 min, being longer if visiting doctor was an oncologist (p = 0.002). The engagement level was high in 70% of the patients, and all but one were compliant. The analysis of doctor-patient interactions showed a median of 121 conversational turns for doctors, 75 for patients, and 20 for caregivers (p < 0.0001), and the median percentage of speaking time was 77% for doctors, 13% for patients, and 2% for caregivers (p < 0.0001). Female caregivers spent more time speaking than did male caregivers (median 11.6% vs. 1.3%; p = 0.06). There were 290 instances of problematic understanding, most of which occurred during the taking of patients' personal medical history for doctors, while for patients and caregivers, these occurred mainly during the discussion of diagnosis/treatment (p < 0.0001). In a multivariable analysis, only origin from central or southern Italy was associated with high engagement (p = 0.0087). CONCLUSION: In this first attempt to measure clarity of communication and engagement in patients with PDAC, typical features of conversation and problematic understanding emerged, which deserves further investigation.

Cyclophosphamide maintenance to extend combination chemotherapy-free interval in metastatic pancreatic ductal adenocarcinoma.

BACKGROUND: Administering chemotherapy until progression to metastatic pancreatic ductal adenocarcinoma (PDAC) patients lacks of supporting evidence and causes cumulative toxicity. We explored the role of cyclophosphamide as maintenance therapy. METHODS: PDAC germline BRCA1-2 wild-type patients who were progression-free after ≥6 months of any regimen and line of chemotherapy and received maintenance cyclophosphamide (mCTX) (50 mg/day), were included in the analysis. RESULTS: 42 patients were included in the analysis. Thirty-nine patients had progression of disease. Median PFS was 3.5 (range 1.0-31+) months. PFS rates at 6 and 12 months were 26.2% and 11.9%. At a median follow-up of 20.0 months (range 12.1-31.0 months), 20 patients died and 22 are alive. Median OS was 20.0 months (range 2.2-31.0+). OS at 6 and 12 months was 97.6% (95%CI: 93.4-100), and 73.8% (95% CI: 61.1-86.5), respectively. Only 2 patients receiving mCTX had Grade 3 toxicity. CONCLUSIONS: mCTX therapy yielded promising PFS and OS outcome in PDAC patients who were progression-free after induction chemotherapy, with unremarkable toxicity. Accordingly, this approach warrants further investigation.

Exploring the optimal therapeutic management of stage ypIA pancreatic ductal adenocarcinoma patients in the era of primary chemotherapy.

BACKGROUND: Data on the proper post-surgical chemotherapy (PSC) in pancreatic ductal adenocarcinoma (PDAC) patients already treated with neoadjuvant therapy (NAT) are lacking, especially for stage ypIA. AIM AND METHODS: We retrospectively analyzed ypT1N0M0 (ypIA) PDAC patients resected after NAT between 2015 and 2020 at our Institution. Primary endpoint was median disease free-survival (DFS) according to PSC treatment. RESULTS: Seventy-five out of 363 patients achieved a pathological ypIA after NAT (20.6%) and 72 were analyzed. Among the study population 34 patients (47%) were treated with NAT ≤4 months and 38 (53%) >4 months. After surgery, 10 patients (14%) received PSC using the same multidrug NAT regimen (Group A); 35 (49%) received PSC with a different regimen (Group B), with either single agents in 24 patients (68.5%) or combination schedules in 11 (31.5%); 27 patients (14%) did not receive any PSC (Group C). DFS was longer in group A and C as opposed to group B (p = 0.006). CONCLUSION: Patients affected by ypIA PDAC treated with a proper multi-agent chemotherapy for more than 4 months show an improved DFS, regardless of the peri­operative or totally pre-surgical administration of treatment.

Clinical outcomes and response to chemotherapy in a cohort of pancreatic cancer patients with germline variants of unknown significance (VUS) in BRCA1 and BRCA2 genes.

PURPOSE: The clinical outcome and the efficacy of chemotherapy in pancreatic cancer patients with BRCA1/2 Variants of Unknown Significance (VUS) is unknown. We explored the effects of chemotherapy with or without Platinum in non metastatic and metastatic pancreatic cancer patients with BRCA1/2 VUS. METHODS: A retrospective analysis of non-metastatic or metastatic pancreatic cancer patients with gBRCA1/2 VUS treated in 13 Italian centers between November 2015 and December 2020 was performed. All patients were assessed for toxicity and RECIST 1.1 response. Metastatic patients were evaluated for survival outcome. RESULTS: 30 pancreatic cancer patients with gBRCA1/2 VUS were considered: 20 were M+ and 10 were non-M+. Pl-CT was recommended to 16 patients: 10 M+ (6 FOLFIRINOX and 4 PAXG) and 6 non-M+ (3 FOLFIRINOX and 3 PAXG); 11 patients received Nabpaclitaxel-Gemcitabine (AG; 8 M+) and 3 patients (2 M+) were treated with Gemcitabine (G). The RECIST 1.1 response rate was 27% for AG and 44% for Pl-CT (22% for (m) FOLFIRINOX and 71% PAXG). 1 year Progression-Free Survival was 37.5% for patients treated with AG and 33% in the Pl-CT subgroup. Median Overall Survival (OS) was 23.5 months for patients treated with AG and 14 months for the Pl-CT subgroup. 1 Year and 2 Year OS were numerically better for AG (1 Year OS: 75% vs 60% and 2 Year OS: 50% and 20% in AG and Pl-CT subgroups, respectively) as well. CONCLUSIONS: Pl-CT does not seem to be associated with a better outcome compared to AG chemotherapy in PDAC patients with BRCA 1/2 VUS.

Tff2 defines transit-amplifying pancreatic acinar progenitors that lack regenerative potential and are protective against Kras-driven carcinogenesis.

While adult pancreatic stem cells are thought not to exist, it is now appreciated that the acinar compartment harbors progenitors, including tissue-repairing facultative progenitors (FPs). Here, we study a pancreatic acinar population marked by trefoil factor 2 (Tff2) expression. Long-term lineage tracing and single-cell RNA sequencing (scRNA-seq) analysis of Tff2-DTR-CreERT2-targeted cells defines a transit-amplifying progenitor (TAP) population that contributes to normal homeostasis. Following acute and chronic injury, Tff2+ cells, distinct from FPs, undergo depopulation but are eventually replenished. At baseline, oncogenic KrasG12D-targeted Tff2+ cells are resistant to PDAC initiation. However, KrasG12D activation in Tff2+ cells leads to survival and clonal expansion following pancreatitis and a cancer stem/progenitor cell-like state. Selective ablation of Tff2+ cells prior to KrasG12D activation in Mist1+ acinar or Dclk1+ FP cells results in enhanced tumorigenesis, which can be partially rescued by adenoviral Tff2 treatment. Together, Tff2 defines a pancreatic TAP population that protects against Kras-driven carcinogenesis.

EUS-guided gastroenterostomy for management of malignant gastric outlet obstruction: a prospective cohort study with matched comparison with enteral stenting.

BACKGROUND AND AIMS: Retrospective studies on malignant gastric outlet obstruction (mGOO) highlighted several advantages of EUS-guided gastroenterostomy (EUS-GE) over enteral stenting (ES). However, no prospective evidence is available. The aim of this study was to report on clinical outcomes of EUS-GE in a prospective cohort study, with a subgroup comparison versus ES. METHODS: All consecutive patients endoscopically treated for mGOO between December 2020 and December 2022 in a tertiary, academic center were enrolled in a prospective registry (Prospective Registry of Therapeutic Endoscopic Ultrasound [PROTECT]; NCT04813055) and followed up every 30 days to register efficacy/safety outcomes. EUS-GE and ES cohorts were matched according to baseline frailty and oncologic disease. RESULTS: A total of 104 patients were treated for mGOO during the study; 70 (58.6% male subjects; median age, 64 [interquartile range, 58-73] years; 75.7% pancreatic cancer, 60.0% metastatic cancer) underwent EUS-GE via the wireless simplified technique. Technical success was 97.1% and clinical success was 97.1% after a median of 1.5 (interquartile range, 1-2) days. Adverse events occurred in 9 (12.9%) patients. After a median follow-up of 105 (49-187) days, symptom recurrence was 7.6%. In the matched comparison versus ES (28 patients per arm), EUS-GE-treated patients experienced higher and faster clinical success (100% vs 75.0%, P = .006), reduced recurrences (3.7% vs 33.3%, P = .02), and a trend toward shorter time to chemotherapy. CONCLUSIONS: In this first, prospective, single-center comparison, EUS-GE showed excellent efficacy in treating mGOO, with an acceptable safety profile and long-term patency, and several clinically significant advantages over ES. While awaiting randomized trials, these results might endorse EUS-GE as first-line strategy for mGOO, where adequate expertise is available.

The role of biliary events in treatment and survival of patients with advanced pancreatic ductal adenocarcinoma.

BACKGROUND: Systemic chemotherapy (CT) is the treatment of choice for advanced pancreatic ductal adenocarcinoma (PDAC). Biliary obstruction is common in this setting and may interfere with CT administration due to jaundice or cholangitis related to biliary stent malfunction. AIMS: To evaluate the impact of biliary events on CT administration and survival in patients with stage III-IV PDAC. METHODS: Patients enrolled in a randomized trial of nab-paclitaxel plus gemcitabine with/without capecitabine and cisplatin in advanced PDAC were included. Data on management of jaundice, biliary stents/complications and CT were prospectively collected and retrospectively analyzed. Modified overall (mOS) and progression-free (mPFS) survival were evaluated. RESULTS: Eighty-eight patients met the inclusion criteria (50% females; median age 65years). Seven of eight (87.5%) patients who placed plastic stents developed biliary complications versus 14/30 (46.7%) with metallic stents (p = 0.071). Patients without biliary complications completed planned CT in 64.2% versus 47.6% of cases (p = 0.207). CT completion was related to longer mOS (17 vs 12 months, p = 0.005) and mPFS (9 vs 6 months, p = 0.011). mOS was shorter when biliary complications occurred (12 vs 17 months, p = 0.937), as was mPFS (6 vs 8 months, p = 0.438). CONCLUSION: Complications related to biliary obstruction influence chemotherapy completion and survival in patients with advanced PDAC.

Second-line therapy in pancreatic ductal adenocarcinoma (PDAC) patients with germline BRCA1-2 pathogenic variants (gBRCA1-2pv).

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) harbouring germline BRCA1-2 pathogenic variants (gBRCA1-2pv) is a distinct nosological entity. Information on second-line therapy (2LT) outcome in this setting is lacking. METHODS: Data of gBRCA1-2pv metastatic PDAC patients treated with chemotherapy were collected. A primary analysis of 2LT RECIST response, median progression-free survival (mPFS2) and overall survival (mOS2), was performed. A secondary analysis addressed the impact of timing of platinum introduction on the outcome of patients receiving at least a first-line combination chemotherapy (1LT). RESULTS: Eighty-four gBRCA1-2pv metastatic PDAC patients were enrolled. The primary analysis, including 43 patients, highlighted a significant improvement of mPFS2 and a doubled response rate, in the platinum-based 2LT subgroup as compared to the platinum-free (8.8 versus 3.7 months, p = 0.013). Seventy-seven patients were included in the secondary analysis. Median PFS1 of 3- and 4-drug platinum-based 1LT significantly outperformed both platinum-free combinations and platinum-based doublets (11.4 versus 6.4 versus 7.9 months, p = 0.01). Albeit still immature, data on mOS paralleled those on mPFS. CONCLUSIONS: This study highlighted the beneficial role of platinum agents in gBRCA1-2pv PDAC patients also in second-line treatment setting. However, our data suggest that early use of 3- and 4-drug platinum-based chemotherapy combinations provides a survival outcome advantage.

Routine Molecular Profiling in Both Resectable and Unresectable Pancreatic Adenocarcinoma: Relevance of Cytologic Samples.

BACKGROUND & AIMS: Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive disease, for which it is crucial to promptly detect actionable and prognostic alterations to drive specific therapeutic decisions, regardless of tumor resectability status. Endoscopic ultrasonography-guided fine-needle aspiration (EUS-FNA) is of key importance for PDAC diagnosis and can contribute significantly to tumor molecular profiling. METHODS: Comprehensive genomic profile by targeted next-generation sequencing (NGS) was performed on 2 independent PDAC patient cohorts. Cohort 1 consisted of 77 patients with resectable PDAC for whom the histologic sample at the time of resection was available; for 56 patients cytologic specimens at the time of diagnosis also were obtained by EUS-FNA. Cohort 2 consisted of 20 patients with unresectable PDAC, for whom only the EUS-FNA cytologic sample was available. RESULTS: In cohort 1, a complete concordant mutational profile between the cytologic sample at diagnosis and the corresponding histologic specimen after surgery was observed in 88% of the cases, proving the ability to detect potential clinically relevant alterations in cytologic samples by NGS analysis. Notably, clinically actionable mutations were identified in 20% of patients. In cohort 2, comprehensive mutational profiling was obtained successfully for all samples. Consistent with the findings of cohort 1, KRAS, TP53, CDKN2A, and SMAD4 were the most altered genes. Most importantly, 15% of the patients harbored actionable mutations. CONCLUSIONS: Our findings show the feasibility of an NGS approach using both surgical specimens and cytologic samples. The model proposed in this study can be included successfully in the clinical setting for comprehensive molecular profiling of all PDAC patients irrespective of their surgical eligibility.

Trotabresib (CC-90010) in combination with adjuvant temozolomide or concomitant temozolomide plus radiotherapy in patients with newly diagnosed glioblastoma.

Background: Standard-of-care treatment for newly diagnosed glioblastoma (ndGBM), consisting of surgery followed by radiotherapy (RT) and temozolomide (TMZ), has improved outcomes compared with RT alone; however, prognosis remains poor. Trotabresib, a novel bromodomain and extraterminal inhibitor, has demonstrated antitumor activity in patients with high-grade gliomas. Methods: In this phase Ib, dose-escalation study (NCT04324840), we investigated trotabresib 15, 30, and 45 mg combined with TMZ in the adjuvant setting and trotabresib 15 and 30 mg combined with TMZ+RT in the concomitant setting in patients with ndGBM. Primary endpoints were to determine safety, tolerability, maximum tolerated dose, and/or recommended phase II dose (RP2D) of trotabresib. Secondary endpoints were assessment of preliminary efficacy and pharmacokinetics. Pharmacodynamics were investigated as an exploratory endpoint. Results: The adjuvant and concomitant cohorts enrolled 18 and 14 patients, respectively. Trotabresib in combination with TMZ or TMZ+RT was well tolerated; most treatment-related adverse events were mild or moderate. Trotabresib pharmacokinetics and pharmacodynamics in both settings were consistent with previous data for trotabresib monotherapy. The RP2D of trotabresib was selected as 30 mg 4 days on/24 days off in both settings. At last follow-up, 5 (28%) and 6 (43%) patients remain on treatment in the adjuvant and concomitant settings, respectively, with 1 patient in the adjuvant cohort achieving complete response. Conclusions: Trotabresib combined with TMZ in the adjuvant setting and with TMZ+RT in the concomitant setting was safe and well tolerated in patients with ndGBM, with encouraging treatment durations. Trotabresib 30 mg was established as the RP2D in both settings.

Modulation of the Estrogen/erbB2 Receptors Cross-talk by CDK4/6 Inhibition Triggers Sustained Senescence in Estrogen Receptor- and ErbB2-positive Breast Cancer.

PURPOSE: The interplay between estrogen receptor (ER) and erbB tyrosine-kinase receptors (RTK) impacts growth and progression of ER-positive (ER+)/HER2-positive (HER2+) breast cancer and generates mitogenic signals converging onto the Cyclin-D1/CDK4/6 complex. We probed this cross-talk combining endocrine-therapy (fulvestrant), dual HER2-blockade (trastuzumab and pertuzumab), and CDK4/6-inhibition (palbociclib; PFHPert). EXPERIMENTAL DESIGN: Cytotoxic drug effects, interactions, and pharmacodynamics were studied after 72 hours of treatment and over 6 more days of culture after drug wash-out in three ER+/HER2+, two HER2low, and two ER-negative (ER-)/HER2+ breast cancer cell lines. We assessed gene-expression dynamic and association with Ki67 downregulation in 28 patients with ER+/HER2+ breast cancer treated with neoadjuvant PFHPert in NA-PHER2 trial (NCT02530424). RESULTS: In vitro, palbociclib and/or fulvestrant induced a functional activation of RTKs signalling. PFHPert had additive or synergistic antiproliferative activity, interfered with resistance mechanisms linked to the RTKs/Akt/MTORC1 axis and induced sustained senescence. Unexpected synergism was found in HER2low cells. In patients, Ki67 downregulation at week 2 and surgery were significantly associated to upregulation of senescence-related genes (P = 7.7E-4 and P = 1.8E-4, respectively). Activation of MTORC1 pathway was associated with high Ki67 at surgery (P = 0.019). CONCLUSIONS: Resistance associated with the combination of drugs targeting ER and HER2 can be bypassed by cotargeting Rb, enhancing transition from quiescence to sustained senescence. MTORC1 pathway activation is a potential mechanism of escape and RTKs functional activation may be an alternative pathway for survival also in ER+/HER2low tumor. PFHPert combination is an effective chemotherapy-free regimen for ER+/HER2+ breast cancer, and the mechanistic elucidation of sensitivity/resistance patterns may provide insights for further treatment refinement.

Epidemiology and geographic distribution of BRCA1-2 and DNA Damage response genes pathogenic variants in pancreatic ductal adenocarcinoma patients.

Incidence of pancreatic ductal adenocarcinoma (PDAC) is increasing over the last years, while patients prognosis remains grim. Recently germline BRCA1 and 2 pathogenic variants (gBRCA1-2) have emerged as risk factors for PDAC development, as well as new predictors of response to specific therapeutic interventions. However, data on gBRCA1-2 incidence in PDAC are currently sparse and limited to selected categories of patients, as for positive cancer history cases, for patients affected only by early or late stages of disease and mainly from the North-American population, thus generating incomplete information about the gBRCA1/2 epidemiology. In Western Countries gBRCA1-2 incidence ranges between 4.5% and 8% in unselected PDAC patients, raising up to 26% in cohorts with positive family cancer history. To date a limited number of studies from Asian countries are available, reporting a 10% as highest incidence of gBRCA1-2 in familiar PDAC, claiming at least in part a role of ethnicity in the gBRCA1-2 incidence and in other genes potentially implicated in the therapeutic decisions. Drawing a better defined map for the incidence of gBRCA1-2 and other germline pathogenic variants of DNA Damage Response genes (gDDR) might help assessing the therapeutic strategies for mutated patients according to the geographic areas. These informations may enhance the chance to predict efficacy and toxicity of selected chemotherapy regimens, fostering the development and implementation of the pharmaco-ethnicity knowledge in the routine-clinical practice, and increasing the awareness of the potential incorrect generalization of trials results outside of the geographic area where they are conducted.

The impact of nutritional status on pancreatic cancer therapy.

INTRODUCTION: Pancreatic Ductal Adenocarcinoma (PDAC) is an aggressive disease with poor outcomes. One of the reasons for the dismal prognosis resides in its impressive ability to alter the nutritional status of patients who develop malnutrition, cachexia, anorexia, and sarcopenia in most cases. The ideal way to measure such changes in PDAC patients, in order to readily identify them and avoid complications or discontinuations of treatment is a relatively unexplored area. In addition, most PDAC patients experience pancreatic exocrine insufficiency (PEI) that contributes to the complex puzzle of malnutrition and that can be treated with Pancreatic Enzyme Replacement Therapy (PERT). AREAS COVERED: We review current knowledge on the impact of nutritional status on both surgical and medical treatments for PDAC, reporting available data on the causes of malnutrition, characteristics, and advantages of different tools to investigate nutritional status and possible strategies to improve patient outcomes. EXPERT OPINION: All PDAC patients should receive a careful nutritional assessment at diagnosis, and this should be repeated alongside their treatment path. Screening tools and biochemical variables or scores are associated with prognosis, but bioimpedance vector analysis (BIVA) and radiological assessment of body composition seem more accurate in predicting clinical outcomes and postoperative complications.

Evolving pancreatic cancer treatment: From diagnosis to healthcare management.

The prognosis of pancreatic ductal adenocarcinoma is still the worst among solid tumors. In this review, a panel of experts addressed the main unanswered questions about the clinical management of this disease, with the aim of providing practical decision support for physicians. On the basis of the evidence available from the literature, the main topics concerning pancreatic cancer are discussed: the diagnosis, as the need for a pathological characterization and the role for germ-line and somatic molecular profiling; the therapeutic management of resectable disease, as the role of upfront surgery or neoadjuvant chemotherapy, the post-operative restaging and the optimal timing foradjuvant chemotherapy, the management of the borderline resectable and locally advanced disease; the metastatic disease and the role of surgery for the management of patients with isolated metastasis and the use of biomarkers of metastatic potential; the role of supportive care and the healthcare management of pancreatic ductal adenocarcinoma.

Treatment opportunities and future perspectives for pancreatic cancer patients with germline BRCA1-2 pathogenic variants.

Personalized treatments and predictive biomarkers of pancreatic cancer (PDAC) are still lacking. Recently germline mutations in BRCA 1 and 2 genes, leading to homologous repair deficiency, have emerged as new targets for more specific and effective therapies, exploiting the increased susceptibility to platinum salts and PARP inhibitors. In addition to BRCA, pathogenic variants in PALB2 and in other genes involved in the DNA damage response pathway (DDR) represent potential targets, as well as their respective somatic alterations. This enlarged molecularly-selected population sharing the BRCAness phenotype, is expected to show a higher sensibility to a number of DNA damaging agents and DDR inhibitors. However, the possibility of new therapeutic opportunities for DDR defective PDAC patients has to face the lack of solid evidence about the proper type and timing of targeted-treatments, the potential combination strategies and most importantly, the lack of informations on the functional impact of each specific pathogenic variant on the DDR pathway. This review summarizes the current and near-future options for the clinical management of PDAC patients harboring a DDR deficiency, analyzing the state of the art of the indications of platinum salts and other cytotoxic agents in the advanced and early stage PDAC, the development of PARP inhibitors and the rational for new combinations with immunotherapy and cycle checkpoint inhibitors, as well as the strategy to overcome the development of resistance over treatments.

Interleukin-1ß-induced pancreatitis promotes pancreatic ductal adenocarcinoma via B lymphocyte-mediated immune suppression.

OBJECTIVE: Long-standing chronic pancreatitis is an established risk factor for pancreatic ductal adenocarcinoma (PDAC). Interleukin-1ß (IL-1ß) has been associated in PDAC with shorter survival. We employed murine models to investigate the mechanisms by which IL-1ß and chronic pancreatitis might contribute to PDAC progression. DESIGN: We crossed LSL-Kras+/G12D;Pdx1-Cre (KC) mice with transgenic mice overexpressing IL-1ß to generate KC-IL1ß mice, and followed them longitudinally. We used pancreatic 3D in vitro culture to assess acinar-to-ductal metaplasia formation. Immune cells were analysed by flow cytometry and immunohistochemical staining. B lymphocytes were adoptively transferred or depleted in Kras-mutant mice. B-cell infiltration was analysed in human PDAC samples. RESULTS: KC-IL1ß mice developed PDAC with liver metastases. IL-1ß treatment increased Kras+/G12D pancreatic spheroid formation. CXCL13 expression and B lymphocyte infiltration were increased in KC-IL1ß pancreata. Adoptive transfer of B lymphocytes from KC-IL1ß mice promoted tumour formation, while depletion of B cells prevented tumour progression in KC-IL1ß mice. B cells isolated from KC-IL1ß mice had much higher expression of PD-L1, more regulatory B cells, impaired CD8+ T cell activity and promoted tumorigenesis. IL-35 was increased in the KC-IL1ß pancreata, and depletion of IL-35 decreased the number of PD-L1+ B cells. Finally, in human PDAC samples, patients with PDAC with higher B-cell infiltration within tumours showed significantly shorter survival. CONCLUSION: We show here that IL-1ß promotes tumorigenesis in part by inducing an expansion of immune-suppressive B cells. These findings point to the growing significance of B suppressor cells in pancreatic tumorigenesis.