Immunotherapy in the neoadjuvant treatment of gastrointestinal tumors: is the time ripe?

Immune checkpoint inhibitors (ICIs) revolutionized the management of mismatch repair-deficient (dMMR)/microsatellite instability-high (MSI-H) gastrointestinal (GI) cancers. Based on notable results observed in the metastatic setting, several clinical trials investigated ICIs as neoadjuvant treatment (NAT) for localized dMMR/MSI-H GI cancers, achieving striking results in terms of clinical and pathological responses and creating the opportunity to spare patients from neoadjuvant chemotherapy and/or radiotherapy and even surgical resection. Nevertheless, these impressive findings are mainly derived from small proof of concept phase II studies and there are still several open questions to address. Moreover, dMMR/MSI-H represents a limited subgroup accounting for less than 10% of GI cancers. Consequently, many efforts have been produced to investigate neoadjuvant ICIs also in mismatch repair-proficient/microsatellite stable (MSS) cancers, considering the potential synergistic effect in combining immune-targeted agents with standard therapies such as chemo and/or radiotherapy. However, results for combining ICIs to the standard of care in the unselected population are still unsatisfactory, without improvements in event-free survival in esophago-gastric adenocarcinoma for the addition of pembrolizumab to chemotherapy, and sometimes limited benefit in patients with locally advanced rectal cancer. Therefore, a major challenge will be to identify among the heterogenous spectrum of this disease, those patients that could take advantage of neoadjuvant immunotherapy and deliver the most effective treatment. In this review we discuss the rationale of NAT in GI malignancies, summarize the available evidence regarding the completed trials that evaluated this treatment strategy in both MSI-H and MSS tumors. Finally, we discuss ongoing studies and future perspectives to render neoadjuvant immunotherapy another arrow in the quiver for the treatment of locally advanced GI tumors.

Efficacy and safety of systemic chemotherapy for radically resectable esophago-gastric adenocarcinoma in older patients: A systematic review and meta-analysis.

INTRODUCTION: A significant proportion of locally-advanced esophago-gastric adenocarcinoma (EGA) is diagnosed in patients ≥70 years old (y.o.) who are commonly underrepresented in clinical trials. MATERIALS AND METHODS: The PubMed database was searched for phase 2/3 clinical trials enrolling patients ≥70 y.o and reporting efficacy/safety information of chemotherapy for resectable EGA. The main outcomes were overall survival (OS) and recurrence-free survival (RFS). RESULTS: Among 6,128 records, only seven studies reported these outcomes (three peri-operative, three adjuvant, and one neoadjuvant), including 1004 older patients, <20% of the overall population. No significant benefit in terms of OS and RFS was observed for perioperative or adjuvant chemotherapy vs surgery alone. No trial reported safety endpoints in this subgroup. DISCUSSION: This work did not show any significant benefit in OS or RFS for chemotherapy vs surgery alone or conventional vs de-escalated chemotherapy in the curative setting of EGA in ≥70 y.o patients. Specific ad hoc trials should be performed to derive reliable data.

Textbook outcome as indicator of surgical quality in a single Western center: results from 300 consecutive gastrectomies.

Textbook outcome (TO) has been proposed as a tool to evaluate surgical quality. Textbook oncological outcome (TOO) adds chemotherapeutic compliance to TO. This study was conducted to analyze the TO and TOO of patients with gastric adenocarcinoma who underwent surgery at our center. Data from a prospective database of patients operated on for gastric adenocarcinoma between September 2018 and September 2022 were analyzed. Postoperative management followed Enhanced Recovery After Surgery guidelines. The Dutch Upper Gastrointestinal Cancer Audit group defined TO as a multidimensional measure (10 items). TOO also considers guideline-accordant chemotherapeutic compliance. Three hundred patients underwent surgery during the study period (167 men, 133 women). One hundred seventy-six (58.7%) reached TO. Achieving TO was influenced by patients' comorbidities, calculated via the Charlson Comorbidity Score (3 vs. 4; p = 0.002) and surgery type (subtotal gastrectomy; p < 0.001), but not by the American Society of Anesthesiologists (ASA) score (p = 0.057) or surgical approach (laparoscopic vs. open; p = 0.208). The analysis of TOO included 213 patients. Of these, 71 (33%) underwent complete adequate systemic treatment. Compared with the non-TOO group, patients who achieved TOO had a lower median age (64 vs. 73 years; p < 0.001) and lower ASA score (p < 0.001) and more frequently underwent preoperative chemotherapy (p < 0.001). Our results represent the experience of a single team at a high-volume Western institute. Patients' comorbidities and surgery type influenced whether TO was achieved. Conversely, younger age, lower ASA score and preoperative chemotherapy were associated with TOO.

Role of microsatellite instability and HER2 positivity in locally advanced esophago-gastric cancer patients treated with peri-operative chemotherapy

Purpose Neoadjuvant chemotherapy (NAC) significantly improved the prognosis of patients with locally advanced gastric cancer (LAGC). Several biomarkers, including HER2 and MMR/MSI are crucial for treatment decisions in the advanced stage but, currently, no biomarkers can guide the choice of NAC in clinical practice. Our aim was to evaluate the role of MSI and HER2 status on clinical outcomes. Methods We retrospectively collected LAGC patients treated with NAC and surgery +/- adjuvant chemotherapy from 2006 to 2018. HER2 and MSI were assessed on endoscopic and surgical samples. Pathologic complete response (pCR) rate, overall survival (OS), and event‐free survival (EFS) were estimated and evaluated for association with downstaging and MSI. Results We included 76 patients, 8% were classified as MSI-H, entirely consistent between endoscopic and surgical samples. Six percent of patients were HER2 positive on endoscopic and 4% on surgical samples. Tumor downstaging was observed in 52.5% of cases, with three pCR (5.1%), none in MSI-H cancers. According to MSI status, event-free survival (EFS) and overall survival (OS) were higher for MSI-H patients to MSS [EFS not reached vs 30.0 months, p = 0.08; OS not reached vs 39.6 months, p = 0.10]. Conclusion Our work confirms the positive prognostic effect of MSI-H in the curative setting of LAGC, not correlated with pathologic tumor downstaging. Prospective ad-hoc trial and tumor molecular profiling are eagerly needed (AU)

Multimodal treatment for resectable neuroendocrine carcinoma of the cervix.

Non-metastatic neuroendocrine carcinoma of the cervix (NECC) is a rare and aggressive disease. Lacking prospective studies, the optimal multimodal treatment approach has not yet been clearly defined. This study aims to assess the clinical outcomes of patients with non-metastatic NECC treated with surgery and (neo)adjuvant chemotherapy, according to pathologic prognostic factors and multimodal treatments received. We retrospectively examined data from patients with non-metastatic NECC candidate to receive surgery and (neo)adjuvant chemotherapy and discussed at the European Institute of Oncology's Multidisciplinary Neuroendocrine Tumor Board, between January 2003 and December 2021. Primary endpoints were event-free survival and overall survival. A total of 27 consecutive patients were evaluated, 15 with early stage NECC and 12 with a locally advanced NECC. Eight patients received neoadjuvant and 19 adjuvant platinum-based chemotherapy; 14 received adjuvant pelvic radiotherapy, half with external-beam radiation therapy alone, and half combined with brachytherapy. No patients progressed or relapsed during (neo)adjuvant chemotherapy. The median event-free survival was 21.1 months and the median overall survival was 33.0 months. Pathological FIGO stage ≥ IIB, adjuvant external-beam radiation therapy with or without brachytherapy emerged as significant and independent prognostic factors for event-free survival. Brachytherapy was also prognostic for overall survival. Non-metastatic NECC requires a multimodal approach, mainly weighted on the FIGO stage. The addition of brachytherapy should be considered, especially in patients with locally advanced disease. Because of the scarcity of robust clinical data, treatment strategy should be discussed in multidisciplinary board, taking into account patient.

Risk of thromboembolic events in patients with metastatic solid tumors treated with PARP inhibitors: A systematic review and meta-analysis of phase 3 randomized controlled trials.

BACKGROUND AND SCOPE: Poly(ADP-ribose) polymerase inhibitors (PARPi) have revolutionized cancer treatment in recent years. These drugs present a favorable safety profile, even though the potential risk of thromboembolic events (TEs) during their use has not been addressed yet. In addition, PARPi have been involved in an active scientific debate regarding non-oncologic indications, particularly during the Coronavirus Disease 2019 pandemic, including potential anti-thromboembolic effect. METHODS: To clarify whether patients treated with PARPi for metastatic solid tumors are either at increased or decreased risk of TEs, we conducted a systematic review of the literature and meta-analysis, including all phase 3 randomized controlled trials (RCTs) which investigated PARPi in this setting. Search was conducted through Medline, EMBASE, Pubmed, SCOPUS and Google Scholar in February 2023, including the proceedings of the principal oncology meetings of the last 10 years, with no time restriction. For each included study, frequencies of TEs in experimental and control arm were collected. RESULTS: Our search identified 2,369 reports, of which 20 were lastly selected. A total of 4,946 patients were included, across 12 different RCTs. The meta-analysis did not demonstrate either an increased or a reduced risk in TEs in patients treated with PARPi for metastatic disease (OR 1.50, range: 1.00-2.24; 95% CI; P = 0.050), with low heterogeneity and low publication bias. CONCLUSION: Although our research did not confirm either increased or decreased risk of TEs for PARPi use, no safety alerts emerged. Thromboembolic risk assessment models should always be integrated in daily clinical routine, to identify high-risk patients.

Hereditary Gastric Cancer: Single-Gene or Multigene Panel Testing? A Mono-Institutional Experience.

Gastric cancer (GC) has long been a 'Cinderella' among hereditary cancers. Until recently, single-gene testing (SGT) was the only approach to identify high-risk individuals. With the spread of multigene panel testing (MGPT), a debate arose on the involvement of other genes, particularly those pertaining to homologous recombination (HR) repair. We report our mono-institutional experience in genetic counseling and SGT for 54 GC patients, with the detection of nine pathogenic variants (PVs) (9/54:16.7%). Seven out of fifty (14%) patients who underwent SGT for unknown mutations were carriers of a PV in CDH1 (n = 3), BRCA2 (n = 2), BRCA1 (n = 1), and MSH2 (n = 1), while one patient (2%) carried two variants of unknown significance (VUSs). CDH1 and MSH2 emerged as genes involved in early-onset diffuse and later-onset intestinal GCs, respectively. We additionally conducted MGPT on 37 patients, identifying five PVs (13.5%), including three (3/5:60%) in an HR gene (BRCA2, ATM, RAD51D) and at least one VUS in 13 patients (35.1%). Comparing PV carriers and non-carriers, we observed a statistically significant difference in PVs between patients with and without family history of GC (p-value: 0.045) or Lynch-related tumors (p-value: 0.036). Genetic counseling remains central to GC risk assessment. MGPT appeared advantageous in patients with unspecific phenotypes, although it led to challenging results.

Role of microsatellite instability and HER2 positivity in locally advanced esophago-gastric cancer patients treated with peri-operative chemotherapy.

PURPOSE: Neoadjuvant chemotherapy (NAC) significantly improved the prognosis of patients with locally advanced gastric cancer (LAGC). Several biomarkers, including HER2 and MMR/MSI are crucial for treatment decisions in the advanced stage but, currently, no biomarkers can guide the choice of NAC in clinical practice. Our aim was to evaluate the role of MSI and HER2 status on clinical outcomes. METHODS: We retrospectively collected LAGC patients treated with NAC and surgery +/- adjuvant chemotherapy from 2006 to 2018. HER2 and MSI were assessed on endoscopic and surgical samples. Pathologic complete response (pCR) rate, overall survival (OS), and event-free survival (EFS) were estimated and evaluated for association with downstaging and MSI. RESULTS: We included 76 patients, 8% were classified as MSI-H, entirely consistent between endoscopic and surgical samples. Six percent of patients were HER2 positive on endoscopic and 4% on surgical samples. Tumor downstaging was observed in 52.5% of cases, with three pCR (5.1%), none in MSI-H cancers. According to MSI status, event-free survival (EFS) and overall survival (OS) were higher for MSI-H patients to MSS [EFS not reached vs 30.0 months, p = 0.08; OS not reached vs 39.6 months, p = 0.10]. CONCLUSION: Our work confirms the positive prognostic effect of MSI-H in the curative setting of LAGC, not correlated with pathologic tumor downstaging. Prospective ad-hoc trial and tumor molecular profiling are eagerly needed.

COVID-19 in patients with neuroendocrine neoplasms: 2-year results of the INTENSIVE study.

We conducted a retrospective/prospective worldwide study on patients with neuroendocrine neoplasms (NENs) and a molecularly proven SARS-CoV-2 positivity. Preliminary results regarding 85 patients of the INTENSIVE study have been published in 2021. Now we are reporting the 2-year analysis.Here, we are reporting data from consecutive patients enrolled between 1 June 2020, and 31 May 2022. Among the 118 contacted centers, 25 were active to enroll and 19 actively recruiting at the time of data cut-off for a total of 280 patients enrolled. SARS-CoV-2 positivity occurred in 47.5% of patients in 2020, 35.1% in 2021, and 17.4% in 2022. The median age for COVID-19 diagnosis was 60 years. Well-differentiated tumors, non-functioning, metastatic stage, and gastroenteropancreatic (GEP) primary sites represented most of the NENs. COVID-19-related pneumonia occurred in 22.8% of the total, with 61.3% of them requiring hospitalization; 11 patients (3.9%) needed sub-intensive or intensive care unit therapies and 14 patients died (5%), in 11 cases (3.9%) directly related to COVID-19. Diabetes mellitus and age at COVID-19 diagnosis > 70 years were significantly associated with COVID-19 mortality, whereas thoracic primary site with COVID-19 morbidity. A significant decrease in both hospitalization and pneumonia occurred in 2022 vs 2020. In our largest series of NEN patients with COVID-19, the NEN population is similar to the general population of patients with NEN regardless of COVID-19. However, older age, non-GEP primary sites and diabetes mellitus should be carefully considered for increased COVID-19 morbidity and mortality. Relevant information could be derived by integrating our results with NENs patients included in other cancer patients with COVID-19 registries.

Observational Study on Antibody Response to COVID-19 Vaccines in PAtients with Gastro-Entero-PanCreatic Cancers and NeuroendocrIne NeoplAsms on Systemic TreatmEnts (VACCINATE).

The coronavirus disease-19 (COVID-19) pandemic dramatically impacted oncological patients' care. Since the introduction of vaccines and the demonstration of their benefit on frail patients, COVID-19 vaccinations were indicated to also be beneficial to oncological population. However, data about the impact of anticancer-treatments and the timing between vaccinations and systemic therapy delivery were not available. We aimed to evaluate potential factors influencing the outcome of the COVID-19 vaccination in cancer patients. We prospectively collected data of patients undergoing the COVID-19 vaccination with gastro-entero-pancreatic and neuroendocrine neoplasms, treated at our institute, between 03/2021 and 12/2021. We enrolled 46 patients, 63.1% males; at the time of data collection, 86.9% had received two-doses of Pfizer-BioNTech and the rest had received the Moderna vaccine. All patients obtained a subsequent immune-response. Chemotherapy seems to determinate a significantly lower antibody response after vaccination compared to the other anti-cancer agents (p = 0.004). No significant effect on immune-response was reported for both vaccinations performed ≤7 vs. >7 days from the last systemic treatment (p = 0.77) and lymphocytes count (p = 0.11). The findings suggest that the optimal timing for COVID-19 vaccination and lymphocytes count are not the issue, but rather that the quality of the subset of lymphocytes before the vaccination determine the efficacy level of immune-response in this population.

Validation of the ONKOTEV Risk Prediction Model for Venous Thromboembolism in Outpatients With Cancer.

Importance: The assessment of the risk of venous thromboembolism (VTE) among outpatients with cancer represents an unsolved topic. Current international guidelines recommend primary prophylaxis for patients at intermediate to high risk of VTE, indicated by a Khorana score of 2 or more. A previous prospective study developed the ONKOTEV score, a 4-variable risk assessment model (RAM) consisting of a Khorana score of more than 2, metastatic disease, vascular or lymphatic compression, and previous VTE event. Objective: To validate the ONKOTEV score as a novel RAM to assess the risk of VTE among outpatients with cancer. Design, Setting, and Participants: ONKOTEV-2 is a noninterventional prognostic study conducted in 3 European centers located in Italy, Germany, and the United Kingdom among a prospective cohort of 425 ambulatory patients with a histologically confirmed diagnosis of a solid tumor who were receiving active treatments. The total study duration was 52 months, with an accrual period of 28 months (from May 1, 2015, to September 30, 2017) and an overall follow up-period of 24 months (data were censored September 30, 2019). Statistical analysis was performed in October 2019. Exposures: The ONKOTEV score was calculated for each patient at baseline by collecting clinical, laboratory, and imaging data from tests performed for routine practice. Each patient was then observed to detect any thromboembolic event throughout the study period. Main Outcomes and Measures: The primary outcome of the study was the incidence of VTE, including deep vein thrombosis and pulmonary embolism. Results: A total of 425 patients (242 women [56.9%]; median age, 61 years [range, 20-92 years]) were included in the validation cohort of the study. The cumulative incidences for the risk of developing VTE at 6 months were 2.6% (95% CI, 0.7%-6.9%), 9.1% (95% CI, 5.8%-13.2%), 32.3% (95% CI, 21.0%-44.1%), and 19.3% (95% CI, 2.5%-48.0%), respectively, among 425 patients with an ONKOTEV score of 0, 1, 2, and greater than 2 (P < .001). The time-dependent area under the curve at 3, 6, and 12 months was 70.1% (95% CI, 62.1%-78.7%), 72.9% (95% CI, 65.6%-79.1%), and 72.2% (95% CI, 65.2%-77.3%), respectively. Conclusions and Relevance: This study suggests that, because the ONKOTEV score has been validated in this independent study population as a novel predictive RAM for cancer-associated thrombosis, it can be adopted into practice and into clinical interventional trials as a decision-making tool for primary prophylaxis.

Metronomic chemotherapy in patients with advanced neuroendocrine tumors: A single-center retrospective analysis.

Neuroendocrine tumors (NETs) are more commonly slow-growing, therefore patients often receive chronic systemic therapies for tumor growth control and preservation of quality of life. Metronomic chemotherapy (mCT) is in line with this goal as it leads to stabilization of tumor growth over time without severe systemic toxicity. This is a retrospective analysis of patients with metastatic NETs receiving metronomic capecitabine (mCAP) or temozolomide (mTEM), at a NET-referral center. The aims of the study were to explore activity and safety of mCT and relationships between some characteristics of the patient population and clinical outcomes. Among a total of 67 patients with metastatic well or moderately differentiated (W/M-D) NETs, mostly gastroenteropancreatic (GEP) and nonfunctioning, 1.2 years (95% CI: 0.8-1.8) median progression-free survival (mPFS), and 3.0 years (95% CI: 2.3-4.9) median overall survival (mOS) were observed. Disease control rate was 85%. Grade 3 adverse events occurred in 15% of patients in mCAP and 13% in mTEM, and were mostly hematological and gastrointestinal. At univariate and multivariate analysis none of the variables analyzed (treatment regimen, sex, age at diagnosis, site of primary tumor and metastases, number of previous mCT lines, baseline tumor status before mCT, Ki67 value) were significantly correlated to OS and PFS. Our retrospective study suggested that mCAP and mTEM can be active and well tolerated in patients with metastatic W/M-D NETs, irrespective of the primary site, site of metastases, line of treatment and baseline tumor status.

Nodal Merkel Cell Carcinoma with Unknown Primary Site and No Distant Metastasis: A Single-Center Series.

Merkel cell carcinoma (MCC) is a very rare and aggressive neuroendocrine carcinoma originating from Merkel cells, typically with a skin nodule; however, it exceptionally presents with only a basin lymph node localization, with neither a cutaneous primary site nor distant metastases. From 1996 to 2020, among patients with histologically confirmed MCC managed at a neuroendocrine neoplasm-referral center, we selected those with an exclusive nodal basin, no distant metastasis, and an unknown primary site defined by cross-sectional and physical examination. A total of 55 out of 310 patients fulfilled the selection criteria. The median age was 64 years and the majority were males. Inguinal lymph-nodes were the most common anatomic site. With a median follow-up of 4.3 years, the 5-year relapse-free survival (RFS) rate was 56.6 (95% CI 42.0-68.8%) and the 5-year cancer specific survival (CSS) rate was 68.5 (95% CI 52.8-79.9%) for the whole population. The 36 patients (65.5%) undergoing lymphadenectomy (LND) + radiotherapy (RT) ± chemotherapy had a 5-year RFS rate of 87.2% (95% CI 65.5-95.7%) and a 5-year CSS rate of 90.5% (95% CI 67.0-97.5), which were better than those receiving LND alone. In a multivariable analysis, the survival benefit for LND + RT remained significant. Results from one of the largest single-center series of nMCC-UP suggest that a curative approach including RT can be effective, similar to what is observed for stage IIIB MCC. Multicentric studies with homogenous populations should be carried out in this controversial clinical entity, to minimize the risk of biases and provide robust data.

Addressing the Role of Angiogenesis in Patients with Advanced Pancreatic Neuroendocrine Tumors Treated with Everolimus: A Biological Prospective Analysis of Soluble Biomarkers and Clinical Outcomes.

BACKGROUND: The success of targeted therapies in the treatment of pancreatic neuroendocrine tumors has emphasized the strategy of targeting angiogenesis and the PI3K/AKT/mTOR pathway. However, the major challenge in the targeted era remains the early identification of resistant tumors especially when the efficacy is rarely associated to a clear tumor shrinkage at by imaging assessment. METHODS: In this prospective study (NCT02305810) we investigated the predictive and prognostic role of soluble biomarkers of angiogenesis turnover (VEGF, bFGF, VEGFR2, TSP-1) circulating endothelial cells and progenitors, in 43 patients with metastatic panNET receiving everolimus. RESULTS: Among all tested biomarkers, we found a specific subpopulation of circulating cells, CD31+CD140b-, with a significantly increased tumor progression hazard for values less or equal to the first quartile. CONCLUSION: Our study suggested the evidence that circulating cells might be surrogate biomarkers of angiogenesis activity in patients treated with everolimus and their baseline levels can be correlated with survival. However, further studies are now needed to validate the role of these cells as surrogate markers for the selection of patients to be candidates for antiangiogenic treatments.

Cyclin-dependent Kinases 4/6 Inhibitors in Neuroendocrine Neoplasms: from Bench to Bedside.

PURPOSE OF REVIEW: Cyclin-dependent kinases (CDKs) are key regulators that play an important role in cell division. Palbociclib, ribociclib and abemaciclib showed significant antitumor activity in several malignancies and, recently, also a myeloprotective effect for trilaciclib when added to chemotherapy. The purpose of this review is to highlight the current evidence for CDK4/6 inhibitors in neuroendocrine neoplasms (NENs). RECENT FINDINGS: Preclinical results showed a promising antitumor activity of CDK4/6 inhibitors in neuroendocrine tumors (NETs), but so far, the very few small clinical trials did not show a strong impact on progression free survival (PFS) and objective response in NETs. Meanwhile, the CDK4/6 inhibitor trilaciclib revealed significant effects in reducing chemotherapy-induced myelosuppression in small cell lung cancer (SCLC). Up to date, CDK4/6 inhibitors are still considered investigational in NETs as antitumor agents, whereas trilaciclib can be used in the routine clinical practice in extensive stage SCLC patients for reducing myelotoxicity of standard chemotherapy.

Chemotherapy in pancreatic ductal adenocarcinoma: When cytoreduction is the aim. A systematic review and meta-analysis.

BACKGROUND: In pancreatic ductal adenocarcinoma cytoreduction can be curative, or palliative. FOLFIRINOX and GEM-NAB are the two FDA/EMA approved regimens for advanced disease. We aim to identified the most cytoreductive regimen on the basis of current literature. MATERIAL AND METHODS: PUBMED was searched for studies published to April 2021. Abstracts of annual meetings ASCO 2009-2021, and ESMO 2015-2020, were searched as well. Phase II, phase III clinical trials, prospective, observational and retrospective studies, reporting overall response rate (complete + partial response) (ORR) in patients treated either with FOLFIRINOX or GEM-NAB were included. The meta-analysis was performed using a randomized-effects model. Main outcome was cytoreduction with each regimen reported as ORR according to RECIST. RESULTS: Among 2183 studies identified, 40 fulfilled the selection criteria (22 FOLFIRINOX, 18 GEM-NAB), totaling 2883 patients. Pooling of data found similar ORR between regimens: FOLFIRINOX [30% (95 CI 26-34%)] and GEM-NAB [30% (95 CI 26-35%),] P = 0.928. Disease control rate (DCR) was significantly higher with FOLFIRINOX [85% (95CI 82-88%)] compared to GEM-NAB [80% (95CI 77-84%)], P = 0.012. A significantly higher ORR irrespective of the regimen was observed in stage IV [36% (95CI 32-40%)] versus stage II-III [25% (95CI 20-31%)], P = 0.002. CONCLUSIONS AND RELEVANCE: Our meta-analysis did not find significant superiority of one regimen over the other in terms of RECIST-based cytoreduction both in palliative and curative setting of patients with pancreatic adenocarcinoma. The significantly better DCR with FOLFIRINOX compared with GEM-NAB deserves further investigation including waterfall plot and correlations with potential predictive factors.