A systematic review and meta-analysis of morbidity and pancreatic fistula after distal pancreatectomy with versus without prophylactic intra-abdominal drainage.

BACKGROUND: The omission of a prophylactic intra-abdominal drainage has been under debate in pancreatic surgery due to the high risk of complications and especially of postoperative pancreatic fistula (POPF). Recently, the second randomized controlled trial (RCT) and two propensity score-matched comparative studies assessing risks and benefits of a no-drainage policy versus prophylactic drainage after distal pancreatectomy (DP) have been published. This systematic review with meta-analysis provides an updated summary of the available evidence on this topic. METHODS: RCTs and non-randomized comparative studies (NCS) investigating outcomes of no drainage versus drainage after DP were searched systematically in MEDLINE, Embase and CENTRAL. Random effects meta-analyses were performed, and the results presented as weighted odds ratios (OR) or mean differences (MD) with their corresponding 95% confidence intervals (c.i.). Subgroup analyses were performed to account for inter-study heterogeneity between RCTs and NCS. RESULTS: Two RCTs and six NCS with a total of 3,610 patients undergoing DP were included of whom 1,038 (28.8%) patients did not receive prophylactic drainage. A no-drainage policy was associated with significantly lower risks of POPF (OR 0.38, 95% c.i. 0.25-0.56; P<0.00001), reduced major morbidity (OR 0.64, 95% c.i. 0.47-0.89; P=0.008), less reinterventions (OR 0.70, 95% c.i. 0.52-0.95; P=0.02) and fewer readmissions (OR 0.69, 95% c.i. 0.54-0.88; P=0.003) as well as shorter length of hospital stay (MD -1.74, 95% c.i. -2.70- -0.78; P=0.0004). Subgroup analyses including only RCTs confirmed benefits of the no-drainage policy. CONCLUSION: A no-drainage policy is associated with reduced POPF and morbidity and can therefore be recommended as standard procedure in patients undergoing DP.

Prognostic Factors for Early Recurrence After Resection of Pancreatic Cancer: A Systematic Review and Meta-Analysis.

BACKGROUND & AIMS: More than half of pancreatic ductal adenocarcinomas (PDACs) recur within 12 months after curative-intent resection. This systematic review and meta-analysis was conducted to identify all reported prognostic factors for early recurrence in resected PDACs. METHODS: After a systematic literature search, a meta-analysis was conducted using a random effects model. Separate analyses were performed for adjusted vs unadjusted effect estimates as well as reported odds ratios (ORs) and hazard ratios (HRs). Risk of bias was assessed using the Quality in Prognostic Studies tool, and evidence was rated according to Grading of Recommendations Assessment, Development and Evaluation recommendations. RESULTS: After 2903 abstracts were screened, 65 studies were included. Of these, 28 studies (43.1%) defined early recurrence as evidence of recurrence within 6 months, whereas 34 (52.3%) defined it as evidence of recurrence within 12 months after surgery. Other definitions were uncommon. Analysis of unadjusted ORs and HRs revealed 41 and 5 prognostic factors for early recurrence within 6 months, respectively. When exclusively considering adjusted data, we identified 25 and 10 prognostic factors based on OR and HR, respectively. Using a 12-month definition, we identified 38 (OR) and 15 (HR) prognostic factors from unadjusted data and 38 (OR) and 30 (HR) prognostic factors from adjusted data, respectively. On the basis of frequency counts of adjusted data, preoperative carbohydrate antigen 19-9, N status, nondelivery of adjuvant therapy, grading, and tumor size based on imaging were identified as key prognostic factors for early recurrence. CONCLUSIONS: Reported prognostic factors of early recurrence vary considerably. Identified key prognostic factors could aid in the development of a risk stratification framework for early recurrence. However, prospective validation is necessary.

Prognostic impact of resection margin status on survival after neoadjuvant treatment for pancreatic cancer: systematic review and meta-analysis.

BACKGROUND: A greater than 1 mm tumour-free resection margin (R0 >1 mm) is a prognostic factor in upfront-resected pancreatic ductal adenocarcinoma. After neoadjuvant treatment (NAT); however, the prognostic impact of resection margin (R) status remains controversial. METHODS: Randomised and non-randomised studies assessing the association of R status and survival in resected pancreatic ductal adenocarcinoma after NAT were sought by systematic searches of MEDLINE, Web of Science and CENTRAL. Hazard ratios (HR) and their corresponding 95% CI were collected to generate log HR using the inverse-variance method. Random-effects meta-analyses were performed and the results presented as weighted HR. Sensitivity and meta-regression analyses were conducted to account for different surgical procedures and varying length of follow-up, respectively. RESULTS: Twenty-two studies with a total of 4929 patients were included. Based on univariable data, R0 greater than 1 mm was significantly associated with prolonged overall survival (OS) (HR 1.76, 95% CI 1.57-1.97; P<0.00001) and disease-free survival (DFS) (HR 1.66, 95% CI 1.39-1.97; P<0.00001). Using adjusted data, R0 greater than 1 mm was significantly associated with prolonged OS (HR 1.65, 95% CI 1.39-1.97; P<0.00001) and DFS (HR 1.76, 95% CI 1.30-2.39; P=0.0003). Results for R1 direct were comparable in the entire cohort; however, no prognostic impact was detected in sensitivity analysis including only partial pancreatoduodenectomies. CONCLUSION: After NAT, a tumour-free margin greater than 1 mm is independently associated with improved OS as well as DFS in patients undergoing surgical resection for pancreatic cancer.

Smoking impairs the effect of neoadjuvant FOLFIRINOX on postresection survival in pancreatic cancer.

INTRODUCTION: Smoking plays an important role in carcinogenesis, including pancreatic ductal adenocarcinoma (PDAC). However, little is known about the association between smoking status and prognosis in resected PDAC. METHODS: All patients who underwent resection for PDAC were identified from two prospective institutional databases. Clinicopathologic data as well as demographics including smoking status were extracted. Survival analysis and multivariable Cox regression modelling was performed. Restricted cubic splines were used for linear data to define cut-off points. RESULTS: Out of 848 patients, 357 (42.1%) received neoadjuvant treatment (NAT), 491 upfront resection (57.9%), and 475 (56%) adjuvant therapy. The median overall survival (OS) was 27.8 months, 36.1 months, and 23.0 months for the entire cohort, after NAT and upfront resection. 464 patients were never smokers (54.7%), 250 former smokers (29.5%), and 134 active smokers (15.8%). In the multivariable model, the interaction of neoadjuvant FOLFIRINOX and active smoking was associated with the highest risk for decreased OS (harzard ratio (HR) 2.35; 95% confidence interval 1.13-4.90) and strongly mitigated the benefit of FOLFIRNOX (HR 0.40; 95% CI 0.25-0.63). Adjusted median OS in NAT patients with FOLFIRINOX was not reached for never and former smokers, compared to 26.2 months in active smokers. Based on the model, a nomogram was generated to illustrate the probability of 5-year survival after PDAC resection. CONCLUSION: The present study confirms that neoadjuvant FOLFIRINOX is associated with excellent survival and demonstrates that active smoking reduces its benefit. The nomogram can assist in daily clinical practice and emphasises the importance of smoking cessation in patients with PDAC, especially prior to NAT with FOLFIRINOX.

GABAB Receptor-Mediated Impairment of Intermediate Progenitor Maturation During Postnatal Hippocampal Neurogenesis of Newborn Rats.

The neurotransmitter GABA and its receptors assume essential functions during fetal and postnatal brain development. The last trimester of a human pregnancy and early postnatal life involves a vulnerable period of brain development. In the second half of gestation, there is a developmental shift from depolarizing to hyperpolarizing in the GABAergic system, which might be disturbed by preterm birth. Alterations of the postnatal GABA shift are associated with several neurodevelopmental disorders. In this in vivo study, we investigated neurogenesis in the dentate gyrus (DG) in response to daily administration of pharmacological GABAA (DMCM) and GABAB (CGP 35348) receptor inhibitors to newborn rats. Six-day-old Wistar rats (P6) were daily injected (i.p.) to postnatal day 11 (P11) with DMCM, CGP 35348, or vehicle to determine the effects of both antagonists on postnatal neurogenesis. Due to GABAB receptor blockade by CGP 35348, immunohistochemistry revealed a decrease in the number of NeuroD1 positive intermediate progenitor cells and a reduction of proliferative Nestin-positive neuronal stem cells at the DG. The impairment of hippocampal neurogenesis at this stage of differentiation is in line with a significantly decreased RNA expression of the transcription factors Pax6, Ascl1, and NeuroD1. Interestingly, the number of NeuN-positive postmitotic neurons was not affected by GABAB receptor blockade, although strictly associated transcription factors for postmitotic neurons, Tbr1, Prox1, and NeuroD2, displayed reduced expression levels, suggesting impairment by GABAB receptor antagonization at this stage of neurogenesis. Antagonization of GABAB receptors decreased the expression of neurotrophins (BDNF, NT-3, and NGF). In contrast to the GABAB receptor blockade, the GABAA receptor antagonization revealed no significant changes in cell counts, but an increased transcriptional expression of Tbr1 and Tbr2. We conclude that GABAergic signaling via the metabotropic GABAB receptor is crucial for hippocampal neurogenesis at the time of rapid brain growth and of the postnatal GABA shift. Differentiation and proliferation of intermediate progenitor cells are dependent on GABA. These insights become more pertinent in preterm infants whose developing brains are prematurely exposed to spostnatal stress and predisposed to poor neurodevelopmental disorders, possibly as sequelae of early disruption in GABAergic signaling.