Clinical impact of neoadjuvant treatment in resectable pancreatic cancer: a systematic review and meta-analysis protocol

Neoadjuvant Treatment in Resectable Pancreatic Cancer. Is It Time for Pushing on It?

Pancreatic resection still represents the only curative option for patients affected by pancreatic ductal adenocarcinoma (PDAC). However, the association with modern chemotherapy regimens is a key factor in improving the inauspicious oncological outcome. The benefit of neoadjuvant treatment (NAT) for borderline resectable/locally advanced PDAC has been demonstrated; this evidence raises the question of whether even resectable PDAC should undergo NAT rather than upfront surgery. NAT may avoid futile surgery because of undetected distant metastases or aggressive tumor biology, providing more effective systemic control of the disease, which is hampered when adjuvant chemotherapy is delayed or precluded. However, recent data show controversial results regarding the efficacy and safety of NAT in resectable PDAC compared to upfront surgery. Although several prospective studies and meta-analyses indicate better oncologic outcomes after NAT, there are some biases, such as the methodological approaches used to capture the events of interest, which could make these results hardly reproducible. For instance, per-protocol studies, considering only the postoperative outcomes, tend to overestimate the performance of NAT by excluding patients who will never be suitable for surgery due to the development of chemotoxicity or tumor progression. To draw reliable conclusions, the studies should capture the events of interest of both strategies (NAT/upfront surgery) from the time of allocation to a specific treatment in an intention-to-treat fashion. This critical review highlights the current literature data concerning the use of NAT in resectable PDAC, summarizing the results of high-quality studies and focusing on the methodological issues of the most recent pieces of evidence.

Neoadjuvant therapy vs. upfront surgery for resectable pancreatic cancer: An update on a systematic review and meta-analysis

The effectiveness of neoadjuvant therapy (NAT) remains controversial in the treatment of pancreatic cancer (PC). Therefore, this meta-analysis aimed to investigate the clinical differences between NAT and upfront surgery (US) in resectable pancreatic cancer (RPC). Eligible studies were retrieved from PubMed, Embase, and Cochrane Library. The endpoints assessed were R0 resection rate, pathological T stage < 2 rate, positive lymph node rate, and overall survival. A total of 4,588 potentially relevant studies were identified, and 13 studies were included in this study. In patients with RPC, this meta-analysis showed that NAT presented an increased R0 resection rate, pathological T stage < 2 rate, and a remarkably reduced positive lymph node rate compared to US. However, patients receiving NAT did not result in a significantly increased overall survival. These findings supported the application of NAT, especially as a patient selection strategy, in the management of RPC. Additional large clinical studies are needed to determine whether NAT is superior to US.

Are We Sure that Adjuvant Chemotherapy is the Best Approach for Resectable Pancreatic Cancer? Are We in the Era of Neoadjuvant Treatment? A Review of Current Literature

The outcome of pancreatic cancer is poor, with a 9% 5-year survival rate. Current treatment recommendations in the 10%–20% of patients who present with resectable disease support upfront resection followed by adjuvant therapy. Until now, only early complete surgical (R0) resection and adjuvant chemotherapy (AC) with either FOLFIRINOX (5-fluorouracil, leucovorin, irinotecan, and oxaliplatin) or nab-paclitaxel plus gemcitabine have been shown to prolong the survival. However, up to 30% of patients do not receive adjuvant therapy because of the development of early recurrence, postoperative complications, comorbidities, and reduced performance status. The aims of neoadjuvant chemotherapy (NAC) are to identify rapidly progressing patients to avoid futile surgery, eliminate micrometastases, increase the feasibility of R0 resection, and ensure the completion of multimodal treatment. Neoadjuvant treatments are effective, but there is no consensus on their use in resectable pancreatic cancer (RPC) because of its lack of a survival benefit over adjuvant therapy. In this review, we analyze the advantages and disadvantages of the two therapeutic approaches in RPC. We need studies that compare the two approaches and can identify the appropriate sequence of adjuvant therapy after neoadjuvant treatment and surgery.

A prognostic Bayesian network that makes personalized predictions of poor prognostic outcome post resection of pancreatic ductal adenocarcinoma

BACKGROUND

The narrative surrounding the management of potentially resectable pancreatic cancer is complex. Surgical resection is the only potentially curative treatment. However resection rates are low, the risk of operative morbidity and mortality are high, and survival outcomes remain poor. The aim of this study was to create a prognostic Bayesian network that pre-operatively makes personalized predictions of post-resection survival time of 12months or less and also performs post-operative prognostic updating.

METHODS

A Bayesian network was created by synthesizing data from PubMed post-resection survival analysis studies through a two-stage weighting process. Input variables included: inflammatory markers, tumour factors, tumour markers, patient factors and, if applicable, response to neoadjuvant treatment for pre-operative predictions. Prognostic updating was performed by inclusion of post-operative input variables including: pathology results and adjuvant therapy.

RESULTS

77 studies (n = 31,214) were used to create the Bayesian network, which was validated against a prospectively maintained tertiary referral centre database (n = 387). For pre-operative predictions an Area Under the Curve (AUC) of 0.7 (P value: 0.001; 95% CI 0.589-0.801) was achieved accepting up to 4 missing data-points in the dataset. For prognostic updating an AUC 0.8 (P value: 0.000; 95% CI:0.710-0.870) was achieved when validated against a dataset with up to 6 missing pre-operative, and 0 missing post-operative data-points. This dropped to AUC: 0.7 (P value: 0.000; 95% CI:0.667-0.818) when the post-operative validation dataset had up to 2 missing data-points.

CONCLUSION

This Bayesian network is currently unique in the way it utilizes PubMed and patient level data to translate the existing empirical evidence surrounding potentially resectable pancreatic cancer to make personalized prognostic predictions. We believe such a tool is vital in facilitating better shared decision-making in clinical practice and could be further developed to offer a vehicle for delivering personalized precision medicine in the future.

Personalized Pancreatic Cancer Management: A Systematic Review of How Machine Learning Is Supporting Decision-making

This review critically analyzes how machine learning is being used to support clinical decision-making in the management of potentially resectable pancreatic cancer. Following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines, electronic searches of MEDLINE, Embase, PubMed, and Cochrane Database were undertaken. Studies were assessed using the checklist for critical appraisal and data extraction for systematic reviews of prediction modeling studies (CHARMS) checklist. In total 89,959 citations were retrieved. Six studies met the inclusion criteria. Three studies were Markov decision-analysis models comparing neoadjuvant therapy versus upfront surgery. Three studies predicted survival time using Bayesian modeling (n = 1) and artificial neural network (n = 1), and one study explored machine learning algorithms including Bayesian network, decision trees, k-nearest neighbor, and artificial neural networks. The main methodological issues identified were limited data sources, which limits generalizability and potentiates bias; lack of external validation; and the need for transparency in methods of internal validation, consecutive sampling, and selection of candidate predictors. The future direction of research relies on expanding our view of the multidisciplinary team to include professionals from computing and data science with algorithms developed in conjunction with clinicians and viewed as aids, not replacement, to traditional clinical decision-making.

Upfront Surgery versus Neoadjuvant Therapy for Resectable Pancreatic Cancer: Systematic Review and Bayesian Network Meta-analysis

Current treatment recommendations for resectable pancreatic cancer support upfront resection and adjuvant therapy. Randomized controlled trials offering comparison with the emerging neoadjuvant approach are lacking. This review aims to compare both treatment strategies for resectable pancreatic cancer. PubMed, MEDLINE, Embase, Cochrane Database and Cochrane Databases were searched for studies comparing neoadjuvant and surgery-first with adjuvant therapy for resectable pancreatic cancer. A Bayesian network meta-analysis was conducted using the Markov chain Monte Carlo method. Cochrane Collaboration’s risk of bias, ROBINS-I and GRADE tools were used to assess quality and risk of bias of included trials. 9 studies compared neoadjuvant therapy and surgery-first with adjuvant therapy (n = 22,285). Aggregate rate (AR) of R0 resection for neoadjuvant therapy was 0.8008 (0.3636–0.9144) versus 0.7515 (0.2026–0.8611) odds ratio (O.R.) 1.27 (95% CI 0.60–1.96). 1-year survival AR for neoadjuvant therapy was 0.7969 (0.6061–0.9500) versus 0.7481 (0.4848–0.8500) O.R. 1.38 (95% CI 0.69–2.96). 2-year survival AR for neoadjuvant therapy was 0.5178 (0.3000–0.5970) versus 0.5131 (0.2727–0.5346) O.R. 1.26 (95% CI 0.94–1.74). 5-year AR survival for neoadjuvant therapy was 0.2069 (0.0323–0.3300) versus 0.1783 (0.0606–0.2300) O.R. 1.19 (95% CI 0.65–1.73). In conclusion neoadjuvant therapy may offer benefit over surgery-first and adjuvant therapy. However, further randomized controlled trials are needed.

Neoadjuvant therapy versus upfront surgery for potentially resectable pancreatic cancer: A Markov decision analysis

Background

Neoadjuvant therapy has emerged as an alternative treatment strategy for potentially resectable pancreatic cancer. In the absence of large randomized controlled trials offering a direct comparison, this study aims to use Markov decision analysis to compare efficacy of traditional surgery first (SF) and neoadjuvant treatment (NAT) pathways for potentially resectable pancreatic cancer.

Methods

An advanced Markov decision analysis model was constructed to compare SF and NAT pathways for potentially resectable pancreatic cancer. Transition probabilities were calculated from randomized control and Phase II/III trials after comprehensive literature search. Utility outcomes were measured in overall and quality-adjusted life months (QALMs) on an intention-to-treat basis as the primary outcome. Markov cohort analysis of treatment received was the secondary outcome. Model uncertainties were tested with one and two-way deterministic and probabilistic Monte Carlo sensitivity analysis.

Results

SF gave 23.72 months (18.51 QALMs) versus 20.22 months (16.26 QALMs). Markov Cohort Analysis showed that where all treatment modalities were received NAT gave 35.05 months (29.87 QALMs) versus 30.96 months (24.86QALMs) for R0 resection and 34.08 months (29.87 QALMs) versus 25.85 months (20.72 QALMs) for R1 resection. One-way deterministic sensitivity analysis showed that NAT was superior if the resection rate was greater than 51.04% or below 75.68% in SF pathway. Two-way sensitivity analysis showed that pathway superiority depended on obtaining multimodal treatment in either pathway.

Conclusion

Whilst NAT is a viable alternative to traditional SF approach, superior pathway selection depends on the individual patient’s likelihood of receiving multimodal treatment in either pathway.

Restoration of miRNA-148a in pancreatic cancer reduces invasion and metastasis by inhibiting the Wnt/β-catenin signaling pathway via downregulating maternally expressed gene-3

Various microRNAs (miRNA) have been recognized potential novel tumor markers and have a critical role in cancer development and progression. Recently, methylation of miRNA-148a was identified as a crucial biochemical process in the progression of cancer. However, its potential role and in pancreatic cancer as well as the underlying mechanisms have remained largely elusive. The present study investigated the potential antitumor effect of miR-148a as well as its impact on invasion and metastasis in pancreatic cancer. It was found that the expression of miRNA-148a and the potential predictive biomarker maternally expressed gene-3 (MEG-3) were obviously decreased in human pancreatic cancer tissues compared with those in adjacent non-tumorous tissues. Furthermore, miR-148a was found to be downregulated in pancreatic cancer cell lines compared with normal pancreatic cells through promoter methylation. An MTT assay and a clonogenic assay demonstrated that restoration of miRNA-148a inhibited the proliferation and colony formation of pancreatic cancer cells. In addition, miR-148a transduction led to the upregulation of MEG-3 expression and promoted apoptosis of pancreatic cancer cells. Western blot analysis revealed that transduction of miR-148a markedly decreased the expression levels of C-myc, cyclin D1 and β-catenin in pancreatic cancer cells. Methylation of miR-148a not only decreased the endogenous β-catenin levels but also inhibited the nuclear translocation of β-catenin to delay cell cycle progression. Furthermore, ectopic miR-148a methylation inhibited pancreatic cancer cell migration and invasion via causing an upregulation of MEG-3 expression. Most importantly, ectopic overexpression of miR-148a in pancreatic cancer cells inhibited tumor formation in an animal experiment. Taken together, miR-148a methylation is a crucial regulatory process to inhibit the proliferation and invasion of pancreatic cancer cells, and transduction of miR-148a suppressed the proliferation of pancreatic cancer cells through negative regulation of the Wnt/β-catenin signaling pathway. The findings of the present study suggested that miRNA-148a acts as a tumor suppressor in pancreatic cancer and may contribute to the development of novel treatments for pancreatic cancer.