Neoadjuvant radiation followed by resection versus upfront resection for locally advanced pancreatic cancer patients: a propensity score matched analysis

Survival equivalence in patients treated for borderline resectable and unresectable locally advanced pancreatic ductal adenocarcinoma: a systematic review and network meta-analysis

BACKGROUND

The clinical relevance of subdivision of non-metastatic pancreatic ductal adenocarcinoma (PDAC) into locally advanced borderline resectable (LA-BR) and locally advanced unresectable (LA-UR) has been questioned. We assessed equivalence of overall survival (OS) in patients with LA-BR and LA-UR PDAC.

METHODS

A systematic review was performed of studies published January 1, 2009 to August 21, 2019, reporting OS for LA-BR and LA-UR patients treated with or without neoadjuvant therapy (NAT), with or without surgical resection. A frequentist network meta-analysis was used to assess the primary outcome (hazard ratio for OS) and secondary outcomes (OS in LA-BR, LA-UR, and upfront resectable (UFR) PDAC).

RESULTS

Thirty-nine studies, comprising 14,065 patients in a network of eight unique treatment subgroups were analysed. Overall survival was better for LA-BR than LA-UR patients following surgery both with and without NAT. Neoadjuvant therapy prior to surgery was associated with longer OS for UFR, LA-BR, and LA-UR tumours, compared to upfront surgery.

CONCLUSION

Survival between the LA-BR and LA-UR subgroups was not equivalent. This subdivision is useful for prognostication, but likely unhelpful in treatment decision making. Our data supports NAT regardless of initial disease extent. Individual patient data assessment is needed to accurately estimate the benefit of NAT.

Recurrence Patterns for Pancreatic Ductal Adenocarcinoma after Upfront Resection Versus Resection Following Neoadjuvant Therapy: A Comprehensive Meta-Analysis

Background: Neoadjuvant therapy (NAT) represents a paradigm shift in the management of patients with pancreatic ductal adenocarcinoma (PDAC) with perceived benefits including a higher R0 rate. However, it is unclear whether NAT affects the sites and patterns of recurrence after surgery. This review seeks to compare sites and patterns of recurrence after resection between patients undergoing upfront surgery (US) or after NAT. Methods: The EMBASE, SCOPUS, PubMed, and Cochrane library databases were systematically searched to identify eligible studies that compare recurrence patterns between patients who had NAT (followed by resection) with those that had US. The primary outcome included site-specific recurrence. Results: 26 articles were identified including 4986 patients who underwent resection. Borderline resectable pancreatic cancer (BRPC, 47% 1074/2264) was the most common, followed by resectable pancreatic cancer (RPC 42%, 949/2264). The weighted overall recurrence rates were lower among the NAT group, 63.4% vs. 74% (US) (OR 0.67 (CI 0.52–0.87), p = 0.006). The overall weighted locoregional recurrence rate was lower amongst patients who received NAT when compared to US (12% vs. 27% OR 0.39 (CI 0.22–0.70), p = 0.004). In BRPC, locoregional recurrence rates improved with NAT (NAT 25.8% US 37.7% OR 0.62 (CI 0.44–0.87), p = 0.007). NAT was associated with a lower weighted liver recurrence rate (NAT 19.4% US 30.1% OR 0.55 (CI 0.34–0.89), p = 0.023). Lung and peritoneal recurrence rates did not differ between NAT and US cohorts (p = 0.705 and p = 0.549 respectively). NAT was associated with a significantly longer weighted mean time to first recurrence 18.8 months compared to US (15.7 months) (OR 0.18 (CI 0.05–0.32), p = 0.015). Conclusion: NAT was associated with lower overall recurrence rate and improved locoregional disease control particularly for those with BRPC. Although the burden of liver metastases was less, there was no overall effect upon distant metastatic disease.

Systemic neoadjuvant chemotherapy in modern pancreatic cancer treatment: a systematic review and meta-analysis

BACKGROUND

Pancreatic ductal adenocarcinoma remains a disease with a poor prognosis despite advances in surgery and systemic therapies. Neoadjuvant therapy strategies are a promising alternative to adjuvant chemotherapy. However, their role remains controversial. This meta-analysis aims to clarify the benefits of neoadjuvant therapy in resectable pancreatic ductal adenocarcinoma.

METHODS

Eligible studies were identified from MEDLINE, Embase, Web of Science and the Cochrane Library. Studies comparing neoadjuvant therapy with a surgery first approach (with or without adjuvant therapy) in resectable pancreatic ductal adenocarcinoma were included. The primary outcome assessed was overall survival. A random-effects meta-analysis was performed, together with pooling of unadjusted Kaplan-Meier curve data.

RESULTS

A total of 533 studies were identified that analysed the effect of neoadjuvant therapy in pancreatic ductal adenocarcinoma. Twenty-seven studies were included in the final data synthesis. Meta-analysis suggested beneficial effects of neoadjuvant therapy with prolonged survival compared with a surgery-first approach, (hazard ratio 0.72, 95% confidence interval 0.69-0.76). In addition, R0 resection rates were significantly higher in patients receiving neoadjuvant therapy (relative risk 0.51, 95% confidence interval 0.47-0.55). Individual patient data analysis suggested that overall survival was better for patients receiving neoadjuvant therapy (P = 0.008).

CONCLUSIONS

Current evidence suggests that neoadjuvant chemotherapy has a beneficial effect on overall survival in resectable pancreatic ductal adenocarcinoma in comparison with upfront surgery and adjuvant therapy. Further trials are needed to address the need for practice change.

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.