Neoadjuvant vs adjuvant therapy for resectable pancreatic cancer: the evolving role of radiation

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.

Survival Trends for Resectable Pancreatic Cancer Using a Multidisciplinary Conference: the Impact of Post-operative Chemotherapy

PURPOSE

Despite advances in various treatment modalities, surgical resection for pancreatic ductal adenocarcinoma (PDA) remains the only curative treatment. Data remains limited regarding survival rates for resectable PDA when managed by a multidisciplinary pancreas conference (MDPC). The aim of this study is to assess survival rates, identify significant predictors of mortality, and assess the benefits of adjuvant chemotherapy for resectable PDA following presentation at a MDPC.

METHODS

All patients presented from April 2013 to August 2016 with resectable PDA were discussed at a MDPC at a tertiary care center and were followed prospectively until November 2017. Survival analysis was performed using Kaplan-Meier for age, tumor size, tumor differentiation, T-stage, lymph node status, and completion of adjuvant chemotherapy cycles. Independent predictors of survival were determined using multivariate Cox regression modeling.

RESULTS

After MDPC consensus and exclusions, total of 64 patients underwent successful surgery. Amongst this cohort, 1-, 2-, and 3-year survival was 78.13%, 46.30%, and 27.27%, respectively. A total of 37 patients (58%) initiated and 16 patients (25%) finished chemotherapy following surgery. Log-rank analysis revealed that tumor size, age, surgical margins, lymph node status, and number of adjuvant chemotherapy cycles received significantly influenced post-operative survival. Tumor size (p < 0.001), lymph node status (p = 0.035), and number of adjuvant chemotherapy cycles (p = 0.041) remained significant after multivariate Cox regression model.

CONCLUSIONS

Our results suggest that patients with PDA with tumor size > 50 mm and/or lymph node involvement have poor outcomes despite being surgically resectable. Successful completion of adjuvant chemotherapy has better survival outcomes as compared with incomplete or no adjuvant chemotherapy. The role of alternative management such as down-staging with neoadjuvant therapy should be considered.

Novel strategies using modern radiotherapy to improve pancreatic cancer outcomes: toward a new standard?

Pancreatic ductal adenocarcinoma (PDAC) remains one of the most aggressive solid tumours with an estimated 5-year overall survival rate of 7% for all stages combined. In this highly resistant disease that is located in the vicinity of many radiosensitive organs, the role of radiotherapy (RT) and indications for its use in this setting have been debated for a long time and are still under investigation. Although a survival benefit has yet to be clearly demonstrated for RT, it is the only technique, other than surgery, that has been demonstrated to lead to local control improvement. The adjuvant approach is now strongly challenged by neoadjuvant treatments that could spare patients with rapidly progressive systemic disease from unnecessary surgery and may increase free margin (R0) resection rates for those eligible for surgery. Recently developed dose-escalated RT treatments, designed either to maintain full-dose chemotherapy or to deliver a high biologically effective dose, particularly to areas of contact between the tumour and blood vessels, such as hypofractionated ablative RT (HFA-RT) or stereotactic body RT (SBRT), are progressively changing the treatment landscape. These modern strategies are currently being tested in prospective clinical trials with encouraging preliminary results, paving the way for more effective treatment combinations using novel targeted therapies. This review summarizes the current literature regarding the use of RT for the treatment of primary PDAC, describes the limitations of conventional RT, and discusses the emerging role of dose-escalated RT and heavy-particle RT.

White paper on pancreatic ductal adenocarcinoma from society of abdominal radiology's disease-focused panel for pancreatic ductal adenocarcinoma: Part I, AJCC staging system, NCCN guidelines, and borderline resectable disease

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive gastrointestinal malignancy with a poor 5-year survival rate. Accurate staging of PDAC is an important initial step in the development of a stage-specific treatment plan. Different staging systems/consensus statements convened by different societies and academic practices are currently used. The most recent version of the American Joint Committee on Cancer (AJCC) tumor/node/metastases (TNM) staging system for PDAC has shifted its focus from guiding management to assessing prognosis. In order to preoperatively define the resectability of PDAC and to guide management, additional classification systems have been developed. The National Comprehensive Cancer Network (NCCN) guidelines, one of the most commonly used systems, provide recommendations on the management and the determination of resectability for PDAC. The NCCN divides PDAC into three categories of resectability based on tumor-vessel relationship: 'resectable,' 'borderline resectable,' and 'unresectable'. Among these, the borderline disease category is of special interest given its evolution over time and the resulting variations in the definition and the associated recommendations for management between different societies. It is important to be familiar with the evolving criteria, and treatment and follow-up recommendations for PDAC. In this article, the most current AJCC staging (8th edition), NCCN guidelines (version 2.2019-April 9, 2019), and challenges and controversies in borderline resectable PDAC are reviewed.

K-RAS Mutant Gene Found in Pancreatic Juice Activated Chromatin From Peri-ampullary Adenocarcinomas

External pancreatic duct stents inserted after resection of pancreatic head tumors provide unique access to pancreatic juice analysis of genetic and metabolic components that may be associated with peri-ampullary tumor progression. For this pilot study, portal venous blood and pancreatic juice samples were collected from 17 patients who underwent pancreaticoduodenectomy for peri-ampullary tumors. Portal vein circulating tumor cells (CTC) were isolated by high-speed fluorescence-activated cell sorting (FACS) and analyzed by quantitative reverse transcription polymerase chain reaction (RT-PCR) for K-RAS exon 12 mutant gene expression (K-RASmut). DNA, chromatin, and histone acetylated active chromatin were isolated from pancreatic juice samples by chromatin immunoprecipitation (ChIP) and the presence of K-RASmut and other cancer-related gene sequences detected by quantitative polymerase chain reaction (PCR) and ChIP-Seq. Mutated K-RAS gene was detectable in activated chromatin in pancreatic juice secreted after surgical resection of pancreatic, ampullary and bile duct carcinomas and directly correlated with the number of CTC found in the portal venous blood (P = .0453). ChIP and ChIP-Seq detected acetylated chromatin in peri-ampullary cancer patient juice containing candidate chromatin loci, including RET proto-oncogene, not found in similar analysis of pancreatic juice from non-malignant ampullary adenoma. The presence of active tumor cell chromatin in pancreatic juice after surgical removal of the primary tumor suggests that viable cancer cells either remain or re-emerge from the remnant pancreatic duct, providing a potential source for tumor recurrence and cancer relapse. Therefore, epigenetic analysis for active chromatin in pancreatic juice and portal venous blood CTC may be useful for prognostic risk stratification and potential identification of molecular targets in peri-ampullary cancers.

Comparison of neoadjuvant therapy and upfront surgery in resectable pancreatic cancer: a meta-analysis and systematic review

Objective

The role of neoadjuvant therapy (NAT) in resectable pancreatic cancer (RPC) remains controversial. Therefore, this meta-analysis was performed to compare the clinical differences between NAT and upfront surgery in RPC.

Materials and methods

A systematic literature search was performed in PubMed, Embase, Web of Science, and the Cochrane Register of Controlled Trials databases. Only patients with RPC who underwent tumor resection and received adjuvant or neoadjuvant treatment were enrolled. The OR or HR and 95% CIs were calculated employing fixed-effects or random-effects models. The HR and its 95% CI were extracted from each article that provided survival curve. Publication bias was estimated using funnel plots and Egger’s regression test.

Results

In total, eleven studies were included with 9,386 patients. Of these patients, 2,508 (26.7%) received NAT. For patients with RPC, NAT resulted in an increased R0 resection rate (OR=1.89; 95% CI=1.26–2.83) and a reduced positive lymph node rate (OR=0.34; 95% CI=0.31–0.37) compared with upfront surgery. Nevertheless, patients receiving NAT did not exhibit a significantly increased overall survival (OS) time (HR=0.91; 95% CI=0.79–1.05).

Conclusion

In patients with RPC, R0 resection rate and positive lymph node rate after NAT were superior to those of patients with upfront surgery. The NAT group exhibited no significant effect on OS time when compared with the upfront surgery group. However, this conclusion requires more clinical evidence to improve its credibility.

The Management of Older Adults with Pancreatic Adenocarcinoma

Pancreatic cancer is the eleventh most common cancer, yet it is the third leading cause of mortality. It is also largely a disease of older adults, with the median age of 71 at diagnosis in the US, with <1% of diagnoses occurring prior to age 50. Current NCCN guidelines recommend surgery for localized disease, followed by adjuvant therapy and/or consideration of enrollment in a clinical trial. For metastatic disease, current guidelines recommend clinical trial enrollment or systemic chemotherapy based on results from the landmark ACCORD-11 and MPACT trials. However, these trials focused heavily on younger, more fit patients, with the ACCORD-11 trial excluding patients over age 75 and the MPACT trial having 92% of its patients with a Karnofsky performance score >80. This article summarizes the available evidence in current literature in regards to the best treatment options for older adults, who represent the majority of pancreatic cancer diagnoses.

Management of Borderline Resectable Pancreatic Cancer

With the rapid development of imaging modalities and surgical techniques, the clinical entity representing tumors that are intermediate between resectable and unresectable pancreatic adenocarcinoma has been identified has been termed "borderline resectable" (BR). These tumors are generally amenable for resection but portend an increased risk for positive margins after surgery and commonly necessitate vascular resection and reconstruction. Although there is a lack of consensus regarding the appropriate definition of what constitutes a BR pancreatic tumor, it has been demonstrated that this intermediate category carries a particular prognosis that is in between resectable and unresectable disease. In order to downstage the tumor and increase the probability of clear surgical margins, neoadjuvant therapy is being increasingly utilized and studied. There is a lack of high-level evidence to establish the optimal treatment regimen for BR tumors. When resection with negative margins is achieved after neoadjuvant therapy, the prognosis for BR tumors approaches and even exceeds that for resectable disease. This review presents the current definitions, different treatment approaches, and the clinical outcomes of BR pancreatic cancer.

Adjuvant chemoradiotherapy (gemcitabine-based) in pancreatic adenocarcinoma: the Pisa University experience

INTRODUCTION

The role of adjuvant chemoradiotherapy in patients with pancreatic adenocarcinoma (PA) is controversial. In this study we aimed to assess the feasibility, disease-free survival (DFS) and overall survival (OS) of adjuvant chemoradiotherapy (gemcitabine based) in patients with resected PA and their correlation with prognostic factors.

METHODS

122 resected patients (stage ≥IIa) treated between February 1999 and December 2013 were analyzed. Two cycles of gemcitabine (1,000 mg/m2 on days 1, 8 and 15 every 28 days) were administered before concomitant radiotherapy (45 Gy/25 fractions) and chemotherapy (gemcitabine 300 mg/m2 weekly).

RESULTS

Median follow-up was 22.7 months (range 4-109). Gastrointestinal toxicity (G3), neutropenia (G3-G4) and cardiac toxicity (G2-G3) were observed in 2.4%, 10.6% and 1.6% of patients, respectively. OS at 12, 24 and 60 months was 79%, 55% and 31%, respectively (median 25 months). Two-year OS in patients with postoperative Karnofsky performance status (KPS) ≤70 and ≥80 was 37.1% and 62.3%, respectively (p<0.0001). OS was better in the group of patients with a postoperative CA 19-9 level ≤100 U/mL (p = 0.014). Median DFS was 17 months.

CONCLUSIONS

The combination of concomitant gemcitabine and radiotherapy in patients with radically resected PA was well tolerated and associated with a low incidence of local recurrences. Five-year OS was significantly influenced by postoperative KPS and CA 19-9 values.

Activation of PPARα by clofibrate sensitizes pancreatic cancer cells to radiation through the Wnt/β-catenin pathway

Radiotherapy is emerging as an important modality for the local control of pancreatic cancer, but pancreatic cancer cell radioresistance remains a serious concern. Peroxisome proliferator-activated receptor α (PPARα) is a member of the PPAR nuclear hormone receptor superfamily, which can be activated by fibrate ligands. The clinical relevance of PPARα and its biological function in pancreatic cancer radiosensitivity have not been previously described. In this study, we examined PPARα expression in tissue samples of pancreatic cancer patients. We found significantly higher expression of PPARα in pancreatic cancer tissues than in tumor-adjacent tissues and that the PPARα expression level is inversely associated with higher overall patient survival rate. We further observed that PPARα activation by its agonist clofibrate sensitizes pancreatic cancer cells to radiation by modulating cell cycle progression and apoptosis in several pancreatic cancer cell lines. Small interfering RNA-mediated PPARα silencing and PPARα blockade by the antagonist GW6471 abolish the effect of clofibrate on radiosensitization. An in vivo study showed that PANC1 xenografts treated with clofibrate are more sensitive to radiation than untreated xenografts. mRNA profiling by microarray analysis revealed that the expression of PTPRZ1 and Wnt8a, two core components of the β-catenin pathway, is downregulated by clofibrate. Chromatin immunoprecipitation analysis confirmed that clofibrate abrogates the binding of nuclear factor-κB to the PTPRZ1 and Wnt8a promoters, ultimately decreasing Wnt/β-catenin signaling activity, which is associated with radiosensitivity. Overall, we demonstrate that PPARα is overexpressed in pancreatic cancer tissues and clofibrate-mediated PPARα activation sensitizes pancreatic cancer cells to radiation through the Wnt/β-catenin pathway.

Predictors and survival for pathologic tumor response grade in borderline resectable and locally advanced pancreatic cancer treated with induction chemotherapy and neoadjuvant stereotactic body radiotherapy

BACKGROUND

Neoadjuvant therapy response correlates with survival in multiple gastrointestinal malignancies. To potentially augment neoadjuvant response for pancreas adenocarcinoma, we intensified treatment with stereotactic body radiotherapy (SBRT) following multi-agent chemotherapy. Using this regimen, we analyzed whether the College of American Pathology (CAP) tumor regression grade (TRG) at pancreatectomy correlated with established response biomarkers and survival.

MATERIALS AND METHODS

We identified borderline resectable (BRPC) and locally advanced (LAPC) pancreatic cancer patients treated according to our institutional clinical pathway who underwent surgical resection with reported TRG (n = 81, median follow-up after surgery 24.2 months). Patients had baseline CA19-9, computed tomography (CT), endoscopic ultrasound, and FDG positron emission tomography (PET)/CT then underwent multi-agent chemotherapy (79% with three cycles of gemcitabine, docetaxel and capecitabine) followed by 5-fraction SBRT. They then underwent restaging CT, PET/CT and CA19-9. Overall (OS) and progression-free (PFS) survival were estimated and compared by Kaplan-Meier and log-rank methods. Univariate ordinal logistic regression correlated TRG with baseline, restaging and change in CA19-9 and the PET maximum standardized uptake value (SUVmax).

RESULTS

Restaging level and decrease in CA19-9 correlated with improved TRG (p = .02 for both) as did restaging SUVmax (p < .01), yet there was no TRG correlation with decrease in SUVmax (p = .10) or CT response (p = .30). The TRG groups had similar OS and PFS except the TRG 0 (complete response) group. Compared to partial response levels (TRG 1-3, median OS 33.9 months, median PFS 13.0 months), the six (7%) patients with TRG 0 had no deaths (p = .05) and only one progression (p = .03). A group of 10 (12%) TRG 1 patients with only residual isolated tumor cells had similar outcomes to the other TRG 1-3 patients.

CONCLUSION

Pre-operative PET-CT and CA19-9 response correlate with histopathologic tumor regression. Patients with complete pathologic response have superior outcomes, suggesting a rationale for intensification and personalization of neoadjuvant therapy in BRPC and LAPC.

Managing Pancreatic Adenocarcinoma: A Special Focus in MicroRNA Gene Therapy

Pancreatic cancer is an aggressive disease and the fourth most lethal cancer in developed countries. Despite all progress in medicine and in understanding the molecular mechanisms of carcinogenesis, pancreatic cancer still has a poor prognosis, the median survival after diagnosis being around 3 to 6 months and the survival rate of 5 years being less than 4%. For pancreatic ductal adenocarcinoma (PDAC), which represents more than 90% of new pancreatic cancer cases, the prognosis is worse than for the other cancers with a patient mortality of approximately 99%. Therefore, there is a pressing need for developing new and efficient therapeutic strategies for pancreatic cancer. In this regard, microRNAs not only have been seen as potential diagnostic and prognostic molecular markers but also as promising therapeutic agents. In this context, this review provides an examination of the most frequently deregulated microRNAs (miRNAs) in PDAC and their putative molecular targets involved in the signaling pathways of pancreatic
carcinogenesis. Additionally, it is presented a summary of gene therapy clinical trials involving miRNAs and it is illustrated the therapeutic potential associated to these small non-coding RNAs, for PDAC treatment. The facts presented here constitute a strong evidence of the remarkable opportunity associated to the application of microRNA-based therapeutic strategies as a novel approach for cancer therapy.

Neoadjuvant radiotherapeutic strategies in pancreatic cancer

This review summarizes the current status of neoadjuvant radiation approaches in the treatment of pancreatic cancer, including a description of modern radiation techniques, and an overview on the literature regarding neoadjuvant radio- or radiochemotherapeutic strategies both for resectable and irresectable pancreatic cancer. Neoadjuvant chemoradiation for locally-advanced, primarily non- or borderline resectable pancreas cancer results in secondary resectability in a substantial proportion of patients with consecutively markedly improved overall prognosis and should be considered as possible alternative in pretreatment multidisciplinary evaluations. In resectable pancreatic cancer, outstanding results in terms of response, local control and overall survival have been observed with neoadjuvant radio- or radiochemotherapy in several phase I/II trials, which justify further evaluation of this strategy. Further investigation of neoadjuvant chemoradiation strategies should be performed preferentially in randomized trials in order to improve comparability of the current results with other treatment modalities. This should include the evaluation of optimal sequencing with newer and more potent systemic induction therapy approaches. Advances in patient selection based on new molecular markers might be of crucial interest in this context. Finally modern external beam radiation techniques (intensity-modulated radiation therapy, image-guided radiation therapy and stereotactic body radiation therapy), new radiation qualities (protons, heavy ions) or combinations with alternative boosting techniques widen the therapeutic window and contribute to the reduction of toxicity.

Outcomes of resected pancreatic cancer in patients age ≥70

OBJECTIVE

To determine outcomes of patients ≥70 years with resected pancreatic cancer.

METHODS

A study was conducted to identify pancreatic cancer patients ≥70 years who underwent surgery for pancreatic carcinoma from 2000 to 2012. Patients were excluded if they had neoadjuvant therapy. The primary endpoint was overall survival (OS).

RESULTS

We identified 112 patients with a median follow-up of surviving patients of 36 months. The median patient age was 77 years. The median and 5 year OS was 20.5 months and 19%, respectively. Univariate analysis (UVA) showed a significant correlation for increased mortality with N1 (P=0.03) as well as post-op CA19-9 >90 (P<0.001), with a trend towards decreased mortality with adjuvant chemoradiation (P=0.08). Multivariate analysis (MVA) showed a statistically significant increased mortality associated with N1 (P=0.008), post-op CA19-9 >90 (P=0.002), while adjuvant chemoradiation (P=0.04) was associated with decreased mortality.

CONCLUSIONS

These data show that in patients ≥70, nodal status, post-op CA19-9, and adjuvant chemoradiation, were associated with OS. The data suggests that outcomes of patients ≥70 years who undergo upfront surgical resection are not inferior to younger patients.

Comparative long-term outcomes of upfront resected pancreatic cancer after preoperative biliary drainage

BACKGROUND

We evaluated whether preoperative biliary drainage was predictive of recurrence and survival among patients with resectable pancreatic cancer.

METHODS

Patients with pancreatic cancer who were treated with upfront surgery between 2000 and 2012 were identified and stratified by preoperative percutaneous transhepatic cholangiogram-guided drainage (PTBD), placement of endoscopic stents (ERCP), or no biliary drainage (NBD). The primary endpoint was overall survival.

RESULTS

We identified 193 patients with resectable pancreatic head cancer (33 PTBD; 96 ERCP; and 64 NBD). Key differences between the three groups were more patients who underwent >1 preoperative biliary procedures (p = 0.004) in the PTBD cohort. PTBD patients had a significant increase in hepatic recurrence rate compared with patients who did not undergo PTBD (44.8 vs. 23.3 %, p = 0.02). PTBD patients also had worse overall survival. Median and 5-year survival for PTBD, ERCP, and NBD patients were 17.5 months and 3 %, 22.4 months and 24 %, and 28.9 months and 32 %, respectively (p = 0.002). MVA revealed that percutaneous drainage was an independent predictor of worse overall survival [HR 1.76, 95 % CI (1.05-2.99), p = 0.03].

CONCLUSIONS

Patients with resectable pancreatic cancer who receive PTBD have more advanced disease, higher hepatic recurrence, and worse survival.