Adjuvant and neoadjuvant therapies in resectable pancreatic cancer: a systematic review of randomized controlled trials

HGF/c-Met pathway facilitates the perineural invasion of pancreatic cancer by activating the mTOR/NGF axis

Perineural invasion (PNI) is a pathologic feature of pancreatic cancer and is associated with poor outcomes, metastasis, and recurrence in pancreatic cancer patients. However, the molecular mechanism of PNI remains unclear. The present study aimed to investigate the mechanism that HGF/c-Met pathway facilitates the PNI of pancreatic cancer. In this study, we confirmed that c-Met expression was correlated with PNI in pancreatic cancer tissues. Activating the HGF/c-Met signaling pathway potentiated the expression of nerve growth factor (NGF) to recruit nerves and promote the PNI. Activating the HGF/c-Met signaling pathway also enhanced the migration and invasion ability of cancer cells to facilitate cancer cells invading nerves. Mechanistically, HGF/c-Met signaling pathway can active the mTOR/NGF axis to promote the PNI of pancreatic cancer. Additionally, we found that knocking down c-Met expression inhibited cancer cell migration along the nerve, reduced the damage of the sciatic nerve caused by cancer cells and protected the function of the sciatic nerve in vivo. Taken together, our findings suggest a supportive mechanism of the HGF/c-Met signaling pathway in promoting PNI by activating the mTOR/NGF axis in pancreatic cancer. Blocking the HGF/c-Met signaling pathway may be an effective target for the treatment of PNI.

Honokiol Suppresses Perineural Invasion of Pancreatic Cancer by Inhibiting SMAD2/3 Signaling

Background

Perineural invasion (PNI) is an important pathologic feature of pancreatic cancer, and the incidence of PNI in pancreatic cancer is 70%-100%. PNI is associated with poor outcome, metastasis, and recurrence in pancreatic cancer patients. There are very few treatments for PNI in pancreatic cancer. Honokiol (HNK) is a natural product that is mainly obtained from Magnolia species and has been indicated to have anticancer activity. HNK also has potent neurotrophic activity and may be effective for suppressing PNI. However, the potential role of HNK in the treatment of PNI in pancreatic cancer has not been elucidated.

Methods

In our study, pancreatic cancer cells were treated with vehicle or HNK, and the invasion and migration capacities were assessed by wound scratch assays and Transwell assays. A cancer cell-dorsal root ganglion coculture model was established to evaluate the effect of HNK on the PNI of pancreatic cancer. Western blotting was used to detect markers of EMT and neurotrophic factors in pancreatic tissue. Recombinant TGF-β1 was used to activate SMAD2/3 to verify the effect of HNK on SMAD2/3 and neurotrophic factors. The subcutaneous tumor model and the sciatic nerve invasion model, which were established in transgenic engineered mice harboring spontaneous pancreatic cancer, were used to investigate the mechanism by which HNK inhibits EMT and PNI in vivo.

Results

We found that HNK can inhibit the invasion and migration of pancreatic cancer cells. More importantly, HNK can inhibit the PNI of pancreatic cancer. The HNK-mediated suppression of pancreatic cancer PNI was partially mediated by inhibition of SMAD2/3 phosphorylation. In addition, the inhibitory effect of HNK on PNI can be reversed by activating SMAD2/3. In vivo, we found that HNK can suppress EMT in pancreatic cancer. HNK can also inhibit cancer cell migration along the nerve, reduce the damage to the sciatic nerve caused by tumor cells and protect the function of the sciatic nerve.

Conclusion

Our results demonstrate that HNK can inhibit the invasion, migration, and PNI of pancreatic cancer by blocking SMAD2/3 phosphorylation, and we conclude that HNK may be a new strategy for suppressing PNI in pancreatic cancer.

Improved survival after pancreatic re-resection of positive neck margin in pancreatic cancer patients. A systematic review and network meta-analysis

The oncological benefit of achieving a negative pancreatic neck margin through re-resection after a positive frozen section (FS) is debated. Aim of this network meta-analysis is to evaluate the survival benefit of re-resection after intraoperative FS neck margin examination following pancreatectomy for ductal adenocarcinoma. A systematic search of studies comparing different strategies for the management of positive FS was performed. Patients were classified in three groups based on FS and permanent section (PS): Group A (FS-, PS-R0), Group B (FS+, PS-R0), Group C (FS±, PS-R1). A frequent random-effects network-meta-analysis was made reporting the surface under the cumulative ranking (SUCRA). Primary endpoint was overall survival (OS). Secondary endpoints were pathological outcomes. Seven retrospectives studies with 4205 patients were included and 99.1% of the pancreatic resections were pancreatoduodenectomies. Group A had the highest probability of better OS (SUCRA = 90%), compared to Group B (SUCRA = 48.7%) and Group C, which was the worst prognostic scenario (SUCRA = 11.3%). Group B had still a probability of longer OS compared to Group C (SUCRA = 48.7% vs 11.3%). Pathological features were more favourable in Group A, with the highest SUCRA for T1-T2 tumors (92.6%), N0 status (89.4%), absence of perineural invasion (92.3%). Heterogeneity was low (τ-value <0.1) for OS, and moderate (τ-values: 0.1-0.6) for pT, pN, and perineural invasion. In conclusion, negative neck margin after primary resection (FS negative) or re-resection of a positive FS was associated with improved survival compared with PS-R1. However, any intraoperative positive FS can be considered as a prognostic factor associated with a more aggressive disease.

Radiological prediction of portal vein infiltration in patients with pancreatic ductal adenocarcinoma

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive gastrointestinal malignancy characterized by early loco-regional invasion. Portal vein resection (PVR) during pancreatoduodenectomy (PD) for PDAC is performed if tumor cell invasion to the venous wall (PVI) is suspected. The aim of this study is to evaluate radiological criteria for predicting PVR and PVI.

METHODS

Patients undergoing PD for PDAC were identified from a prospectively maintained database. On the basis of CT- and MRI-based imaging portal vein tumor contact (PV), stranding of the superior mesenteric artery (SMA) and any alterations of the superior mesenterico-portal vein (SMPV) were evaluated. The accuracy of PVI and PVR prediction based on the radiological parameters was calculated.

RESULTS

143 patients were included in the study. 48 patients underwent PVR (34%), PVI was diagnosed in 23 patients (16%). Median overall survival was 22 months. Prediction of PVR (sensitivity 79%, negative predictive value 88%, p = 0.010) and PVI (sensitivity 95%, negative predictive value 99%, p = 0.002) was most accurate for any SMPV alterations as compared to the other radiological parameters. SMPV alterations qualified as an independent prognostic parameter (26.5 months vs. 33.5months, p = 0.034).

CONCLUSION

Radiological evaluation of any SMPV alterations is a simple preoperative method to accurately predict PVI. Assessing SMPV alterations may help to identify candidates for neoadjuvant therapy.

Recurrence of Pancreatic Ductal Adenocarcinoma after Complete Histopathological Remission Caused by FOLFIRINOX

We previously reported 2 cases of pathologic complete response (pCR) of a pancreatic cancer (PC) following neoadjuvant FOLFIRINOX treatment. We now complete our report by a follow-up on both patients. Patient 1 achieved a disease-free survival of 12 months after initial resection until she developed a singular hepatic metastasis. Treatment by FOLFIRINOX and complete removal of the metastasis by atypical liver resection after 6 months allowed for another 12 months of disease control. After intra-abdominal tumor recurrence and development of intracerebral metastases, the patient died 34 months after primary diagnosis. Patient 2 developed hepatic tumor recurrence only 3 months after initial resection. However, treatment by FOLFIRINOX led to a stable disease for 27 months after resection and was followed by atypical liver resection of multiple segments. Six months later, another hepatic recurrence was suspected. Via next-generation sequencing (NGS) of the tumor genome, a deleterious mutation in the ataxia telangiectasia-mutated (ATM) gene, causing a BRCAness, was detected. After initial treatment by FOLFOX, maintenance therapy with the poly-ADP-ribose-polymerase (PARP) inhibitor olaparib was initiated. The patient is now alive for 54 months after initial diagnosis of metastasized pancreatic adenocarcinoma. Tumor recurrence is possible even after pCR of PC and remains challenging. In case of multifocal tumor recurrence, chemotherapy remains the standard treatment. Recently, genetic sequencing allows individualized treatments. In selected cases, highly specialized teams can offer a variety of therapeutic options leading to previously unseen clinical courses.

Neoadjuvant Therapy is Essential for Resectable Pancreatic Cancer

BACKGROUND

Awareness of the benefits of neoadjuvant therapy is increasing, but its use as an initial therapeutic option for patients with resectable pancreatic cancer remains controversial, especially for those patients without high-risk prognostic features. Even for patients with high-risk features who are candidates to receive neoadjuvant therapy, no standard regimen exists.

METHODS

In this review, we examined available data on the neoadjuvant therapy in patients with resectable pancreatic cancer, including prospective studies, retrospective studies, and ongoing clinical trials, by searching PubMed/MEDLINE, ClinicalTrials.gov, Web of Science, and Cochrane Library. The characteristics and results of screened studies were described.

RESULTS

Retrospective and prospective studies with reported results and ongoing randomized studies were included. For patients with resectable pancreatic cancer, neoadjuvant therapy provides benefits such as increased survival, decreased risk of comorbidities and mortality, and improved cost-effectiveness due to an increased completion rate of multimodal treatment. Highly active regimens such as FOLFIRINOX (folinic acid, fluorouracil, irinotecan, and oxaliplatin) or gemcitabine plus nab-paclitaxel are considered acceptable therapeutic regimens. Additionally, platinum-containing regimens other than FOLFIRINOX are acceptable for selected patients. Other therapies, such as chemoradiation treatment, immuno-oncology agents, and targeted therapies are being explored and the results are highly anticipated.

CONCLUSION

This review highlights the benefits of neoadjuvant therapy for resectable pancreatic cancer. Some regimens are currently acceptable, but need more evidence from well-designed clinical trials or should be used after being carefully examined by a multidisciplinary team.

Potentially Curable Pancreatic Adenocarcinoma: ASCO Clinical Practice Guideline Update

PURPOSE

The purpose of this guideline update is to incorporate recently reported practice-changing evidence into ASCO's recommendations on potentially curable pancreatic adenocarcinoma.

METHODS

ASCO convened an Expert Panel to evaluate data from PRODIGE 24/CCTG PA.6, a phase III, multicenter, randomized clinical trial of postoperative leucovorin calcium, fluorouracil, irinotecan hydrochloride, and oxaliplatin (FOLFIRINOX) versus gemcitabine alone, presented at the 2018 ASCO Annual Meeting. In addition, PubMed was searched for additional papers that may influence the existing recommendations.

RECOMMENDATIONS

The Expert Panel only updated Recommendation 4.1 as a result of the practice-changing data. Recommendation 4.1 states that all patients with resected pancreatic adenocarcinoma who did not receive preoperative therapy should be offered 6 months of adjuvant chemotherapy in the absence of medical or surgical contraindications. The modified combination regimen of 5-fluorouracil, oxaliplatin, and irinotecan (mFOLFIRINOX; oxaliplatin 85 mg/m2, leucovorin 400 mg/m2, irinotecan 150 mg/m2 D1, and 5-fluorouracil 2.4 g/m2 over 46 hours every 14 days for 12 cycles) is now preferred in the absence of concerns for toxicity or tolerance; alternatively, doublet therapy with gemcitabine and capecitabine or monotherapy with gemcitabine alone or fluorouracil plus folinic acid alone can be offered.Additional information can be found at www.asco.org/gastrointestinal-cancer-guidelines.

Outcomes after neoadjuvant treatment with gemcitabine and erlotinib followed by gemcitabine-erlotinib and radiotherapy for resectable pancreatic cancer (GEMCAD 10-03 trial)

BACKGROUND

Neoadjuvant therapy (NAT) for pancreatic adenocarcinoma (PDAC) patients has shown promising results in non-randomized trials. This is a multi-institutional phase II trial of NAT in resectable PDAC patients.

METHODS

Patients with confirmed resectable PDAC after agreement by two expert radiologists were eligible. Patients received three cycles of GEM (1000 mg/m²/week) plus daily erlotinib (ERL) (100 mg/day). After re-staging, patients without progressive disease underwent 5 weeks of therapy with GEM (300 mg/m²/week), ERL 100 mg/day and concomitant radiotherapy (45 Gy). Efficacy was assessed using tumor regression grade (TRG) and resection margin status. Using a single-arm Simon's design, considering the therapy not useful if R0 < 40% and useful if the R0 > 70% (alpha 5%, beta 10%), 24 patients needed to be recruited. This trial was registered at ClinicalTrials.gov, number NCT01389440.

RESULTS

Twenty-five patients were enrolled. Adverse effects of NAT were mainly mild gastrointestinal disorders. Resectability rate was 76%, with a R0 rate of 63.1% among the resected patients. Median overall survival (OS) and disease-free survival (DFS) were 23.8 (95% CI 11.4-36.2) and 12.8 months (95% CI 8.6-17.1), respectively. R0 resection patients had better median OS, compared with patients with R1 resection or not resected (65.5 months vs. 15.5 months, p = 0.01). N0 rate among the resected patients was 63.1%, and showed a longer median OS (65.5 vs. 15.2 months, p = 0.009).

CONCLUSION

The results of this study confirm promising oncologic results with NAT for patients with resectable PDAC. Therefore, the present trial supports the development of phase II randomized trials comparing NAT vs. upfront surgery in resectable pancreatic cancer.

A Therapeutic Strategy for Resectable Pancreatic Cancer Based on Risk Factors of Early Recurrence

OBJECTIVES

The aim of this study was to identify risk factors for early recurrence and assess the prognostic benefit of neoadjuvant therapy (NAT) for resectable pancreatic cancer.

METHODS

Patients with radiographically resectable pancreatic cancer according to the National Comprehensive Cancer Network guidelines were enrolled. We regarded recurrence within 6 months after surgery as early recurrence.

RESULTS

This study involved 115 patients (80 who underwent upfront surgery and 35 who received NAT). Serum carbohydrate antigen 19-9 greater than 85 U/mL and p53 expression in 0 or more than 80% of tumor cells were independent risk factors for early recurrence after upfront surgery. We classified patients into a high-risk group (1 or 2 risk factors) and a low-risk group (no risk factors). In the high-risk group, the median overall survival time of patients with NAT was significantly longer than that of patients without NAT (P = 0.028). By contrast, the median overall survival time was not different according to NAT in the low-risk group.

CONCLUSIONS

Serum carbohydrate antigen 19-9 and p53 expression of the primary tumor could be predictors of early recurrence in patients with resectable pancreatic cancer. The prognosis of patients with a high risk of early recurrence may be improved using NAT.

Evolution of pancreatectomy with en bloc venous resection for pancreatic cancer in Italy. Retrospective cohort study on 425 cases in 10 pancreatic referral units

INTRODUCTION

The aim of this study is to analyze the evolution of pancreatectomy with venous resection in 10 referral Italian centers in the last 25 years.

METHODS

A multicenter database of 425 patients submitted to pancreatectomy with venous resection between 1991 and 2015 was retrospectively analyzed. Patients were classified in 5 periods: 1 (1991-1995); 2 (1996-2000); 3 (2001-2005); 4 (2006-2010); 5 (2011-2015). Indications and outcomes were compared according to the period of surgery.

RESULTS

Nineteen patients were operated in period 1, 28 in period 2, 91 in period 3, 140 in period 4, and 147 in period 5. Use of neoadjuvant therapy increased from 0% in period 1 and 2-12.1% in period 5. Postoperative complications ranged from 46.3% to 67.8%, and mortality from 5.3% to 9.2%. Median survival progressively increased, from 6 months in period 1-16 months in period 2, 24 months in period 3 and 4 and 35 months in period 5 (p = 0.004). Period, venous and nodal invasion were significant prognostic factors for survival.

CONCLUSION

Management and outcomes of pancreatectomy with venous resection have evolved in the last 25 years in Italy. Improvement in patients' multidisciplinary management has lead to significant improvement of median survival.

Periostin promotes tumor angiogenesis in pancreatic cancer via Erk/VEGF signaling

Pancreatic cancer (PaC) consists of a bulk of stroma cells which contribute to tumor progression by releasing angiogenic factors. Recent studies have found that periostin (POSTN) is closely associate with the metastatic potential and prognosis of PaC. The purpose of this study is to determine the role of POSTN in tumor angiogenesis and explore the precise mechanisms. In this study, we used lentiviral shRNA and human recombinant POSTN protein (rPOSTN) to negatively and positively regulate POSTN expression in vitro. We found that increased POSTN expression promoted the tubule formation dependent on human umbilical vein endothelial cells (HUVECs). Moreover, knockdown of POSTN in PaC cells reduced tumor growth and VEGF expression in vivo. In accordance with these observations, we found that Erk phosphorylation and its downstream VEGF expression were upregulated achieved in rPOSTN-treated groups, opposing results were obversed in POSTN-slienced group. Meanwhile, Erk inhibitor SCH772984 significantly decreased VEGF expression as well as tubule formation of HUVECs in rPOSTN-treated PaC cells. Taken together, these findings suggest that POSTN promotes tumor angiogenesis via Erk/VEGF signaling in PaC and POSTN may be a new target for cancer anti-vascular treatment.

Pancreatectomy combined with multivisceral resection for pancreatic malignancies: is it justified? Results of a systematic review

BACKGROUND

Multivisceral resections combined with pancreatectomy have been proposed in selected patients with tumor invasion into adjacent organs, in order to allow complete tumor resection. Some authors have also reported multivisceral resection combined with metastasectomy in very selected cases. The utility of this practice is debated. The aim of the review is to compare the postoperative results and survival of pancreatectomies combined with multivisceral resections with those of standard pancreatectomies.

METHODS

A systematic literature search was performed to identify all studies published up to February 2017 that analyzed data of patients undergoing multivisceral and standard pancreatectomies. Clinical effectiveness was synthetized through a narrative review with full tabulation of results.

RESULTS

Three studies were retrieved, including 713 (80%) patients undergoing standard pancreatectomies and 176 (20%) undergoing multivisceral resections (MVR). Postoperative morbidity ranged from 37% to 50% after standard resections and from 56% to 69% after MVR. In-hospital mortality ranged from 4% after standard pancreatectomies to 10% after MVR. Median survival ranged from 20 to 23 months in standard resections and from 12 to 20 months after MVR, without significant differences.

DISCUSSION

The current literature suggests that multivisceral pancreatectomies are feasible and may increase the number of completely resected patients. Morbidity and mortality are higher than after standard pancreatectomies, and these procedures should be reserved to selected patients in referral centers. Further studies on the role of neoadjuvant therapy in this setting are advisable.

Neoadjuvant therapy for resectable pancreatic cancer

The use of neoadjuvant therapies has played a major role for borderline resectable and locally advanced pancreatic cancers (PCs). For this group of patients, preoperative chemotherapy or chemoradiation has increased the likelihood of surgery with negative resection margins and overall survival. On the other hand, for patients with resectable PC, the main rationale for neoadjuvant therapy is that the overall survival with current strategies is unsatisfactory. There is a consensus that we need new treatments to improve the overall survival and quality of life of patients with PC. However, without strong scientific evidence supporting the theoretical advantages of neoadjuvant therapies, these potential benefits might turn out not to be worth the risk of tumors progression while waiting for surgery. The focus of this paper is to provide the readers an overview of the most recent evidence on this subject.

Frozen section analysis of the pancreatic margin during pancreaticoduodenectomy for cancer: Does extending the resection to obtain a secondary R0 provide a survival benefit? Results of a systematic review

BACKGROUND

During pancreaticoduodenectomy, frozen section pancreatic margin analysis permits to extend the resection in case of a positive margin, to achieve R0 margin. We aim to assess if patients having an R0 margin following the extension of the pancreatectomy after a positive frozen section (secondary R0) have different survival compared to those with R1 resection or primary R0 resection.

METHODS

A systematic search was performed to identify all studies published up to March 2016 analyzing the survival of patients undergoing pancreaticoduodenectomy according to the results of frozen section pancreatic margin examination. Clinical effectiveness was synthetized through a narrative review with full tabulation of results.

RESULTS

Four studies published between 2010 and 2014 were retrieved, including 2580 patients. A primary R0 resection was obtained in a percentage of patients ranging from 36.2% to 85.5%, whereas secondary R0 in 9.4%-57.8% of cases and R1 in 5.1%-9.2%. Median survival ranged from 19 to 29 months in R0 patients, from 11.9 to 18 months in secondary R0, and from 12 to 23 months in R1 patients. None of the study demonstrated a survival benefit of extending the resection to obtain a secondary R0 pancreatic margin.

CONCLUSIONS

All the studies were concordant, and failed to demonstrate the survival benefit of additional pancreatic resection to obtain a secondary R0. However, inadequate surgery should not be advocated. This review suggests that re-resection of the pancreatic margin may have limited impact on patients' survival.