Meta-analysis of phase III randomized trials of molecular targeted therapies for advanced pancreatic cancer

Clinical Perspectives on the Histomolecular Features of the Pancreatic Precursor Lesions: A Narrative Review

Pancreatic cancer (PC) is a lethal cancer with poor prognoses. Identifying and characterizing pancreatic cystic lesions (PCLs) in the early detection and follow-up plans is thought to help detect pancreatic malignancy. Besides, the molecular features of PCLs are thought to unravel potentials for targeted therapies. We present a narrative review of the existing literature on the role of PCLs in the early detection, risk stratification, and medical management of PC. High-grade intraductal papillary mucinous neoplasms (IPMN) and pancreatic intraepithelial neoplasia (PanIN) stage III are high-risk lesions for developing PC. These lesions often require thorough histomolecular characterization using endoscopic ultrasound (EUS), before a surgical decision is made. EUS is also useful in the risk assessment of PCLs with tentative plans-for instance, in branch-duct IPMNs (BD-IPMN)- where the final decision might change. Besides the operative decisions, recent improvements in the application of targeted therapies are expected to improve survival measures. Knowledge of molecular features has helped develop targeted therapies. In summary, the histomolecular characterization of PCLs is helpful in optimizing management plans in PC. Further improvements are still needed for the broad application of this knowledge in the clinical setting.

hnRNPC Promotes Malignancy in Pancreatic Cancer through Stabilization of IQGAP3

Due to challenges in early-stage detection, aggressive behavior, and poor response to systemic therapy, pancreatic cancer is one of the most fatal cancer types globally. The role of RNA-binding protein (RBP) transcription and translation of cancer cells has been well demonstrated, although their roles in pancreatic cancer is less well understood. In this study, we found that heterogeneous nuclear ribonucleoprotein C (hnRNPC), a RBP, is highly expressed in pancreatic ductal adenocarcinoma (PDAC) tissues and cells. In addition, we discovered that overexpression of hnRNPC in PDAC cells in vitro increased cell proliferation, migration, invasion, and metastasis. The presence of hnRNPC promoted tumorigenesis of pancreatic cells in metastatic in vivo models, which was also validated. In silico analyses revealed that hnRNPC is a strong positive regulator of IQ Motif Containing GTPase Activating Protein 3 (IQGAP3) activity. The experimental confirmation of this association revealed a direct interaction of IQGAP3 and hnRNPC to induce cell growth and invasion in PDAC cells by activating the epithelial-mesenchymal transition. In light of the findings that hnRNPC accelerates PDAC progression by interfering with IQGAP3, it appears that this technique for diagnosis and treatment of PDAC may have promise.

Microorganisms in chemotherapy for pancreatic cancer: An overview of current research and future directions

Pancreatic cancer is a malignant tumor of the digestive system with a very high mortality rate. While gemcitabine-based chemotherapy is the predominant treatment for terminal pancreatic cancer, its therapeutic effect is not satisfactory. Recently, many studies have found that microorganisms not only play a consequential role in the occurrence and progression of pancreatic cancer but also modulate the effect of chemotherapy to some extent. Moreover, microorganisms may become an important biomarker for predicting pancreatic carcinogenesis and detecting the prognosis of pancreatic cancer. However, the existing experimental literature is not sufficient or convincing. Therefore, further exploration and experiments are imperative to understanding the mechanism underlying the interaction between microorganisms and pancreatic cancer. In this review, we primarily summarize and discuss the influences of oncolytic viruses and bacteria on pancreatic cancer chemotherapy because these are the two types of microorganisms that are most often studied. We focus on some potential methods specific to these two types of microorganisms that can be used to improve the efficacy of chemotherapy in pancreatic cancer therapy.

A Critical Overview of Systematic Reviews of Chemotherapy for Advanced and Locally Advanced Pancreatic Cancer using both AMSTAR2 and ROBIS as Quality Assessment Tools

BACKGROUND

We performed a critical overview of published systematic reviews (SRs) of chemotherapy for advanced and locally advanced pancreatic cancer, and evaluated their quality using AMSTAR2 and ROBIS tools.

MATERIALS AND METHODS

PubMed and Cochrane Central Library were searched for SRs on 13th June 2020. SRs with meta-analysis which included only randomized controlled trials and that had assessed chemotherapy as one of the treatment arms were included. The outcome measures, which were looked into, were progression-free survival (PFS), overall survival (OS), and adverse events (AEs) of grade 3 or above. Two reviewers independently assessed all the SRs with both ROBIS and AMSTAR2.

RESULTS

Out of the 1,879 identified records, 26 SRs were included for the overview. Most SRs had concluded that gemcitabine-based combination regimes, prolonged OS and PFS, but increased the incidence of grade 3-4 toxicities when compared to gemcitabine monotherapy, but survival benefits were not consistent when gemcitabine was combined with molecular targeted agents. As per ROBIS, 24/26 SRs had 'high' risk of bias, with only 1/26 SR having 'low' risk of bias. As per AMSTAR2, 25/26 SRs had 'critically low', and 1/26 SR had 'low' confidence in the results. The study which scored 'low risk of bias' in ROBIS scored 'low confidence in results' in AMSTAR2. The inter- rater reliability for scoring the overall confidence in the SRs with AMSTAR2 and the overall domain in ROBIS was substantial; ROBIS: kappa=0.785, SEM=0.207, p<0.001; AMSTAR2: kappa= 0.649, SEM=0.323, p<0.001.

CONCLUSION

Gemcitabine-based combination regimens can prolong OS and PFS but also worsen AEs when compared to gemcitabine monotherapy. The included SRs have an overall low methodological quality and high risk of bias as per AMSTAR2 and ROBIS respectively.

Pancreatic cancer: yesterday, today and tomorrow

Pancreatic cancer is one of our most lethal malignancies. Despite substantial improvements in the survival rates for other major cancer forms, pancreatic cancer survival rates have remained relatively unchanged since the 1960s. Pancreatic cancer is usually detected at an advanced stage and most treatment regimens are ineffective, contributing to the poor overall prognosis. Herein, we review the current understanding of pancreatic cancer, focusing on central aspects of disease management from radiology, surgery and pathology to oncology.

Meta-analyses of treatment standards for pancreatic cancer

Pancreatic cancer is the most lethal common cancer with an estimated 5-year survival rate of 6-7% (across all stages). The only potential curative therapy is surgical resection in those with localized disease. Adjuvant (postoperative) therapy confers a survival advantage over postoperative observation alone. Neoadjuvant (preoperative) therapy offers the potential to downstage initially unresectable tumors for resection, sterilize resection margins and decrease locoregional recurrence, and identify a subset of patients with aggressive disease for whom surgery will not be beneficial. Induction chemotherapy followed by consolidation chemoradiation is another recommended approach in those with locally advanced disease. For those who cannot be downstaged, cannot tolerate surgery, or were diagnosed with metastatic disease, treatment remains palliative with chemotherapy being a critical component of this approach. Recently, intensive combination chemotherapy has been shown to improve survival rates in comparison to gemcitabine alone in advanced disease. The past few decades have afforded an accumulation of high-level evidence regarding neoadjuvant, adjuvant and palliative therapies in pancreatic cancer. There are numerous reviews discussing recent retrospective studies, prospective studies and randomized controlled trials in each of these areas. However, reviews of optimal and recommended treatment strategies across all stages of pancreatic cancer that focus on the highest levels of hierarchical evidence, such as meta-analyses, are limited. The discussion of novel therapeutics is beyond the scope of this review. However, an extensive and the most current collection of meta-analyses of first-line systemic and locoregional treatment options for all stages of pancreatic cancer to date has been accumulated.

The addition of S-1 to gemcitabine-based chemotherapy improves survival with increased toxicity for patients with advanced pancreatic cancer: combined meta-analysis of efficacy and safety profile

PURPOSE

To investigate the efficiency and safety profile of the addition of S-1 to gemcitabine (GEM)-based chemotherapy for advanced pancreatic cancer (APC).

METHODS

Computerized search was undertaken to identify randomized controlled trials of S-1 plus GEM versus GEM monotherapy in APC patients. The outcomes included overall survival (OS), progression-free survival (PFS), response rate, and toxicities.

RESULTS

Five studies with 917 patients were included. Overall, there was a significant difference between the two regimens in terms of OS (HR=0.83, 95%CI=0.72-0.96, P=0.01), PFS (HR=0.64, 95%CI=0.56-0.74, P<0.0001), and overall response rate (ORR; RR=2.36, 95%CI=1.73-3.22, P<0.00001). Occurrence of grade 3/4 hematological toxicities (neutropenia, thrombocytopenia) and non-hematological toxicities (diarrhea, nausea/vomit, rush, stomatitis/mucositis) were significantly higher with GEM/S-1 treatment.

CONCLUSIONS

This meta-analysis indicated a significant survival benefit with increased toxicity when S-1 was combined with GEM. GEM/S-1 might be an option of first-line chemotherapy for APC patients, at least in Asia.

Clinical characteristics of long-term survivors of inoperable pancreatic cancer: an 8-year cohort analysis in Korea

OBJECTIVES

Inoperable pancreatic ductal adenocarcinoma is known to have an extremely poor prognosis. Although rare, there are some patients who have unexpected long-term survival, but the reason is not yet clear.

METHODS

A total of 482 inoperable pancreatic ductal adenocarcinoma of 1602 patients diagnosed at Severance Hospital between 2002 and 2009 were evaluated, who were selected statistically with a retrospective cohort study. They were divided into locally advanced pancreatic cancer (LAPC) and metastatic pancreatic cancer (MPC). Short-term survivors (SS group) were defined as patients who survived less than 9 months with LAPC and 6 months with MPC. Patients who survived 3 times longer than the SS group were classified as long-term survivors (LS group). Predictive factors of long-survival were identified by comparing the 2 groups, and effects of these factors on survival were investigated statistically.

RESULTS

In multivariate analysis, better performance status and lower CA19-9 were related to overall survival in LAPC. In MPC, younger age, better performance status, peritoneal metastasis, higher serum albumin, lower CA19-9, and CA19-9 variation were related to overall survival.

CONCLUSIONS

These parameters related to long-term survivors of advanced pancreatic cancer can be useful for the expectation of survival. In the near future, conjunction of these clinical factors and novel molecular biologic characteristics of individual patients can be used for the personalized therapy.

Effect of pre-operative red blood cell distribution on cancer stage and morbidity rate in patients with pancreatic cancer

BACKGROUND

The red blood cell distribution (RDW) is a test measure of erythrocyte variation and the volume level which shows the heterogeneity and it is a proven test in literature for the determination of survival on cardiovascular diseases. The main purpose of this research is to investigate the relationship between the RDW level and postoperative morbidity as well as its stages in diagnosed pancreatic cancer patients.

METHODS

In this study we covered 104 diagnosed pancreatic cancer patients who have been operated in 2011-2014. The RDW levels were separated into two groups. Group 1 contains higher level RDW patients (> 14) whereas group 2 contains only lower level RDW patients. We compared both groups in terms of the patients' demographic data, duration of hospitalization, ratio of pancreatic fistula, disease period, and the mortality rates.

RESULTS

In group 1 contains 39 patients whereas group 2 contains only 65 patients. We determined the positive correlation between stages of disease with RDW levels as well as the correlation between low level of blood albumin and Ca 19.9 levels (p = 0001). However we did not observe statistically important difference in postoperative morbidity.

CONCLUSIONS

Based on this study we report that RDW levels can be use as a marker to show the stages of pancreatic cancer in diagnosed patients.

The current state of pancreatic cancer in Canada: incidence, mortality, and surgical therapy

OBJECTIVE

This study aimed to evaluate the trends in the incidence, survival, and surgical therapy for Canadian patients affected by pancreatic cancer (PC).

METHODS

The incidence, mortality, number of resections, and outcomes of patients with PC stratified by year, sex, and province were extracted from Canadian cancer databases.

RESULTS

In 2012, PC was diagnosed in 4600 Canadians and it was responsible for 4300 deaths. The age-standardized incidence was 9 to 10 new cases per 100,000 individuals. The mortality rate remained the highest among all the solid tumors with a case-to-fatality ratio of 0.93. The age-standardized 5-year relative survival was 9.1% (95% confidence interval [CI], 8.3-10). There were geographic variations among provinces with the highest survival registered in Ontario (10.9%; 95% CI, 9.9-12) and the lowest survival reported in Nova Scotia (4.7%; 95% CI, 2.8-7.2). The percentage of patients who underwent surgery decreased from 19% (2006-2007) to 17% (2009-2010). Pancreatic resections were performed in high-volume centers in 74% of cases. In-hospital mortality was 5%, 93% of patients were discharged home, and 36% of patients required home support after discharge.

CONCLUSIONS

Long-term outcomes of Canadian patients affected by PC remain unsatisfactory, with only 9% of the patients surviving at 5 years. Surgical therapy was performed only in 17% to 19% of patients.

Comparison of gemcitabine combined with targeted agent therapy versus gemcitabine monotherapy in the management of advanced pancreatic cancer

PURPOSE

Targeted therapy has brought great clinical benefits for patients with multiple solid tumors, but its effects in patients with locally advanced/metastatic pancreatic cancer (LA/MPC) are disputed. This systematic evaluation compared the efficacy and safety profiles of gemcitabine combined with targeted agents (GEM + TA) versus gemcitabine administered as monotherapy or combined with placebo (GEM ± PLC) in LA/MPC patients.

METHODS

PubMed and EMBASE were searched for relevant randomized controlled trials published on or before April 30, 2013. The primary end points were overall survival (OS) and progression-free survival (PFS); the secondary end points were 1-year survival rate, objective response rate (ORR), and toxicity rates (TRs), defined as the prevalence of grade 3/4 adverse events. The systematic evaluation was performed by using Review Manager version 5.1.7.

FINDINGS

A total of 10 randomized controlled trials involving 3899 patients (2195 males; mean age, 63.6 years) were included in the systematic evaluation. The results reported that there was no significant difference in OS (hazard ratio [HR] = 0.97 [P = 0.85]), PFS (HR = 0.95 [P = 0.14]), or ORR (odds ratio [OR] = 0.95 [P = 0.69]) between GEM + TA and GEM ± PLC. However, a marginal difference in 1-year survival rate (OR = 0.80 [P = 0.05]) between the 2 groups was observed. The grade 3/4 TRs of anemia, diarrhea, nausea, neutropenia, thrombocytopenia, and vomiting were not significantly different between the 2 groups. However, the prevalence of grade 3/4 rash was significantly greater in the GEM + TA group (OR = 8.31 [P < 0.01]).

IMPLICATIONS

Based on the results from this analysis, the addition of targeted agents to a regimen of gemcitabine treatment does not bring survival benefits except 1-year survival rate to patients with LA/MPC.

Systemic treatment for inoperable pancreatic adenocarcinoma: review and update

There have been many clinical trials conducted to evaluate novel systemic regimens for unresectable pancreatic cancer. However, most of the trial results were negative, and gemcitabine monotherapy has remained the standard systemic treatment for years. A number of molecular targeted agents, including those against epidermal growth factor receptor and vascular endothelial growth factor receptors, have also been tested. In recent years, there have been some breakthroughs in the deadlock: three regimens, namely gemcitabine-erlotinib, FOLFIRINOX, and gemcitabine-nab-paclitaxel, have been shown to prolong the overall survival of patients when compared with gemcitabine monotherapy. In addition, emerging data suggested that the membrane protein human equilibrative nucleotide transporter 1 is a potential biomarker with which to predict the efficacy of gemcitabine. Here we review the literature on the development of systemic agents for pancreatic cancer, discuss the current choices of treatment, and provide future directions on the development of novel agents.

MicroRNA-301b promotes cell invasiveness through targeting TP63 in pancreatic carcinoma cells

Recent studies have demonstrated that deregulated microRNA (miR) expression is implicated in the development of human cancers. In the aberrant miR expression, miR-301 is upregulated in cancers, such as pancreatic, colorectal and oral carcinoma. Based on this evidence, we investigated the contribution of miR-301 to pancreatic carcinoma and the novel target genes of miR-301 in pancreatic carcinoma. In this study, we analyzed the effects of enforced and inhibited expression of miR-301b expression in the Panc-1 and BxPC-3 cell lines. MiR-301b expression levels were associated with cell invasiveness in both cell lines. Additional experiments indicated that miR-301b influences invasiveness through CDH1. Moreover microRNA target search algorithms and experimental strategies suggested that miR-301b suppressed TP63 expression as a novel target of miR-301b. Remarkably, miR-301b was also found to be associated with NF-κB activity in both cell lines. In summary, overexpressed miR-301b may suppress TP63 expression and contributes to promote cell invasiveness and to enhance gemcitabine resistance in pancreatic carcinoma cells. Thus, miR-301b may have potential as a novel therapeutic target for cancer treatment due to its stimulatory effects on cell invasiveness.

Efficacy of nimotuzumab plus gemcitabine usage as first-line treatment in patients with advanced pancreatic cancer

Advanced pancreatic cancer patients have poor prognosis and scarcely respond to conventional therapies. Clinical trials support the use of molecular-targeted therapy against epidermal growth factor receptor (EGFR) signaling. The objective of the current study was to evaluate the contribution of a monoclonal antibody against EGFR, nimotuzumab, to standard gemcitabine therapy. Patients with unresectable locally advanced or metastatic pancreatic adenocarcinoma were assigned to receive gemcitabine plus nimotuzumab. The primary end point was overall survival, whereas the secondary end points included progression-free survival, objective response, and adverse side effects. A total of 18 eligible patients were accrued between December 2007 and July 2010. The disease control rate, calculated as the sum of complete response, partial response, and stable disease, was 55.6%. The median overall survival time was 9.29 months (95% CI, 5.499 to 13.072). The median progression-free survival was 3.71 months (95% CI, 2.526 to 4.902), and the 1-year survival rate was 38.9%. Of all the patients, 88.8% had at least one adverse side effect; however, no grade 4 adverse side effect was reported. Nimotuzumab as a high-purity humanized monoclonal antibody with favorable safety profile, its value in the treatment of pancreatic cancer along with gemcitabine, particularly in the comprehensive treatment of advanced pancreatic cancer, is appealing for further prospective randomized large-scale clinical trials.

Clinical, molecular and genetic validation of a murine orthotopic xenograft model of pancreatic adenocarcinoma using fresh human specimens

BACKGROUND

Relevant preclinical models that recapitulate the key features of human pancreatic ductal adenocarcinoma (PDAC) are needed in order to provide biologically tractable models to probe disease progression and therapeutic responses and ultimately improve patient outcomes for this disease. Here, we describe the establishment and clinical, pathological, molecular and genetic validation of a murine, orthotopic xenograft model of PDAC.

METHODS

Human PDACs were resected and orthotopically implanted and propagated in immunocompromised mice. Patient survival was correlated with xenograft growth and metastatic rate in mice. Human and mouse tumor pathology were compared. Tumors were analyzed for genetic mutations, gene expression, receptor tyrosine kinase activation, and cytokine expression.

RESULTS

Fifteen human PDACs were propagated orthotopically in mice. Xenograft-bearing mice developed peritoneal and liver metastases. Time to tumor growth and metastatic efficiency in mice each correlated with patient survival. Tumor architecture, nuclear grade and stromal content were similar in patient and xenografted tumors. Propagated tumors closely exhibited the genetic and molecular features known to characterize pancreatic cancer (e.g. high rate of KRAS, P53, SMAD4 mutation and EGFR activation). The correlation coefficient of gene expression between patient tumors and xenografts propagated through multiple generations was 93 to 99%. Analysis of gene expression demonstrated distinct differences between xenografts from fresh patient tumors versus commercially available PDAC cell lines.

CONCLUSIONS

The orthotopic xenograft model derived from fresh human PDACs closely recapitulates the clinical, pathologic, genetic and molecular aspects of human disease. This model has resulted in the identification of rational therapeutic strategies to be tested in clinical trials and will permit additional therapeutic approaches and identification of biomarkers of response to therapy.

Personalizing pancreatic cancer medicine: what are the challenges?

The P4 paradigm for future medicine promises changes in cancer management with improved Prediction of treatment response, Prevention of disease, Personalization of therapy, and Participation by patients. Significant challenges remain for the implementation of the P4 principles for pancreatic cancer, but many strides have been made in the past several years that should facilitate a future in which the disease can be detected at earlier stages and treatments can be customized to target features of a particular patient’s disease. This article summarizes the basic molecular biology of pancreatic tumors and the current state of pancreatic cancer treatment, as well as targeted treatments in the pipeline that might enable future personalized pancreatic cancer treatment and prediction of response to treatment. It also discusses possible directions for screening patients at high risk of developing the disease, detecting tumors at earlier stages, and increasing patient involvement in designing treatment.