Chemotherapy for pancreatic cancer

Neoadjuvant treatment of localized pancreatic adenocarcinoma

Pancreatic adenocarcinoma is one of the deadliest malignancies worldwide and its incidence is rising in the United States. The only potential curative treatment for this disease is surgical resection, however, due to the lack of an effective screening strategy, the majority of patients present with advanced or metastatic disease which preclude resectability. Further, the best clinical outcomes occur in those patients that receive multimodality treatment with surgical resection combined with chemotherapy with or without the addition of radiation therapy. Despite decades of innovation in treatment modalities, including chemotherapy, radiation therapy and advancements in surgical techniques, the long term outcomes for this disease remain poor with high rates of both local and distant recurrence despite curative intent treatment. The dismal outcomes of this disease highlight the dire need for more effective treatment strategies and therapeutics. This review focuses on the treatment of localized pancreatic adenocarcinoma with an in depth review of the literature to support the use of chemotherapy in the adjuvant and neoadjuvant setting in this disease and exploration and discussion of the growing paradigm shift to neoadjuvant treatment. Further, this review highlights the ongoing and planned clinical trials evaluating neoadjuvant treatment strategies and novel therapeutics in localized pancreatic adenocarcinoma.

Chemoradiotherapy after curative surgery for locally advanced pancreatic cancer: A 20-year single center experience

INTRODUCTION

Pancreatic adenocarcinoma (PAC) is a highly malignant tumor with relevant morbidity and mortality. The role of adjuvant chemoradiotherapy (CRT) for primarily resected tumors remains controversial. We aimed to assess the outcome of patients treated at our institution with postoperative CRT for PAC.

METHODS

We present a retrospective case series of patients with pancreatic adenocarcinoma at a single center in Switzerland. These patients were treated by primary surgery followed by adjuvant CRT between 1995 and 2015. The results were compared with published data.

RESULTS

Median follow-up for the 60 patients was 33 months (range 19.9-193.9); median overall survival (OS) for patients undergoing a resection followed by combined CRT was 25.5 months. Overall, disease-free survival (DFS) was 15.2 months. A local recurrence occurred in 14 patients (23.3%) after a median time of 8.8 months, and in 43 patients (71.7%) distant metastasis was demonstrated with a median time to metastasis of 10.6 months.

CONCLUSION

This retrospective study represents one of the sole reviews of outcome data after adjuvant CRT in resected PAC in Europe within the past years. OS was comparable to that of other institutional outcome data published previously but inferior when compared to most recent published results with an intense chemotherapy. However, not all patients are suitable to undergo such an intense chemotherapy with modified FOLFIRINOX after the extensive surgery for the PAC - these patients could benefit from adding adjuvant CRT to a less intensive chemotherapy with gemcitabine to enhance the benefit regarding locoregional recurrence-free survival.

Pancreatic Adenocarcinoma, Version 1.2019

The NCCN Guidelines for Pancreatic Adenocarcinoma discuss the diagnosis and management of adenocarcinomas of the exocrine pancreas and are intended to assist with clinical decision-making. These NCCN Guidelines Insights discuss important updates to the 2019 version of the guidelines, focusing on postoperative adjuvant treatment of patients with pancreatic cancers.

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.

Identifying Clinical Factors Which Predict for Early Failure Patterns Following Resection for Pancreatic Adenocarcinoma in Patients Who Received Adjuvant Chemotherapy Without Chemoradiation

OBJECTIVES

The role of radiation therapy (RT) in resected pancreatic cancer (PC) remains incompletely defined. We sought to determine clinical variables which predict for local-regional recurrence (LRR) to help select patients for adjuvant RT.

MATERIALS AND METHODS

We identified 73 patients with PC who underwent resection and adjuvant gemcitabine-based chemotherapy alone. We performed detailed radiologic analysis of first patterns of failure. LRR was defined as recurrence of PC within standard postoperative radiation volumes. Univariate analyses (UVA) were conducted using the Kaplan-Meier method and multivariate analyses (MVA) utilized the Cox proportional hazard ratio model. Factors significant on UVA were used for MVA.

RESULTS

At median follow-up of 20 months, rates of local-regional recurrence only (LRRO) were 24.7%, LRR as a component of any failure 68.5%, metastatic recurrence (MR) as a component of any failure 65.8%, and overall disease recurrence (OR) 90.5%. On UVA, elevated postoperative CA 19-9 (>90 U/mL), pathologic lymph node positive (pLN+) disease, and higher tumor grade were associated with increased LRR, MR, and OR. On MVA, elevated postoperative CA 19-9 and pLN+ were associated with increased MR and OR. In addition, positive resection margin was associated with increased LRRO on both UVA and MVA.

CONCLUSIONS

About 25% of patients with PC treated without adjuvant RT develop LRRO as initial failure. The only independent predictor of LRRO was positive margin, while elevated postoperative CA 19-9 and pLN+ were associated with predicting MR and overall survival. These data may help determine which patients benefit from intensification of local therapy with radiation.

Radiation therapy for pancreatic adenocarcinoma, a treatment option that must be considered in the management of a devastating malignancy

Clinical outcomes for patients with pancreatic adenocarcinoma (PAC) remain dismal. Local recurrences, proportions of margin positive surgical resections, and overall survival outcomes remain inferior in PAC than any other solid tumor. This stems from a current standard of care management approach that needs to be inspired and transformed with modern treatment techniques and novel therapeutic options. Radiation therapy has historically been a central component in the treatment of pancreatic adenocarcinoma; however, the role of radiation therapy has been called into question based on the publication of clinical trials with conflicting results. We present an overview of the rationale for radiation therapy in resectable, borderline resectable, and unresectable pancreatic adenocarcinoma. We further present a summary of emerging clinical data and future directions to improve outcomes in this devastating malignancy.

Population-based study of the impact of surgical and adjuvant therapy at the same or a different institution on survival of patients with pancreatic adenocarcinoma

Background

Pancreatic cancer surgery is increasingly regionalized in high‐volume centres. Provision of adjuvant chemotherapy in the same institution can place a burden on patients, whereas receiving adjuvant chemotherapy at a different institution closer to home may create disparities in care. This study compared long‐term outcomes of patients with pancreatic adenocarcinoma receiving adjuvant chemotherapy at the institution where they had undergone surgery with outcomes for those receiving chemotherapy at a different institution.

Methods

This was a population‐based study of patients receiving adjuvant chemotherapy after resection of pancreatic adenocarcinoma performed at ten designated hepatopancreatobiliary centres in Ontario, Canada, between 2004 and 2014. Patients were divided into those receiving chemotherapy at the same institution as surgery or a different institution from where surgery was performed. The primary outcome was overall survival (OS). Multivariable Cox regression assessed the association between OS and each chemotherapy group, adjusted for potential confounders.

Results

Of 589 patients, 374 (63·5 per cent) received adjuvant chemotherapy at the same institution as surgery. After adjusting for age, sex, co‐morbidity, socioeconomic status, rural living, tumour stage, margin positivity and year of surgery, the location of adjuvant chemotherapy was not independently associated with OS (hazard ratio 1·03, 95 per cent c.i. 0·85 to 1·24). For patients who underwent chemotherapy at a different institution, mean travel distance to receive chemotherapy was less (22·9 km) than that needed for surgery (106·7 km).

Conclusion

After pancreatectomy for pancreatic adenocarcinoma at specialized hepatopancreatobiliary surgery centres, OS was not affected by the location of the centre delivering adjuvant chemotherapy. Receiving this treatment in a local centre reduced patients' travel burden.

Adjuvant radiotherapy and chemotherapy improve survival in patients with pancreatic adenocarcinoma receiving surgery: adjuvant chemotherapy alone is insufficient in the era of intensity modulation radiation therapy

In the era of intensity modulation radiation therapy (IMRT), no prospective randomized trial has evaluated the efficacy of adjuvant therapies such as adjuvant concurrent chemoradiotherapy (CCRT), adjuvant sequential chemotherapy and radiotherapy (CT-RT), and adjuvant CT alone in resectable pancreatic adenocarcinoma (PA). Through propensity score matching, we designed a nationwide, population-based, head-to-head cohort study to determine the effects of dissimilar adjuvant treatments on resectable PA. We minimized the confounding of various adjuvant treatment outcomes among the following resectable PA groups of patients from the Taiwan Cancer Registry database: group 1, adjuvant CCRT; group 2, adjuvant sequential CT-RT; and group 3, adjuvant CT alone. All the studied techniques are IMRTs. The matching process yielded a final cohort of 588 patients (196, 196, and 196 patients in groups 1, 2, and 3, respectively). In both univariate and multivariate Cox regression analyses, adjusted hazard ratios (aHRs; 95% confidence interval [CI]) of death derived for the adjuvant CCRT and adjuvant sequential CT-RT cohorts compared with the adjuvant CT alone cohort were 0.398 (0.314-0.504) and 0.307 (0.235-0.402), respectively. A combination of adjuvant IMRT and CT for resectable PA treatment improves survival to a greater extent than does adjuvant CT alone.

dCK negatively regulates the NRF2/ARE axis and ROS production in pancreatic cancer

Objectives

Decreased deoxycytidine kinase (dCK) expression is a reported indicator of gemcitabine efficacy in pancreatic cancer, due to the impact of this kinase on gemcitabine metabolism. The transcription factor NF‐E2 p45‐related factor 2 (NRF2, also called Nfe2l2), a master regulator of redox homoeostasis, has been reported to tightly control the expression of numerous ROS‐detoxification genes and participates in drug resistance. However, the contribution of dCK to the NRF2 signalling axis has seldom been discussed and needs investigation.

Materials and methods

By overexpressing dCK in pancreatic cancer cells, we assessed the impact of dCK on NRF2 transcriptional activity. Furthermore, we measured the impact of dCK expression on the intracellular redox balance and reactive oxygen species (ROS) production. By utilizing immunohistochemical staining and tissues from pancreatic cancer patients, we assessed the correlation between dCK and NRF2 expression. Through proliferation and metastasis assays, we examined the impact of dCK expression on cell proliferation and metastasis.

Results

dCK negatively regulates NRF2 transcriptional activity, leading to the decreased expression of ARE‐driven antioxidant genes. In addition, dCK negatively regulates intracellular redox homoeostasis and ROS production. Negative correlations between dCK and NRF2 levels in pancreatic cancer cell lines and patient samples were observed. In vitro cell line studies suggested that dCK negatively regulated proliferation and metastasis.

Conclusion

Decreased dCK expression promotes NRF2‐driven antioxidant transcription, which further enhances gemcitabine treatment resistance, forming a feedback loop.

The Role of Radiation Therapy for Pancreatic Cancer in the Adjuvant and Neoadjuvant Settings

Pancreatic cancer is the third leading cause of cancer-related death in the United States. Although surgery remains the only curative treatment, chemotherapy and radiation therapy are frequently used. In the adjuvant setting, radiation is usually delivered with chemotherapy to eradicate residual microscopic or macroscopic disease in the resection bed. Neoadjuvant radiation therapy has become more frequently utilized. This article reviews the historical and modern literature regarding radiation therapy in the neoadjuvant and adjuvant settings, focusing on the evolution of radiation therapy techniques and clinical trials in an attempt to identify patients best suited to receiving radiation therapy.

Enhanced tumor targeting of cRGD peptide-conjugated albumin nanoparticles in the BxPC-3 cell line

The emerging albumin nanoparticle brings new hope for the delivery of antitumor drugs. However, a lack of robust tumor targeting greatly limits its application. In this paper, cyclic arginine-glycine-aspartic-conjugated, gemcitabine-loaded human serum albumin nanoparticles (cRGD-Gem-HSA-NPs) were successfully prepared, characterized, and tested in vitro in the BxPC-3 cell line. Initially, 4-N-myristoyl-gemcitabine (Gem-C14) was formed by conjugating myristoyl to the 4-amino group of gemcitabine. Then, cRGD-HSA was synthesized using sulfosuccinimidyl-(4-N-maleimidomethyl)cyclohexane-1-carboxylate (Sulfo-SMCC) cross-linkers. Finally, cRGD-Gem-HSA-NPs were formulated based on the nanoparticle albumin-bound (nab) technology. The resulting NPs were characterized for particle size, zeta potential, morphology, encapsulation efficiency, and drug loading efficiency. In vitro cellular uptake and inhibition studies were conducted to compare Gem-HSA-NPs and cRGD-Gem-HSA-NPs in a human pancreatic cancer cell line (BxPC-3). The cRGD-Gem-HSA-NPs exhibited an average particle size of 160 ± 23 nm. The encapsulation rate and drug loading rate were approximately 83 ± 5.6% and 11 ± 4.2%, respectively. In vitro, the cRGD-anchored NPs exhibited a significantly greater affinity for the BxPC-3 cells compared to non-targeted NPs and free drug. The cRGD-Gem-HSA-NPs also showed the strongest inhibitory effect in the BxPC-3 cells among all the analyzed groups. The improved efficacy of cRGD-Gem-HSA-NPs in the BxPC-3 cell line warrants further in vivo investigations.

Addition of radiotherapy to adjuvant chemotherapy is associated with improved overall survival in resected pancreatic adenocarcinoma: An analysis of the National Cancer Data Base

BACKGROUND

The optimal treatment for resected pancreatic cancer is controversial because direct comparisons of adjuvant chemotherapy (CT) alone and chemotherapy and radiotherapy (CRT) are limited. This study assessed outcomes of CT versus CRT in a national cohort to provide a modern estimate of comparative effectiveness.

METHODS

Patients with pT1-3N0-1M0 pancreatic adenocarcinoma after pancreatectomy were identified in the National Cancer Data Base. Overall survival (OS) was compared for CT and CRT groups with Cox regression and propensity score matching. Subset analyses by clinicopathologic characteristics were performed.

RESULTS

This study identified 6165 patients treated with CT (n = 2334 or 38%) or CRT (n = 3831 or 62%). Most were classified as pT3 (72%), pN1 (67%), and status-post R0 resection (84%). For CRT patients, the median radiotherapy dose was 50.4 Gy. Compared with CT, CRT was associated with improved OS in a univariate analysis (median, 20.0 vs 22.3 months; at 5 years, 16.5% vs 19.6%; P < .001) and a multivariate analysis (hazard ratio [HR], 0.893; 95% confidence interval [CI], 0.837-0.953; P = .001). CRT remained associated with improved OS after propensity score matching (HR, 0.851; 95% CI, 0.793-0.913; P < .001). Subset analyses showed that CRT was associated with improved OS among patients with pT3 (HR, 0.892; 95% CI, 0.828-0.962; P = .003) or pN1 disease (HR, 0.856; 95% CI, 0.793-0.924; P < .001) and both R0 resection (HR, 0.901; 95% CI, 0.839-0.969; P = .005) and R1 resection (HR, 0.842; 95% CI, 0.722-0.983; P = .030).

CONCLUSIONS

CRT was independently associated with improved OS after the resection of pancreatic adenocarcinoma in a large national cohort and particularly among patients with R1 resection and pN1 disease. Well-designed randomized comparisons of CRT and CT are urgently needed.

Conditional survival of pancreatic ductal adenocarcinoma in surgical and nonsurgical patients: a retrospective analysis report from a single institution in China

Background

Conditional survival (CS) could offer reliable prognostic information for patients who survived beyond a specified time since diagnosis when the impact of late effects have the greatest influence on prognosis. We aim to investigate CS for pancreatic ductal adenocarcinoma (PDAC) patients with surgery and nonsurgery.

Methods

Chinese PDAC patients between January 2002 and September 2012 were reviewed for analyses. CS rates were calculated for survivors after surgery and nonsurgery at different time points.

Results

Several clinicopathologic features were associated with overall survival (OS) in each subgroup including curative resection, palliative surgery, and nonsurgery. Both univariate and multivariate analyses showed that chemotherapy was a critical predictor for OS regardless of treatment status. CS rates were higher in the curative resected patients than other cases at the same time points. Importantly, stratification of 1-year CS by carcinoembryonic antigen (CEA), (carbohydrate antigen) CA19-9, and tumor stage showed lower CEA, CA19-9, and tumor stage associated with favorable 1-year CS over time (P = 0.016, 0.009 and 0.003).

Conclusions

Dynamic CS estimates could be an accurate assessment for the prognosis of PDAC patients, allowing patients and clinicians to project subsequent survival based on time change.

Lymph node status predicts the benefit of adjuvant chemoradiotherapy for patients with resected pancreatic cancer

BACKGROUND

The role of adjuvant chemoradiotherapy in pancreatic cancer remains limited. The primary aim of this study was to determine the prediction of lymph node (LN) status to the benefit of adjuvant chemoradiotherapy for patients with resected pancreatic adenocarcinoma.

METHODS

Between December 2010 and December 2012, a total of 152 patients undergoing curative R0 resection for pancreatic adenocarcinoma from multi-institutions were retrospectively analyzed.

RESULTS

Overall median survival was 16.3 months. Sixty-four patients (42.1%) received adjuvant chemoradiotherapy, whereas 88 (57.9%) did not receive adjuvant therapy after surgery. Patients who received chemoradiotherapy could achieve an improved median OS compared with surgery alone (20.3 versus 13.9 months, p=0.027). Stratified by different lymph node status, multivariate analysis demonstrated the benefit of adjuvant chemoradiotherapy was only seen among patients with lymphatic positive disease (HR = 0.54, 95% CI, 0.33-0.88; p=0.014), not lymphatic negative disease (HR = 0.80, 95% CI, 0.44-1.46; p=0. 468).

CONCLUSIONS

This study suggests adjuvant chemoradiotherapy is associated with a significant improvement of survival only in patients with LN-positive disease, while the effects of chemoradiotherapy on patients with LN-negative disease may be limited. This study may add incremental knowledge of the role of lymph node status in offering treatment with adjuvant chemoradiotherapy.

Pancreatic cancer: from state-of-the-art treatments to promising novel therapies

Pancreatic cancer is expected to be the second deadliest malignancy in the USA by 2020. The survival rates for patients with other gastrointestinal malignancies have increased consistently during the past 30 years; unfortunately, however, the outcomes of patients with pancreatic cancer have not changed significantly. Although surgery remains the only curative treatment for pancreatic cancer, therapeutic strategies based on initial resection have not substantially improved the survival of patients with resectable disease over the past 25 years; presently, more than 80% of patients suffer disease relapse after resection. Preclinical evidence that pancreatic cancer is a systemic disease suggests a possible benefit for early administration of systemic therapy in these patients. In locally advanced disease, the role of chemoradiotherapy is increasingly being questioned, particularly considering the results of the LAP-07 trial. Novel biomarkers are clearly needed to identify subsets of patients likely to benefit from chemoradiotherapy. In the metastatic setting, FOLFIRINOX (folinic acid, 5-fluorouracil, irinotecan, and oxaliplatin), and nab-paclitaxel plus gemcitabine have yielded only modest improvements in survival. Thus, new treatments are urgently needed for patients with pancreatic cancer. Herein, we review the state-of-the-art of pancreatic cancer treatment, and the upcoming novel therapeutics that hold promise in this disease are also discussed.

Multi-institutional pooled analysis on adjuvant chemoradiation in pancreatic cancer

PURPOSE

To determine the impact of chemoradiation therapy (CRT) on overall survival (OS) after resection of pancreatic adenocarcinoma.

METHODS AND MATERIALS

A multicenter retrospective review of 955 consecutive patients who underwent complete resection with macroscopically negative margins (R0-1) for invasive carcinoma (T1-4; N0-1; M0) of the pancreas was performed. Exclusion criteria included metastatic or unresectable disease at surgery, macroscopic residual disease (R2), treatment with intraoperative radiation therapy (IORT), and a histological diagnosis of no ductal carcinoma, or postoperative death (within 60 days of surgery). In all, 623 patients received postoperative radiation therapy (RT), 575 patients received concurrent chemotherapy (CT), and 462 patients received adjuvant CT.

RESULTS

Median follow-up was 21.0 months. Median OS after adjuvant CRT was 39.9 versus 24.8 months after no adjuvant CRT (P<.001) and 27.8 months after CT alone (P<.001). Five-year OS was 41.2% versus 24.8% with and without postoperative CRT, respectively. The positive impact of CRT was confirmed by multivariate analysis (hazard ratio [HR] = 0.72; confidence interval [CI], 0.60-0.87; P=.001). Adverse prognostic factors identified by multivariate analysis included the following: R1 resection (HR = 1.17; CI = 1.07-1.28; P<.001), higher pT stage (HR = 1.23; CI = 1.11-1.37; P<.001), positive lymph nodes (HR = 1.27; CI = 1.15-1.41; P<.001), and tumor diameter >20 mm (HR = 1.14; CI = 1.05-1.23; P=.002). Multivariate analysis also showed a better prognosis in patients treated in centers with >10 pancreatic resections per year (HR = 0.87; CI = 0.78-0.97; P=.014) CONCLUSION: This study represents the largest comparative study on adjuvant therapy in patients after resection of carcinoma of the pancreas. Overall survival was better in patients who received adjuvant CRT.

Adjuvant chemoradiation for pancreatic cancer: what does the evidence tell us?

The role of adjuvant chemoradiation (CRT) for pancreas cancer remains unclear. A handful of randomized trials conducted decades of ago ignited a debate that continues today about whether CRT improves survival after surgery. The many flaws in these trials are well described in the literature, which include the use of antiquated radiation delivery techniques and suboptimal doses. Recent prospective randomized data is lacking, and we eagerly await the results the ongoing Radiation Therapy Oncology Group (RTOG) 0848 trial that is evaluating the utility of high quality adjuvant CRT in resected pancreas cancer patients. Until the results of RTOG 0848 are available we should look to other studies from the modern era to guide adjuvant treatment recommendations. Here we review the current state of the art for adjuvant pancreas CRT with respect to patient selection, radiation techniques, radiation dose, and integration with novel systemic agents.

Targeting elongation factor-2 kinase (eEF-2K) induces apoptosis in human pancreatic cancer cells

Pancreatic cancer (PaCa) is one of the most aggressive, apoptosis-resistant and currently incurable cancers with a poor survival rate. Eukaryotic elongation factor-2 kinase (eEF-2K) is an atypical kinase, whose role in PaCa survival is not yet known. Here, we show that eEF-2K is overexpressed in PaCa cells and its down-regulation induces apoptotic cell death. Rottlerin (ROT), a polyphenolic compound initially identified as a PKC-δ inhibitor, induces apoptosis and autophagy in a variety of cancer cells including PaCa cells. We demonstrated that ROT induces intrinsic apoptosis, with dissipation of mitochondrial membrane potential (ΔΨm), and stimulates extrinsic apoptosis with concomitant induction of TNF-related apoptosis inducing ligand (TRAIL) receptors, DR4 and DR5, with caspase-8 activation, in PANC-1 and MIAPaCa-2 cells. Notably, while none of these effects were dependent on PKC-δ inhibition, ROT down-regulates eEF-2K at mRNA level, and induce eEF-2K protein degradation through ubiquitin-proteasome pathway. Down-regulation of eEF-2K recapitulates the events observed after ROT treatment, while its over-expression suppressed the ROT-induced apoptosis. Furthermore, eEF-2K regulates the expression of tissue transglutaminase (TG2), an enzyme previously implicated in proliferation, drug resistance and survival of cancer cells. Inhibition of eEF-2K/TG2 axis leads to caspase-independent apoptosis which is associated with induction of apoptosis-inducing factor (AIF). Collectively, these results indicate, for the first time, that the down-regulation of eEF-2K leads to induction of intrinsic, extrinsic as well as AIF-dependent apoptosis in PaCa cells, suggesting that eEF-2K may represent an attractive therapeutic target for the future anticancer agents in PaCa.

NCI-RTOG translational program strategic guidelines for the early-stage development of radiosensitizers

The addition of chemotherapeutic agents to ionizing radiation has improved survival in many malignancies. Cure rates may be further improved by adding novel targeted agents to current radiotherapy or radiochemotherapy regimens. Despite promising laboratory data, progress in the clinical development of new drugs with radiation has been limited. To define and address the problems involved, a collaborative effort between individuals within the translational research program of the Radiation Oncology Therapy Group and the National Cancer Institute was established. We discerned challenges to drug development with radiation including: 1) the limited relevance of preclinical work, 2) the pharmaceutical industry's diminished interest, and 3) the important individual skills and institutional commitments required to ensure a successful program. The differences between early-phase trial designs with and without radiation are noted as substantial. The traditional endpoints for early-phase clinical trials-acute toxicity and maximum-tolerated dose-are of limited value when combining targeted agents with radiation. Furthermore, response rate is not a useful surrogate marker of activity in radiation combination trials.Consequently, a risk-stratified model for drug-dose escalation with radiation is proposed, based upon the known and estimated adverse effects. The guidelines discuss new clinical trial designs, such as the time-to-event continual reassessment method design for phase I trials, randomized phase II "screening" trials, and the use of surrogate endpoints, such as pathological response. It is hoped that by providing a clear pathway, this article will accelerate the rate of drug development with radiation.

Adjuvant therapy of pancreatic cancer

Pancreatic adenocarcinoma is one of the most aggressive tumors, with a high potential for early dissemination and a relatively poor sensitivity to radiation therapy and cytotoxic agents. Complete resection of the tumor is currently the only curative option but only 10-15% of patients present with localized, potentially resectable disease at the time of diagnosis. Median overall survival for all resected patients (R0 and R1) averages between 11 and 23 months, 5-year overall survival ranges from 10 to 25% (R0) and 0 to 5% (R1), leading to a case-fatality index of 95%. Despite the latest trend toward adjuvant chemotherapy with gemcitabine due to the results from the Charité Onkologie-001 trial, there is no broad consensus regarding the adjuvant regimen that should be applied. Early data from the European Study Group for Pancreatic Cancer-3(v2) trial revealed no difference in terms of overall survival between 5-fluorouracil/folinic acid and gemcitabine after resection of pancreatic cancer.

Adjuvant chemoradiation for pancreatic adenocarcinoma: the Johns Hopkins Hospital-Mayo Clinic collaborative study

BACKGROUND

Survival for pancreatic ductal adenocarcinoma is low, the role of adjuvant therapy remains controversial, and recent data suggest adjuvant chemoradiation (CRT) may decrease survival compared with surgery alone. Our goal was to examine efficacy of adjuvant CRT in resected pancreatic adenocarcinoma compared with surgery alone.

MATERIALS AND METHODS

Patients with pancreatic adenocarcinoma at Johns Hopkins Hospital (n = 794, 1993-2005) and Mayo Clinic (n = 478, 1985-2005) following resection who were observed (n = 509) or received adjuvant 5-FU based CRT (median dose 50.4 Gy; n = 583) were included. Cox survival and propensity score analyses assessed associations with overall survival. Matched-pair analysis by treatment group (1:1) based on institution, age, sex, tumor size/stage, differentiation, margin, and node positivity with N = 496 (n = 248 per treatment arm) was performed.

RESULTS

Median survival was 18.8 months. Overall survival (OS) was longer among recipients of CRT versus surgery alone (median survival 21.1 vs. 15.5 months, P < .001; 2- and 5-year OS 44.7 vs. 34.6%; 22.3 vs. 16.1%, P < .001). Compared with surgery alone, adjuvant CRT improved survival in propensity score analysis for all patients by 33% (P < .001), with improved survival when stratified by age, margin, node, and T-stage (RR = 0.57-0.75, P < .05). Matched-pair analysis demonstrated OS was longer with CRT (21.9 vs. 14.3 months median survival; 2- and 5-year OS 45.5 vs. 31.4%; 25.4 vs. 12.2%, P < .001).

CONCLUSIONS

Adjuvant CRT is associated with improved survival after pancreaticoduodenectomy. Adjuvant CRT was not associated with decreased survival in any risk group, even in propensity score and matched-pair analyses. Further studies evaluating adjuvant chemotherapy compared with adjuvant chemoradiation are needed to determine the most effective combination of systemic and local-regional therapy to achieve optimal survival results.

Rottlerin stimulates apoptosis in pancreatic cancer cells through interactions with proteins of the Bcl-2 family

Rottlerin is a polyphenolic compound derived from Mallotus philipinensis. In the present study, we show that rottlerin decreased tumor size and stimulated apoptosis in an orthotopic model of pancreatic cancer with no effect on normal tissues in vivo. Rottlerin also induced apoptosis in pancreatic cancer (PaCa) cell lines by interacting with mitochondria and stimulating cytochrome c release. Immunoprecipitation results indicated that rottlerin disrupts complexes of prosurvival Bcl-xL with Bim and Puma. Furthermore, siRNA knockdown showed that Bim and Puma are necessary for rottlerin to stimulate apoptosis. We also showed that rottlerin and Bcl-2 and Bcl-xL inhibitor BH3I-2' stimulate apoptosis through a common mechanism. They both directly interact with mitochondria, causing increased cytochrome c release and mitochondrial depolarization, and both decrease sequestration of BH3-only proteins by Bcl-xL. However, the effects of rottlerin and BH3I-2' on the complex formation between Bcl-xL and BH3-only proteins are different. BH3I-2' disrupts complexes of Bcl-xL with Bad but not with Bim or Puma, whereas rottlerin had no effect on the Bcl-xL interaction with Bad. Also BH3I-2', but not rottlerin, required Bad to stimulate apoptosis. In conclusion, our results demonstrate that rottlerin has a potent proapoptotic and antitumor activity in pancreatic cancer, which is mediated by disrupting the interaction between prosurvival Bcl-2 proteins and proapoptotic BH3-only proteins. Thus rottlerin represents a promising novel agent for pancreatic cancer treatment.

Accrediting radiation technique in a multicentre trial of chemoradiation for pancreatic cancer

Before a multicentre trial of 3-D conformal radiotherapy to treat cancer of the pancreas, participating clinicians were asked to complete an accreditation exercise. This involved planning two test cases according to the study protocol, then returning hard copies of the plans and dosimetric data for review. Any radiation technique that achieved the specified constraints was allowed. Eighteen treatment plans were assessed. Seven plans were prescribed incorrect doses and two of the planning target volumes did not comply with protocol guidelines. All plans met predefined normal tissue dose constraints. The identified errors were attributable to unforeseen ambiguities in protocol documentation. They were addressed by feedback and corresponding amendments to protocol documentation. Summary radiobiological measures including total weighted normal tissue equivalent uniform dose varied significantly between centres. This accreditation exercise successfully identified significant potential sources of protocol violations, which were then easily corrected. We believe that this process should be applied to all clinical trials involving radiotherapy. Due to the limitations of data analysis with hard-copy information only, it is recommended that complete planning datasets from treatment-planning systems be collected through a digital submission process.

Adjuvant radiotherapy for pancreatic cancer is associated with a survival benefit primarily in stage IIB patients

BACKGROUND

The role of adjuvant radiotherapy (RT) for pancreatic cancer remains controversial despite the completion of three multi-institutional randomized trials. This study examines the survival impact of postoperative RT in a large population-based database.

METHODS

Patients with pancreatic cancer diagnosed from 1988 to 2003 were identified in the Surveillance, Epidemiology, and End Results (SEER) database. The cohort was limited to patients who underwent resection of nonmetastatic disease to yield a population of 3252 patients. The primary end point was overall survival. Survival analyses were conducted using corrections for perioperative mortality as well as a propensity score analysis to account for baseline differences in patient characteristics.

RESULTS

Multiple independent factors were associated with RT use, including patient age and disease stage (P < 0.0001). In general, younger patients and those with more advanced disease were more likely to receive RT. Disease stage significantly affected survival (P < 0.0001). For patients who survived at least 6 months, adjuvant RT was associated with increased survival [hazard ratio (HR), 0.87; 95% confidence interval (CI), 0.80-0.96]. On subgroup analysis, only stage IIB (T1-3N1) patients enjoyed a statistically significant benefit associated with RT (HR, 0.70; 95% CI, 0.62-0.79).

CONCLUSIONS

Adjuvant RT is frequently given to patients in the United States after resection of their pancreatic cancer. Although RT is associated with a survival benefit for nonmetastatic patients as a whole, this trend appears to predominantly derive from a survival benefit in patients with stage IIB disease.

SU11248 (sunitinib) sensitizes pancreatic cancer to the cytotoxic effects of ionizing radiation

PURPOSE

SU11248 (sunitinib) is a small-molecule tyrosine kinase inhibitor which targets VEGFR and PDGFR isoforms. In the present study, the effects of SU11248 and ionizing radiation on pancreatic cancer were studied.

METHODS AND MATERIALS

For in vitro studies human pancreatic adenocarcinoma cells lines were treated with 1 microM SU11248 1 h before irradiation. Western blot analysis was used to determine the effect of SU11248 on radiation-induced signal transduction. To determine if SU11248 sensitized pancreatic cancer to the cytotoxic effects of ionizing radiation, a clonogenic survival assay was performed using 0-6 Gy. For in vivo assays, CAPAN-1 cells were injected into the hind limb of nude mice for tumor volume and proliferation studies.

RESULTS

SU11248 attenuated radiation-induced phosphorylation of Akt and ERK at 0, 5, 15, and 30 min. Furthermore, SU11248 significantly reduced clonogenic survival after treatment with radiation (p < 0.05). In vivo studies revealed that SU11248 and radiation delayed tumor growth by 6 and 10 days, respectively, whereas combined treatment delayed tumor growth by 30 days. Combined treatment with SU11248 and radiation further attenuated Brdu incorporation by 75% (p = 0.001) compared to control.

CONCLUSIONS

SU11248 (sunitinib) sensitized pancreatic cancer to the cytotoxic effects of radiation. This compound is promising for future clinical trials with chemoradiation in pancreatic cancer.

Full-Dose Gemcitabine With Concurrent Radiation Therapy in Patients With Nonmetastatic Pancreatic Cancer: A Multicenter Phase II Trial

Purpose

Gemcitabine is effective in the treatment of pancreatic cancer and is a potent radiosensitizer. This study assessed safety and efficacy of full-dose gemcitabine administered before and during concurrent three-dimensional conformal radiation (3D-CRT) in patients with nonmetastatic pancreatic cancer.

Patients and Methods

During cycles 1 and 3, patients received gemcitabine at 1,000 mg/m2on days 1 and 8 of each 21-day cycle. Cycle 2 included the same dose of gemcitabine on days 1, 8, and 15 of a 28-day cycle with concurrent 3D-CRT at 36 Gy, administered in 15 fractions of 2.4 Gy, over 3 weeks. Resectable patients underwent surgery 4 to 6 weeks after treatment. The primary objective was evaluation of toxicity. Tumor response, CA 19-9, and 1-year survival were also assessed.

Results

Forty-one patients enrolled at six institutions between April 2002 and October 2003. Among the 39 treated patients, the most common toxicities were grade 3 neutropenia (12.8%), grade 3 nausea (10.3%), and grade 3 vomiting (10.3%). The response rate was 5.1% and disease control rate was 84.6%. Mean post-treatment CA 19-9 levels (228 ± 347 U/mL) were significantly (P = .006) reduced compared with pretreatment levels (1,241 ± 2,124 U/mL). Thirteen (81%) of 16 patients initially judged resectable, three (33%) of nine borderline-resectable patients, and one (7%) of 14 unresectable patients underwent resection after therapy. One-year survival rates were 73% for all patients, 94% for resectable patients, 76% for borderline-resectable patients, and 47% for unresectable patients.

Conclusion

Full-dose gemcitabine with concurrent radiotherapy was well tolerated and active. Evaluation of this regimen in a larger, randomized trial for patients with resectable or borderline-resectable disease may be warranted.

Adjuvant therapy in pancreatic cancer: a critical appraisal

Adenocarcinoma of the pancreas carries a grim prognosis. Surgery is currently the only curative option, but even the few patients undergoing complete resection of early localised disease run a high risk for relapse and death. Although numerous clinical trials have been conducted during the past 20 years to find an effective adjuvant treatment, thus far no general consensus on the most appropriate regimen has been reached. In a small randomised study performed in the 1980s by the GITSG (Gastrointestinal Tumor Study Group), encouraging results were obtained with fluorouracil (5-FU)-based split-course chemoradiotherapy, but these findings were not confirmed in a randomised study initiated some years later by the EORTC (European Organisation for Research and Treatment of Cancer). More recently, the ESPAC (European Study Group for Pancreatic Cancer)-1 trial even indicated a detrimental effect of chemoradiotherapy, while chemotherapy with 5-FU was shown to have a significant positive impact on long-term survival. However, this latter finding is in contrast to earlier studies of adjuvant chemotherapy with 5-FU combinations from Norway and Japan that did not suggest a prolonged beneficial effect of 5-FU on survival. Thus, the results for adjuvant regimens based on systemic 5-FU with or without external radiotherapy are conflicting. Clinical experience with intraoperative radiotherapy or regionally targeted chemotherapy to prevent local relapse, though encouraging, is still preliminary. More recently, gemcitabine, which is the most effective single agent in advanced pancreatic cancer, has also been evaluated in the adjuvant setting. The RTOG (Radiation Therapy Oncology Group)-9704 trial demonstrated that gemcitabine is superior to 5-FU as an addition to chemoradiotherapy, but the results did not allow conclusions about the value of radiation in the combined modality approach. The Charité Onkologie CONKO-001 is a randomised trial from Germany and Austria that compared adjuvant gemcitabine with observation alone. Gemcitabine was very well tolerated and almost doubled median disease-free survival and overall survival rate at 5 years, although the advantage in overall survival failed to reach statistical significance. In summary, the available data from randomised clinical trials of adjuvant therapy suggest that (i) chemoradiotherapy has no obvious advantage compared with chemotherapy alone; and (ii) chemotherapy with gemcitabine is effective and probably offers the best benefit-risk ratio of all currently available adjuvant treatment options.

3D radiotherapy can be safely combined with sandwich systemic gemcitabine chemotherapy in the management of pancreatic cancer: factors influencing outcome

PURPOSE

The aim of this Phase II study was to examine whether concurrent continuous infusion 5-fluorouracil (CI 5FU) plus three-dimensional conformal planning radiotherapy sandwiched between gemcitabine chemotherapy is effective, tolerable, and safe in the management of pancreatic cancer.

METHODS AND MATERIALS

Patients were enrolled in two strata: (1) resected pancreatic cancer at high risk of local relapse (postsurgery arm, n = 22) or (2) inoperable pancreatic cancer in head or body without metastases (locally advanced arm, n = 41). Gemcitabine was given at 1,000 mg/m(2) weekly for 3 weeks followed by 1 week rest then 5-6 weeks of radiotherapy and concurrent CI 5FU (200 mg/m(2)/day). After 4 weeks' rest, gemcitabine treatment was reinitiated for 12 weeks.

RESULTS

For the two arms combined, treatment-related Grade 3 and 4 toxicities were reported by 25 (39.7%) and 7 (11.1%) patients, respectively. No significant late renal or hepatic toxicity was observed. In the postsurgery arm (R1 54.5%), median time to progressive disease from surgery was 11.0 months, median time to failure of local control was 32.9 months, and median survival time was 15.6 months. The 1- and 2-year survival rates were 63.6% and 31.8%. No significant associations between outcome and mutations in K-ras or TP53 or microsatellite instability were identified. Post hoc investigation of cancer antigen 19-9 levels found baseline levels and increases postbaseline were associated with shorter survival (p = 0.0061 and p < 0.0001, respectively).

CONCLUSIONS

This three-dimensional chemoradiotherapy regimen is safe and promising, with encouraging local control for a substantial proportion of patients, and merits testing in a randomized trial.

Adjuvant therapy for pancreas cancer: advances and controversies

Although the benefit of adjuvant therapy for pancreas cancer is clear, the most effective therapy remains elusive. In the United States, combination therapy with chemotherapy and radiation remains the standard of care, while in other parts of the world the contribution of radiation is questioned. Clinical trials are reported evaluating the benefit of post-resection radiation and chemotherapy with 5-fluoruoracil (5FU), gemcitabine, and combination therapy; chemotherapy alone with either 5FU or gemcitabine; and pre-resection chemotherapy and radiation. Attention to pancreas cancer staging, radiation techniques, and clinical trial design are paramount to interpreting the outcomes from adjuvant therapy. Therapeutic advances will be made with new approaches studied in carefully controlled trials.

The case for routine use of adjuvant therapy in pancreatic cancer

Pancreatic cancer is a devastating disease with a poor prognosis for most patients. Surgical resection remains the cornerstone of treatment, providing the only realistic hope of long-term survival. Even with optimal surgical management, 5-year survival averages 15% to 20% for resectable disease. Progress is being made, however. Currently, the benefits of postoperative therapy for resected pancreatic ductal adenocarcinoma appear clear, and recommendations for such therapy appear to us to be well justified. Additional benefit to patients awaits the development of new agents, molecular targeted drugs, and novel approaches such as immunotherapy.

Current therapies and advances in the treatment of pancreatic cancer

Pancreatic cancer is a common, highly lethal disease with a rising incidence. In the last years continued efforts in pancreatic cancer research have led to a change in the classic approaches and to the development of new biological agents that appear to show promise. Adjuvant chemotherapy with gemcitabine has recently demonstrated better survival outcomes following surgical resection compared to no treatment, especially in patients with positive margins or lymph nodes. The addition of anti-VEGF agents to adjuvant regimens could improve long-term outcomes. In locally advanced disease, neoadjuvant regimens have not produced complete remissions, but partial responses have been reported ranging between 10 and 20%, with conflicting survival results. Combination trials with radiochemotherapy and new drugs appear well tolerated with encouraging preliminary results. In the metastatic setting, novel chemotherapeutic combinations and molecular targeted agents have shown promise in improving outcomes. To date, second line therapy is increasingly proposed and may even provide survival benefits in the future. This article summarizes the current standards of therapy for patients with resectable, advanced and metastatic pancreatic cancer.

The case for adjuvant chemoradiation for pancreatic cancer

Despite the best current therapies, treatment outcomes in pancreatic cancer continue to be poor. Surgery remains the single most important curative modality for the minority of patients who present with resectable disease and continues to be the cornerstone of curative-intent therapy in such patients. The value of adjuvant treatment in these patients has been the subject of much debate and has led to several phase III randomized clinical trials in both the United States and Europe. Inconsistent trial results as well as trial design critiques have led to differing conclusions with regard to the value of adjuvant chemoradiotherapy. This chapter will critically review the randomized trials that have led to this controversy and establish a rationale for the use of adjuvant chemoradiation in patients with resectable pancreatic cancer. Modern radiotherapy delivery techniques will also be discussed and future trial designs suggested.