Phase II study of bevacizumab with concurrent capecitabine and radiation followed by maintenance gemcitabine and bevacizumab for locally advanced pancreatic cancer: Radiation Therapy Oncology Group RTOG 0411

Impact of on-trial IGRT quality assurance in an international adaptive radiotherapy trial for participants with bladder cancer

BACKGROUND AND PURPOSE

Radiotherapy trial quality assurance (RT QA) is crucial for ensuring the safe and reliable delivery of radiotherapy trials, and minimizing inter-institutional variations. While previous studies focused on outlining and planning quality assurance (QA), this work explores the process of Image-Guided Radiotherapy (IGRT), and adaptive radiotherapy. This study presents findings from during-accrual QA in the RAIDER trial, evaluating concordance between online and offline plan selections for bladder cancer participants undergoing adaptive radiotherapy. RAIDER had two seamless stages; stage 1 assessed adherence to dose constraints of dose escalated radiotherapy (DART) and stage 2 assessed safety. The RT QA programme was updated from stage 1 to stage 2.

MATERIALS AND METHODS

Data from all participants in the adaptive arms (standard dose adaptive radiotherapy (SART) and DART) of the trial was requested (33 centres across the UK, Australia and New Zealand). Data collection spanned September 2015 to December 2022 and included the plans selected online, on Cone-beam computed tomography (CBCT) data. Concordance with the plans selected offline by the independent RT QA central reviewer was evaluated.

RESULTS

Analysable data was received for 72 participants, giving a total of 884 CBCTs. The overall concordance rate was 83% (723/884). From stage 1 to stage 2 the concordance in the plans selected improved from 75% (369/495) to 91% (354/389).

CONCLUSION

During-accrual IGRT QA positively influenced plan selection concordance, highlighting the need for ongoing support when introducing a new technique. Overall, it contributes to advancing the understanding and implementation of QA measures in adaptive radiotherapy trials.

Recent advances in targeted therapy for pancreatic adenocarcinoma

Pancreatic adenocarcinoma (PDAC) is a fatal disease with a 5-year survival rate of 8% and a median survival of 6 mo. In PDAC, several mutations in the genes are involved, with Kirsten rat sarcoma oncogene (90%), cyclin-dependent kinase inhibitor 2A (90%), and tumor suppressor 53 (75%–90%) being the most common. Mothers against decapentaplegic homolog 4 represents 50%. In addition, the self-preserving cancer stem cells, dense tumor microenvironment (fibrous accounting for 90% of the tumor volume), and suppressive and relatively depleted immune niche of PDAC are also constitutive and relevant elements of PDAC. Molecular targeted therapy is widely utilized and effective in several solid tumors. In PDAC, targeted therapy has been extensively evaluated; however, survival improvement of this aggressive disease using a targeted strategy has been minimal. There is currently only one United States Food and Drug Administration-approved targeted therapy for PDAC – erlotinib, but the absolute benefit of erlotinib in combination with gemcitabine is also minimal (2 wk). In this review, we summarize current targeted therapies and clinical trials targeting dysregulated signaling pathways and components of the PDAC oncogenic process, analyze possible reasons for the lack of positive results in clinical trials, and suggest ways to improve them. We also discuss emerging trends in targeted therapies for PDAC: combining targeted inhibitors of multiple pathways. The PubMed database and National Center for Biotechnology Information clinical trial website (www.clinicaltrials.gov) were queried to identify completed and published (PubMed) and ongoing (clinicaltrials.gov) clinical trials (from 2003-2022) using the keywords pancreatic cancer and targeted therapy. The PubMed database was also queried to search for information about the pathogenesis and molecular pathways of pancreatic cancer using the keywords pancreatic cancer and molecular pathways.

Outcomes and Toxicities of Modern Combined Modality Therapy with Atezolizumab Plus Bevacizumab and Radiation Therapy for Hepatocellular Carcinoma

Atezolizumab plus bevacizumab has become frontline therapy for unresectable HCC. The compatibility of atezolizumab/bevacizumab with liver-directed RT has not been reported. Methods: HCC patients treated with liver-directed RT and atezolizumab/bevacizumab between 1/2020−11/2021 were included. Toxicity and outcomes were retrospectively recorded. For ALCs, we matched the analysis to a previously cohort of RT-treated HCC patients who did not receive atezolizumab/bevacizumab. Survival and time-to-liver-failure were analyzed using Kaplan−Meier. Results: Of 21 patients, with a median follow-up of 9.5 months, the median OS was 16.1 months. Post-RT, all patients had reduced tumors or treatment response. There were no ≥Grade 3 RT-related toxicities. Autoimmune complications occurred in two patients (9.5%), and GI bleeding in three patients (14.3%). Liver function remained stable post-RT. There was a marked decrease in ALCs immediately post-RT (post-RT/pre-RT ratio 47.3%, p < 0.0001), restored by 1 month to pre-treatment baseline (1-month post-RT/pre-RT ratio 95.1%, n.s.). Compared to HCC patients treated with RT alone, post-RT ALC recovery was faster with atezolizumab/bevacizumab (p = 0.009). Conclusion: In this first reported experience of RT with modern systemic therapy for HCC, combination therapy is safe and well-tolerated. As a favorable prognosticator, there appears to be faster recovery of ALC among patients who received RT with atezolizumab/bevacizumab.

Opportunities and challenges in targeted therapy and immunotherapy for pancreatic cancer

Pancreatic cancer is one of the most malignant tumours with a poor prognosis. In recent years, the incidence of pancreatic cancer is on the rise. Traditional chemotherapy and radiotherapy for pancreatic cancer have been improved, first-line and second-line palliative treatments have been developed, and adjuvant treatments have also been used in clinical. However, the 5-year survival rate is still less than 10% and new treatment methods such as targeted therapy and immunotherapy need to be investigated. In the past decades, many clinical trials of targeted therapies and immunotherapies for pancreatic cancer were launched and some of them showed an ideal prospect in a subgroup of pancreatic cancer patients. The experience of both success and failure of these clinical trials will be helpful to improve these therapies in the future. Therefore, the current research progress and challenges of selected targeted therapies and immunotherapies for pancreatic cancer are reviewed.

Targeting Tumor-Stromal Interactions in Pancreatic Cancer: Impact of Collagens and Mechanical Traits

Pancreatic ductal adenocarcinoma (PDAC) has one of the worst outcomes among cancers with a 5-years survival rate of below 10%. This is a result of late diagnosis and the lack of effective treatments. The tumor is characterized by a highly fibrotic stroma containing distinct cellular components, embedded within an extracellular matrix (ECM). This ECM-abundant tumor microenvironment (TME) in PDAC plays a pivotal role in tumor progression and resistance to treatment. Cancer-associated fibroblasts (CAFs), being a dominant cell type of the stroma, are in fact functionally heterogeneous populations of cells within the TME. Certain subtypes of CAFs are the main producer of the ECM components of the stroma, with the most abundant one being the collagen family of proteins. Collagens are large macromolecules that upon deposition into the ECM form supramolecular fibrillar structures which provide a mechanical framework to the TME. They not only bring structure to the tissue by being the main structural proteins but also contain binding domains that interact with surface receptors on the cancer cells. These interactions can induce various responses in the cancer cells and activate signaling pathways leading to epithelial-to-mesenchymal transition (EMT) and ultimately metastasis. In addition, collagens are one of the main contributors to building up mechanical forces in the tumor. These forces influence the signaling pathways that are involved in cell motility and tumor progression and affect tumor microstructure and tissue stiffness by exerting solid stress and interstitial fluid pressure on the cells. Taken together, the TME is subjected to various types of mechanical forces and interactions that affect tumor progression, metastasis, and drug response. In this review article, we aim to summarize and contextualize the recent knowledge of components of the PDAC stroma, especially the role of different collagens and mechanical traits on tumor progression. We furthermore discuss different experimental models available for studying tumor-stromal interactions and finally discuss potential therapeutic targets within the stroma.

Radiation combines with immune checkpoint blockade to enhance T cell priming in a murine model of poorly immunogenic pancreatic cancer

Radiation has been a pillar of cancer therapy for decades. The effects of radiation on the anti-tumour immune response are variable across studies and have not been explicitly defined in poorly immunogenic tumour types. Here, we employed combination checkpoint blockade immunotherapy with stereotactic body radiation therapy and examined the effect on tumour growth and immune infiltrates in subcutaneous and orthotopic mouse models of pancreatic cancer. Although immune checkpoint blockade and radiation were ineffective alone, their combination produced a modest growth delay in both irradiated and non-irradiated tumours that corresponded with significant increases in CD8+ T cells, CD4+ T cells and tumour-specific T cells as identified by IFNγ ELISpot. We conclude that radiation enhances priming of tumour-specific T cells in poorly immunogenic tumours and that the frequency of these T cells can be further increased by combination with immune checkpoint blockade.

Total neoadjuvant therapy for initially inoperable pancreatic cancer: A systematic review of phase 2-3 studies

INTRODUCTION

Patients with initially inoperable non-metastatic pancreatic cancer (PC) have a poor prognosis, often similar to those with metastatic disease. Neoadjuvant chemotherapy (CT) plus concomitant or sequential radiotherapy (RT) may cause tumor shrinkage and allow for radical surgery. We pooled data of studies in which patients with locally advanced (unresectable) or borderline resectable PC were treated with a course of induction (or consolidation) CT followed or preceded by neoadjuvant CTRT regimen.

MATERIALS AND METHODS

We searched articles, including phase 2 or 3 studies, published in English from 2010 up to December 2020 in PubMed, SCOPUS, the Cochrane Library, and EMBASE. The primary outcomes were the pooled radical and R0 resection rates, median PFS and OS of included patients (those included in the intent to treat analysis).

RESULTS

A total of 28 studies were finally considered eligible for inclusion in quantitative analysis for a total of 2446 patients with locally advanced/borderline resectable PC. Overall the pooled rate of resection was 29.7% (95%CI 26.7-32.8%). In patients who completed the CT + CTRT program, the overall resection rate was 31.8% (95% 28.4-35.4%). After exclusion of studies that included resectable PCs, the overall resection rate was 19.9% (95%CI 17.3-22.7%). In studies were all patients had unresectable PC (n = 20 studies), the resection rate was 12.1% (95%CI 10-14.5%). In two studies that enrolled all borderline resectable PCs the resection rate was 59.2% (95%CI 48.9-68.8%). The pooled R0 resection rate was 68.7% (95%CI 64.7-72.3%). The median pooled OS was 15.7 months (95%CI 14-17.2 months) and the median pooled PFS was 10.7 (95%CI 9.3-12.1 months).

CONCLUSIONS

Surgery is a treatment option in about one third of patients with initially inoperable PC, following total neoadjuvant therapy. In unresectable cases the resection rate was 12%. Median OS and PFS rates were comparable with historical data of advanced PCs. Optimal integration and sequence of chemo- and radiotherapy in unresectable PC must still be defined.

Investigation of Relation of Radiation Therapy Quality With Toxicity and Survival in LAP07 Phase 3 Trial for Locally Advanced Pancreatic Carcinoma

PURPOSE

The LAP07 multicenter randomized study assessed whether chemoradiation therapy increases overall survival versus continuation chemotherapy in patients whose locally advanced pancreatic cancer was controlled after 4 months of induction chemotherapy. This analysis investigated whether failure to adhere to radiation therapy (RT) guidelines influenced survival and toxicity.

METHODS AND MATERIALS

This is a planned analysis of secondary objectives in the framework of a randomized international phase 3 trial. The protocol included detailed written RT guidelines. All participating institutions undertook an initial benchmark case to check adherence to protocol guidelines. Centers with major deviation were not allowed to include patients until they achieved a significant improvement and rigorously followed the guidelines. On-trial RT quality assurance consisted of a central review of treatment plan with dose-volume histograms for each patient. Adherence to guidelines was graded as per protocol (PP), minor deviation (MiD), or major deviation (MaD).

RESULTS

Fifty-seven benchmark cases were evaluated, 26% were classified as PP, 60% were MiD, and 14% were MaD. Among the 442 included patients, 133 patients were randomized in the chemoradiation therapy arm, and 117 patients were assessable for RT quality analysis. RT quality was graded as PP in 38.5% of patients, MiD in 43.6% of patients, and MaD in 17.9% of patients. The most frequent protocol violations were dose distribution heterogeneities. Median overall survival was 17 months with PP and MiD versus 13.4 months with MaD (hazard ratio [HR], 1.63; 95% confidence interval [CI], 0.99-2.71; P = .055). There was no difference in terms of progression-free survival (HR, 1.09; 95% CI, 0.66-1.8; P = .72). Patients with MaD had more nausea than patients treated PP or with MiD (P = .0045).

CONCLUSIONS

MaD was associated with a trend for worst survival. There was no difference in terms of progression-free survival. Because of the low rate of major deviations, their effects on the LAP07 trial results may be negligeable.

Therapeutic Application of Monoclonal Antibodies in Pancreatic Cancer: Advances, Challenges and Future Opportunities

Pancreatic cancer remains as one of the most aggressive cancer types. In the absence of reliable biomarkers for its early detection and more effective therapeutic interventions, pancreatic cancer is projected to become the second leading cause of cancer death in the Western world in the next decade. Therefore, it is essential to discover novel therapeutic targets and to develop more effective and pancreatic cancer-specific therapeutic agents. To date, 45 monoclonal antibodies (mAbs) have been approved for the treatment of patients with a wide range of cancers; however, none has yet been approved for pancreatic cancer. In this comprehensive review, we discuss the FDA approved anticancer mAb-based drugs, the results of preclinical studies and clinical trials with mAbs in pancreatic cancer and the factors contributing to the poor response to antibody therapy (e.g. tumour heterogeneity, desmoplastic stroma). MAb technology is an excellent tool for studying the complex biology of pancreatic cancer, to discover novel therapeutic targets and to develop various forms of antibody-based therapeutic agents and companion diagnostic tests for the selection of patients who are more likely to benefit from such therapy. These should result in the approval and routine use of antibody-based agents for the treatment of pancreatic cancer patients in the future.

Advances in Targeted Therapy and Immunotherapy for Pancreatic Cancer

Pancreatic cancer is a highly aggressive malignancy with an overall 5-year survival rate of <6% due to therapeutic resistance and late-stage diagnosis. These statistics have not changed despite 50 years of research and therapeutic development. Pancreatic cancer is predicted to become the second leading cause of cancer mortality by the year 2030. Currently, the treatment options for pancreatic cancer are limited. This disease is usually diagnosed at a late stage, which prevents curative surgical resection. Chemotherapy is the most frequently used approach for pancreatic cancer treatment and has limited effects. In many other cancer types, targeted therapy and immunotherapy have made great progress and have been shown to be very promising prospects; these treatments also provide hope for pancreatic cancer. The need for research on targeted therapy and immunotherapy is pressing due to the poor prognosis of pancreatic cancer, and in recent years, there have been some breakthroughs for targeted therapy and immunotherapy in pancreatic cancer. This review summarizes the current preclinical and clinical studies of targeted therapy and immunotherapy for pancreatic cancer and ends by describing the challenges and outlook.

Reduction of inter-observer contouring variability in daily clinical practice through a retrospective, evidence-based intervention

BACKGROUND

Inter-observer variations (IOVs) arising during contouring can potentially impact plan quality and patient outcomes. Regular assessment of contouring IOV is not commonly performed in clinical practice due to the large time commitment required of clinicians from conventional methods. This work uses retrospective information from past treatment plans to facilitate a time-efficient, evidence-based intervention to reduce contouring IOV.

METHODS

The contours of 492 prostate cancer treatment plans created by four radiation oncologists were analyzed in this study. Structure volumes, lengths, and DVHs were extracted from the treatment planning system and stratified based on primary oncologist and inclusion of a pelvic lymph node (PLN) target. Inter-observer variations and their dosimetric consequences were assessed using Student's t-tests. Results of this analysis were presented at an intervention meeting, where new consensus contour definitions were agreed upon. The impact of the intervention was assessed one-year later by repeating the analysis on 152 new plans.

RESULTS

Significant IOV in prostate and PLN target delineation existed pre-intervention between oncologists, impacting dose to nearby OARs. IOV was also present for rectum and penile-bulb structures. Post-intervention, IOV decreased for all previously discordant structures. Dosimetric variations were also reduced. Although target contouring concordance increased significantly, some variations still persisted for PLN structures, highlighting remaining areas for improvement.

CONCLUSION

We detected significant contouring IOV in routine practice using easily accessible retrospective data and successfully decreased IOV in our clinic through a reflective intervention. Continued application of this approach may aid improvements in practice standardization and enhance quality of care.

Single-fraction prostate stereotactic body radiotherapy: Dose reconstruction with electromagnetic intrafraction motion tracking

PURPOSE

To reconstruct the dose delivered during single-fraction urethra-sparing prostate stereotactic body radiotherapy (SBRT) accounting for intrafraction motion monitored by intraprostatic electromagnetic transponders (EMT).

METHODS

We analyzed data of 15 patients included in the phase I/II "ONE SHOT" trial and treated with a single fraction of 19 Gy to the planning target volume (PTV) and 17 Gy to the urethra planning risk volume. During delivery, prostate motion was tracked with implanted EMT. SBRT was interrupted when a 3-mm threshold was trespassed and corrected unless the offset was transient. Motion-encoded reconstructed (MER) plans were obtained by splitting the original plans into multiple sub-beams with isocenter shifts based on recorded EMT positions, mimicking prostate motion during treatment. We analyzed intrafraction motion and compared MER to planned doses.

RESULTS

The median EMT motion range (±SD) during delivery was 0.26 ± 0.09, 0.22 ± 0.14 and 0.18 ± 0.10 cm in the antero-posterior, supero-inferior, and left-right axes, respectively. Treatment interruptions were needed for 8 patients because of target motion beyond limits in the antero-posterior (n = 6) and/or supero-inferior directions (n = 4). Comparing MER vs. original plan there was a median relative dose difference of -1.9% (range, -7.9 to -1.0%) and of +0.5% (-0.3-1.7%) for PTV D_98% and D_2%, respectively. The clinical target volume remained sufficiently covered with a median D_98% difference of -0.3% (-1.6-0.5%). Bladder and rectum dosimetric parameters showed significant differences between original and MER plans, but mostly remained within acceptable limits.

CONCLUSIONS

The dosimetric impact of intrafraction prostate motion was minimal for target coverage for single-fraction prostate SBRT with real-time electromagnetic tracking combined with beam gating.

An Aggressive Approach to Locally Confined Pancreatic Cancer: Defining Surgical and Oncologic Outcomes Unique to Pancreatectomy with Celiac Axis Resection (DP-CAR)

Background:

Modern chemotherapeutics have led to improved systemic disease control for patients with locally advanced pancreatic cancer (LAPC). Surgical strategies such as distal pancreatectomy with celiac axis resection (DP-CAR) are increasingly entertained. Herein we review procedure specific outcomes and assess biologic rationale for DP-CAR.

Methods:

A prospectively maintained single-institution database of all pancreatectomies was queried for patients undergoing DP-CAR. We excluded all patients for whom complete data were not available and those who were not treated with contemporary multi-agent therapy. Data was supplemented with dedicated chart review and outreach for long-term oncologic outcomes.

Results:

Fifty-four patients underwent DP-CAR between 2008–2018. The median age was 62.7 years. 98% received induction chemotherapy. Arterial reconstruction was performed in 17% and concomitant visceral resection in 30%. R0 resection rate was 87%. Postoperative complications were common (43%) with chyle leak being the most frequent (17%). Length of stay was 8 days, readmission occurred in one-third, and ninety-day mortality was 2%. Disease recurrence occurred in 74% during a median follow up of 17.4 months. Median recurrence-free (RFS) and overall survival (OS) were 9 and 25 months, respectively.

Conclusions:

Following modern induction paradigms, DP-CAR can be performed with low mortality, manageable morbidity, and excellent rates of margin-negative resection in high volume settings. The profile of complications of DP-CAR is distinct from pancreaticoduodenectomy and simple distal pancreatectomy. OS and RFS are similar to those undergoing resection of borderline resectable and resectable disease. Improved systemic disease control will likely lead to increasing utilization of aggressive surgical approaches to LAPC.

Clinical and Pre-Clinical Evidence of Carbonic Anhydrase IX in Pancreatic Cancer and Its High Expression in Pre-Cancerous Lesions

Hypoxia is a common phenomenon that occurs in most solid tumors. Regardless of tumor origin, the evolution of a hypoxia-adapted phenotype is critical for invasive cancer development. Pancreatic ductal adenocarcinoma is also characterized by hypoxia, desmoplasia, and the presence of necrosis, predicting poor outcome. Carbonic anhydrase IX (CAIX) is one of the most strict hypoxia regulated genes which plays a key role in the adaptation of cancer cells to hypoxia and acidosis. Here, we summarize clinical data showing that CAIX expression is associated with tumor necrosis, vascularization, expression of Frizzled-1, mucins, or proteins involved in glycolysis, and inevitably, poor prognosis of pancreatic cancer patients. We also describe the transcriptional regulation of CAIX in relation to signaling pathways activated in pancreatic cancers. A large part deals with the preclinical evidence supporting the relevance of CAIX in processes leading to the aggressive behavior of pancreatic tumors. Furthermore, we focus on CAIX occurrence in pre-cancerous lesions, and for the first time, we describe CAIX expression within intraductal papillary mucinous neoplasia. Our review concludes with a detailed account of clinical trials implicating that treatment consisting of conventionally used therapies combined with CAIX targeting could result in an improved anti-cancer response in pancreatic cancer patients.

Urethra-Sparing Stereotactic Body Radiation Therapy for Prostate Cancer: Quality Assurance of a Randomized Phase 2 Trial

PURPOSE

To present the radiation therapy quality assurance results from a prospective multicenter phase 2 randomized trial of short versus protracted urethra-sparing stereotactic body radiation therapy (SBRT) for localized prostate cancer.

METHODS AND MATERIALS

Between 2012 and 2015, 165 patients with prostate cancer from 9 centers were randomized and treated with SBRT delivered either every other day (arm A, n = 82) or once a week (arm B, n = 83); 36.25 Gy in 5 fractions were prescribed to the prostate with (n = 92) or without (n = 73) inclusion of the seminal vesicles (SV), and the urethra planning-risk volume received 32.5 Gy. Patients were treated either with volumetric modulated arc therapy (VMAT; n = 112) or with intensity modulated radiation therapy (IMRT; n = 53). Deviations from protocol dose constraints, planning target volume (PTV) homogeneity index, PTV Dice similarity coefficient, and number of monitor units for each treatment plan were retrospectively analyzed. Dosimetric results of VMAT versus IMRT and treatment plans with versus without inclusion of SV were compared.

RESULTS

At least 1 major protocol deviation occurred in 51 patients (31%), whereas none was observed in 41. Protocol violations were more frequent in the IMRT group (P < .001). Furthermore, the use of VMAT yielded better dosimetric results than IMRT for urethra planning-risk volume D_98% (31.1 vs 30.8 Gy, P < .0001), PTV D_2% (37.9 vs 38.7 Gy, P < .0001), homogeneity index (0.09 vs 0.10, P < .0001), Dice similarity coefficient (0.83 vs 0.80, P < .0001), and bladder wall V_50% (24.5% vs 33.5%, P = .0001). To achieve its goals volumetric modulated arc therapy required fewer monitor units than IMRT (2275 vs 3378, P <.0001). The inclusion of SV in the PTV negatively affected the rectal wall V_90% (9.1% vs 10.4%, P = .0003) and V_80% (13.2% vs 15.7%, P = .0003).

CONCLUSIONS

Protocol deviations with potential impact on tumor control or toxicity occurred in 31% of patients in this prospective clinical trial. Protocol deviations were more frequent with IMRT. Prospective radiation therapy quality assurance protocols should be strongly recommended for SBRT trials to minimize potential protocol deviations.

Clinical outcomes and prognostic factors of stereotactic body radiation therapy combined with gemcitabine plus capecitabine for locally advanced unresectable pancreatic cancer

PURPOSE

This study aimed to evaluate the clinical outcomes, toxicity, and prognostic factors of SBRT combined with gemcitabine plus capecitabine (GEM-CAP) in treating locally advanced pancreatic cancer (LAPC).

METHODS

A total of 56 patients with LAPC treated with SBRT combined with GEM-CAP were reviewed from October 2010 to October 2016. The median total prescription dose at five fractions was 40 Gy (30-50 Gy). The patients were subjected to two cycles of GEM-CAP before SBRT. GEM-CAP chemotherapy was then offered for four cycles or until disease tolerance or progression. The primary endpoints included overall survival (OS) and progression-free survival (PFS).

RESULTS

The median OS and PFS from the date of diagnosis was 19 (95% CI 14.6-23.4) and 12 months (95% CI 8.34-15.66), respectively. The 1-year and 2-year survival rates were 82.1% and 35.7%, whereas the 1-year and 2-year PFS rates were 48.2% and 14.3%, respectively. The median carbohydrate antigen 19-9-determined PFS time was 11 months (95% CI 5.77-16.24). Multivariate analysis demonstrated that tumor diameter, lymph node metastasis, pre-treatment CA19-9 level, and post-treatment CA19-9 decline were independent prognostic factors (p < 0.05). Acute toxicity was minimal, with two cases (3.6%) experiencing grade 3 duodenal obstruction. No adverse events greater than grade 3 occurred. In late toxicity, three patients (5.4%) developed grade 3 gastrointestinal toxicity and two (3.6%) suffered from perforation caused by grade 4 radiation enteritis and intestinal fistula.

CONCLUSIONS

The combination of Cyberknife SBRT and GEM-CAP achieved excellent efficacy with acceptable toxicity for LAPC.

Implementation of the Chick Chorioallantoic Membrane (CAM) Model in Radiation Biology and Experimental Radiation Oncology Research

Radiotherapy (RT) is part of standard cancer treatment. Innovations in treatment planning and increased precision in dose delivery have significantly improved the therapeutic gain of radiotherapy but are reaching their limits due to biologic constraints. Thus, a better understanding of the complex local and systemic responses to RT and of the biological mechanisms causing treatment success or failure is required if we aim to define novel targets for biological therapy optimization. Moreover, optimal treatment schedules and prognostic biomarkers have to be defined for assigning patients to the best treatment option. The complexity of the tumor environment and of the radiation response requires extensive in vivo experiments for the validation of such treatments. So far in vivo investigations have mostly been performed in time- and cost-intensive murine models. Here we propose the implementation of the chick chorioallantoic membrane (CAM) model as a fast, cost-efficient model for semi high-throughput preclinical in vivo screening of the modulation of the radiation effects by molecularly targeted drugs. This review provides a comprehensive overview on the application spectrum, advantages and limitations of the CAM assay and summarizes current knowledge of its applicability for cancer research with special focus on research in radiation biology and experimental radiation oncology.

Toxicity of locoregional radiotherapy in combination with bevacizumab in patients with non-metastatic breast cancer (TOLERAB): Final long-term evaluation

BACKGROUND AND PURPOSE

Few data are available concerning the safety of bevacizumab (B) in combination with locoregional radiation therapy (RT). The objective of this study was to evaluate the 5-year late toxicity of concurrent B and RT in non-metastatic breast cancer.

MATERIALS AND METHODS

This multicentre prospective study included non-metastatic breast cancer patients enrolled in phase 3 clinical trials evaluating B with concurrent RT versus RT alone. All patients received neoadjuvant or adjuvant chemotherapy and normofractionated breast or chest wall RT, with or without regional lymph node RT. B was administered at an equivalent dose of 5 mg/kg once a week for 1 year. The safety profile was evaluated 1, 3 and 5 years after completion of radiotherapy.

RESULTS

A total of 64 patients were included between November 2007 and April 2010. Median follow-up was 60 months (12-73) and 5-year late toxicity data were available for 46 patients. The majority of tumours were triple-negative (68.8%), tumour size <2cm (41.3%) with negative nodal status (50.8%). Median total dose of B was 15,000mg and median duration was 11.2 months. No grade ≥3 toxicity was observed. Only 8 patients experienced grade 1-2 toxicities: n = 3 (6.5%) grade 1 lymphedema, n = 2 (4.3%) grade 1 pain, n = 1 (2.2%) grade 2 lymphedema, n = 1 (2.2%) grade 1 fibrosis. Five-year overall survival was 93.8%, disease-free survival was 89% and locoregional recurrence-free survival was 93.1%.

CONCLUSION

Concurrent B and locoregional RT are associated with acceptable 5-year toxicity in patients with non-metastatic breast cancer. No grade ≥3 toxicity was observed.

The Impact of Clinical Trial Quality Assurance on Outcome in Head and Neck Radiotherapy Treatment

Purpose: To investigate the impact of radiation treatment quality assurance (RTQA) on treatment outcomes in a phase III trial for advanced head and neck cancer.

Materials and Methods: A total of 767 patients from NRG/RTOG 0522 were included in this study. The contours of target volume (TV) and organ at risk (OAR), and dose-volume coverage of targets were reviewed and scored (per-protocol, variation-acceptable and deviation-unacceptable) according to the protocol. We performed log-rank tests for RTQA scores with patients' outcomes, including local control (LC), distant control (DC) and overall survival (OS). Cox models with and without RTQA score data were established. To obtain a more reasonable model, per-protocol and variation acceptable were combined into a single acceptable score.

Results: The log-rank test showed that all RTQA scores correlated with LC, which was significantly different between the per-protocol and variation-acceptable patients in target and OAR contouring (p-value = 0.004 and 0.043). For dose-volume score, the per-protocol and variation-acceptable patients were significantly different from unacceptable patients in the LC, with a p-value = 0.020 and 0.006, respectively. The DC of patients with variation-acceptable was significantly different than that of the unacceptable patients (p-value = 0.043). There were no correlations between RTQA scores with other outcomes. By incorporating RTQA scores into outcome modeling, the performance of LC model can be improved from 0.62 to 0.63 (c-index). The RTQA scores had no impact on DC and OS.

Conclusion: RTQA scores are related to patients' local control rates in head and neck cancer radiotherapy.

Impact of deviations in target volume delineation - Time for a new RTQA approach?

The international radiotherapy community has recognised that non-adherence to RT protocols can influence trial endpoints. However this conclusion is based on studies predominantly assessing the impact of deviations in dosimetric or treatment delivery protocol parameters rather than target volume delineation (TVD). This review evaluates the assessment of TVD within Radiation Therapy Quality Assurance (RTQA) programmes in clinical trials and the clinical impact of TVD protocol deviations. The implications for RTQA programmes are discussed. MEDLINE, PreMEDLINE, Embase, Cochrane Library, Web of Science, OpenGrey, WHO International Clinical Trials Registry Platform portal and ClinicalTrials.gov were searched. Full-length articles and conference abstracts were included to avoid publication bias. 5864 abstracts were screened for relevance; 94 full-length articles were reviewed and 5 relevant trials identified. Various classification systems were used to assess protocol deviations; 'unacceptable' or 'major' deviations in TVD occurred in 2.9-13.4% of assessed RT plans (when reported). It was often not possible to establish deviation rates specifically related to TVD as these were frequently combined with other types of protocol deviations. Details on the nature of unacceptable deviations was also not routinely reported and difficulties in establishing a 'consensus' for appropriate TVD for on-trial patients highlighted. Results suggest that deviations in TVD were associated with poorer outcomes for overall survival, local control and treatment-related toxicity; however the data were heterogeneous. RTQA of TVD was retrospective and feedback on the quality of TVD to recruiting centres was not standard. In summary, few trials have published outcomes on the impact of assessing the quality of TVD in trials. We propose that a new approach is now required. Unacceptable TVD deviations must be clearly defined at the time of protocol development to minimise interobserver variation, thereby promoting consistency in RTQA feedback. Prospective TVD reviews should be implemented for trials involving novel or complex RT techniques to identify deviations that require modification prior to treatment delivery. Furthermore, the consistent reporting of RTQA programme outcomes, both within and across trial groups, is of paramount importance to accelerate the evidence-base for the best RTQA approach when assessing TVD and to enable the impact on clinical outcomes within RT trials to be assessed.

Clinical Trials Targeting the Stroma in Pancreatic Cancer: A Systematic Review and Meta-Analysis

The tumor microenvironment plays an important role in the initiation and progression of pancreatic adenocarcinoma (PDAC). In this systematic review, we provide an overview of clinical trials with stroma-targeting agents. We systematically searched MEDLINE/PubMed and the EMBASE database, using the PRISMA guidelines, for eligible clinical trials. In total, 2330 records were screened, from which we have included 106 articles. A meta-analysis could be performed on 51 articles which describe the targeting of the vascular endothelial growth factor (VEGF) pathway, and three articles which describe the targeting of hyaluronic acid. Anti-VEGF therapies did not show an increase in median overall survival (OS) with combined hazard ratios (HRs) of 1.01 (95% confidence interval (CI) 0.90-1.13). Treatment with hyaluronidase PEGPH20 showed promising results, but, thus far, only in combination with gemcitabine and nab-paclitaxel in selected patients with hyaluronic acid (HA)high tumors: An increase in median progression free survival (PFS) of 2.9 months, as well as a HR of 0.51 (95% CI 0.26-1.00). In conclusion, we found that anti-angiogenic therapies did not show an increased benefit in median OS or PFS in contrast to promising results with anti-hyaluronic acid treatment in combination with gemcitabine and nab-paclitaxel. The PEGPH20 clinical trials used patient selection to determine eligibility based on tumor biology, which underlines the importance to personalize treatment for pancreatic cancer patients.

Angiogenesis in Pancreatic Cancer: Pre-Clinical and Clinical Studies

Angiogenesis is a crucial event in tumor development and progression, occurring by different mechanisms and it is driven by pro- and anti-angiogenic molecules. Pancreatic cancer vascularization is characterized by a high microvascular density, impaired microvessel integrity and poor perfused vessels with heterogeneous distribution. In this review article, after a brief introduction on pancreatic cancer classification and on angiogenesis mechanisms involved in its progression, the pre-clinical and clinical trials conducted in pancreatic cancer treatment using anti-angiogenic inhibitors will be described. Finally, we will discuss the anti-angiogenic therapy paradox between the advantage to abolish vessel supply to block tumor growth and the disadvantage due to reduction of drug delivery at the same time. The purpose is to identify new anti-angiogenic molecules that may enhance treatment regimen.

Association between measures of treatment quality and disease progression in prostate cancer radiotherapy: An exploratory analysis from the TROG 03.04 RADAR trial

INTRODUCTION

Quality assurance methods are incorporated into multicentre radiotherapy clinical trials for ensuring consistent application of trial protocol and quantifying treatment uncertainties. The study's purpose was to determine whether post-treatment disease progression is associated with measures of the quality of radiotherapy treatment.

METHODS

The TROG 03.04 RADAR trial tested the impact of androgen deprivation on prostate cancer patients receiving dose-escalated external beam radiation therapy. The trial incorporated a plan-review process and Level III dosimetric intercomparison at each centre, from which variables suggestive of treatment quality were collected. Kaplan-Meier statistics and Fine and Gray competing risk modelling were employed to test for associations between quality-related variables and the participant outcome local composite progression.

RESULTS

Increased 'dose-difference' at the prostatic apex and at the anterior rectal wall, between planned and measured dose, was associated with reduced progression. Participants whose treatment plans included clinical target volume (CTV) to planning target volume (PTV) margins exceeding protocol requirements also experienced reduced progression. Other quality-related variables, including total accrual from participating centres, measures of target coverage and other variations from protocol, were not significantly associated with progression.

CONCLUSIONS

This analysis has revealed the association of several treatment quality factors with disease progression. Increased dose and dose margin coverage in the prostate region can reduce disease progression. Extensive and rigorous monitoring has helped to maximise treatment quality, reducing the incidence of quality-indicator outliers, and thus reduce the chance of observing significant associations with progression rates.

Postoperative course and prognostic value of circulating angiogenic cytokines after pancreatic cancer resection

Background

Circulating angiogenic cytokines (CACs) have been confirmed as prognostic biomarkers and therapeutic targets in several solid tumors. However, their role as prognostic biomarkers in resected pancreatic ductal adenocarcinoma (PDAC) is unknown.

Results

The expression of CACs in patients with PDAC differs from those with CP both pre- and postoperatively. Correlation analyses show significant correlations between circulating levels of CACs: VEGF was correlated with IL-6 (r = 0.457), FGF (r = 0.44), G-CSF (r = 0.543), HGF (r = 0.586) and SDF-1α (r = 0.784) before the surgery. The circulating levels of TNF-α correlated with the serum concentration of IL-4 before (r= 0.656) and after the resection (r = 0.776 on POD 3, r = 0.865 on POD 7). Gender did not show any correlation with serum levels of CAC, except for significantly higher levels of EGF in males (P = 0.002). Other clinicopathological variables such as age (< 65 vs. > 65 years), T, N, or UICC stage did not have an association with the cytokine levels. The multivariate model including the entire angiogenic panel revealed that postoperative increasing levels of EGF (P = 0.023), PDGFA-A (P = 0.024), TNF-α (P = 0.001) and IL-8 (P = 0.049) were associated with a favorable prognosis, whereas elevating levels of VEGF (P = 0.005) correlated with a poor cancer-specific survival.

Materials and Methods

Preoperative and postoperative blood samples were collected in patients undergoing surgery for PDAC (n = 40) or chronic pancreatitis (CP; n = 9). Serum levels of 13 angiogenic cytokines (IL-4, IL-6, FGF-b, G-CSF, TNF-α, VEGF, HGF, SDF-1α, IL-8, EGF, Ang-1, PDGF-AA and PlGF) were analyzed using ELISA and Multiplex. Prognostic factors were identified by a Cox proportional hazards model.

Conclusions

Postoperative changes of serum levels of certain angiogenic cytokines correlate with patients’ prognosis after resection for pancreatic cancer. CACs should thus be considered as biomarkers in patients with resected pancreatic cancer.

Stereotactic Body Radiation Therapy (SBRT) Combined With Chemotherapy for Unresected Pancreatic Adenocarcinoma

Objectives:

The role of radiation therapy in the management of unresectable pancreatic cancer is controversial. One concern about concurrent chemoradiation relates to the timing of chemotherapy. In contrast to conventional radiation therapy, stereotactic body radiation therapy (SBRT) delivers high doses in a shorter duration resulting in minimal disruption in chemotherapy. Here, we report our results of patients treated with SBRT and chemotherapy for inoperable pancreatic cancer.

Materials and Methods:

Thirty-eight patients treated with SBRT and chemotherapy for locally advanced, borderline resectable, and medically inoperable pancreatic cancer at our institution from January 2008 to December 2012 were included in this retrospective analysis. Treatment was delivered in 5 fractions of 5 or 6 Gy per fraction over 5 days. Toxicities were scored using the Common Terminology Criteria for Adverse Events version 3. Survival was calculated using the Kaplan-Meier method.

Results:

The median age was 70 years (range, 45 to 90 y). Eastern Cooperative Oncology Group performance status ranged from 0 to 3. Thirty-four patients received concurrent chemotherapy. Four patients received sequential chemotherapy. Median overall survival was 14.3 months and median progression-free survival was 9.2 months from diagnosis. From radiation, overall survival and progression-free survival were 12.3 and 6.8 months, respectively. The overall local control rate was 79%. Acute toxicity was minimal. Severe late SBRT-related toxicities included 1 grade 3 gastric outlet obstruction, 1 grade 4 biliary stricture, and 1 grade 5 gastric hemorrhage.

Conclusions:

SBRT combined with chemotherapy for unresectable pancreatic cancer is convenient, feasible, and generally well tolerated. Outcomes of SBRT combined with chemotherapy compare favorably to results obtained with chemotherapy and conventional radiation therapy.

Systematic review on the treatment of isolated local recurrence of pancreatic cancer after surgery; re-resection, chemoradiotherapy and SBRT

BACKGROUND

The majority of patients who have undergone a pancreatic resection for pancreatic cancer develop disease recurrence within two years. In around 30% of these patients, isolated local recurrence (ILR) is found. The aim of this study was to systematically review treatment options for this subgroup of patients.

METHODS

A systematic search was performed in PubMed, Embase and the Cochrane Library. Studies reporting on the treatment of ILR after initial curative-intent resection of primary pancreatic cancer were included. Primary endpoints were morbidity, mortality and survival after ILR treatment.

RESULTS

After screening 1152 studies, 18 studies reporting on 313 patients undergoing treatment for ILR were included. Treatment options for ILR included surgical re-resection (8 studies, 100 patients), chemoradiotherapy (7 studies, 153 patients) and stereotactic body radiation therapy (SBRT) (4 studies, 60 patients). Morbidity and mortality were reported for re-resection (29% and 1%, respectively), chemoradiotherapy (54% and 0%) and SBRT (3% and 1%). Most patients had a prolonged disease-free interval before recurrence. Median survival after treatment of ILR of up to 32, 19 and 16 months was reported for re-resection, chemoradiotherapy and SBRT, respectively.

CONCLUSION

In selected patients, treatment of ILR following pancreatic resection for pancreatic cancer seems safe, feasible and associated with relatively good survival.

Conformity analysis to demonstrate reproducibility of target volumes for Margin-Intense Stereotactic Radiotherapy for borderline-resectable pancreatic cancer

BACKGROUND AND PURPOSE

Margin-directed neoadjuvant radiotherapy for borderline-resectable pancreatic cancer (BRPC) aims to facilitate clear surgical margins. A systematic method was developed for definition of a boost target volume prior to a formal phase-I study.

MATERIAL AND METHODS

Reference structures were defined by two oncologists and one radiologist, target structures were submitted by eight oncologist investigators and compared using conformity indices. Resultant risk of duodenal bleed (NTCP) was modelled.

RESULTS

For GTV, reference volume was 2.1cm3 and investigator mean was 6.03cm3 (95% CI 3.92-8.13cm3), for boost volume 1.1cm3 and 1.25cm3 (1.02-1.48cm3). Mean Dice conformity coefficient for GTV was 0.47 (0.38-0.56), and for boost volume was significantly higher at 0.61 (0.52-0.70, p=0.01). Discordance index (DI) for GTV was 0.65 (0.56-0.75) and for boost volume was significantly lower at 0.39 (0.28-0.49, p=0.001). NTCP using reference contours was 2.95%, with mean for investigator contour plans 3.93% (3.63-4.22%). Correlations were seen between NTCP and GTV volume (p=0.02) and NTCP and DI (correlation coefficient 0.83 (0.29-0.97), p=0.01).

CONCLUSIONS

Better conformity with reference was shown for boost volume compared with GTV. Investigator GTV volumes were larger than reference, had higher DI scores and modelled toxicity risk. A consistent method of target structure definition for margin-directed pancreatic radiotherapy is demonstrated.

Successes and Failures of Combined Modalities in Upper Gastrointestinal Malignancies: New Directions

Upper gastrointestinal malignancies generally have moderate to poor cure rates, even in the earliest stages, thereby implying that both local and systemic treatments have room for improvement. Therapeutic options are broadening, however, with the development of new immunotherapies and targeted agents, which can have synergistic effects with radiotherapy. Here we discuss the current state of combined modality therapy for upper gastrointestinal malignancies, specifically recent successes and setbacks in trials of radiation therapy with targeted therapies, vaccines, immunotherapies, and chemotherapies.

Nanomedicine strategies to overcome the pathophysiological barriers of pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is one of the leading causes of cancer- related deaths. PDAC remains one of the most difficult-to-treat cancers, owing to its unique pathobiological features: a nearly impenetrable desmoplastic stroma, and hypovascular and hypoperfused tumour vessels render most treatment options largely ineffective. Progress in understanding the pathobiology and signalling pathways involved in disease progression is helping researchers to develop novel ways to fight PDAC, including improved nanotechnology-based drug-delivery platforms that have the potential to overcome the biological barriers of the disease that underlie persistent drug resistance. So-called 'nanomedicine' strategies have the potential to enable targeting of the Hedgehog-signalling pathway, the autophagy pathway, and specific RAS-mutant phenotypes, among other pathological processes of the disease. These novel therapies, alone or in combination with agents designed to disrupt the pathobiological barriers of the disease, could result in superior treatments, with increased efficacy and reduced off-target toxicities compared with the current standard-of-care regimens. By overcoming drug-delivery challenges, advances can be made in the treatment of PDAC, a disease for which limited improvement in overall survival has been achieved over the past several decades. We discuss the approaches to nanomedicine that have been pursued to date and those that are the focus of ongoing research, and outline their potential, as well as the key challenges that must be overcome.

Prospective review of radiotherapy trials through implementation of standardized multicentre workflow and IT infrastructure

OBJECTIVE:

We sought to develop a process that would allow us to perform a prospective review of outlining in trials using expert reviewers based in multiple centres.

METHODS:

We implemented a specific information technology infrastructure and workflow that could serve all organizations involved in the radiotherapy quality assurance (RTQA) process.

RESULTS:

Data were processed and packaged in the computational environment for radiotherapy research (CERR) binary format and securely transmitted to the expert reviewer at the designated remote organization. It was opened and reviewed using the distributed CERR-compiled application, and a standardized report was sent to the respective centre. Centres were expected to correct any unacceptable deviations and resubmit outlining for approval prior to commencing treatment. 75% of reviews were completed and fed back to centres within 3 working days. There were no delays in treatment start date.

CONCLUSION:

Our distributed RTQA review approach provides a method of prospective outlining review at multiple centres, without compromising the quality, delaying the start of treatment or the need for significant additional infrastructure resources. Future progress in the area of prospective individual case review will need to be supported by additional resources for clinician time to undertake the reviews.

ADVANCES IN KNOWLEDGE:

Trial groups around the world have formulated different approaches to address the need for the prospective review of radiotherapy (RT) data with clinical trials, in line with available resources. We report a UK solution that has allowed the workload for outlining review to be distributed across a wider group of volunteer reviewers without the need for any additional infrastructure costs and has already been adopted within the UK RT trials community.

Targeted agents in GI radiotherapy: Clinical efficacy and side effects

Approximately 50% of all patients with cancer receive radiotherapy (RT) at some point during their treatment. Despite the advent of modern imaging and advances in planning and delivering highly-conformal and precise RT, further dose escalation to improve clinical outcome is often limited by the potential side-effects to adjacent tissues. Addition of chemotherapy to radiotherapy (CRT) has led to significant clinical improvements in many gastrointestinal malignancies but at the expense of increased toxicity as most chemotherapy drugs lack specificity. Targeted agents modulate specific biological pathways and can potentially enhance RT efficacy. However, so far, the majority of clinical studies incorporating targeted agents into RT and CRT have produced disappointing results in gastrointestinal malignancies. Also, we lack validated biomarkers and methods for monitoring and predicting the efficacy of these agents when combined with RT/CRT. In the present article, we will review the most important targeted therapies, and examine the efficacy and toxicity of these agents when combined with RT/CRT in gastrointestinal malignancies. The shortcomings as well as future challenges and perspectives for the successful use of these compounds with RT/CRT in future trials will also be outlined.

Phase I Trial of Consolidative Radiotherapy with Concurrent Bevacizumab, Erlotinib and Capecitabine for Unresectable Pancreatic Cancer

Purpose

To determine the safety, tolerability and maximum tolerated dose (MTD) of addition of erlotinib to bevacizumab and capecitabine-based definitive chemoradiation (CRT) in unresectable pancreatic cancer.

Methods

Seventeen patients with CT-staged, biopsy-proven unresectable pancreatic cancer were enrolled between 3/2008 and 10/2010. Prior chemotherapy was permitted. Two patients each were enrolled at dose levels (DLs) 1–4 and 9 patients at DL 5. All patients received 50.4 Gy (GTV only) in 28 fractions with concurrent capecitabine, bevacizumab and erlotinib. Dose of each drug was escalated in 5 DLs using the continual reassessment method. Bevacizumab was escalated from 5mg/Kg q2weeks (DLs 1–4) to 10mg/Kg q2weeks (DL 5); daily erlotinib from 100mg/day (DLs 1–2) to 150 mg/Kg (DLs 3–5); and capecitabine from 400mg/m² twice daily on days of radiation (DL 1) to 650mg/m² (DLs 2–3) to 825 mg/m² (DLs 4–5). Reassessment for potential resection was performed 6–8 weeks later.

Results

Sixteen patients received gemcitabine-based chemotherapy prior to CRT. With a median clinical follow-up of 10 months, no grade 3 toxicities were observed in DLs 1–4. Three (33%) patients at DL 5 developed a grade 3 acute toxicity (2 diarrhea, 1 rash). No grade 4 or 5 toxicities were seen. DL 4 was selected as the MTD; therefore, the recommended doses in combination with radiation are: bevacizumab, 5mg/Kg q2weeks; erlotinib, 150 mg/Kg daily; and capecitabine, 825mg/m² BID. Median survival was 17.4 months. Of the five patients who underwent resection, 4 were originally deemed locally advanced and 1 was borderline resectable. Three patients had excellent pathological response (2 complete response and 20% viable tumor) at surgery, and the 2 patients with complete response are still alive at 61 and 67 months of follow up with no local or distant failures.

Conclusions

This chemoradiation regimen at the recommended dose levels is safe and tolerable for patients with unresectable pancreatic cancer and merits further evaluation.

Recent Advances and Prospects for Multimodality Therapy in Pancreatic Cancer

The outcomes for treatment of pancreatic cancer have not improved dramatically in many decades. However, the recent promising results with combination chemotherapy regimens for metastatic disease increase optimism for future treatments. With greater control of overt or occult metastatic disease, there will likely be an expanding role for local treatment modalities, especially given that nearly a third of pancreatic cancer patients have locally destructive disease without distant metastatic disease at the time of death. Technical advances have allowed for the safe delivery of dose-escalated radiation therapy, which can then be combined with chemotherapy, targeted agents, immunotherapy, and nanoparticulate drug delivery techniques to produce novel and improved synergistic effects. Here we discuss recent advances and future directions for multimodality therapy in pancreatic cancer.

Toward stratification of patients with pancreatic cancer: Past lessons from traditional approaches and future applications with physical biomarkers

Pancreatic ductal adenocarcinoma (PDAC) has a high mortality rate and outcomes have not improved substantially for decades. Significant attention has focused on the biological drivers of the disease, and preclinical work has pointed to multiple biomarker candidates and therapeutic avenues. However, translation of these promising biomarkers and treatment strategies to patients has not been overwhelmingly successful. New strategies to account for the significant heterogeneity of the disease are needed so that rational treatments can be administered. Here, we focus on how physical sciences-based approaches may play a role in stratifying patients for clinical trials, and how this view of PDAC may reinvigorate treatment strategies that have been abandoned after "failing" to fulfill their potential in unselected patient populations. By complementing biological approaches, the development of physical biomarkers of PDAC may help deliver on the promise of personalized medicine for this devastating disease.

Overview of pre-clinical and clinical studies targeting angiogenesis in pancreatic ductal adenocarcinoma

The importance of angiogenesis in pancreatic ductal adenocarcinoma (PDAC) and its therapeutic potential have been explored in both pre-clinical and clinical studies. Human PDACs overexpress a number of angiogenic factors and their cognate high-affinity receptors, and anti-angiogenic agents reduce tumor volume, metastasis, and microvessel density (MVD), and improve survival in subcutaneous and orthotopic pre-clinical models. Nonetheless, clinical trials using anti-angiogenic therapy have been overwhelmingly unsuccessful. This review will focus on these pre-clinical and clinical studies, the potential reasons for failure in the clinical setting, and ways these shortcomings could be addressed in future investigations of angiogenic mechanisms in PDAC.

Modeling Combined Chemotherapy and Particle Therapy for Locally Advanced Pancreatic Cancer

Pancreatic ductal adenocarcinoma is the only cancer for which deaths are predicted to increase in 2014 and beyond. Combined radiochemotherapy protocols using gemcitabine and hypofractionated X-rays are ongoing in several clinical trials. Recent results indicate that charged particle therapy substantially increases local control of resectable and unresectable pancreas cancer, as predicted from previous radiobiology studies considering the high tumor hypoxia. Combination with chemotherapy improves the overall survival (OS). We compared published data on X-ray and charged particle clinical results with or without adjuvant chemotherapy calculating the biological effective dose. We show that chemoradiotherapy with protons or carbon ions results in 1 year OS significantly higher than those obtained with other treatment schedules. Further hypofractionation using charged particles may result in improved local control and survival. A comparative clinical trial using the standard X-ray scheme vs. the best current standard with carbon ions is crucial and may open new opportunities for this deadly disease.

Phase I Clinical Trial to Determine the Feasibility and Maximum Tolerated Dose of Panitumumab to Standard Gemcitabine-Based Chemoradiation in Locally Advanced Pancreatic Cancer

PURPOSE

Epidermal growth factor receptor (EGFR) inhibitors may improve both the therapeutic efficacy of radiotherapy and the radiosensitizing activity of gemcitabine. Based on this rationale and the nonoverlapping toxicity profiles of gemcitabine and the monoclonal EGFR antibody panitumumab, we designed a phase I trial to investigate the maximum-tolerated dose (MTD), safety, and activity of panitumumab added to gemcitabine-based chemoradiotherapy (CRT) in patients with locally advanced pancreatic cancer (LAPC).

EXPERIMENTAL DESIGN

Patients with LAPC and WHO performance status 0 to 1 were treated with weekly panitumumab at four dose levels (1-2.5 mg/kg), combined with weekly gemcitabine 300 mg/m(2) and radiotherapy (50.4 Gy in 28 fractions) for 6 weeks, followed by gemcitabine 1,000 mg/m(2) weekly for 3 weeks every 4 weeks until disease progression or unacceptable toxicity. Each cohort was monitored during the combination therapy to establish dose limiting toxicity. Tumor evaluation was performed after CRT and during gemcitabine monotherapy.

RESULTS

Fourteen patients were enrolled; 14 were evaluable for toxicity and 13 for response. The MTD for panitumumab was 1.5 mg/kg. Three of the 6 patients, treated at MTD, experienced grade 3 adverse events during the combination therapy; neutropenia (n = 2; 33%), fatigue (n = 1; 17%), nausea (n = 1; 17%), and vomiting (n = 1; 17%). Partial response was achieved by 3 patients (23%), 1 in each dose cohort. Median progression free survival of the three cohorts together was 8.9 months.

CONCLUSIONS

The addition of panitumumab to gemcitabine-based chemoradiotherapy in LAPC has manageable toxicity and potential clinical efficacy.

Treatment Approaches to Locally Advanced Pancreatic Adenocarcinoma

This article focuses on the management of locally advanced pancreatic cancer, which should be treated as a distinct entity separate from metastatic disease and borderline resectable disease. Although the role, timing, and sequencing of radiation relative to systemic therapy in this disease are controversial, an emerging treatment paradigm involves induction chemotherapy, followed by consolidative chemoradiation in patients who do not progress. In addition, new chemotherapy regimens as well as novel radiosensitizers have shown promise and need to be tested further in the locally advanced setting. Advances in radiotherapy have enabled stereotactic body radiotherapy and should continue to be prospectively evaluated.

New targeted therapies in pancreatic cancer

Patients with pancreatic cancer have a poor prognosis with a median survival of 4-6 mo and a 5-year survival of less than 5%. Despite therapy with gemcitabine, patient survival does not exceed 6 mo, likely due to natural resistance to gemcitabine. Therefore, it is hoped that more favorable results can be obtained by using guided immunotherapy against molecular targets. This review summarizes the new leading targeted therapies in pancreatic cancers, focusing on passive and specific immunotherapies. Passive immunotherapy may have a role for treatment in combination with radiochemotherapy, which otherwise destroys the immune system along with tumor cells. It includes mainly therapies targeting against kinases, including epidermal growth factor receptor, Ras/Raf/mitogen-activated protein kinase cascade, human epidermal growth factor receptor 2, insulin growth factor-1 receptor, phosphoinositide 3-kinase/Akt/mTOR and hepatocyte growth factor receptor. Therapies against DNA repair genes, histone deacetylases, microRNA, and pancreatic tumor tissue stromal elements (stromal extracellular matric and stromal pathways) are also discussed. Specific immunotherapies, such as vaccines (whole cell recombinant, peptide, and dendritic cell vaccines), adoptive cell therapy and immunotherapy targeting tumor stem cells, have the role of activating antitumor immune responses. In the future, treatments will likely include personalized medicine, tailored for numerous molecular therapeutic targets of multiple pathogenetic pathways.

Neoadjuvant gemcitabine, docetaxel, and capecitabine followed by gemcitabine and capecitabine/radiation therapy and surgery in locally advanced, unresectable pancreatic adenocarcinoma

BACKGROUND

This prospective study was undertaken to assess toxicity, resectability, and survival in pancreatic adenocarcinoma patients presenting with locally advanced, unresectable disease treated with neoadjuvant gemcitabine, docetaxel, and capecitabine (GTX) and gemcitabine and capecitabine (GX)/radiation therapy (RT).

METHODS

All patients presenting to the Pancreas Center were evaluated for eligibility. Forty-five patients (mean age, 64 years; range, 44-83 years)-34 patients deemed unresectable because of arterial involvement and 11 patients deemed unresectable because of extensive venous involvement-were treated with 6 cycles of GTX. Those with arterial involvement were treated with GX/RT after chemotherapy.

RESULTS

The GTX and GX/RT treatments were tolerated with the expected drug-related toxicities. There were no bowel perforations, cases of pancreatitis, or delayed strictures. Among those with arterial involvement, 29 underwent subsequent resection, with 20 (69%) achieving R0 resections. All 11 patients with venous-only involvement underwent resection, with 8 achieving R0 resections and 3 achieving complete pathologic responses. For the arterial arm, the 1-year survival rate was 71% (24 of 34 patients), and the median survival was 29 months (95% confidence interval, 21-38 months). Thirteen patients (38%) have not relapsed (range, 5-49+ months). For the venous arm, the median survival has not been reached at more than 42 months. Six patients (55%) in the venous arm did not experience recurrence (range, 6.2-42+ months).

CONCLUSIONS

GTX plus GX/RT is an effective neoadjuvant regimen that can be safely administered to patients up to at least the age of 83 years. It is associated with a high response rate, a high rate of R0 resections, and prolonged overall survival.

Microvessel Landscape Assessment in Pancreatic Ductal Adenocarcinoma: Unclear Value of Targeting Endoglin (CD105) as Prognostic Factor of Clinical Outcome

OBJECTIVES

Tumor angiogenesis based on microvessel density assessment has been associated with poor prognosis in several studies of patients with pancreatic ductal adenocarcinoma (PDAC). Expression of endoglin (CD105), a tumor-induced vascularization marker, has been found to represent a negative prognostic factor in many malignant tumors. The aim of our study was to assess the value of tumoral microvascularity both with pan-endothelial markers and endoglin as well, in correlation with the clinical outcome of patients with PDAC.

METHODS

Fifty-eight patients with PDAC, 36 males and 22 females, with a mean (SD) age of 65.4 (10.0) years were included in the study. Deparaffinized sections from formalin-fixed areas both from the center and periphery (invasion front) of the tumors were immunostained for CD105 as well as for the endothelial markers CD31 and CD34. Tumoral angiogenesis was assessed on the basis of microvessel density (number of vessels per square millimeter) and on microvascular area (square micrometers) as well.

RESULTS

High intratumoral microvascular area, in endoglin-stained sections, was found to be of marginal prognostic significance for recurrence (log rank, P 0.05). Survival was also marginally associated with CD31 intratumoral microvascular area (log rank, P 0.05).

CONCLUSIONS

Further studies are needed before endoglin replaces the conventional angiogenesis markers in PDCA.

Interaction of radiation therapy with molecular targeted agents

The development of molecular targeted therapeutics in oncology builds on many years of scientific investigation into the cellular mechanics of malignant transformation and progression. The past two decades have brought an accelerating pace to the clinical investigation of new molecular targeted agents, particularly in the setting of metastatic disease. The integration of molecular targeted agents into phase III clinical trial design has lagged in the curative treatment setting, particularly in combination with established therapeutic modalities such as radiation. In this review, we discuss the interaction of radiation and molecular targeted therapeutics. The dynamics of cellular and tumor response to radiation offer unique opportunities for beneficial interplay with molecular targeted agents that may go unrecognized with conventional screening and monotherapy clinical testing of novel agents. By using epidermal growth factor receptor (EGFR) as a primary example, we discuss recent clinical studies that illustrate the potential synergy of molecular targeted agents with radiation and highlight the clinical value of such interactions. For various molecular targeted agents, their greatest clinical impact may rest in combination with radiation, and efforts to facilitate systematic investigation of this approach appear highly warranted.

Locally advanced pancreatic cancer: the role of definitive chemoradiotherapy

At the time of diagnosis, around 20% of patients with pancreatic cancer present at a resectable stage, 50% have metastatic disease and 30% have locally advanced tumour, non-metastatic but unresectable because of superior mesenteric artery or coeliac encasement. Despite advances in chemoradiotherapy and improved systemic chemotherapeutic agents, patients with locally advanced pancreatic cancer suffer from high rates of distant metastatic failure and from local progression, with a median survival time ranging from 5 to 11 months. In the past 30 years, modest improvements in median survival have been attained for these patients treated by chemoradiotherapy or chemotherapy protocols. The optimal therapy for patients with locally advanced pancreatic carcinoma remains controversial. This review aims to evaluate the role of radiotherapy for these patients.