Adjuvant therapy in pancreatic cancer: a critical appraisal

IQ Motif Containing GTPase-Activating Protein 3 Is Associated with Cancer Stemness and Survival in Pancreatic Ductal Adenocarcinoma

INTRODUCTION

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal types of malignancy, with poor prognosis and rising incidence. IQ motif containing GTPase-activating protein 3 (IQGAP3) is a member of the IQGAPs family of scaffolding proteins that govern multiple cellular activities like cytoskeletal remodeling and cellular signal transduction. This study aimed to analyze the expression and biological function of IQGAP3 in PDAC.

METHODS

We analyzed IQGAP3 expression in 81 PDAC samples by immunohistochemistry. RNA interference was used to inhibit IQGAP3 expression in PDAC cell lines.

RESULTS

Immunohistochemical analysis of IQGAP3 showed that 54.3% of PDACs were positive for cytoplasmic expression of IQGAP3, with no expression found in non-neoplastic tissue. Furthermore, IQGAP3 expression was an independent poor prognostic factor in our immunostaining-based studies and analyses of public databases. Our cohort and the Cancer Genome Atlas database indicated that IQGAP3 is co-localized with kinesin family member C1 (KIFC1), which we previously reported as a cancer stem cell-associated protein. IQGAP3 small interfering RNA treatment decreased PDAC cell proliferation and spheroid colony formation via ERK and AKT pathways.

DISCUSSION/CONCLUSION

These results suggest that IQGAP3, a transmembrane protein, is involved in survival and stemness and may be a promising new therapeutic target for PDAC.

Comparison the efficacy and safety of different neoadjuvant regimens for resectable and borderline resectable pancreatic cancer: a systematic review and network meta-analysis

BACKGROUND

To date, the optimal recommended specific neoadjuvant regimens for resectable or borderline resectable pancreatic cancer (RPC or BRPC) remain an unanswered issue.

METHODS

We systematically searched the electronic databases to identify randomized controlled trials (RCTs) comparing different neoadjuvant therapy strategies for RPC or BRPC. The primary outcome was overall survival (OS). Comprehensive analyses and evaluations were performed using the single-arm, paired, and network meta-analyses.

RESULTS

Twelve RCTs involving 1279 patients with RPC or BRPC were enrolled. The paired meta-analysis showed that neoadjuvant therapy improved OS for both RPC (hazard ratio (HR) 0.69, 95% c.i. 0.54 to 0.87) and BRPC (HR 0.60, 0.42 to 0.86) compared with upfront surgery (UP-S). Neoadjuvant chemotherapy (NAC) also improved OS for both RPC (HR 0.63, 0.47 to 0.85) and BRPC (HR 0.44, 0.27 to 0.71), while neoadjuvant chemoradiotherapy (NACR) improved OS only for BRPC (HR 0.68, 0.52 to 0.89) and not for RPC (HR 0.79, 0.54 to 1.16). Network meta-analysis found that NAC was superior to NACR in OS for RPC/BRPC (HR 0.58, 0.37 to 0.90). Neoadjuvant chemotherapy based on modified fluorouracil/folinic acid/irinotecan/oxaliplatin (NAC-mFFX) and neoadjuvant chemotherapy based on abraxane/gemcitabine (NAC-AG) ranked first and second in OS for RPC/BRPC.

CONCLUSIONS

Both RPC and BRPC could obtain OS benefits from neoadjuvant therapy compared with UP-S, and NAC improved OS both in RPC and BRPC while NACR only improved OS in BRPC. Furthermore, NAC was superior to NACR, and NAC-mFFX and NAC-AG might be recommended sequentially as the best neoadjuvant therapy strategies.

Extracts of the Medicinal Plants Pao Pereira and Rauwolfia vomitoria Inhibit Ovarian Cancer Stem Cells In Vitro

Ovarian cancer has an enrichment of cancer stem cells (CSCs) which contribute to the treatment resistant tumor’s high rate of recurrence and metastasis. Here we investigated 2 plant extracts from the medicinal plants Pao Pereira (Pao) and Rauwolfia vomitoria (Rau) each for their activities against ovarian CSCs. Both Pao and Rau inhibited overall proliferation of human ovarian cancer cell lines with IC₅₀ ranging from 210 to 420 μg/mL and had limited cytotoxicity to normal epithelial cells. Ovarian CSC population was examined using cell surface markers and tumor spheroid formation assays. The results showed that both Pao and Rau treatment significantly reduced the ovarian CSC population. Pao and Rau had similar activities in inhibiting ovarian CSCs, with IC₅₀s of ~120 μg/mL for 24 hours treatment, and ~50 μg/mL for long-term tumor spheroid formation. Nuclear β-catenin levels were decreased, suggesting suppression of Wnt/β-catenin signaling pathway. Taken together, data here showed that Pao and Rau both inhibited ovarian cancer stem cells, probably in preference to the bulk of tumor cells. Further mechanistic studies and in vivo investigation validating these findings are warranted, given that inhibition of cancer stem cells holds the promise of comprehensively inhibiting cancer metastasis, drug resistance and recurrence.

Pancreatic cancer in the era of COVID-19 pandemic: Which one is the lesser of two evils?

Pancreatic adenocarcinoma remains one of the deadliest malignancies affecting the older population. We are experiencing a paradigm shift in the treatment of pancreatic cancer in the era of coronavirus disease 2019 (COVID-19) pandemic. Utilizing neoadjuvant treatment and further conducting a safe surgery while protecting patients in a controlled environment can improve oncological outcomes. On the other hand, an optimal oncologic procedure performed in a hazardous setting could shorten patient survival if recovery is complicated by COVID-19 infection. We believe that oncological treatment protocols must adapt to this new health threat, and pancreatic cancer is not unique in this regard. Although survival may not be as optimistic as most other malignancies, as caregivers and researchers, we are committed to innovating and reshaping the treatment algorithms to minimize morbidity and maximize survival as caregivers and researchers.

Evaluation of response using FDG-PET/CT and diffusion weighted MRI after radiochemotherapy of pancreatic cancer: a non-randomized, monocentric phase II clinical trial-PaCa-DD-041 (Eudra-CT 2009-011968-11)

Background

Pancreatic cancer is a devastating disease with a 5-year survival rate of 20–25%. As approximately only 20% of patients diagnosed with pancreatic cancer are initially staged as resectable, it is necessary to evaluate new therapeutic approaches. Hence, neoadjuvant (radio)chemotherapy is a promising therapeutic option, especially in patients with a borderline resectable tumor. The aim of this non-randomized, monocentric, prospective, phase II clinical study was to assess the prognostic value of functional imaging techniques, i.e., [¹⁸F]2-fluoro-2-deoxy-d-glucose positron emission tomography/computed tomography (FDG-PET/CT) and diffusion weighted magnetic resonance imaging (DW-MRI), prior to and during neoadjuvant radiochemotherapy.

Methods

Patients with histologically proven resectable, borderline resectable or unresectable non-metastatic pancreatic adenocarcinoma received induction chemotherapy followed by neoadjuvant radiochemotherapy. Patients underwent FDG-PET/CT and DW-MRI including T1- and T2-weighted sequences prior to and after neoadjuvant chemotherapy as well as following induction radiochemotherapy. The primary endpoint was the evaluation of the response as quantified by the standardized uptake value (SUV) measured with FDG-PET. Response to treatment was evaluated by FDG-PET and DW-MRI during and after the neoadjuvant course. Morphologic staging was performed using contrast-enhanced CT and contrast-enhanced MRI to decide inclusion of patients and resectability after neoadjuvant therapy. In those patients undergoing subsequent surgery, imaging findings were correlated with those of the pathologic resection specimen.

Results

A total of 25 patients were enrolled in the study. The response rate measured by FDG-PET was 85% with a statistically significant decrease of the maximal SUV (SUV_max) during therapy (p < 0.001). Using the mean apparent diffusion coefficient (ADC), response was not detectable with DW-MRI. After neoadjuvant treatment 16 patients underwent surgery. In 12 (48%) patients tumor resection could be performed. The median overall survival of all patients was 25 months (range: 7–38 months).

Conclusion

Based on these limited patient numbers, it was possible to show that this trial design is feasible and that the neoadjuvant therapy regime was well tolerated. FDG-PET/CT may be a reliable method to evaluate response to the combined therapy. In contrast, when evaluating the response using mean ADC, DW-MRI did not show conclusive results.

Electronic supplementary material

The online version of this article (10.1007/s00066-020-01654-4) contains supplementary material, which is available to authorized users.

Glutathione S-Transferase pi-1 Knockdown Reduces Pancreatic Ductal Adenocarcinoma Growth by Activating Oxidative Stress Response Pathways

Glutathione S-transferase pi-1 (GSTP1) plays an important role in regulating oxidative stress by conjugating glutathione to electrophiles. GSTP1 is overexpressed in breast, colon, lung, and prostate tumors, where it contributes to tumor progression and drug resistance; however, the role of GSTP1 in pancreatic ductal adenocarcinoma (PDAC) is not well understood. Using shRNA, we knocked down GSTP1 expression in three different PDAC cell lines and determined the effect on cell proliferation, cell cycle progression, and reactive oxygen species (ROS) levels. Our results show GSTP1 knockdown reduces PDAC cell growth, prolongs the G0/G1 phase, and elevates ROS in PDAC cells. Furthermore, GSTP1 knockdown results in the increased phosphorylation of c-Jun N-terminal kinase (JNK) and c-Jun and the decreased phosphorylation of extracellular signal-regulated kinase (ERK), p65, the reduced expression of specificity protein 1 (Sp1), and the increased expression of apoptosis-promoting genes. The addition of the antioxidant glutathione restored cell viability and returned protein expression levels to those found in control cells. Collectively, these data support the working hypothesis that the loss of GSTP1 elevates oxidative stress, which alters mitogen-activated protein (MAP) kinases and NF-κB signaling, and induces apoptosis. In support of these in vitro data, nude mice bearing orthotopically implanted GSTP1-knockdown PDAC cells showed an impressive reduction in the size and weight of tumors compared to the controls. Additionally, we observed reduced levels of Ki-67 and increased expression of cleaved caspase-3 in GSTP1-knockdown tumors, suggesting GSTP1 knockdown impedes proliferation and upregulates apoptosis in PDAC cells. Together, these results indicate that GSTP1 plays a significant role in PDAC cell growth and provides support for the pursuit of GSTP1 inhibitors as therapeutic agents for PDAC.

Markers of pancreatic cancer stem cells and their clinical and therapeutic implications

Pancreatic cancer (PC) is the fourth most common cause of death among all cancers. Poor prognosis of PC may be caused by a prevalence of cancer stem cells (CSCs). CSCs are a population of cancer cells showing stem cell-like characteristics. CSCs have the ability to self-renew and may initiate tumorigenesis. PC CSCs express markers such as CD133, CD24, CD44, DCLK1, CXCR4, ESA, Oct4 and ABCB1. There is a wide complexity of interaction and relationships between CSC markers in PC. These markers are negative prognostic factors and are connected with tumor recurrence and clinical progression. Additionally, PC CSCs are resistant to treatment with gemcitabine. Thus, most current therapies for PC are ineffective. Numerous studies have shown, that targeting of these proteins may increase both disease-free and overall survival in PC.

Inhibition of pancreatic cancer stem cells by Rauwolfia vomitoria extract

The poor treatment outcomes of pancreatic cancer are linked to an enrichment of cancer stem cells (CSCs) in these tumors, which are resistant to chemotherapy and promote metastasis and tumor recurrence. The present study investigated an extract from the root of the medicinal plant Rauwolfia vomitoria (Rau) for its activity against pancreatic CSCs. In vitro tumor spheroid formation and CSC markers were tested, and in vivo tumorigenicity was evaluated in nude mice. Rau inhibited the overall proliferation of human pancreatic cancer cell lines with a 50% inhibitory concentration (IC₅₀) ranging between 125 and 325 µg/ml, and showed limited cytotoxicity towards normal epithelial cells. The pancreatic CSC population, identified using cell surface markers or a tumor spheroid formation assay, was significantly reduced, with an IC₅₀ value of ~100 µg/ml treatment for 48 h and ~27 µg/ml for long-term tumor spheroid formation. The levels of CSC-related gene Nanog and nuclear β-catenin were decreased, suggesting suppression of the Wnt/β-catenin signaling pathway. In vivo, 20 mg/kg of Rau administered five times per week by oral gavage significantly reduced the tumorigenicity of PANC-1 cells in immunocompromised mice. Taken together, these data showed that Rau preferentially inhibited pancreatic cancer stem cells. Further investigation is warranted to examine the potential of Rau as a novel treatment for pancreatic cancer.

Extract of the Medicinal Plant Pao Pereira Inhibits Pancreatic Cancer Stem-Like Cell In Vitro and In Vivo

Pancreatic cancers are enriched with cancer stem-like cells (CSCs), which are resistant to chemotherapies, and responsible for tumor metastasis and recurrence. Here, we investigated the extract of a medicinal plant Pao Pereira (Pao) for its activity against pancreatic CSCs. Pao inhibited overall proliferation of human pancreatic cancer cell lines with IC₅₀ ranging from 125 to 325 μg/mL and had limited cytotoxicity to normal epithelial cells. Pancreatic CSC population, identified using surface markers CD24+ CD44+ EpCam+ or tumor spheroid formation assay, was significantly reduced, with IC₅₀s of ~100 μg/mL for 48 hours treatment, and ~27 μg/mL for long-term treatment. Nuclear β-catenin levels were decreased, suggesting suppression of Wnt/β-catenin signaling pathway. In vivo, Pao at 20 mg/kg, 5 times/week gavage, significantly reduced tumorigenicity of PANC-1 cells in immunocompromised mice, indicating inhibition of CSCs in vivo. Further investigation is warranted in using Pao as a novel treatment targeting pancreatic CSCs.

Evaluation of Treatment Patterns and Survival Outcomes in Elderly Pancreatic Cancer Patients: A Surveillance, Epidemiology, and End Results-Medicare Analysis

BACKGROUND

Management of pancreatic cancer (PC) in elderly patients is unknown; clinical trials exclude patients with comorbidities and those of extreme age. This study evaluated treatment patterns and survival outcomes in elderly PC patients using linked Surveillance, Epidemiology, and End Results (SEER) and Medicare data.

MATERIALS AND METHODS

Histology codes 8140, 8500, 8010, 8560, 8490, 8000, 8260, 8255, 8261, 8263, 8020, 8050, 8141, 8144, 8210, 8211, or 8262 in Medicare Parts A and B were identified. Data regarding demographic, characteristics, treatments, and vital status between 1998 and 2009 were collected from the SEER. Determinants of treatment receipt and overall survival were examined using logistic regression and Cox proportional hazards models, respectively.

RESULTS

A total of 5,975 patients met inclusion. The majority of patients were non-Hispanic whites (85%) and female (55%). Most cases presented with locoregional stage disease (74%); 41% received only chemotherapy, 30% chemotherapy and surgery, 10% surgery alone, 3% radiation, and 16% no cancer-directed therapy. Patients with more advanced cancer, older age, and those residing in areas of poverty were more likely to receive no treatment. Among patients 66-74 years of age with locoregional disease, surgery alone (hazard ratio [HR] = 0.54; 95% confidence interval [CI]: 0.39-0.74) and surgery in combination with chemotherapy (HR = 0.69; 95% CI: 0.53-0.91) showed survival benefit as compared with the no treatment group. Among patients ≥75 years of age with locoregional disease, surgery alone (HR = 2.04; 95% CI: 0.87-4.8) or in combination with chemotherapy (HR = 1.59; 95% CI: 0.87-2.91) was not associated with better survival.

CONCLUSION

Treatment modality and survival differs by age and stage. Low socioeconomic status appears to be a major barrier to the receipt of PC therapy among Medicare patients.

IMPLICATIONS FOR PRACTICE

Elderly patients with cancer are under-represented on clinical trials and usually have comorbid illnesses. The management of elderly patients with pancreatic cancer is unknown, with many retrospective experiences but low sample sizes. Using Surveillance, Epidemiology, and End Results-Medicare linked data to analyze treatment patterns and survival of elderly patients with pancreatic cancer on a larger population scale, this study highlights treatment patterns and their effect on survival and proposes possible obstacles to access of care in elderly patients with pancreatic cancer other than Medicare coverage.

Smad4 Loss Correlates With Higher Rates of Local and Distant Failure in Pancreatic Adenocarcinoma Patients Receiving Adjuvant Chemoradiation

OBJECTIVES

The tumor suppressor gene SMAD4 (DPC4) is genetically inactivated in approximately half of pancreatic ductal adenocarcinomas (PDAs). We examined whether Smad4 tumor status was associated with outcomes after adjuvant chemoradiation (CRT) for resected PDAs.

METHODS

Patients treated with adjuvant CRT were identified (N = 145). Smad4 status was determined by immunolabeling and graded as intact or lost. Kaplan-Meier method and multivariable competing risk analyses were performed.

RESULTS

On multivariate competing risk analysis, Smad4 loss was associated with increased risk of local recurrence (LR) (hazard ratio, 2.37; 95% confidence interval, 1.10-5.11; P = 0.027), distant failure (DF) (hazard ratio, 1.71; 95% confidence interval, 1.03-2.83; P = 0.037), and synchronous LR and DF at first recurrence (14.9 % vs 5.3%, P = 0.07) compared with Smad4 intact cancers. Smad4 loss was not associated with median overall survival (22 vs 22 months; P = 0.63) or disease-free survival (lost [13.6 months] vs intact [13.5 months], P = 0.79).

CONCLUSIONS

After PDA resection and adjuvant CRT, Smad4 loss correlated with higher risk of LR and DF, but not with survival. Smad4 loss may help predict which surgical patients are at higher risk for failure after definitive management and may benefit from intensified adjuvant therapy.

Role of PET/CT in the Clinical Management of Locally Advanced Pancreatic Cancer

Aim

To evaluate the role of 18F-fluorodeoxyglucose (FDG) PET/CT in: a) the selection of patients with locally advanced pancreatic cancer for helical tomotherapy with concurrent chemotherapy (HTT-ChT); b) monitoring HTT-ChT treatment efficacy in comparison with contrast-enhanced CT (c.e.CT).

Methods

Forty-two consecutive patients with unresectable locally advanced pancreatic cancer referred for HTT-ChT were enrolled in the study. All patients were pretreated with induction ChT. Before the beginning of HTT-ChT treatment patients underwent diagnostic c.e.CT (CT0) and FDG PET/CT (PET/CT0) for staging. After staging, patients received HTT-ChT. Three months after the end of HTT-ChT a control c.e.CT (CT1) was done. FDG PET/CT (PET/CT1) was repeated only in patients with positive PET/CT0. PET/CT1 and CT1 were compared with baseline imaging results to assess treatment efficacy.

Results

In 31/42 cases (74%) PET/CT0 documented pathological uptake in pancreatic lesions, while in the remaining 11/42 cases it showed no uptake. In 7/42 (17%) patients, PET/CT0 also detected distant metastases, prompting a change in the therapeutic approach. Compared to PET/CT0, PET/CT1 (n = 18) documented 3 complete metabolic responses, 9 partial metabolic responses, 2 instances of stable metabolic disease, and 4 instances of progressive metabolic disease. In the same group of 18 patients, CT1 showed 0 complete responses, 3 partial responses, 8 instances of stable disease, and 7 instances of progressive disease compared to CT0. Concordance between PET/CT and CT response was seen in 33% of cases. In 50% of cases, PET/CT1 documented a response to therapy that was not evident on CT.

Conclusions

PET/CT influenced the treatment strategy by detecting distant metastases not documented by CT, thus accurately selecting patients for HTT-ChT after induction ChT. In monitoring treatment efficacy, PET/CT can detect a metabolic response to treatment not identified by CT.

Cancer of the Pancreas: Molecular Pathways and Current Advancement in Treatment

Pancreatic cancer is one of the most lethal cancers among all malignances, with a median overall survival of <1 year and a 5-year survival of ~5%. The dismal survival rate and prognosis are likely due to lack of early diagnosis, fulminant disease course, high metastasis rate, and disappointing treatment outcome. Pancreatic cancers harbor a variety of genetic alternations that render it difficult to treat even with targeted therapy. Recent studies revealed that pancreatic cancers are highly enriched with a cancer stem cell (CSC) population, which is resistant to chemotherapeutic drugs, and therefore escapes chemotherapy and promotes tumor recurrence. Cancer cell epithelial to mesenchymal transition (EMT) is highly associated with metastasis, generation of CSCs, and treatment resistance in pancreatic cancer. Reviewed here are the molecular biology of pancreatic cancer, the major signaling pathways regulating pancreatic cancer EMT and CSCs, and the advancement in current clinical and experimental treatments for pancreatic cancer.

Integrinβ1 modulates tumour resistance to gemcitabine and serves as an independent prognostic factor in pancreatic adenocarcinomas

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies because of its broad resistance to chemotherapy. Numerous evidence indicates that integrinβ1 is upregulated in some human cancers, and it is correlated with resistance to various therapies. However, the role of integrinβ1 in chemotherapy is not clear in pancreatic cancer. The present study evaluates the potential of integrinβ1 to predict chemoresistance and prognosis in patients and to modulate resistance to gemcitabine in PDAC cells. Primary drug-resistance (DR) cancer cells were isolated, and DR cells from MiaPaCa-2 and AsPC-1 parent cell lines (PCL) were selected. Integrinβ1 expression was determined using immunohistochemistry (IHC), quantitative real-time PCR (qRT-PCR) and Western blotting. Changes in drug response after knockdown of integrinβ1 via RNA interference (RNAi) were evaluated using the viability of cancer cells as colon formation, proliferation using Western blot of Ki-67 and apoptosis using cleaved caspase-3 immunofluorescence. qRT-PCR and Western blot also detected variations in the activities of cdc42 and AKT after integrinβ1 suppression. Patient survival and relative factors were assessed using Kaplan-Meier and Cox regression analyses. Integrinβ1 expression was upregulated in PDAC, which was significantly associated with intrinsic and acquired gemcitabine resistance and worse outcomes. The downregulation of integrinβ1 attenuated PDAC chemoresistance, and this attenuation partially correlated with reduced Cdc42 and AKT activity, which are target molecules of integrinβ1 in some human cancers. These findings identified integrinβ1 as a special marker of drug resistance and a serious prognosis, and they furthermore support the use of integrinβ1 as a novel potential therapeutic target to overcome chemotherapy resistance. The results also suggest a possible drug-resistant signalling pathway of integrinβ1 in PDAC.

Pearls and pitfalls of imaging metastatic disease from pancreatic adenocarcinoma: a systematic review

Pancreatic adenocarcinoma is a systemic disease due to the presence of metastatic disease at the time of diagnosis and local recurrence as well as distant metastatic disease after treatment in a majority of patients. Recognition of these metastatic sites may help in accurate staging and assessment of therapeutic response. The authors discuss and illustrate imaging findings of metastatic disease from pancreatic adenocarcinoma in different organ systems with emphasis on entities that can mimic metastatic pancreatic cancer.

Survival after surgical resection of distal cholangiocarcinoma: A systematic review and meta-analysis of prognostic factors

BACKGROUND/OBJECTIVE

This study aimed to assess the available evidence on the survival of distal cholangiocarcinoma (DCC) patients following resection with curative intent and analyze the prognostic factors.

METHODS

Relevant studies published between January 2000 and January 2015 were identified by searching PubMed and Embase and reviewed systematically. Summary relative risks (RR) and 95% confidence intervals (95% CI) were estimated using random-effects models.

RESULTS

A total of 39 observational studies involving 3258 patients were included in the review. R0 resection was achieved in 84% (range, 46-100%) of patients. The median 5-year overall survival rate after resection was 37% (range, 13-54%), with corresponding rate of 44% (range, 27-63%) in R0 resection. The meta-analysis for 25 studies showed that R1 resection (RR 2.36, 95% CI 1.89-2.93), lymph node metastasis (RR 2.35, 95% CI 1.89-2.93), perineural invasion (RR 1.96, 95% CI 1.64-2.34), lymphatic invasion (RR 1.84, 95% CI 1.47-2.31), vascular invasion (RR 1.99, 95% CI 1.40-2.82), pancreatic invasion (RR 2.13, 95% CI 1.39-3.27), and pathological tumor stage ≥ T3 (RR 1.56, 95% CI 1.25-1.93) were associated with shorter survival.

CONCLUSION

In general, prognosis of DCC after resection is poor. R0 resection results in a substantially improved survival and represents one of the most important prognostic variables.

A patient-derived subrenal capsule xenograft model can predict response to adjuvant therapy for cancers in the head of the pancreas

BACKGROUND

Although gemcitabine is commonly used as adjuvant therapy for pancreatic adenocarcinoma and pancreaticobiliary-type periampullary cancers, not all patients appear to benefit. This translational study evaluates the potential of a patient-derived subrenal capsule pancreatic cancer xenograft (SRCPCX) model to identify within eight weeks after surgery those tumours which will respond to gemcitabine.

METHODS

SRCPCXs from 32 pancreatectomy patients were established in six to ten NOD/SCID mice per patient. After four weeks the mice were randomly assigned to receive gemcitabine or saline for four more weeks. After eight weeks, gemcitabine response in the grafts was evaluated by the percentage of tumour growth inhibition (%TGI), histological morphology and immunohistochemical markers (Ki-67, CK7 and cleaved caspase-3). These were collated into an Overall Response. Survival was assessed by Kaplan-Meier and Cox multivariate analyses.

RESULTS

375 of 450 pieces of tissue from 27 of 31 patients were evaluable. In 90% of patients, histopathological and immunostaining features of saline-treated control grafts were concordant with their original tumours. At follow up, six of 15 patients whose tumours had an Overall Response to gemcitabine died, compared with ten of 12 whose tumours did not respond (P = 0.025, Fisher's exact test). This was associated with improved survival on Kaplan-Meier analysis (P = 0.013). Cox multivariate analysis indicated that Overall Response, stage and grade were independent predictors of survival.

CONCLUSION

This SRCPCX model retains major histopathological and immunohistochemical characteristics of the original tumour and when a combination of measures is used, enables early assessment of tumour sensitivity to gemcitabine in pancreatic cancers.

Selection of pancreatic cancer cell-binding landscape phages and their use in development of anticancer nanomedicines

It is hypothesized that the use of targeted drug delivery systems can significantly improve the therapeutic index of small molecule chemotherapies by enhancing accumulation of the drugs at the site of disease. Phage display offers a high-throughput approach for selection of the targeting ligands. We have successfully isolated phage fusion proteins selective and specific for PANC-1 pancreatic cancer cells. Doxorubicin liposomes (Lipodox) modified with tumor-specific phage fusion proteins enhanced doxorubicin uptake specifically in PANC-1 cells as compared with unmodified Lipodox and also compared with normal breast epithelial cells. Phage protein-targeted Lipodox substantially increased the concentration of doxorubicin in the nuclei of PANC-1 cells in spite of P-glycoprotein-mediated drug efflux. The in vitro cytotoxic activity obtained with pancreatic cell-targeted Lipodox was greater than that of unmodified Lipodox. We present a novel and straightforward method for preparing pancreatic tumor-targeted nanomedicines by anchoring pancreatic cancer-specific phage proteins within the liposome bilayer.

Enhancement of Gemcitabine sensitivity in pancreatic adenocarcinoma by novel exosome-mediated delivery of the Survivin-T34A mutant

Background

Current therapeutic options for advanced pancreatic cancer have been largely disappointing with modest results at best, and though adjuvant therapy remains controversial, most remain in agreement that Gemcitabine should stand as part of any combination study. The inhibitor of apoptosis (IAP) protein Survivin is a key factor in maintaining apoptosis resistance, and its dominant-negative mutant (Survivin-T34A) has been shown to block Survivin, inducing caspase activation and apoptosis.

Methods

In this study, exosomes, collected from a melanoma cell line built to harbor a tetracycline-regulated Survivin-T34A, were plated on the pancreatic adenocarcinoma (MIA PaCa-2) cell line. Evaluation of the presence of Survivin-T34A in these exosomes followed by their ability to induce Gemcitabine-potentiative cell killing was the objective of this work.

Results

Here we show that exosomes collected in the absence of tetracycline (tet-off) from the engineered melanoma cell do contain Survivin-T34A and when used alone or in combination with Gemcitabine, induced a significant increase in apoptotic cell death when compared to Gemcitabine alone on a variety of pancreatic cancer cell lines.

Conclusion

This exosomes/Survivin-T34A study shows that a new delivery method for anticancer proteins within the cancer microenvironment may prove useful in targeting cancers of the pancreas.

Octreotide prophylaxis is not beneficial for biochemical activity and clinical severity of postoperative pancreatic fistula after pancreatic surgery

BACKGROUND

Prospective randomized trials indicate that prophylactic octreotide treatment does not decrease the incidence of postoperative pancreatic fistula (POPF). The aim of this study was to analyze if octreotide prophylaxis could decrease the severity grade of POPFs after pancreatic surgery.

METHOD

Seventy-eight of 684 patients undergoing pancreatic resection with POPF were included in the study. Prophylactic octreotide treatment was started immediately after surgery and was performed in 22 patients, whereas 56 patients had no octreotide treatment and served as controls. Lipase activity was measured in the abdominal drainage on postoperative days (POD) 3, 5 and 7. Primary endpoints of the study were clinical severity of the POPF and lipase activity in the drainage.

RESULTS

There was no significant difference concerning length of postoperative hospital stay. Lipase activity in the abdominal drainage was not influenced by octreotide prophylaxis at POD 5 or 7 compared to POD 3. Multivariate analysis showed that the risk to develop a type B or C fistula in the octreotide group was independent of the kind of operation and the consistency of the pancreas (RR = 3.4; CI = 1.0-11.7; p = 0.050 and RR = 6.3; CI = 1.4-29.6; p = 0.019).

CONCLUSION

Octreotide prophylaxis after pancreatic surgery has no beneficial effect on clinical severity of POPF.

Laparoscopic pancreatectomy for malignancy

Utilization of laparoscopic techniques for resection of the pancreas has slowly gained acceptance in specific situations and is now being applied to more challenging endeavors, such as pancreaticoduodenectomy for cancer. This review provides a summary of laparoscopic applications for pancreatic malignancy, with specific attention to the most common methods of pancreatic resection and their respective oncologic outcomes, including margin status, lymph node retrieval, and survival.

Attenuation of phosphorylation by deoxycytidine kinase is key to acquired gemcitabine resistance in a pancreatic cancer cell line: targeted proteomic and metabolomic analyses in PK9 cells

PURPOSE

Multiple proteins are involved in activation and inactivation of 2',2'-difluorodeoxycytidine (gemcitabine, dFdC). We aimed to clarify the mechanism of dFdC resistance in a pancreatic cancer cell line by applying a combination of targeted proteomic and metabolomic analyses.

METHODS

Twenty-five enzyme and transporter proteins and 6 metabolites were quantified in sensitive and resistant pancreatic cancer cell lines, PK9 and RPK9, respectively.

RESULTS

The protein concentration of deoxycytidine kinase (dCK) in RPK9 cells was less than 0.02-fold (2 %) compared with that in PK9 cells, whereas the differences (fold) were within a factor of 3 for other proteins. Targeted metabolomic analysis revealed that phosphorylated forms of dFdC were reduced to less than 0.2 % in RPK9 cells. The extracellular concentration of 2',2'-difluorodeoxyuridine (dFdU), an inactive metabolite of dFdC, reached the same level as the initial dFdC concentration in RPK9 cells. However, tetrahydrouridine treatment did not increase phosphorylated forms of dFdC and did not reverse dFdC resistance in RPK9 cells, though this treatment inhibits production of dFdU.

CONCLUSIONS

Combining targeted proteomics and metabolomics suggests that acquisition of resistance in RPK9 cells is due to attenuation of dFdC phosphorylation via suppression of dCK.

Impact of dihydropyrimidine dehydrogenase and γ-glutamyl hydrolase on the outcomes of patients treated with gemcitabine or S-1 as adjuvant chemotherapy for advanced pancreatic cancer

Gene expression analyses may play useful roles in determining the prognosis of cancer patients and in selecting antitumor drugs. This retrospective study examined potential prognostic factors in patients with pancreatic cancer who received adjuvant chemotherapy after surgery. The study group consisted of 79 patients who had received gemcitabine or S-1 as adjuvant chemotherapy for advanced pancreatic cancer. Using laser-captured microdissection and real-time RT-PCR assay, we quantitatively evaluated the mRNA levels of 10 genes associated with patient prognosis and sensitivity to chemotherapy using paraffin-embedded specimens of the primary tumors resected before the start of adjuvant chemotherapy. In univariate analyses, a low gene expression level of γ-glutamyl hydrolase (GGH) and a high gene expression level of folylpolyglutamate synthase correlated with a favorable outcome. In a multivariate analysis, a low gene expression level of dihydropyrimidine dehydrogenase (DPD) and GGH significantly correlated with outcome (hazard ratio of the high DPD group to the low DPD group: 5.55; 95% confidence interval (CI) 1.27-24.05; P=0.022; the high GGH group to the low GGH group: 3.77; 95% CI 1.04-13.79, P=0.043). For adjuvant chemotherapy of patients with pancreatic cancer, the mRNA level of DPD and GGH may affect the prognosis of these patients.

Severe cholestatic liver failure associated with gemcitabine adjuvant monotherapy for pancreatic cancer

We report a case of severe hepatic failure caused by gemcitabine hydrochloride (GEM) monotherapy after pancreaticoduodenectomy for advanced pancreatic cancer. A 73-year-old woman received GEM as an adjuvant chemotherapy. She suffered from progressive edema, fatigue, and jaundice after the third GEM administration. Severe liver dysfunction and elevation of bilirubin was observed. A computed tomography scan and magnetic resonance imaging showed diffuse liver swelling suggesting severe hepatic edema with fat accumulation. Needle biopsy of the liver revealed remarkable cholestasis and fat deposition with mild damage of hepatocytes. Drug-induced liver failure was suspected. GEM-stimulated lymphocyte test was negative, but antinuclear antibody was elevated with a marked inflammatory response. She improved to an almost normal condition by steroid and liver protective therapies within a week. Although the frequency of liver failure induced by GEM monotherapy is very rare, it could be fatal. It is important to distinguish it from other causes of liver dysfunction following pancreaticoduodenectomy. Early detection and appropriate drug therapy can improve the prognosis.

Prognostic implications of intraoperative radiotherapy for unresectable pancreatic cancer

BACKGROUND/AIMS

To assess the prognostic effect of intraoperative radiotherapy (IORT) in unresectable pancreatic cancer.

METHODS

We reviewed 198 patients with unresectable pancreatic cancer, which was found during experimental laparotomy. Liver metastasis was observed in 70 patients, peritoneal metastasis in 44, liver and peritoneal metastasis in 23 and locally advanced tumor in 61. Treatment consisted of IORT with or without postoperative chemotherapy. Overall survival (OS) and prognostic factors were evaluated for each pattern of disease spread.

RESULTS

IORT was performed in 120 patients, and chemotherapy was administered in 80. Sixty patients did not receive either treatment. OS in the untreated group was significantly inferior to that for IORT alone and IORT plus gemcitabine (GEM)-based chemotherapy. IORT and GEM-based chemotherapy were identified as independent prognostic factors [hazard ratio (HR) = 0.51, p < 0.001; HR = 0.43, p < 0.001]. IORT was an independent prognostic determinant for patients with peritoneal metastasis (HR = 0.24, p = 0.011) but not for those with liver metastasis (HR = 0.78, p = 0.381).

CONCLUSION

IORT followed by GEM-based chemotherapy is the recommended treatment strategy in unresectable pancreatic cancer. and IAP.

Long-term follow-up of patients with resected pancreatic cancer following vaccination against mutant K-ras

K-ras mutations are frequently found in adenocarcinomas of the pancreas and can elicit mutation-specific immune responses. Targeting the immune system against mutant Ras may thus influence the clinical course of the disease. Twenty-three patients who were vaccinated after surgical resection for pancreatic adenocarcinoma (22 pancreaticoduodenectomies, one distal resection), in two previous Phase I/II clinical trials, were followed for more than 10 years with respect to long-term immunological T-cell reactivity and survival. The vaccine was composed of long synthetic mutant ras peptides designed mainly to elicit T-helper responses. Seventeen of 20 evaluable patients (85%) responded immunologically to the vaccine. Median survival for all patients was 27.5 months and 28 months for immune responders. The 5-year survival was 22% and 29%, respectively. Strikingly, 10-year survival was 20% (four patients out of 20 evaluable) versus zero (0/87) in a cohort of nonvaccinated patient treated in the same period. Three patients mounted a memory response up to 9 years after vaccination. The present observation of long-term immune response together with 10-year survival following surgical resection indicates that K-ras vaccination may consolidate the effect of surgery and represent an adjuvant treatment option for the future.

Failure to adhere to protocol specified radiation therapy guidelines was associated with decreased survival in RTOG 9704--a phase III trial of adjuvant chemotherapy and chemoradiotherapy for patients with resected adenocarcinoma of the pancreas

PURPOSE

In Radiation Therapy Oncology Group 9704, as previously published, patients with resected pancreatic adenocarcinoma received continuous infusion 5-FU and concurrent radiotherapy (5FU-RT). 5FU-RT treatment was preceded and followed by randomly assigned chemotherapy, either 5-FU or gemcitabine. This analysis explored whether failure to adhere to specified RT guidelines influenced survival and/or toxicity.

METHODS AND MATERIALS

RT requirements were protocol specified. Adherence was scored as per protocol (PP) or less than per protocol (<PP). Scoring occurred after therapy but before trial analysis and without knowledge of individual patient treatment outcomes. Scoring was done for all tumor locations and for the subset of pancreatic head location.

RESULTS

RT was scored for 416 patients: 216 PP and 200 <PP. For all pancreatic sites (head, body/tail) median survival (MS) for PP vs. <PP was 1.74 vs. 1.46 years (log-rank p = 0.0077). In multivariate analysis, PP vs. <PP score correlated more strongly with MS than assigned treatment arm (p = 0.014, p = NS, respectively); for patients with pancreatic head tumors, both PP score and gemcitabine treatment correlated with improved MS (p = 0.016, p = 0.043, respectively). For all tumor locations, PP score was associated with decreased risk of failure (p = 0.016) and, for gemcitabine patients, a trend toward reduced Grade 4/5 nonhematologic toxicity (p = 0.065).

CONCLUSIONS

This is the first Phase III, multicenter, adjuvant protocol for pancreatic adenocarcinoma to evaluate the impact of adherence to specified RT protocol guidelines on protocol outcomes. Failure to adhere to specified RT guidelines was associated with reduced survival and, for patients receiving gemcitabine, trend toward increased nonhematologic toxicity.

cis-Hydroxyproline-mediated pancreatic carcinoma growth inhibition in mice

PURPOSE

This study addressed the question of whether the collagen metabolism modulator cis-4-Hydroxy-L-proline (CHP) is applicable for potential use as a therapeutic inhibitor of pancreatic carcinoma cell growth.

METHODS

Cell proliferation, as well as quantification of apoptosis of murine Panc02 cells, was assessed after CHP treatment. Supplementary, the effect of CHP on tumor growth was examined in the subcutaneous Panc02 model in vivo. Mice received daily intraperitoneal injections of CHP (300, 400, and 500 mg/kg bw). In addition to the assessment of systemic parameters (blood count, enzyme activities), histology (HE) and immunohistochemistry (Ki-67) were performed from resected tumor specimens.

RESULTS

Like reduction of metabolic activity, CHP also induced inhibition of cell growth in a dose-dependent manner, with however only slight increases in apoptosis. In vivo treatment of Panc02 tumors with CHP resulted in pronounced delay of tumor growth and decreases in tumor cell proliferation. Moreover, these effects were accompanied by a massive systemic leukocytosis as well increased leukocyte infiltration into the tumors subsequent to CHP therapy.

CONCLUSIONS

CHP inhibits the proliferation of Panc02 tumor cells in a dose-dependent manner both in vitro and in vivo. Our presented data show that modulation of the collagen metabolism is an interesting strategy for treatment of pancreatic carcinoma.

Translational advances and novel therapies for pancreatic ductal adenocarcinoma: hope or hype?

Biological complexity, inaccessible anatomical location, nonspecific symptoms, lack of a screening biomarker, advanced disease at presentation and drug resistance epitomise pancreatic ductal adenocarcinoma (PDA) as a poor-prognosis, lethal disease. Twenty-five years of research (basic, translational and clinical) have barely made strides to improve survival, mainly because of a fundamental lack of knowledge of the biological processes initiating and propagating PDA. However, isolation of pancreas cancer stem cells or progenitors, whole-genome sequencing for driver mutations, advances in functional imaging, mechanistic dissection of the desmoplastic reaction and novel targeted therapies are likely to shed light on how best to treat PDA. Here we summarise current knowledge and areas where the field is advancing, and give our opinion on the research direction the field should be focusing on to better deliver promising therapies for our patients.

Resected pancreatic adenosquamous carcinoma: clinicopathologic review and evaluation of adjuvant chemotherapy and radiation in 38 patients

Pancreatic adenosquamous carcinoma is a rare morphological variant of pancreatic adenocarcinoma with an especially poor prognosis. The purpose of this study is to identify clinicopathologic features associated with prognosis, assess whether the percentage of squamous differentiation in pancreatic adenosquamous carcinoma is associated with an inferior prognosis, and examine the impact of adjuvant chemoradiation therapy on overall survival. Forty-five (1.2%) of 3651 patients who underwent pancreatic resection at the Johns Hopkins Hospital, Baltimore, MD, between 1986 and 2007 were identified with adenocarcinoma of the pancreas with any squamous differentiation. All pathologic specimens were re-reviewed. Statistical analyses were performed on the 38 patients amenable to adjuvant chemoradiation therapy for whom clinical outcome data could be obtained. Median age was 68 years (61% male). Sixty-one percent underwent pancreaticoduodenectomy. Median tumor size was 5.0 cm. Seventy-six percent of carcinomas were node positive, 37% were margin-positive resections, and 68% had 30% or more squamous differentiation. Median overall survival of the pancreatic adenosquamous carcinoma cohort was 10.9 months (range, 2.1-140.6 months; 95% confidence interval, 8.2-12.5 months). Adjuvant chemoradiation therapy was associated with superior overall survival in patients with pancreatic adenosquamous carcinoma (P = .005). Adjuvant chemoradiation therapy was associated with improved survival in patients with tumors 3 cm or larger and vascular or perineural invasion (P = .02, .03, .02, respectively). The proportion of squamous differentiation was not associated with median overall survival (< 30% versus > or = 30%, P = .82). Survival after pancreatic resection of pancreatic adenosquamous carcinoma is poor. Treatment with adjuvant chemoradiation therapy is associated with improved survival. The proportion of squamous differentiation in resected pancreatic adenosquamous carcinoma specimens does not appear to impact overall survival.

Enhanced antitumor effect of combined gemcitabine and proton radiation in the treatment of pancreatic cancer

OBJECTIVES

This study evaluates the efficacy of combining proton irradiation with gemcitabine, and the role the inhibitor of apoptosis proteins survivin and X-linked inhibitor of apoptosis protein (XIAP) play in the radiosensitive versus radioresistant status of pancreatic cancer.

METHODS

The radioresistant (PANC-1) and radiosensitive (MIA PaCa-2) pancreatic carcinoma cells' response to combined gemcitabine and proton irradiation was compared. Cells were treated with 0.1 to 500 microM gemcitabine and 0- to 15-Gy proton irradiation after which trypan blue and flow cytometry were used to determine changes in the cell cycle and apoptosis. Expression levels of survivin and XIAP were measured using Western blotting. Combination therapy with gemcitabine for 24 hours followed by 10-Gy proton irradiation proved most effective.

RESULTS

Gemcitabine and proton irradiation resulted in increased survivin levels with little apoptosis. However, combination therapy resulted in robust apoptotic induction with a concomitant survivin and XIAP reduction in the MIA PaCa-2 cells with little effect in the PANC-1 cells. Small interfering RNA studies confirmed a role for XIAP in the radioresistance of PANC-1 cells.

CONCLUSIONS

Our data demonstrate that combining gemcitabine and proton irradiation enhances apoptosis in human pancreatic cancer cells when XIAP levels decrease. Therefore, XIAP may play an important role in human pancreatic cancer proton radioresistance.

Adjuvant chemoradiotherapy after pancreatic resection for invasive carcinoma associated with intraductal papillary mucinous neoplasm of the pancreas

PURPOSE

Intraductal papillary mucinous neoplasms are mucin-producing cystic neoplasms of the pancreas. One-third are associated with invasive carcinoma. We examined the benefit of adjuvant chemoradiotherapy (CRT) for this cohort.

METHODS AND MATERIALS

Patients who had undergone pancreatic resection at Johns Hopkins Hospital between 1999 and 2004 were reviewed. Of these patients, 83 with a resected pancreatic mass were found to have an intraductal papillary mucinous neoplasm with invasive carcinoma, 70 of whom met inclusion criteria for the present analysis.

RESULTS

The median age at surgery was 68 years. The median tumor size was 3.3 cm, and invasive carcinoma was present at the margin in 16% of the patients. Of the 70 patients, 50% had metastases to the lymph nodes and 64% had Stage II disease. The median survival was 28.0 months, and 2- and 5-year survival rate was 57% and 45%, respectively. Of the 70 patients, 40 had undergone adjuvant CRT. Those receiving CRT were more likely to have lymph node metastases, perineural invasion, and Stage II-III disease. The 2-year survival rate after surgery with vs. without CRT was 55.8% vs. 59.3%, respectively (p = NS). Patients with lymph node metastases or positive surgical margins benefited significantly from CRT (p = .047 and p = .042, respectively). On multivariate analysis, adjuvant CRT was associated with improved survival, with a relative risk of 0.43 (95% confidence interval, 0.19-0.95; p = .044) after adjusting for major confounders.

CONCLUSION

Adjuvant CRT conferred a 57% decrease in the relative risk of mortality after pancreaticoduodenectomy for intraductal papillary mucinous neoplasms with an associated invasive component after adjusting for major confounders. Patients with lymph node metastases or positive margins appeared to particularly benefit from CRT after definitive surgery.

Pancreatic cancer: current and future treatment strategies

Pancreatic cancer is a disease with a high mortality rate and short survival, as a result of the high incidence of metastatic disease at diagnosis, the fulminant clinical course and the lack of successful therapeutic strategies. The administration of chemotherapeutic agents for the treatment of advanced disease has failed and currently, research focuses on the understanding of molecular pathways in order to investigate the role of targeted therapy. Trials on adjuvant and neo-adjuvant therapy of pancreatic cancer are also ongoing. This review presents the recent developments with newer chemotherapeutic and molecular-targeted agents, identifying the efforts for individualized treatment strategies.

[Pylorus-preserving pancreatic head resection: a new standard for tumors]

Traverso-Longmire pylorus-preserving pancreatic head resection is regarded as the standard surgical procedure for pancreatic head tumors. The mortality, morbidity, and oncological radicality are as low as with the classic Kausch-Whipple resection, with the additional advantage of shorter operating time and reduced blood loss. Important for long-term survival is, however, not the resection of the stomach but the early diagnosis with subsequent R0 tumor resection. Patients can benefit fundamentally from this procedure if it is carried out at a specialized center.

Adjuvant intra-arterial chemotherapy and radiotherapy versus surgery alone in resectable pancreatic and periampullary cancer: a prospective randomized controlled trial

BACKGROUND

Success of surgical treatment for pancreatic and periampullary cancer is often limited due to locoregional recurrence and/or the development of distant metastases.

OBJECTIVE

The survival benefit of celiac axis infusion (CAI) and radiotherapy (RT) versus observation after resection of pancreatic or periampullary cancer was investigated.

METHODS

In a randomized controlled trial, 120 consecutive patients with histopathologically proven pancreatic or periampullary cancer received either adjuvant treatment consisting of intra-arterial mitoxantrone, 5-FU, leucovorin, and cisplatinum in combination with 30 x 1.8 Gy radiotherapy (group A) or no adjuvant treatment (group B). Groups were stratified for tumor type (pancreatic vs. periampullary tumors).

RESULTS

After surgery, 120 patients were randomized (59 patients in the treatment group, 61 in the observation group). The median follow-up was 17 months. No significant overall survival benefit was seen (median, 19 vs. 18 months resp.). Progressive disease was seen in 86 patients: in 37 patients in the CAI/RT group, and in 49 patients in the observation group (log-rank P < 0.02). Subgroup analysis showed significantly less liver metastases after adjuvant treatment in periampullary tumors (log-rank P < 0.03) without effect on local recurrence. Nonetheless, there was no significant effect on overall survival in these patients (log-rank P = 0.15). In patients with pancreatic cancer, CAI/RT had no significant effect on local recurrence (log-rank P = 0.12) neither on the development of liver metastases (log-rank P = 0.76) and consequently, no effect on overall survival.

CONCLUSION

This adjuvant treatment schedule results in a prolonged time to progression. For periampullary tumors, CAI/RT induced a significant reduction in the development of liver metastases, with a possible effect on overall survival. Especially in these tumors, CAI/RT might prove beneficial in larger groups and further research is warranted.