FOLFIRINOX versus gemcitabine for metastatic pancreatic cancer

Uridine diphosphate glucuronosyl transferase 1 family polypeptide A1 gene (UGT1A1) polymorphisms are associated with toxicity and efficacy in irinotecan monotherapy for refractory pancreatic cancer

PURPOSE

The aim of this study was to evaluate the efficacy and safety of irinotecan monotherapy in patients with advanced pancreatic cancer (APC).

METHODS

Patients with APC refractory to gemcitabine and S-1 were included. Irinotecan (100 mg/m(2)) was administered on days 1, 8, and 15 every 4 weeks until disease progression or unacceptable toxicity was observed. The relationship between uridine diphosphate glucuronosyl transferase 1 family polypeptide A1 gene (UGT1A1) polymorphisms and clinical outcomes was evaluated.

RESULTS

Between January 2007 and December 2011, 231 cycles were delivered in 56 patients. Irinotecan was administered as second-line chemotherapy in 35.7% of patients and as third-line chemotherapy or later in 64.3%. A partial response was achieved in two (3.6%) and stable disease in 23 patients (41.0%), giving a disease control rate of 44.6%. The median time to progression (TTP) and overall survival (OS) were 2.9 (95% confidence interval [CI] 1.8-3.5) months and 5.3 (95% CI 4.5-6.8) months, respectively. Median survival from the first-line chemotherapy was 19.5 (95% CI 15.3-23.8) months. Major grade 3/4 adverse events included neutropenia (28.6%), anemia (12.5%), and anorexia (10.7%). Patients with *6 and/or *28 allele(s) (n = 15) were associated with grade 3/4 neutropenia and anorexia but showed longer TTP (5.3 vs. 1.8 months; p = 0.05), and OS (8.0 vs. 4.8 months; p = 0.09) than those without *6 and/or *28 (n = 29).

CONCLUSIONS

Salvage chemotherapy with irinotecan was moderately effective and well-tolerated in patients with APC refractory to gemcitabine and S-1. UGT1A1 polymorphisms were associated with toxicity and efficacy.

5-Fluorouracil/leucovorin combined with irinotecan and oxaliplatin (FOLFIRINOX) as second-line chemotherapy in patients with advanced pancreatic cancer who have progressed on gemcitabine-based therapy

BACKGROUND/AIMS

There is no standard consensus on a strategy in the second-line setting for gemcitabine-refractory advanced pancreatic cancer. This study evaluated the activity and tolerability of oxaliplatin, irinotecan, 5-fluorouracil and leucovorin (FOLFIRINOX) as a second-line therapy in advanced pancreatic adenocarcinoma pretreated with a gemcitabine-based regimen.

METHODS

A retrospective survey was carried out on 18 patients with advanced pancreatic cancer who had been on gemcitabine-based chemotherapy and were then treated with FOLFIRINOX as a second-line therapy.

RESULTS

One patient (5.6%) had a confirmed complete response, 4 (22.2%) had confirmed partial responses and 5 (27.8%) had stable disease, resulting in a rate of disease control of 55.6% (95% CI, 33.3-77.8%). The median progression-free survival and median survival were 2.8 months and 8.4 months, respectively. Seven patients (38.9%) experienced grade 3-4 neutropenia. Grade 3 or 4 nonhematologic adverse events included nausea (38.9%) and vomiting (16.7%).

CONCLUSIONS

These results suggest the modest clinical activity regarding efficacy and the acceptable toxicity profile with the FOLFIRINOX regimen as a second-line treatment.

Toward the goal of personalized therapy in pancreatic cancer by targeting the molecular phenotype

The purpose of this article is to provide a critical review of the molecular alterations in pancreatic cancer that are clinically investigated as therapeutic targets and their potential impact on clinical outcomes. Adenocarcinoma of exocrine pancreas is generally associated with poor prognosis and the conventional therapies are marginally effective. Advances in understanding the genetic regulation of normal and neoplastic development of pancreas have led to development and clinical evaluation of new therapeutic strategies that target the signaling pathways and molecular alterations in pancreatic cancer. Applications have begun to utilize the genetic targets as biomarkers for prediction of therapeutic responses and selection of treatment options. The goal of accomplishing personalized tumor-specific therapy with tolerable side effects for patients with pancreatic cancer is hopefully within reach in the foreseeable future.

LCL124, a cationic analog of ceramide, selectively induces pancreatic cancer cell death by accumulating in mitochondria

Treatment of pancreatic cancer that cannot be surgically resected currently relies on minimally beneficial cytotoxic chemotherapy with gemcitabine. As the fourth leading cause of cancer-related death in the United States with dismal survival statistics, pancreatic cancer demands new and more effective treatment approaches. Resistance to gemcitabine is nearly universal and appears to involve defects in the intrinsic/mitochondrial apoptotic pathway. The bioactive sphingolipid ceramide is a critical mediator of apoptosis initiated by a number of therapeutic modalities. It is noteworthy that insufficient ceramide accumulation has been linked to gemcitabine resistance in multiple cancer types, including pancreatic cancer. Taking advantage of the fact that cancer cells frequently have more negatively charged mitochondria, we investigated a means to circumvent resistance to gemcitabine by targeting delivery of a cationic ceramide (l-t-C6-CCPS [LCL124: ((2S,3S,4E)-2-N-[6'-(1″-pyridinium)-hexanoyl-sphingosine bromide)]) to cancer cell mitochondria. LCL124 was effective in initiating apoptosis by causing mitochondrial depolarization in pancreatic cancer cells but demonstrated significantly less activity against nonmalignant pancreatic ductal epithelial cells. Furthermore, we demonstrate that the mitochondrial membrane potentials of the cancer cells were more negative than nonmalignant cells and that dissipation of this potential abrogated cell killing by LCL124, establishing that the effectiveness of this compound is potential-dependent. LCL124 selectively accumulated in and inhibited the growth of xenografts in vivo, confirming the tumor selectivity and therapeutic potential of cationic ceramides in pancreatic cancer. It is noteworthy that gemcitabine-resistant pancreatic cancer cells became more sensitive to subsequent treatment with LCL124, suggesting that this compound may be a uniquely suited to overcome gemcitabine resistance in pancreatic cancer.

Incidence, prognosis, and possible treatment strategies of peritoneal carcinomatosis of pancreatic origin: a population-based study

OBJECTIVES

Peritoneal carcinomatosis (PC) is an important cause of morbidity and mortality among patients with pancreatic cancer. In an era where therapeutic options for PC of multiple origins are emerging, our aim was to provide population-based data on incidence, treatment, and prognosis of PC of pancreatic origin.

METHODS

All patients with a condition diagnosed as nonendocrine pancreatic cancer between 1995 and 2009 in the area of the Eindhoven Cancer Registry were included.

RESULTS

In total, 2924 patients had a diagnosis of pancreatic cancer of which 265 patients (9%) presented with synchronous PC. An increasing trend could be noted in patients treated with chemotherapy in more recent years (11% in 1995-1999 and 22% in 2005-2009; P = 0.060). Median survival in patients presenting with PC was only 6 weeks (95% confidence interval, 5-7 weeks) and did not improve over time, contrasting improvements among patients with nonmetastasized disease (19-30 weeks) and patients with metastasized disease confined to the liver (8-12 weeks).

CONCLUSION

Prognosis of patients with pancreatic cancer presenting with PC remains extremely poor. Treatment options are scarce and, given the magnitude of the problem, efforts should be undertaken to develop effective treatments in experimental and clinical studies.

Molecular mechanisms underlying the antitumor activity of 3-aminopropanamide irreversible inhibitors of the epidermal growth factor receptor in non-small cell lung cancer

Overcoming the emergence of acquired resistance to clinically approved epidermal growth factor receptor (EGFR) inhibitors is a major challenge in the treatment of advanced non-small cell lung cancer (NSCLC). The aim of this study was to investigate the effects of a series of novel compounds affecting viability of NSCLC NCI-H1975 cells (carrying the EGFR T790M mutation). The inhibition of the autophosphorylation of EGFR occurred at nanomolar concentrations and both UPR1282 and UPR1268 caused a significant induction of apoptosis. Targeting of EGFR and downstream pathways was confirmed by a peptide substrate array, which highlighted the inhibition of other kinases involved in NSCLC cell aggressive behavior. Accordingly, the drugs inhibited migration (about 30% vs. control), which could be, in part, explained also by the increase of E-cadherin expression. Additionally, we observed a contraction of the volume of H1975 spheroids, associated with the reduction of the cancer stem-like cell hallmark CD133. The activity of UPR1282 was retained in H1975 xenograft models where it determined tumor shrinkage (P < .05) and resulted well tolerated compared to canertinib. Of note, the kinase activity profile of UPR1282 on xenograft tumor tissues showed overlapping results with respect to the activity in H1975 cells, unraveling the inhibition of kinases involved in pivotal proliferation and invasive signaling pathways. In conclusion, UPR1282 and UPR1268 are effective against various processes involved in malignancy transformation and progression and may be promising compounds for the future treatment of gefitinib-resistant NSCLCs.

Medikamentöse Therapie der Peritonealkarzinose

<b><i>Hintergrund:</i></b> Die Behandlung der Peritonealkarzinose ist eine interdisziplinäre medizinische Herausforderung. Betreffend der medikamentösen Therapie fehlt bislang eine Standardisierung. <b><i>Methode:</i></b> Relevante Artikel zum Thema Peritonealkarzinose aus den Datenbanken der U.S. National Library of Medicine (PubMed) sowie der Kongressregister der American Society of Clinical Oncology und der European Society of Medical Oncology wurden durchsucht. Die Bedeutung der Berichte für die klinische Praxis wurde zwischen den Autoren diskutiert und interdisziplinär abgestimmt. Es wurden praxisnahe Folgerungen und Empfehlungen abgeleitet. <b><i>Ergebnisse:</i></b> PubMed weist eine ansteigende Zahl an Publikationen zum Thema Peritonealkarzinose auf. In 2012 wurden 563 Arbeiten unter dem Stichwort abgelegt. Die medikamentöse Therapie der Peritonealkarzinose ist ein Teil der multimodalen Behandlung, zu der die lokalen chirurgischen und physikalischen Therapiemaßnahmen zählen. Die Auswahl der Chemotherapeutika richtet sich nach der entsprechenden malignen Grunderkrankung. Aktuelle zielgerichtete Ansätze wie die anti-angiogene Therapie und die gegen das epitheliale Zelladhäsionsmolekül (EpCAM) gerichtete Immuntherapie ergänzen neuerdings das Behandlungsspektrum bei Peritonealkarzinose und malignem Aszites. <b><i>Schlussfolgerungen:</i></b> Die medikamentöse Behandlung der Peritonealkarzinose bleibt eine medizinische Herausforderung. Die zunehmende Zahl an Publikationen und Studien auf dem Gebiet lässt aber mittlerweile mehr evidenzbasierte Entscheidungen zu. Die interdisziplinäre Abstimmung eines individuellen Behandlungskonzepts bleibt bis auf Weiteres der Goldstandard auch für die medikamentöse Therapie der Peritonealkarzinose.

Immunotherapy updates in pancreatic cancer: are we there yet?

Pancreatic cancer is a lethal disease and remains one of the most resistant cancers to traditional therapies. Historically, chemotherapy or radiotherapy did not provide meaningful survival benefit in advanced pancreatic cancer. Gemcitabine and recently FOLFIRINOX (5-flourouracil, leucovorin, oxaliplatin and irinotecan) have provided some limited survival advantage in advanced pancreatic cancer. Targeted agents in combination with gemcitabine had not shown significant improvement in the survival. Current therapies for pancreatic cancer have their limitations; thus, we are in dire need of newer treatment options. Immunotherapy in pancreatic cancer works by recruiting and activating T cells that recognize tumor-specific antigens which is a different mechanism compared with chemotherapy and radiotherapy. Preclinical models have shown that immunotherapy and targeted therapies like vascular endothelial growth factor and epidermal growth factor inhibitors work synergistically. Hence, new immunotherapy and targeted therapies represent a viable option for pancreatic cancer. In this article, we review the vaccine therapy for pancreatic cancer.

Safety and effectiveness of gemcitabine in 855 patients with pancreatic cancer under Japanese clinical practice based on post-marketing surveillance in Japan

OBJECTIVE

When gemcitabine was approved as an anti-cancer drug, there were limited data for Japanese patients treated with gemcitabine. Generally, advanced or metastatic pancreatic cancer patients experience poor prognosis and suffer from debilitating disease-related symptoms. Reports and information on gemcitabine use within a large patient pool will be beneficial to aid physicians. Therefore, this post-marketing surveillance was conducted as a non-interventional, observational study on the use of gemcitabine in a clinical practice setting in Japan.

METHODS

Patients had no previous treatment with gemcitabine and were diagnosed with pancreatic cancer by an attending physician. Patients were registered between May 2001 and December 2003 in Japan. The patients were treated with gemcitabine. Data such as patient background, treatment details, adverse events, tumor response, serum CA19-9 levels and drug-related symptom improvement were assessed.

RESULTS

Of the 890 patients registered for the study, 855 were included in the analysis of gemcitabine for safety. Four hundred and forty-three (51.9%) patients reported drug-related adverse events, with 97 patients (11.4%) experiencing serious adverse events. The incidence of interstitial lung disease was 0.7% (six patients). Six hundred patients were evaluated for tumor response. The overall response rate was 6.0% and the disease control rate was 54.0%. CA19-9 decreased in 63.6% of the 335 evaluable patients, with a ≥75% decrease seen in 19.4% of the total group. Drug-related symptom improvement was observed in 27.0% of the 686 evaluable patients.

CONCLUSIONS

This large-scale surveillance could confirm the safety of gemcitabine for Japanese pancreatic cancer patients as well as elucidate the efficacy profile, measured by drug-related symptom improvement, for Japanese pancreatic cancer patients.

A phase I study of sorafenib, oxaliplatin and 2 days of high dose capecitabine in advanced pancreatic and biliary tract cancer: a Wisconsin oncology network study

Chemotherapy has yielded minimal clinical benefit in pancreatic and biliary tract cancer. A high-dose, short course capecitabine schedule with oxaliplatin, has shown some efficacy with a lower incidence of palmar-plantar erythrodysesthesia. Achieving high exposures of the targeted agent sorafenib may be possible with this shorter schedule of capecitabine by avoiding dermatologic toxicity. All patients had pancreatic or biliary tract cancer. Patients in both cohorts received oxaliplatin 85 mg/m2 followed by capecitabine 2,250 mg/m2 PO every 8 h x 6 doses starting on days 1 and 15 of a 28 day cycle, or 2DOC (2 Day Oxaliplatin/Capecitabine). Cohort 1 used sorafenib 200 mg BID, and cohort 2 used sorafenib 400 mg BID. Sixteen patients were enrolled. Across all cycles the most common grade 1 or 2 adverse events were fatigue (10 pts), diarrhea (10 pts), nausea (9 pts), vomiting (8 pts), sensory neuropathy (8 pts), thrombocytopenia (7 pts), neutropenia (5 pts), and hand-foot syndrome (5 pts). Grade 3 toxicites included neutropenia, mucositis, fatigue, vomiting and diarrhea. Cohort 1 represented the MTD. Two partial responses were seen, one each in pancreatic and biliary tract cancers. The recommended phase II dose of sorafenib in combination with 2DOC is 200 mg BID. There were infrequent grade 3 toxicities, most evident with sorafenib at 400 mg BID.

Gemcitabine and cisplatin combined with regional hyperthermia as second-line treatment in patients with gemcitabine-refractory advanced pancreatic cancer

PURPOSE

There is no standard second-line therapy for patients with advanced pancreatic cancer (APC) after gemcitabine (G) failure. Cisplatin (Cis)-based chemotherapy has shown activity in APC. It is proven that cytotoxicity of G and Cis is enhanced by heat exposure at 40° to 42°C. Therefore G plus Cis with regional hyperthermia (RHT) might be beneficial for patients with G-refractory APC.

PATIENTS AND METHODS

We retrospectively analysed 23 patients with advanced (n = 2) or metastatic (n = 21) pancreatic cancer with relapse after G mono first-line chemotherapy (n = 23). Patients had received G (day 1, 1000 mg/m(2)) and Cis (day 2 and 4, 25 mg/m(2)) in combination with RHT (day 2 and 4, 1 h) biweekly for 4 months. We analysed feasibility, toxicity, time to second progression (TTP2), overall survival (OS) and clinical response.

RESULTS

Between October 1999 and August 2008 23 patients were treated. Haematological toxicity was low with no grade 4 event. Hyperthermia-associated toxicity consisted of discomfort because of bolus pressure (3%), power-related pain (7%) or position-related pain (17%). Median TTP1 was 5.9 months (95% confidence interval (CI): 2.6-9.2), median TTP2 was 4.3 months (95%CI: 1.2-7.4) and OS 12.9 months (95%CI: 9.9-15.9). The disease control rate in 16 patients with available CT scans was 50%.

CONCLUSION

We show first clinical data of G plus Cis with RHT being clinically active in G-pretreated APC with low toxicity. A prospective controlled phase II second-line clinical trial (EudraCT: 2005-003855-11) and a randomised phase III adjuvant clinical trial offering this treatment (HEAT; EudraCT: 2008-004802-14) are currently open for recruitment.

Re-resection for isolated local recurrence of pancreatic cancer is feasible, safe, and associated with encouraging survival

BACKGROUND

Local recurrence of pancreatic cancer occurs in 80% of patients within 2 years after potentially curative resections. Around 30% of patients have isolated local recurrence (ILR) without evidence of metastases. In spite of localized disease these patients usually only receive palliative chemotherapy and have a short survival.

PURPOSE

To evaluate the outcome of surgery as part of a multimodal treatment for ILR of pancreatic cancer.

METHODS

All consecutive operations performed for suspected ILR in our institution between October 2001 and October 2009 were identified from a prospective database. Perioperative outcome, survival, and prognostic parameters were assessed.

RESULTS

Of 97 patients with histologically proven recurrence, 57 (59%) had ILR. In 40 (41%) patients surgical exploration revealed metastases distant to the local recurrence. Resection was performed in 41 (72%) patients with ILR, while 16 (28%) ILR were locally unresectable. Morbidity and mortality were 25 and 1.8% after resections and 10 and 0% after explorations, respectively. Median postoperative survival was 16.4 months in ILR versus 9.4 months in metastatic disease (p < 0.0001). In ILR median survival was significantly longer after resection (26.0 months) compared with exploration without resection (10.8 months, p = 0.0104). R0 resection was achieved in 18 patients and resulted in 30.5 months median survival. Presence of metastases, incomplete resection, and high preoperative CA 19-9 serum values were associated with lesser survival.

CONCLUSIONS

Resection for isolated local recurrence of pancreatic cancer is feasible, safe, and associated with favorable survival outcome. This concept warrants further evaluation in other institutions and in randomized controlled trials.

Phase I trial of gemcitabine combined with capecitabine and erlotinib in advanced pancreatic cancer: a clinical and pharmacological study

BACKGROUND

The aim of this phase I trial was to define the maximum tolerated dose (MTD), the dose-limiting toxicity (DLT) and the recommended dose of erlotinib combined with capecitabine and gemcitabine in the treatment of advanced pancreatic cancer (APC).

METHODS

Gemcitabine was administered intravenously at 1,000 mg/m(2)/week (days 1, 8 and 15) and oral capecitabine from day 1 to day 21 at 1,660 mg/m(2)/day. Oral erlotinib was administered daily continuously at escalating doses (28-day cycle). Dose levels (DLs) 1, 2, 3 and 4 were 50, 75, 100 and 125 mg/day, respectively. Pharmacokinetic analysis of the three drugs was performed in the first cycle.

RESULTS

Nineteen patients were enrolled. At the MTD (DL4; 125 mg/day erlotinib), 100% of patients developed DLT consisting of grade 4 febrile neutropenia and nonhematological grade 3 events (vomiting, diarrhea, stomatitis, rash). The most common toxicities, regardless of grade, were neutropenia, anemia, rash and diarrhea. Erlotinib systemic exposure was significantly related to the administered dose. Of note, toxicity was significantly associated with elevated systemic exposure of capecitabine anabolites.

CONCLUSION

When combined concurrently with 1,000 mg/m(2)/week gemcitabine and 1,660 mg/m(2)/day capecitabine, erlotinib can be administered safely at a daily dose of 100 mg in APC patients.

Metastatic pancreatic cancer: are we making progress in treatment?

Development of systemic treatment for advanced pancreatic cancer (APC) has been challenging. After fluorouracil, gemcitabine (GEM) became the treatment of choice based on its benefit of symptom relief. Many cytotoxic agents have been combined with GEM in search of regimens with improved survival benefit. However, there were only marginal benefits in people with good performance status. Recently, the combination regimen consisting of oxaliplatin, irinotecan, fluorouracil, and leucovorin (FOLFIRINOX) was found to achieve unprecedented survival benefit and has become the preferred option for patients with good clinical conditions. On the other hand, many biological agents have been combined with GEM, but only erlotinib was found to derive statistically significant survival advantage. However, the effect was too small to be appreciated clinically. The effort in development of targeted therapy in APC continues. This paper summarized key findings in the development of chemotherapy and targeted therapy for APC patients and discussed future directions in management.

Impact of FOLFIRINOX compared with gemcitabine on quality of life in patients with metastatic pancreatic cancer: results from the PRODIGE 4/ACCORD 11 randomized trial

PURPOSE

To compare the quality of life (QoL) of patients receiving oxaliplatin, irinotecan, fluorouracil, and leucovorin (FOLFIRINOX) or gemcitabine as first-line chemotherapy and to assess whether pretreatment QoL predicts survival in patients with metastatic pancreatic cancer.

PATIENTS AND METHODS

Three hundred forty-two patients with performance status 0 or 1 were randomly assigned to receive FOLFIRINOX (oxaliplatin, 85 mg/m(2); irinotecan, 180 mg/m(2); leucovorin, 400 mg/m(2); and fluorouracil, 400 mg/m(2) bolus followed by 2,400 mg/m(2) 46-hour continuous infusion, once every 2 weeks) or gemcitabine 1,000 mg/m(2) weekly for 7 of 8 weeks and then weekly for 3 of 4 weeks. QoL was assessed using European Organisation for the Research and Treatment of Cancer Quality of Life Questionnaire C30 every 2 weeks.

RESULTS

Improvement in global health status (GHS; P < .001) was observed in the FOLFIRINOX arm and improvement in emotional functioning (P < .001) was observed in both arms, along with a decrease in pain, insomnia, anorexia, and constipation in both arms. A significant increase in diarrhea was observed in the FOLFIRINOX arm during the first 2 months of chemotherapy. Time until definitive deterioration ≥ 20 points was significantly longer for FOLFIRINOX compared with gemcitabine for GHS, physical, role, cognitive, and social functioning, and six symptom domains (fatigue, nausea/vomiting, pain, dyspnea, anorexia, and constipation). Physical functioning, constipation, and dyspnea were independent significant prognostic factors for survival with treatment arm, age older than 65 years, and low serum albumin.

CONCLUSION

FOLFIRINOX significantly reduces QoL impairment compared with gemcitabine in patients with metastatic pancreatic cancer. Furthermore, baseline QoL scores improved estimation of survival probability when added to baseline clinical and demographic variables.

Response of borderline resectable pancreatic cancer to neoadjuvant therapy is not reflected by radiographic indicators

BACKGROUND

Experience with preoperative therapy for other cancers has led to an assumption that borderline resectable pancreatic cancers can be converted to resectable cancers with preoperative therapy. In this study, the authors sought to determine the rate at which neoadjuvant therapy is associated with a reduction in the size or stage of borderline resectable tumors.

METHODS

Patients who had borderline resectable pancreatic cancer and received neoadjuvant therapy before potentially undergoing surgery at the authors' institution between 2005 and 2010 were identified. The patients' pretreatment and post-treatment pancreatic protocol computed tomography images were rereviewed to determine changes in tumor size or stage using modified Response Evaluation Criteria in Solid Tumors (RECIST) (version 1.1) and standardized anatomic criteria.

RESULTS

The authors identified 129 patients who met inclusion criteria. Of the 122 patients who had their disease restaged after receiving preoperative therapy, 84 patients (69%) had stable disease, 15 patients (12%) had a partial response to therapy, and 23 patients (19%) had progressive disease. Although only 1 patient (0.8%) had their disease downstaged to resectable status after receiving neoadjuvant therapy, 85 patients (66%) underwent pancreatectomy. The median overall survival duration for all 129 patients was 22 months (95% confidence interval, 14-30 months). The median overall survival duration for the patients who underwent pancreatectomy was 33 months (95% confidence interval, 25-41 months) and was not associated with RECIST response (P = .78).

CONCLUSIONS

Radiographic downstaging was rare after neoadjuvant therapy, and RECIST response was not an effective treatment endpoint for patients with borderline resectable pancreatic cancer. The authors concluded that these patients should undergo pancreatectomy after initial therapy in the absence of metastases.

Harnessing gemcitabine metabolism: a step towards personalized medicine for pancreatic cancer

Pancreatic cancer is a lethal malignancy with a 5-year survival rate of only 6%. Surgical resection remains the only cure, yet even after resection the 5-year survival is only 20% due to a high recurrence rate. Thus, a high proportion of patients with this disease will ultimately require systemic chemotherapy for advanced pancreatic cancer (APC). While the advent of personalized medicine has resulted in significant advances in the management of many cancer types, the standard of care for pancreatic cancer remains gemcitabine based, with very few exceptions. This article first aims to provide an overview of the benefits and limitations of gemcitabine alone, gemcitabine combinations, and different modes of administration of gemcitabine in APC. It then discusses research, suggesting that pharmacogenomic differences in enzymes that affect gemcitabine transport and metabolism can predict benefit from this drug in pancreatic cancer. Finally, the article outlines novel therapies and combinations that exploit these interindividual variations in gemcitabine metabolism to improve the efficacy of this drug in the management of APC.

The 'N-factors' in pancreatic cancer: functional relevance of NF-κB, NFAT and Nrf2 in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) represents one of the deadliest malignancies, with an overall life expectancy of 6 months. Despite considerable advances in the understanding of the molecular mechanisms involved in the carcinogenesis of PDAC, the outcome of the disease was not significantly improved over the last 20 years. Although some achievements in molecular-targeted therapies have been made (that is, targeting the epidermal growth factor receptor by erlotinib), which already entered clinical settings, and despite the promising outcome of the FOLFIRINOX trial, there is an urgent need for improvement of the chemotherapy in this disease. A plethora of molecular alterations are thought to be responsible for the profound chemoresistance, including mutations in oncogenes and tumor suppressors. Besides these classical hallmarks of cancer, the constitutive or inducible activity of transcription factor pathways are characteristic changes in PDAC. Recently, three transcription factors-nuclear factor-κB (NF-κB), nuclear factor of activated T cells (NFAT) and nuclear factor-E2-related factor-2 (Nrf2)-have been shown to be crucial for tumor development and chemoresistance in pancreatic cancer. These transcription factors are key regulators of a variety of genes involved in nearly all aspects of tumorigenesis and resistance against chemotherapeutics and death receptor ligands. Furthermore, the pathways of NF-κB, NFAT and Nrf2 are functional, interacting on several regulatory steps, and, especially, natural compounds such as curcumin interfere with more than one pathway. Thus, targeting these pathways by established inhibitors or new drugs might have great potential to improve the outcome of PDAC patients, most likely in combination with established anticancer drugs. In this article, we summarize recent progress in the characterization of these transcription-factor pathways and their role in PDAC and therapy resistance. We also discuss future concepts for the treatment of PDAC relying on these pathways.

Impact of targeted neoadjuvant therapies in the treatment of solid organ tumours

BACKGROUND

The advent of affordable technologies to perform detailed molecular profiling of tumours has transformed understanding of the specific genetic events that promote carcinogenesis and which may be exploited therapeutically. The application of targeted therapeutics has led to improved outcomes in advanced disease and this approach is beginning to become established in the management of potentially curable disease for surgical patients.

METHODS

This review article focuses on recent developments in the management of operable cancers of the gastrointestinal (GI) tract, specifically discussing the currently available data that evaluate the incorporation of targeted therapies in this setting.

RESULTS

A variety of targeted molecules are now available as treatment options in the management of GI cancers. Most are aimed at growth inhibition by acting on cell surface targets or intracellular pathways. Treatment paradigms are gradually shifting towards more prevalent use of systemic treatment prior to surgical intervention for operable disease with the aim of tumour downsizing and improved rates of long-term cure.

CONCLUSION

A large number of ongoing clinical trials are evaluating novel targeted agents as neoadjuvant therapy in operable GI tumours. Therefore, further progress in the management of early-stage disease will undoubtedly be made over the next few years as these trials continue to report potentially practice-changing results.

Gemcitabine-induced gouty arthritis attacks

In this case report, we review the experience of a patient who presented with early stage pancreatic cancer (Stage IIb) who underwent a Whipple procedure and adjuvant chemoradiation. The patient's past medical history included early stage colon cancer in remission, post-traumatic-stress-disorder, hypertension, hyperlipidemia, osteoarthritis, gout, and pre-diabetes. Chemotherapy initially consisted of weekly gemcitabine. The patient developed acute gouty attacks after his second dose of gemcitabine, which brought him to the emergency room for emergent treatment on several occasions. Gemcitabine was held and treatment began with fluorouracil and concurrent radiation. After completion of his chemoradiation with fluorouracil, he was again treated with weekly gemcitabine alone. As soon as the patient started gemcitabine chemotherapy the patient developed gouty arthritis again, requiring discontinuation of chemotherapy. The patient received no additional treatment until his recent recurrence 8 months later where gemcitabine chemotherapy was again introduced with prophylactic medications consisting of allopurinol 100 mg by mouth daily and colchicine 0.6 mg by mouth daily throughout gemcitabine chemotherapy, and no signs of gouty arthritis occurred. To our knowledge, this is the first case report describing gout attacks associated with gemcitabine therapy. There is limited data available describing the mechanism that gouty arthritis may be precipitated from gemcitabine chemotherapy. Further monitoring and management may be required in patients receiving gemcitabine chemotherapy with underlying gout.

Pan-Bcl-2 inhibitor AT-101 enhances tumor cell killing by EGFR targeted T cells

Pancreatic cancer is a deadly disease and has the worst prognosis among almost all cancers and is in dire need of new and improved therapeutic strategies. Conditioning of tumor cells with chemotherapeutic drug has been shown to enhance the anti-tumor effects of cancer vaccines and adoptive cell therapy. In this study, we investigated the immunomodulatory effects of pan-Bcl-2 inhibitor AT-101 on pancreatic cancer (PC) cell cytotoxicity by activated T cells (ATC). The effects of AT-101 on cytotoxicity, early apoptosis, and Granzyme B (GrzB) and IFN-γ signaling pathways were evaluated during EGFR bispecific antibody armed ATC (aATC)-mediated killing of L3.6pl and MiaPaCa-2 PC cells pre-sensitized with AT-101. We found that pretreatment of tumor cells with AT-101 enhanced susceptibility of L3.6pl and MiaPaCa-2 tumor cells to ATC and aATC-mediated cytotoxicity, which was in part mediated via enhanced release of cytolytic granule GrzB from ATC and aATC. AT-101-sensitized L3.6pl cells showed up-regulation of IFN-γ-mediated induction in the phosphorylation of Ser⁷²⁷-Stat1 (pS⁷²⁷-Stat1), and IFN-γ induced dephosphorylation of phospho-Tyr⁷⁰⁵-Stat3 (pY⁷⁰⁵-Stat3). Priming (conditioning) of PC cells with AT-101 can significantly enhance the anti-tumor activity of EGFRBi armed ATC through increased IFN-γ induced activation of pS⁷²⁷-Stat1 and inhibition of pY⁷⁰⁵-Stat3 phosphorylation, and resulting in increased ratio of pro-apoptotic to anti-apoptotic proteins. Our results verify enhanced cytotoxicity after a novel chemotherapy conditioning strategy against PC that warrants further in vivo and clinical investigations.

Understanding resistance to combination chemotherapy

The current clinical application of combination chemotherapy is guided by a historically successful set of practices that were developed by basic and clinical researchers 50-60 years ago. Thus, in order to understand how emerging approaches to drug development might aid the creation of new therapeutic combinations, it is critical to understand the defining principles underlying classic combination therapy and the original experimental rationales behind them. One such principle is that the use of combination therapies with independent mechanisms of action can minimize the evolution of drug resistance. Another is that in order to kill sufficient cancer cells to cure a patient, multiple drugs must be delivered at their maximum tolerated dose - a condition that allows for enhanced cancer cell killing with manageable toxicity. In light of these models, we aim to explore recent genomic evidence underlying the mechanisms of resistance to the combination regimens constructed on these principles. Interestingly, we find that emerging genomic evidence contradicts some of the rationales of early practitioners in developing commonly used drug regimens. However, we also find that the addition of recent targeted therapies has yet to change the current principles underlying the construction of anti-cancer combinatorial regimens, nor have they made substantial inroads into the treatment of most cancers. We suggest that emerging systems/network biology approaches have an immense opportunity to impact the rational development of successful drug regimens. Specifically, by examining drug combinations in multivariate ways, next generation combination therapies can be constructed with a clear understanding of how mechanisms of resistance to multi-drug regimens differ from single agent resistance.

Sensitization of pancreatic cancer stem cells to gemcitabine by Chk1 inhibition

Checkpoint kinase 1 (Chk1) inhibition sensitizes pancreatic cancer cells and tumors to gemcitabine. We hypothesized that Chk1 inhibition would sensitize pancreatic cancer stem cells to gemcitabine. We tested this hypothesis by using two patient-derived xenograft models (designated J and F) and the pancreatic cancer stem cell markers CD24, CD44, and ESA. We determined the percentage of marker-positive cells and their tumor-initiating capacity (by limiting dilution assays) after treatment with gemcitabine and the Chk1 inhibitor, AZD7762. We found that marker-positive cells were significantly reduced by the combination of gemcitabine and AZD7762. In addition, secondary tumor initiation was significantly delayed in response to primary tumor treatment with gemcitabine + AZD7762 compared with control, gemcitabine, or AZD7762 alone. Furthermore, for the same number of stem cells implanted from gemcitabine- versus gemcitabine + AZD7762-treated primary tumors, secondary tumor initiation at 10 weeks was 83% versus 43%, respectively. We also found that pS345 Chk1, which is a measure of DNA damage, was induced in marker-positive cells but not in the marker-negative cells. These data demonstrate that Chk1 inhibition in combination with gemcitabine reduces both the percentage and the tumor-initiating capacity of pancreatic cancer stem cells. Furthermore, the finding that the Chk1-mediated DNA damage response was greater in stem cells than in non-stem cells suggests that Chk1 inhibition may selectively sensitize pancreatic cancer stem cells to gemcitabine, thus making Chk1 a potential therapeutic target for improving pancreatic cancer therapy.

Which patients with advanced cancer and biliary obstruction benefit from biliary stenting most? An analysis of prognostic factors

BACKGROUND

Patients with advanced cancer may present with obstructive jaundice. Biliary stenting is the treatment of choice. However, which patients benefit most is not well-defined, yet. Our aim was to delineate the clinical factors affecting prognosis.

MATERIAL AND METHODS

Charts of 140 patients with advanced cancer who underwent biliary stenting were retrospectively analyzed. Their median age was 63.5 years. Of these patients, 73 (52.1 %) were male, 32 (22.9 %) had ECOG PS 1 and 81 (57.9 %) had PS 2. The most frequent cancer types were cholangiocellular cancer (64, 45.7 %) and pancreatic cancer (36, 25.7 %).

RESULTS

Median overall survival (OS) was 141 (95 % CI, 100.7-185.3) days. Female patients lived longer (161.0 vs. 124.0 days) (p = 0.036). Those patients with colorectal cancer lived the longest (667.0 days), followed by cholangiocellular (211.0 days), and gastric cancers (106.0 days) (p = 0.004). The distribution of primary diagnosis differed significantly between sexes: cholangiocellular cancer was present in 22 (30.1 %) out of 73 men and 42(62.7 %) out of 67 women (chi-square p < 0.001). There was a trend for longer overall survival if ALT (p = 0.08) and AST (p = 0.06) were normalized after stent insertion. Of the 137 patients, 63 (45.5 %) did not experience any complication. In 74 patients with complications, there were 39 (28.5 %) episodes of cholangitic infections and 35 (25.5 %) biliary obstructions. In three patients, we could not find data on infections.

CONCLUSION

Underlying malignancy, hence the natural biology and the therapeutic expectations are probably the most important factors which must be considered during decision-making.

A randomized, placebo-controlled phase 2 study of ganitumab (AMG 479) or conatumumab (AMG 655) in combination with gemcitabine in patients with metastatic pancreatic cancer

BACKGROUND

We evaluated the efficacy and safety of ganitumab (a mAb antagonist of insulin-like growth factor 1 receptor) or conatumumab (a mAb agonist of human death receptor 5) combined with gemcitabine in a randomized phase 2 trial in patients with metastatic pancreatic cancer.

PATIENTS AND METHODS

Patients with a previously untreated metastatic pancreatic adenocarcinoma and an Eastern Cooperative Oncology Group (ECOG) performance status ≤1 were randomized 1 : 1 : 1 to i.v. gemcitabine 1000 mg/m(2) (days 1, 8, and 15 of each 28-day cycle) combined with open-label ganitumab (12 mg/kg every 2 weeks [Q2W]), double-blind conatumumab (10 mg/kg Q2W), or double-blind placebo Q2W. The primary end point was 6-month survival rate. Results In total, 125 patients were randomized. The 6-month survival rates were 57% (95% CI 41-70) in the ganitumab arm, 59% (42-73) in the conatumumab arm, and 50% (33-64) in the placebo arm. The grade ≥3 adverse events in the ganitumab, conatumumab, and placebo arms, respectively, included neutropenia (18/22/13%), thrombocytopenia (15/17/8%), fatigue (13/12/5%), alanine aminotransferase increase (15/5/8%), and hyperglycemia (18/2/3%).

CONCLUSIONS

Ganitumab combined with gemcitabine had tolerable toxicity and showed trends toward an improved 6-month survival rate and overall survival. Additional investigation into this combination is warranted. Conatumumab combined with gemcitabine showed some evidence of activity as assessed by the 6-month survival rate.

PV1 down-regulation via shRNA inhibits the growth of pancreatic adenocarcinoma xenografts

PV1 is an endothelial-specific protein with structural roles in the formation of diaphragms in endothelial cells of normal vessels. PV1 is also highly expressed on endothelial cells of many solid tumours. On the basis of in vitro data, PV1 is thought to actively participate in angiogenesis. To test whether or not PV1 has a function in tumour angiogenesis and in tumour growth in vivo, we have treated pancreatic tumour-bearing mice by single-dose intratumoural delivery of lentiviruses encoding for two different shRNAs targeting murine PV1. We find that PV1 down-regulation by shRNAs inhibits the growth of established tumours derived from two different human pancreatic adenocarcinoma cell lines (AsPC-1 and BxPC-3). The effect observed is because of down-regulation of PV1 in the tumour endothelial cells of host origin, PV1 being specifically expressed in tumour vascular endothelial cells and not in cancer or other stromal cells. There are no differences in vascular density of tumours treated or not with PV1 shRNA, and gain and loss of function of PV1 in endothelial cells does not modify either their proliferation or migration, suggesting that tumour angiogenesis is not impaired. Together, our data argue that down-regulation of PV1 in tumour endothelial cells results in the inhibition of tumour growth via a mechanism different from inhibiting angiogenesis.

Human correlates of provocative questions in pancreatic pathology

Studies of cell lines and of animal models of pancreatic cancer have raised a number of provocative questions about the nature and origins of human pancreatic cancer and have provided several leads into exciting new approaches for the treatment of this deadly cancer. In addition, clinicians with little or no contact with human pathology have challenged the way that pancreatic pathology is practiced, suggesting that "genetic signals" may be more accurate than today's multimodal approach to diagnoses. In this review, we consider 8 provocative issues in pancreas pathology, with an emphasis on "the evidence derived from man."

BAYPAN study: a double-blind phase III randomized trial comparing gemcitabine plus sorafenib and gemcitabine plus placebo in patients with advanced pancreatic cancer

BACKGROUND

Sorafenib is an oral anticancer agent targeting Ras-dependent signaling and angiogenic pathways. A phase I trial demonstrated that the combination of gemcitabine and sorafenib was well tolerated and had activity in advanced pancreatic cancer (APC) patients. The BAYPAN study was a multicentric, placebo-controlled, double-blind, randomized phase III trial comparing gemcitabine/sorafenib and gemcitabine/placebo in the treatment of APC.

PATIENTS AND METHODS

The patient eligibility criteria were locally advanced or metastatic pancreatic adenocarcinoma, no prior therapy for advanced disease and a performance status of zero to two. The primary end point was progression-free survival (PFS). The patients received gemcitabine 1000 mg/m(2) i.v., weekly seven times followed by 1 rest week, then weekly three times every 4 weeks plus sorafenib 200 mg or placebo, two tablets p.o., twice daily continuously.

RESULTS

Between December 2006 and September 2009, 104 patients were enrolled on the study (52 pts in each arm) and 102 patients were treated. The median and the 6-month PFS were 5.7 months and 48% for gemcitabine/placebo and 3.8 months and 33% for gemcitabine/sorafenib (P = 0.902, stratified log-rank test), respectively. The median overall survivals were 9.2 and 8 months, respectively (P = 0.231, log-rank test). The overall response rates were similar (19 and 23%, respectively).

CONCLUSION

The addition of sorafenib to gemcitabine does not improve PFS in APC patients.

VEGF remains an interesting target in advanced pancreas cancer (APCA): results of a multi-institutional phase II study of bevacizumab, gemcitabine, and infusional 5-fluorouracil in patients with APCA

BACKGROUND

We investigated the safety and efficacy of bevacizumab combined with gemcitabine followed by infusional 5-fluorouracil (5-FU) in patients with advanced pancreas cancer (APCA).

DESIGN

Patients with untreated APCA received bevacizumab 10 mg/kg, gemcitabine 1000 mg/m(2) over 100 min, and 5-FU 2400 mg/m(2) over 48 h on days 1 and 15 of each 28-day cycle. The primary end point was the proportion of patients with progression-free survival (PFS) at 6 months from initiation of therapy. If PFS at 6 months was ≥41%, the regimen would be considered promising.

RESULTS

Forty-two patients were enrolled in the study; of which, 39 were evaluable for primary end point. PFS at 6 months was 49% (95% CI 34% to 64%). Median PFS was 5.9 months (95% CI 3.5 to 8.1) and median overall survival (OS) was 7.4 months (95% CI 4.7 to 11.2). Partial response and stable disease occurred in 30% and 45% of patients, respectively. Treatment-related hypertension and normal baseline albumin correlated with an improved response rate, PFS and OS. Grade 3 to 4 toxicities included fatigue (14%), hypertension (5%), and venous thrombosis (5%).

CONCLUSIONS

The study met its primary end point. Further investigation of anti-VEGF therapy in combination with fluoropyrimidine-based therapy is warranted in APCA. Treatment-related hypertension and normal baseline albumin may predict for the efficacy of bevacizumab and should be investigated in prospective studies.

Neoadjuvant cetuximab, twice-weekly gemcitabine, and intensity-modulated radiotherapy (IMRT) in patients with pancreatic adenocarcinoma

BACKGROUND

Neoadjuvant therapy has been investigated for localized and locally advanced pancreatic ductal adenocarcinoma (PDAC) but no standard of care exists. Combination cetuximab/gemcitabine/radiotherapy demonstrates encouraging preclinical activity in PDAC. We investigated cetuximab with twice-weekly gemcitabine and intensity-modulated radiotherapy (IMRT) as neoadjuvant therapy in patients with localized or locally advanced PDAC.

EXPERIMENTAL DESIGN

Treatment consisted of cetuximab load at 400 mg/m(2) followed by cetuximab 250 mg/m(2) weekly and gemcitabine 50 mg/m(2) twice-weekly given concurrently with IMRT to 54 Gy. Following therapy, patients were considered for resection.

RESULTS

Thirty-seven patients were enrolled with 33 assessable for response. Ten patients (30%) manifested partial response and 20 (61%) manifested stable disease by RECIST. Twenty-five patients (76%) underwent resection, including 18/23 previously borderline and 3/6 previously unresectable tumors. Twenty-three (92%) of these had negative surgical margins. Pathology revealed that 24% of resected tumors had grade III/IV tumor kill, including two pathological complete responses (8%). Median survival was 24.3 months in resected patients. Outcome did not vary by epidermal growth factor receptor status.

CONCLUSIONS

Neoadjuvant therapy with cetuximab/gemcitabine/IMRT is tolerable and active in PDAC. Margin-negative resection rates are high and some locally advanced tumors can be downstaged to allow for complete resection with encouraging survival. Pathological complete responses can occur. This combination warrants further investigation.

Neoadjuvant therapy in resectable pancreatic cancer: a critical review

BACKGROUND

Pancreatic cancer is among the deadliest tumors. Due to intrinsic chemo- and radio-resistance, surgical resection remains the only chance for cure. However surgery alone is unable to considerably improve survival and complementary chemotherapy and radiotherapy in a multimodal approach have been tested. Adjuvant chemotherapy yielded a modest outcome improvement, whereas the use of adjuvant chemoradiation is highly controversial. In this scenario, the neoadjuvant approach has a strong theoretical rationale, but limited information on the efficacy of this strategy is available.

MATERIALS AND METHODS

This review critically overviews the current knowledge, the rationale, the available data and information on neoadjuvant treatment in resectable pancreatic cancer.

RESULTS

The very early systemic dissemination of pancreatic cancer endorses the rationale for an up-front use of systemic therapy. However, evidence collected so far depends on retrospective data, small case series that did not balance the different characteristics of patients suitable for surgery before or after neoadjuvant chemotherapy.

CONCLUSION

Currently there is no straightforward evidence to support the routine clinical use of this strategy. Only a properly designed randomized trial testing combination chemotherapy regimens selected on the basis of their efficacy and activity against metastatic disease can address this issue.

Pancreatic Adenocarcinoma, version 2.2012: featured updates to the NCCN Guidelines

The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Pancreatic Adenocarcinoma discuss the workup and management of tumors of the exocrine pancreas. These NCCN Guidelines Insights provide a summary and explanation of major changes to the 2012 NCCN Guidelines for Pancreatic Adenocarcinoma. The panel made 3 significant updates to the guidelines: 1) more detail was added regarding multiphase CT techniques for diagnosis and staging of pancreatic cancer, and pancreas protocol MRI was added as an emerging alternative to CT; 2) the use of a fluoropyrimidine plus oxaliplatin (e.g., 5-FU/leucovorin/oxaliplatin or capecitabine/oxaliplatin) was added as an acceptable chemotherapy combination for patients with advanced or metastatic disease and good performance status as a category 2B recommendation; and 3) the panel developed new recommendations concerning surgical technique and pathologic analysis and reporting.

Systemic therapies for pancreatic cancer--the role of pharmacogenetics

Effective systemic treatment of pancreatic cancer remains a major challenge, with progress hampered by drug resistance and treatment related toxicities. Currently available cytotoxic agents as monotherapy or in combination have provided only a modest survival benefit for patients with advanced disease. Disappointing phase III results with gemcitabine-based combinations in patients with advanced pancreatic cancer might be related to poor efficacy of systemic therapies in unselected patients. Future research strategies should prioritize identification of predictive markers through pharmacogenetic investigations. The individualization of patient treatment through pharmacogenetics may help to improve outcome by maximizing efficacy whilst lowering toxicity. This review provides an update on the pharmacogenetics of pancreatic cancer treatment and its influence on treatment benefits and toxicity.

Systemic therapies for pancreatic cancer--the role of pharmacogenetics

Effective systemic treatment of pancreatic cancer remains a major challenge, with progress hampered by drug resistance and treatment related toxicities. Currently available cytotoxic agents as monotherapy or in combination have provided only a modest survival benefit for patients with advanced disease. Disappointing phase III results with gemcitabine-based combinations in patients with advanced pancreatic cancer might be related to poor efficacy of systemic therapies in unselected patients. Future research strategies should prioritize identification of predictive markers through pharmacogenetic investigations. The individualization of patient treatment through pharmacogenetics may help to improve outcome by maximizing efficacy whilst lowering toxicity. This review provides an update on the pharmacogenetics of pancreatic cancer treatment and its influence on treatment benefits and toxicity.

Epithelial mesenchymal transition and pancreatic tumor initiating CD44+/EpCAM+ cells are inhibited by γ-secretase inhibitor IX

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease with a high rate of metastasis. Recent studies have indicated that the Notch signalling pathway is important in PDAC initiation and maintenance, although the specific cell biological roles of the pathway remain to be established. Here we sought to examine this question in established pancreatic cancer cell lines using the γ-secretase inhibitor IX (GSI IX) to inactivate Notch. Based on the known roles of Notch in development and stem cell biology, we focused on effects on epithelial mesenchymal transition (EMT) and on pancreatic tumor initiating CD44+/EpCAM+ cells. We analyzed the effect of the GSI IX on growth and epithelial plasticity of human pancreatic cancer cell lines, and on the tumorigenicity of pancreatic tumor initiating CD44+/EpCAM+ cells. Notably, apoptosis was induced after GSI IX treatment and EMT markers were selectively targeted. Furthermore, under GSI IX treatment, decline in the growth of pancreatic tumor initiating CD44+/EpCAM+ cells was observed in vitro and in a xenograft mouse model. This study demonstrates a central role of Notch signalling pathway in pancreatic cancer pathogenesis and identifies an effective approach to inhibit selectively EMT and suppress tumorigenesis by eliminating pancreatic tumor initiating CD44+/EpCAM+ cells.

Cancer Stem Cells, EMT, and Developmental Pathway Activation in Pancreatic Tumors

Pancreatic cancer is a disease with remarkably poor patient survival rates. The frequent presence of metastases and profound chemoresistance pose a severe problem for the treatment of these tumors. Moreover, cross-talk between the tumor and the local micro-environment contributes to tumorigenicity, metastasis and chemoresistance. Compared to bulk tumor cells, cancer stem cells (CSC) have reduced sensitivity to chemotherapy. CSC are tumor cells with stem-like features that possess the ability to self-renew, but can also give rise to more differentiated progeny. CSC can be identified based on increased in vitro spheroid- or colony formation, enhanced in vivo tumor initiating potential, or expression of cell surface markers. Since CSC are thought to be required for the maintenance of a tumor cell population, these cells could possibly serve as a therapeutic target. There appears to be a causal relationship between CSC and epithelial-to-mesenchymal transition (EMT) in pancreatic tumors. The occurrence of EMT in pancreatic cancer cells is often accompanied by re-activation of developmental pathways, such as the Hedgehog, WNT, NOTCH, and Nodal/Activin pathways. Therapeutics based on CSC markers, EMT, developmental pathways, or tumor micro-environment could potentially be used to target pancreatic CSC. This may lead to a reduction of tumor growth, metastatic events, and chemoresistance in pancreatic cancer.