FOLFIRINOX versus gemcitabine for metastatic pancreatic cancer

Novel multimodality treatment sequencing for extrahepatic (mid and distal) cholangiocarcinoma

Neoadjuvant chemoradiation has demonstrated significant advantages in the management of pancreatic adenocarcinoma. A similar tumor in a nearby anatomical location is extrahepatic cholangiocarcinoma, which has proven to be largely unresponsive to current forms of therapy. Neoadjuvant therapy for hilar cholangiocarcinoma has been combined with surgical resection and/or liver transplantation with a 25-33 % complete pathological response rate. We propose a wider application of neoadjuvant chemoradiation for patients with distal cholangiocarcinoma and present our rationale for this form of treatment sequencing.

Biomarker-driven trial in metastatic pancreas cancer: feasibility in a multicenter study of saracatinib, an oral Src inhibitor, in previously treated pancreatic cancer

Src tyrosine kinases are overexpressed in pancreatic cancers, and the oral Src inhibitor saracatinib has shown antitumor activity in preclinical models of pancreas cancer. We performed a CTEP-sponsored Phase II clinical trial of saracatinib in previously treated pancreas cancer patients, with a primary endpoint of 6-month survival. A Simon MinMax two-stage phase II design was used. Saracatinib (175 mg/day) was administered orally continuously in 28-day cycles. In the unselected portion of the study, 18 patients were evaluable. Only two (11%) patients survived for at least 6 months, and three 6-month survivors were required to move to second stage of study as originally designed. The study was amended as a biomarker-driven trial (leucine rich repeat containing protein 19 [LRRC19] > insulin-like growth factor-binding protein 2 [IGFBP2] "top scoring pairs" polymerase chain reaction [PCR] assay, and PIK3CA mutant) based on preclinical data in a human pancreas tumor explant model. In the biomarker study, archival tumor tissue or fresh tumor biopsies were tested. Biomarker-positive patients were eligible for the study. Only one patient was PIK3CA mutant in a 3' untranslated region (UTR) portion of the gene. This patient was enrolled in the study and failed to meet the 6-month survival endpoint. As the frequency of biomarker-positive patients was very low (<3%), the study was closed. Although we were unable to conclude whether enriching for a subset of second/third line pancreatic cancer patients treated with a Src inhibitor based on a biomarker would improve 6-month survival, we demonstrate that testing pancreatic tumor samples for a biomarker-driven, multicenter study in metastatic pancreas cancer is feasible.

Aptamer-mediated delivery of chemotherapy to pancreatic cancer cells

Gemcitabine is a nucleoside analog that is currently the best available single-agent chemotherapeutic drug for pancreatic cancer. However, efficacy is limited by our inability to deliver sufficient active metabolite into cancer cells without toxic effects on normal tissues. Targeted delivery of gemcitabine into cancer cells could maximize effectiveness and concurrently minimize toxic side effects by reducing uptake into normal cells. Most pancreatic cancers overexpress epidermal growth factor receptor (EGFR), a trans-membrane receptor tyrosine kinase. We utilized a nuclease resistant RNA aptamer that binds and is internalized by EGFR on pancreatic cancer cells to deliver gemcitabine-containing polymers into EGFR-expressing cells and inhibit cell proliferation in vitro. This approach to cell type-specific therapy can be adapted to other targets and to other types of therapeutic cargo.

A phase I trial of nab-paclitaxel, gemcitabine, and capecitabine for metastatic pancreatic cancer

BACKGROUND

Substantial antitumor activity has previously been demonstrated with the addition of nab-paclitaxel (Abraxane [Celgene, Summit, NJ]), an albumin-bound formulation of paclitaxel, to gemcitabine in patients with advanced pancreatic cancer. Given preclinical evidence of synergy when a fluoropyrimidine is added to gemcitabine plus a taxane in a sequence-specific schedule, we conducted a phase I study to evaluate the combination of nab-paclitaxel, gemcitabine, and capecitabine administered biweekly in patients with metastatic pancreatic adenocarcinoma.

MATERIALS AND METHODS

Patients with previously untreated metastatic pancreatic cancer and an ECOG performance status of 0-1 were eligible to participate. Study design utilized a 3 + 3 dose-escalation schema, with expanded cohort at maximum-tolerated dose (MTD). Treatment was administered in 14-day cycles, with capecitabine given on days 1-7 and both gemcitabine (at fixed-dose rate infusion) and nab-paclitaxel on day 4 of each cycle. Dose-limiting toxicity (DLT) definitions included grade 3-4 hematologic toxicities and grade 2-4 hand-foot syndrome, neuropathy, or diarrhea.

RESULTS

Fifteen patients were enrolled across two dose levels. Final MTD was established at nab-paclitaxel 100 mg/m(2), gemcitabine 750 mg/m(2), and capecitabine 750 mg/m(2) twice daily. Patients received a median of four treatment cycles (range 1-16). The most frequent adverse events (any grade) for the entire study cohort included fatigue, rash/hand-foot syndrome, nausea/vomiting, diarrhea, neuropathy, and elevated liver function tests. Ten patients (66.7 %) experienced at least one grade 3-4 adverse event. Grade 3-4 hematologic toxicities were uncommon. Two of 14 evaluable patients (14.3 %) exhibited a partial response, and 6 of 12 patients (50 %) with elevated CA19-9 at baseline had a ≥50 % biomarker decline.

CONCLUSION

While well tolerated overall, this regimen demonstrated only modest antitumor activity in patients with metastatic pancreatic cancer. Recognizing the limits of cross-study comparisons and small sample size, these results do not match those reported at MTD in the phase I/II trial of gemcitabine/nab-paclitaxel. The lower doses used in the current study suggest that dose intensity may be a critical aspect to optimize multidrug regimens.

Dual ErbB1 and ErbB2 receptor tyrosine kinase inhibition exerts synergistic effect with conventional chemotherapy in pancreatic cancer

Patient survival in pancreatic cancer remains poor with gemcitabine (GEM)-based regimens. The target specific molecular agent lapatinib, a dual ErbB1 and ErbB2 receptor tyrosine kinase inhibitor, has shown significant activity against ErbB1 and ErbB2-expressing tumors. Since pancreatic tumors frequently overexpress these proteins, we investigated its effects, both alone and in conjunction with 5-FU or GEM. The pancreatic cancer cell lines PANC-1 and AsPC were treated with varying doses of lapatinib in vitro. The effects on ErbB1/ErbB2 protein phosphorylation and on the cell survival protein survivin were determined by western blotting. Cytotoxicity was determined by MTT assay and apoptosis was measured using the caspase-3 colorimetric assay. Similar dose-response lapatinib experiments were conducted with varying concentrations of 5-FU or GEM and isobolograms were constructed to evaluate therapeutic synergy. Lapatinib inhibited protein phosphorylation in the range of 4-16 µM, a clinically achievable concentration. The lapatinib-treated cells showed a dose-dependent inhibition of cell proliferation and induction of apoptosis at the same concentrations that blocked ErbB1/ErbB2 phosphorylation. The addition of 5-FU or GEM to these cells resulted in synergistic effects. The lapatinib-treated cells also demonstrated downregulation of survivin. Simultaneous dual ErbB1 and ErbB2 receptor tyrosine kinase inhibition with lapatinib results in significant reduction of pancreatic cancer cell growth and proliferation. These effects occur at clinically achievable concentrations and are synergistic with the effects of 5-FU or GEM. These findings support the potential role of lapatinib in the treatment of pancreatic cancer.

Peroxisome proliferator-activated receptor gamma and regulations by the ubiquitin-proteasome system in pancreatic cancer

Pancreatic cancer is one of the most lethal forms of human cancer. Although progress in oncology has improved outcomes in many forms of cancer, little progress has been made in pancreatic carcinoma and the prognosis of this malignancy remains grim. Several molecular abnormalities often present in pancreatic cancer have been defined and include mutations in K-ras, p53, p16, and DPC4 genes. Nuclear receptor Peroxisome Proliferator-Activated Receptor gamma (PPARγ) has a role in many carcinomas and has been found to be overexpressed in pancreatic cancer. It plays generally a tumor suppressor role antagonizing proteins promoting carcinogenesis such as NF-κB and TGFβ. Regulation of pathways involved in pancreatic carcinogenesis is effectuated by the Ubiquitin Proteasome System (UPS). This paper will examine PPARγ in pancreatic cancer, the regulation of this nuclear receptor by the UPS, and their relationship to other pathways important in pancreatic carcinogenesis.

Outcomes following resection of pancreatic cancer

Pancreatic cancer is an aggressive and highly lethal malignancy. Surgical resection is a modest tool, but it provides the only potential for curative therapy and often prolongs survival. This article reviews the progress made on both local and national levels towards an era of safer pancreatic surgery, while discussing both perioperative outcomes and long-term survival after resection.

Emodin induces Panc-1 cell apoptosis via declining the mitochondrial membrane potential

In this study, we investigated the apoptotic effect of emodin on human pancreatic cancer cell line Panc-1 in vitro and in vivo as well as the possible mechanisms involved. In vitro, human pancreatic cancer cell line Panc-1 was exposed to varying concentrations of emodin (0, 10, 20, 40 or 80 µmol/l). Then the mitochondrial membrane potential (MMP) was analyzed by JC-1 staining, cell apoptosis was analyzed by flow cytometry (FCM) and cell proliferation was analyzed by MTT. In vivo, nude mice orthotopically implanted were randomly divided into five groups to receive treatments by different doses of emodin: control group (normal saline 0.2 ml), E10 group (emodin 10 mg/kg), E20 group (emodin 20 mg/kg), E40 group (emodin 40 mg/kg) and E80 group (emodin 80 mg/kg). Each mouse was treated 5 times by intraperitoneal injection of emodin every 3 days. During the treatment, the feeding stuff was recorded. One week after the last treatment, we recorded the body weight and the maximum diameter of tumor in each group before the mice were sacrificed. Then the cell apoptosis of the tumor was tested by TUNEL assay. The results in vitro showed that the MMP of the cells declined and the apoptosis rate increased with the emodin concentration increasing and the cell proliferation of each group was inhibited in a dose- and time-dependent manner by emodin. The feeding stuff curve did not decline significantly in E40 group and the apoptosis rate of the tumor cells in this group was higher than the lower-dose groups. Taken together, our results demonstrate that emodin may induce the pancreatic cancer cell apoptosis via declining the MMP and a moderate dose of emodin improved the living state of the model mice.

Role of gemcitabine-based combination therapy in the management of advanced pancreatic cancer: a meta-analysis of randomised trials

BACKGROUND

Pancreatic cancer is the fourth leading cause of cancer-related death worldwide. Gemcitabine is the mainstay treatment for advanced disease. However, almost all up-to-date trials, that evaluated the benefit of gemcitabine-combination schedules, failed to demonstrate an improvement in overall survival (OS). In this study, we performed a systematic review and a meta-analysis of randomised clinical trials (RCTs) to investigate the efficacy and safety of gemcitabine-based combination regimens as compared to gemcitabine alone in the management of pancreatic cancer.

METHODS

Clinical trials were collected by searching different databases (PubMed, Embase and the Central Registry of Controlled Trials of the Cochrane Library) and abstracts from major cancer meetings. We considered period ranging from January 1997 to January 2012. Primary end-point was OS, secondary end-points were response rate (RR), disease control rate (DCR) and safety. Hazard ratios (HRs) of OS, odds-ratios (ORs) of RR, DCR and risk ratios of grade 3-4 toxicity rates (TRs), were extracted as presented in retrieved studies and used for statistical analysis. Meta-analytic estimates were derived using random-effects model.

FINDINGS

Thirty-four trials for a total of 10,660 patients were selected and included in the final analysis. The analysis showed that combination chemotherapy confers benefit in terms of OS (HR: 0.93; 95% confidence interval (CI): 0.89-0.97; p=0.001). ORs for both RR and DCR demonstrated a significant advantage for combination therapy (OR for RR: 0.60, 95%CI: 0.47-0.76, p<0.001; OR for DCR: 0.79; 95%CI: 0.66-0.93; p=0.006). Toxicities were more frequent with the combination treatment and significance in terms of risk ratio was reached for diarrhoea (0.53, 95%CI: 0.36-0.79), nausea (0.74, 95%CI: 0.56-0.96), neutropenia (0.71, 95%CI: 0.59-0.85) and thrombocytopenia (0.57, 95%CI: 0.43-0.75).

INTERPRETATION

The combination chemotherapy as compared to gemcitabine alone significantly improves OS in advanced pancreatic cancer (APC). However, this advantage is marginal whereas the treatment-related toxicity is increased, suggesting the use of gemcitabine-based combination regimens only in selected patient populations. New prospective trials, based on translational approaches and innovative validated biomarkers, are eagerly awaited on this topic.

Aberrant glycogen synthase kinase 3β in the development of pancreatic cancer

Development and progression of pancreatic cancer involves general metabolic disorder, local chronic inflammation, and multistep activation of distinct oncogenic molecular pathways. These pathologic processes result in a highly invasive and metastatic tumor phenotype that is a major obstacle to curative surgical intervention, infusional gemcitabine-based chemotherapy, and radiation therapy. Many clinical trials with chemical compounds and therapeutic antibodies targeting growth factors, angiogenic factors, and matrix metalloproteinases have failed to demonstrate definitive therapeutic benefits to refractory pancreatic cancer patients. Glycogen synthase kinase 3β (GSK3β), a serine/threonine protein kinase, has emerged as a therapeutic target in common chronic and progressive diseases, including cancer. Here we review accumulating evidence for a pathologic role of GSK3β in promoting tumor cell survival, proliferation, invasion, and resistance to chemotherapy and radiation in pancreatic cancer. We also discuss the putative involvement of GSK3β in mediating metabolic disorder, local inflammation, and molecular alteration leading to pancreatic cancer development. Taken together, we highlight potential therapeutic as well as preventive effects of GSK3β inhibition in pancreatic cancer.

Advances in medical treatment of advanced pancreatic cancer

Chemotherapy is currently an important means of treating advanced pancreatic cancer. Gemcitabine is a chemotherapeutic agent for the first-line treatment of advanced pancreatic cancer. Some progress has been made to improve survival in patients with advanced pancreatic cancer with gemcitabine-based combination chemotherapy regimens. FOLFIRINOX is the first non-gemcitabine regimen whose efficacy has been demonstrated to be superior to gemcitabine in selected patients. In addition, the development of a variety of targeted drugs (including cytotoxic drugs and biological drugs) has brought a new prospect to the treatment of pancreatic cancer. In this article, we will review recent advances in chemotherapy and targeted therapy of pancreatic cancer.

FOLFIRI regimen in metastatic pancreatic adenocarcinoma resistant to gemcitabine and platinum-salts

AIM: To evaluate the efficacy and safety of the FOLFIRI regimen in patients with metastatic pancreatic adenocarcinoma (PAC) after the failure of gemcitabine and platinum salts.

METHODS: All consecutive patients with histologically confirmed, metastatic PAC and World Health Organization performance status (PS) ≤ 2 received FOLFIRI-1 [irinotecan 180 mg/m² on day 1 and leucovorin 400 mg/m² followed by 5-fluorouracil (5-FU) 400 mg/m² bolus, then 5-FU 2400 mg/m² as a 46-h infusion, biweekly] or FOLFIRI-3 (irinotecan 100 mg/m² on day 1 and leucovorin 400 mg/m², then 5-FU 2400 mg/m² as a 46-h infusion and irinotecan 100 mg/m² repeated on day 3, biweekly) after failure of gemcitabine and platinum-based chemotherapies as a systematic policy in two institutions between January 2005 and May 2010. Tumor response, time to progression (TTP), overall survival rate (OS) and grade 3-4 toxicities were retrospectively studied. Subgroup analyses were performed to search for prognostic factors.

RESULTS: Sixty-three patients (52.4% male, median age 59 years) were analyzed. Among them, 42.9% were PS 0, 38.1% were PS 1 and 19.0% were PS 2. Fifty one patients (81.0%) had liver metastases. Before the FOLFIRI regimen, patients had received 1 line (n = 19), 2 lines (n = 39) or 3 lines (n = 5) of chemotherapy. Median TTP obtained with the line before FOLFIRI was 3.9 mo (95% CI: 3.4-5.3 mo). A total of 480 cycles was completed (median: 6 cycles, range: 1-51 cycles). The main reason for discontinuing FOLFIRI was tumor progression (90.3%). Tumor control was achieved in 25 patients (39.7%) (partial response: n = 5, stable disease: n = 20) with FOLFIRI. Median TTP was 3.0 mo (95% CI: 2.1-3.9 mo) and median OS was 6.6 mo (95% CI: 5.3-8.1 mo). Dose adaptation was required in 36 patients (57.1%). Fifteen patients (23.8%) had grade 3-4 toxicities, mainly hematological (n = 11) or digestive (n = 4). Febrile neutropenia occurred in 3 patients. There was no toxic death. PS 2 was significantly associated with poor TTP [hazard ratio (HR): 16.036, P < 0.0001] and OS (HR: 4.003, P = 0.004).

CONCLUSION: The FOLFIRI regimen had an acceptable toxicity and an interesting efficacy in our study, limited to patients in good condition (PS 0-1).

Role of taxanes in pancreatic cancer

Pancreatic cancer is one of the most deadly cancers and is characterized by a poor prognosis. Single agent gemcitabine, despite its limited activity and modest impact on disease outcome, is considered as the standard therapy in pancreatic cancer. Most of the combination regimens used in the treatment of this disease, also including the targeted agents, did not improve the outcome of patients. Also, taxanes have been tested as single agent and in combination chemotherapy, both in first line and as salvage chemotherapy, as another possible option for treating pancreatic cancer. The inclusion of taxanes in combination with gemcitabine as upfront therapy obtained promising results. Accordingly, taxanes, and above all, new generation taxanes, appear to be suitable candidates for further testing to assess their role against pancreatic cancer in various clinical settings.

Quality of life across chemotherapy lines in patients with cancers of the pancreas and biliary tract

BACKGROUND

In patients with cancers of the pancreatic and biliary tract quality of life (QOL) improvement is the main treatment goal, since survival can be prolonged only marginally. Up to date, knowledge on QOL impairments throughout the entire treatment process, often including several chemotherapy lines, is scarce. Our study aimed at investigating QOL trajectories from adjuvant treatment to palliative 3rd-line therapy

METHODS

Patients were included in routine electronic patient-reported outcome monitoring at Kufstein County Hospital at the time of diagnosis and assessed with the EORTC QLQ-C30 during each chemotherapy cycle.

RESULTS

Eighty out of 147 patients with pancreatic cancer or cancer of the bile ducts treated at the Kufstein County Hospital, fulfilled inclusion criteria and could be included in the study (mean age 67.4 years; 53.8% women). Physical, Emotional and Cognitive Functioning, and Global QOL deteriorated across chemotherapy lines, whereas Fatigue, Pain, Dyspnoea, Sleeping Disturbances, Diarrhoea, and Taste Alterations increased. With regard to Physical Functioning, Global QOL, Fatigue, Dyspnoea, Diarrhoea and Taste Alterations, the patients receiving adjuvant or 1st-line palliative chemotherapy did not differ significantly. Most patients in 2nd- or 3rd-line chemotherapy showed significantly higher impairments and symptom burden. However, patients under 1st and 2nd-line treatment showed stable QOL trajectories, whereas 3rd-line patients perceived substantial deteriorations.

CONCLUSIONS

The results suggest early palliative treatment initiation to stabilise QOL on a level as high as possible. The continuous QOL improvement during adjuvant treatment, probably reflecting post-operative recovery, may indicate that deleterious effects of adjuvant chemotherapy on QOL are highly unlikely.

Anti-DLL4 has broad spectrum activity in pancreatic cancer dependent on targeting DLL4-Notch signaling in both tumor and vasculature cells

PURPOSE

We previously showed that targeting Delta-like ligand 4 (DLL4) in colon and breast tumors inhibited tumor growth and reduced tumor initiating cell frequency. In this report, we have extended these studies to pancreatic cancer and probed the mechanism of action in tumor and stromal cells involved in antitumor efficacy.

EXPERIMENTAL DESIGN

Patient-derived pancreatic xenograft tumor models were used to evaluate the antitumor effect of anti-DLL4. To investigate the mechanism of action, we compared the activity of targeting DLL4 in tumor cells with an anti-human DLL4 antibody (anti-hDLL4) and in the host stroma/vasculature with an anti-mouse DLL4 antibody (anti-mDLL4). The effect of these antibodies on cancer stem cell frequency was examined by in vivo limiting dilution assays.

RESULTS

The combination of anti-hDLL4 and anti-mDLL4 was efficacious in a broad spectrum of pancreatic tumor xenografts and showed additive antitumor activity together with gemcitabine. Treatment with either anti-hDLL4 or anti-mDLL4 delayed pancreatic tumor recurrence following termination of gemcitabine treatment, and the two together produced an additive effect. Anti-hDLL4 had a pronounced effect in reducing the tumorigenicity of pancreatic cancer cells based on serial transplantation and tumorsphere assays. In contrast, disruption of tumor angiogenesis with anti-mDLL4 alone or with anti-VEGF had minimal effects on tumorigenicity. Gene expression analyses indicated that anti-DLL4 treatment regulated genes that participate in Notch signaling, pancreatic differentiation, and epithelial-to-mesenchymal transition.

CONCLUSIONS

Our findings suggest a novel therapeutic approach for pancreatic cancer treatment through antagonism of DLL4/Notch signaling.

Overcoming the stromal barrier: technologies to optimize drug delivery in pancreatic cancer

Pancreatic cancer has historically proven resistant to anticancer agents. On the one hand, drugs might be more efficient if higher levels could be achieved at the tumor site rather than the normal tissues. On the other hand, the thick stroma and the relative absence of abundant vessels may account at least partially for the failure of successive clinical trials to demonstrate effective treatments in this type of malignancy. In this context, the development and testing in clinical trials of treatment strategies that aim to optimize drug delivery is an important target in improving the prognosis of patients with pancreatic cancer.

The implications of positive peritoneal lavage cytology in potentially resectable pancreatic cancer

BACKGROUND

The clinical implications of peritoneal lavage cytology (CY) status in patients with potentially resectable pancreatic cancer have not been established.

METHOD

We retrospectively reviewed clinical data from 254 consecutive patients who underwent macroscopically curative resection for pancreatic cancer from February 2003 to December 2010 in our institution. Correlations between CY status and survival and clinicopathological findings were investigated.

RESULTS

Of the 254 patients, 20 were CY+ (7.9 %). There were no significant differences between CY+ and CY- patients in background data (age, sex, the level of preoperative tumor marker, and adjuvant chemotherapy). Patients with positive serosal invasion were more likely to be CY+ than those with negative serosal invasion (P < 0.001) by univariate analysis. The median overall survival of CY+ patients and CY- patients was 23.8 months (95 % CI = 17.6-29.8) and 26.5 months (95 % CI = 20.7-32.3), respectively (P = 0.302). The median recurrence-free survival of CY+ and CY- patients was 8.1 months (95 % CI = 0.0-17.9) and 13.5 months (95 % CI = 11.5-15.5), respectively (P = 0.089).

CONCLUSION

CY+ status without other distant metastasis does not necessarily preclude resection in patients with pancreatic cancer.

Levels of gemcitabine transport and metabolism proteins predict survival times of patients treated with gemcitabine for pancreatic adenocarcinoma

BACKGROUND & AIMS

Patients who undergo surgery for pancreatic ductal adenocarcinoma (PDAC) frequently receive adjuvant gemcitabine chemotherapy. Key determinants of gemcitabine cytotoxicity include the activities of the human equilibrative nucleoside transporter 1 (hENT1), deoxycytidine kinase (dCK), and ribonucleotide reductase subunit 1 (RRM1). We investigated whether tumor levels of these proteins were associated with efficacy of gemcitabine therapy following surgery.

METHODS

Sequential samples of resected PDACs were retrospectively collected from 434 patients at 5 centers; 142 patients did not receive adjuvant treatment (33%), 243 received adjuvant gemcitabine-based regimens (56%), and 49 received nongemcitabine regimens (11%). We measured protein levels of hENT1, dCK, and RRM1 by semiquantitative immunohistochemistry with tissue microarrays and investigated their relationship with patients' overall survival time.

RESULTS

The median overall survival time of patients was 32.0 months. Among patients who did not receive adjuvant treatment, levels of hENT1, RRM1, and dCK were not associated with survival time. Among patients who received gemcitabine, high levels of hENT1 and dCK were significantly associated with longer survival time (hazard ratios of 0.34 [P < .0001] and 0.57 [P = .012], respectively). Interaction tests for gemcitabine administration and hENT1 and dCK status were statistically significant (P = .0007 and P = .016, respectively). On multivariate analysis of this population, hENT1 and dCK retained independent predictive values, and those patients with high levels of each protein had the longest survival times following adjuvant therapy with gemcitabine.

CONCLUSIONS

High levels of hENT1 and dCK in PDAC predict longer survival times in patients treated with adjuvant gemcitabine.

Adaptive trial designs: a review of barriers and opportunities

Adaptive designs allow planned modifications based on data accumulating within a study. The promise of greater flexibility and efficiency stimulates increasing interest in adaptive designs from clinical, academic, and regulatory parties. When adaptive designs are used properly, efficiencies can include a smaller sample size, a more efficient treatment development process, and an increased chance of correctly answering the clinical question of interest. However, improper adaptations can lead to biased studies. A broad definition of adaptive designs allows for countless variations, which creates confusion as to the statistical validity and practical feasibility of many designs. Determining properties of a particular adaptive design requires careful consideration of the scientific context and statistical assumptions. We first review several adaptive designs that garner the most current interest. We focus on the design principles and research issues that lead to particular designs being appealing or unappealing in particular applications. We separately discuss exploratory and confirmatory stage designs in order to account for the differences in regulatory concerns. We include adaptive seamless designs, which combine stages in a unified approach. We also highlight a number of applied areas, such as comparative effectiveness research, that would benefit from the use of adaptive designs. Finally, we describe a number of current barriers and provide initial suggestions for overcoming them in order to promote wider use of appropriate adaptive designs. Given the breadth of the coverage all mathematical and most implementation details are omitted for the sake of brevity. However, the interested reader will find that we provide current references to focused reviews and original theoretical sources which lead to details of the current state of the art in theory and practice.

Preoperative therapies for resectable and borderline resectable pancreatic cancer

In the era of multidetector high quality CT imaging, it is feasible and critical to use objective criteria to define resectable pancreatic cancer. This allows accurate pretreatment staging and the development of stage-specific therapy. Tumors of borderline resectability have emerged as a distinct subset and the definition has been expanded in the last few years. Borderline resectable tumors are defined as those with tumor abutment of <180degrees (< 50%) of the SMA or celiac axis, short segment abutment or encasement of the common hepatic artery typically at the gastroduodenal artery origin, SMV-PV abutment with impingement and narrowing or segmental venous occlusion with sufficient venous flow above and below the occlusion to allow an option for venous reconstruction. Most of the patients whose cancer meet these CT criteria are candidates for preoperative systemic chemotherapy followed by chemoradiation since they are at a high risk for margin positive resection with upfront surgery. Patients whose imaging studies show radiographic stability or regression proceed to pancreaticoduodenectomy (or pancreatectomy) and this may require vascular resection and reconstruction. Prospective biomarker and functional imaging enriched studies are warranted to determine the best overall treatment strategy for these patients.

Characteristics, therapy and outcome in an unselected and prospectively registered cohort of pancreatic cancer patients

PURPOSE

Pancreatic cancer (PC) is associated with a dismal prognosis. Few studies have examined characteristics and outcome in an unselected population-based cohort of PC patients. Therefore, we investigated patient baseline characteristics, therapy choices and survival in a complete cohort of patients with PC.

METHODS

All cases diagnosed with PC between 2007 and 2009 in the Region of Southern Denmark (pop: 1,200,000) were prospectively registered. Patient characteristics including performance status, information about haematology, liver function and therapy were retrieved from patient charts, and used to compare differently treated and untreated groups.

RESULTS

Six-hundred-eighteen cases were registered as PC; 25 of which did not have adenocarcinomas. Patients were divided in 3 clinical groups based on initial therapy; group 1: resection (n=64), group 2: chemotherapy or chemo-radiotherapy (n=191), group 3: no tumour directed therapy (n=324). Median survival (mOS) (95% confidence interval (CI)) in the three groups was 25.7 months (18-30), 8.1 months (7.0-9.5) and 1.1 months (1.0-1.3) respectively. Three percent of patients participated in clinical trials. An evaluation of baseline factors prognostic value suggested that treated patients differed significantly from non-treated patients.

CONCLUSION

This study reports survival in treated groups comparable to results obtained from clinical trials with highly selected patients. However the majority of patients with PC do not receive cancer directed therapy. This group was significantly different in several baseline factors, which could suggest a different biology. Improving the outcome of PC patients calls for research into the large group of untreated patients, as only a minority of patients receive cancer directed therapy.

Genetic disruption of USP9X sensitizes colorectal cancer cells to 5-fluorouracil

The X-linked deubiquitinase USP9X affects the stability and activity of numerous regulatory proteins that influence cell survival. Recent studies suggest that decreased USP9X expression can confer a selective advantage onto developing cancer cells and thereby promotes disease progression. To examine the effect of USP9X on the cellular responses to anticancer therapies, we derived cancer cell lines in which the USP9X locus was disrupted by homologous recombination. The resulting USP9X-deficient cancer cells exhibited increased activation of apoptotic pathways and markedly decreased clonogenic survival in response to 5-fluorouracil, a chemotherapeutic drug that is widely used for treatment of gastrointestinal malignancies. These unexpected results suggest that cancers with low USP9X expression might be specifically sensitized to some conventional therapeutic agents.

Verteporfin-based photodynamic therapy overcomes gemcitabine insensitivity in a panel of pancreatic cancer cell lines

BACKGROUND AND OBJECTIVE

Pancreatic cancer is notoriously difficult to treat and resistant to virtually all therapeutics including gemcitabine, the standard front line agent for palliative chemotherapy. Early clinical studies point to a potential role for photodynamic therapy (PDT) in the management of this deadly disease. Here we examine PDT with verteporfin for treatment of cells that are nonresponsive to gemcitabine and identify intracellular and extracellular factors that govern sensitivity to each modality.

STUDY DESIGN

Using MTS we assess cytotoxicity of verteporfin-PDT in gemcitabine-treated nonresponsive populations from a panel of five pancreatic cancer cell lines representing a range of tumor histopathology and origin. We conduct Western blots for pro-/anti-apoptotic proteins bax and Bcl-XL to identify factors relevant to PDT and gemcitabine sensitivity. To examine the role of extracellular matrix influences we compare response to each modality in traditional cell culture conditions and cells grown on a laminin-rich basement membrane.

RESULTS

All cell lines have gemcitabine nonresponsive populations (17-33%) at doses up to 1 mM while moderate total verteporfin PDT doses (1-6 µM J/cm2) produce nearly complete killing. Our data shows that cells that are nonresponsive to sustained gemcitabine incubation are sensitive to verteporfin PDT indicating that the latter is agnostic to gemcitabine sensitivity. Verteporfin-based PDT decreases Bcl-XL and increases the bax/Bcl-XL ratio toward a pro-apoptotic balance. Insensitivity to gemcitabine is increased in cells that are adherent to basement membrane relative to traditional tissue culture conditions.

CONCLUSIONS

Collectively these results indicate the ability of verteporfin-based PDT to bypass intracellular and extracellular cues leading to gemcitabine resistance and point to the emerging role of this therapy for treatment of pancreatic cancer.

Adjuvant therapy for pancreas adenocarcinoma

Adjuvant therapy for pancreas adenocarcinoma in 2012 includes consideration of systemic therapy based on high level evidence and combined chemoradiotherapy based on less robust data. Current major adjuvant questions are examining the role of the addition of a second agent, either cytotoxic or targeted agent, to gemcitabine and whether or not the utilization of combined chemoradiotherapy improves overall survival. Progress to date has been modest and incremental in the adjuvant setting.

Phase I trial of gemcitabine and candesartan combination therapy in normotensive patients with advanced pancreatic cancer: GECA1

Our retrospective study showed inhibition of the renin-angiotensin system was associated with better outcomes in patients with advanced pancreatic cancer receiving gemcitabine. The primary objective of this phase I study was to determine the recommended dose of candesartan in combination with gemcitabine in normotensive patients with advanced pancreatic cancer. Candesartan was given orally at an escalating dose (4, 8, 16, and 32 mg) q.d. daily, and gemcitabine was given 1000 mg/m(2) 30 min i.v. on days 1, 8, and 15, repeated every 4 weeks. Dose-limiting toxicity (DLT) was defined as grade 4 hematological toxicities, grade 2 hypotension, abnormal creatinine or potassium, and grade 3 or 4 other non-hematological toxicities. A standard "3+3" phase I dose-escalation design was used. A total of 14 patients (candesartan 4 mg, three patients; 8 mg, three patients; 16 mg, six patients; 32 mg, two patients) were enrolled. One of six patients at 16 mg showed DLT of grade 4 neutropenia and two of two patients at 32 mg showed DLT of grade 2 hypotension. Response rate and disease control rate were 0% and 79%, respectively. Progression-free survival and overall survival were 7.6 and 22.9 months, respectively. Candesartan 16 mg is the recommended dose in combination with gemcitabine in the treatment of advanced pancreatic cancer. (UMIN CTR: UMIN000002152).

Stromal galectin-1 expression is associated with long-term survival in resectable pancreatic ductal adenocarcinoma

The overall 5 year survival rate for pancreatic ductal adenocarcinoma (i.e., PDAC) is a dismal 5%, although patients that have undergone surgical resection have a somewhat better survival rate of up to 20%. Very long-term survivors of PDAC (defined as patients with ≥ 10 year survival following apparently curative resection), on the other hand, are considerably less frequent. The molecular characteristics of very long-term survivors (VLTS) are poorly understood, but might provide novel insights into prognostication for this disease. In this study, a panel of five VLTS and stage-matched short-term survivors (STS, defined as disease-specific mortality within 14 months of resection) were identified, and quantitative proteomics was applied to comparatively profile tumor tissues from both cohorts. Differentially expressed proteins were identified in cancers from VLTS vs. STS patients. Specifically, the expression of galectin-1 was 2-fold lower in VLTS compared with STS tumors. Validation studies were performed by immunohistochemistry (IHC) in two additional cohorts of resected PDAC, including: 1) an independent cohort of VLTS and 2) a panel of sporadic PDAC with a considerable range of overall survival following surgery. Immunolabeling analysis confirmed that significantly lower expression of stromal galectin-1 was associated with VLTS (p = 0.02) and also correlated with longer survival in sporadic, surgically-treated PDAC cases (hazard ratio = 4.9, p = 0.002). The results from this study provide new insights to better understand the role of galectin-1 in PDAC survival, and might be useful for rendering prognostic information, and developing more effective therapeutic strategies aimed at improving survival.

The role of stroma in pancreatic cancer: diagnostic and therapeutic implications

Pancreatic ductal adenocarcinoma (PDAC) is one of the five most lethal malignancies worldwide and survival has not improved substantially in the past 30 years. Desmoplasia (abundant fibrotic stroma) is a typical feature of PDAC in humans, and stromal activation commonly starts around precancerous lesions. It is becoming clear that this stromal tissue is not a bystander in disease progression. Cancer-stroma interactions effect tumorigenesis, angiogenesis, therapy resistance and possibly the metastatic spread of tumour cells. Therefore, targeting the tumour stroma, in combination with chemotherapy, is a promising new option for the treatment of PDAC. In this Review, we focus on four issues. First, how can stromal activity be used to detect early steps of pancreatic carcinogenesis? Second, what is the effect of perpetual pancreatic stellate cell activity on angiogenesis and tissue perfusion? Third, what are the (experimental) antifibrotic therapy options in PDAC? Fourth, what lessons can be learned from Langton's Ant (a simple mathematical model) regarding the unpredictability of genetically engineered mouse models?

Molecular mechanisms involved in the synergistic interaction of the EZH2 inhibitor 3-deazaneplanocin A with gemcitabine in pancreatic cancer cells

Pancreatic ductal adenocarcinoma (PDAC) is characterized by overexpression of enhancer of Zeste homolog-2 (EZH2), which plays a pivotal role in cancer stem cell (CSC) self-renewal through methylation of histone H3 lysine-27 (H3K27me3). Against this background, EZH2 was identified as an attractive target, and we investigated the interaction of the EZH2 inhibitor DZNeP with gemcitabine. EZH2 expression was detected by quantitative PCR in 15 PDAC cells, including seven primary cell cultures, showing that expression values correlated with their originator tumors (Spearman R(2) = 0.89, P = 0.01). EZH2 expression in cancer cells was significantly higher than in normal ductal pancreatic cells and fibroblasts. The 3-deazaneplanocin A (DZNeP; 5 μmol/L, 72-hour exposure) modulated EZH2 and H3K27me3 protein expression and synergistically enhanced the antiproliferative activity of gemcitabine, with combination index values of 0.2 (PANC-1), 0.3 (MIA-PaCa-2), and 0.7 (LPC006). The drug combination reduced the percentages of cells in G(2)-M phase (e.g., from 27% to 19% in PANC-1, P < 0.05) and significantly increased apoptosis compared with gemcitabine alone. Moreover, DZNeP enhanced the mRNA and protein expression of the nucleoside transporters hENT1/hCNT1, possibly because of the significant reduction of deoxynucleotide content (e.g., 25% reduction of deoxycytidine nucleotides in PANC-1), as detected by liquid chromatography/tandem mass spectrometry. DZNeP decreased cell migration, which was additionally reduced by DZNeP/gemcitabine combination (-20% in LPC006, after 8-hour exposure, P < 0.05) and associated with increased E-cadherin mRNA and protein expression. Furthermore, DZNeP and DZNeP/gemcitabine combination significantly reduced the volume of PDAC spheroids growing in CSC-selective medium and decreased the proportion of CD133+ cells. All these molecular mechanisms underlying the synergism of DZNeP/gemcitabine combination support further studies on this novel therapeutic approach for treatment of PDACs.

New biomarkers and targets in pancreatic cancer and their application to treatment

Late diagnosis of pancreatic ductal adenocarcinoma (pancreatic cancer) and the limited response to current treatments results in an exceptionally poor prognosis. Advances in our understanding of the molecular events underpinning pancreatic cancer development and metastasis offer the hope of tangible benefits for patients. In-depth mutational analyses have shed light on the genetic abnormalities in pancreatic cancer, providing potential treatment targets. New biological studies in patients and in mouse models have advanced our knowledge of the timing of metastasis of pancreatic cancer, highlighting new directions for the way in which patients are treated. Furthermore, our increasing understanding of the molecular events in tumorigenesis is leading to the identification of biomarkers that enable us to predict response to treatment. A major drawback, however, is the general lack of an adequate systematic approach to advancing the use of biomarkers in cancer drug development, highlighted in a Cancer Biomarkers Collaborative consensus report. In this Review, we summarize the latest insights into the biology of pancreatic cancer, and their repercussions for treatment. We provide an overview of current treatments and, finally, we discuss novel therapeutic approaches, including the role of biomarkers in therapy for pancreatic cancer.

The role of stroma in pancreatic cancer: diagnostic and therapeutic implications

Pancreatic ductal adenocarcinoma (PDAC) is one of the five most lethal malignancies worldwide and survival has not improved substantially in the past 30 years. Desmoplasia (abundant fibrotic stroma) is a typical feature of PDAC in humans, and stromal activation commonly starts around precancerous lesions. It is becoming clear that this stromal tissue is not a bystander in disease progression. Cancer-stroma interactions effect tumorigenesis, angiogenesis, therapy resistance and possibly the metastatic spread of tumour cells. Therefore, targeting the tumour stroma, in combination with chemotherapy, is a promising new option for the treatment of PDAC. In this Review, we focus on four issues. First, how can stromal activity be used to detect early steps of pancreatic carcinogenesis? Second, what is the effect of perpetual pancreatic stellate cell activity on angiogenesis and tissue perfusion? Third, what are the (experimental) antifibrotic therapy options in PDAC? Fourth, what lessons can be learned from Langton's Ant (a simple mathematical model) regarding the unpredictability of genetically engineered mouse models?

Overcoming nucleoside analog chemoresistance of pancreatic cancer: a therapeutic challenge

Clinical refractoriness to nucleoside analogs (e.g., gemcitabine, capecitabine) is a major scientific problem and is one of the main reasons underlying the extremely poor prognostic state of pancreatic cancer. The drugs' effects are suboptimal partly due to cellular mechanisms limiting their transport, activation, and overall efficacy. Nonetheless, novel therapeutic approaches are presently under study to circumvent nucleoside analog resistance in pancreatic cancer. With these new approaches come additional challenges to be addressed. This review describes the determinants of chemoresistance in the gemcitabine cytotoxicity pathways, provides an overview of investigational approaches for overcoming chemoresistance, and discusses new challenges presented. Understanding the future directions of the field may assist in the successful development of novel treatment strategies for enhancing chemotherapeutic efficacy in pancreatic cancer.

Phase II trial of combined regional hyperthermia and gemcitabine for locally advanced or metastatic pancreatic cancer

PURPOSE

Despite advances in cancer therapy, treating pancreatic cancer remains one of the major challenges in the field of medical oncology. We conducted this phase II study to evaluate the efficacy and safety of regional hyperthermia combined with gemcitabine for the treatment of unresectable advanced pancreatic cancer.

METHODS

Eligibility criteria included histologically proven, locally advanced or metastatic pancreatic cancer. Gemcitabine was administered intravenously at a dose of 1000 mg/m(2) on days 1, 8, and 15 every 4 weeks. Regional hyperthermia was performed once weekly, 1 day preceding or following gemcitabine administration. The primary end point was the 1-year survival rate. Secondary objectives were determination of tumour response and safety.

RESULTS

We enrolled 18 patients with advanced pancreatic cancer between November 2008 and May 2010. The major grade 3-4 adverse events were neutropenia and anaemia; however, there were no episodes of infection. The objective response rate (ORR) and disease control rate (ORR + stable disease) were 11.1% and 61.1%, respectively. Median overall survival (OS) was 8 months, and the 1-year survival rate was 33.3%. Median OS of patients with locally advanced pancreatic cancer was 17.7 months.

CONCLUSIONS

Regional hyperthermia combined with gemcitabine is well tolerated and active in patients with locally advanced pancreatic cancer.

Biliary tract carcinomas: from chemotherapy to targeted therapy

Biliary tract carcinomas (BTC) are a group of tumours arising from the epithelial cells of intra- and extra-hepatic biliaryducts and the gallbladder, characterised by a poor prognosis. Surgery is the only curative procedure, but the risk of recurrence is high and furthermore, the majority of patients present with unresectable disease at the time of diagnosis. Systemic therapy is the mainstay of treatment for patients who present recurrent or metastatic disease. Progress has been made in the last decade to identify the most effective chemotherapy regimens, with the recent recommendation of the combination of gemcitabine-cisplatin as the standard schedule. Comprehension of the molecular basis of cholangiocarcinogenesis and tumour progression has recently led to the experimentation of targeted therapies in patients with BTC, demonstrating promising results. In this review we will discuss the clinical experience with systemic treatment for BTC, focusing on future directions with targeted therapies.

Targeting anticancer drug delivery to pancreatic cancer cells using a fucose-bound nanoparticle approach

Owing to its aggressiveness and the lack of effective therapies, pancreatic ductal adenocarcinoma has a dismal prognosis. New strategies to improve treatment and survival are therefore urgently required. Numerous fucosylated antigens in sera serve as tumor markers for cancer detection and evaluation of treatment efficacy. Increased expression of fucosyltransferases has also been reported for pancreatic cancer. These enzymes accelerate malignant transformation through fucosylation of sialylated precursors, suggesting a crucial requirement for fucose by pancreatic cancer cells. With this in mind, we developed fucose-bound nanoparticles as vehicles for delivery of anticancer drugs specifically to cancer cells. L-fucose-bound liposomes containing Cy5.5 or Cisplatin were effectively delivered into CA19-9 expressing pancreatic cancer cells. Excess L-fucose decreased the efficiency of Cy5.5 introduction by L-fucose-bound liposomes, suggesting L-fucose-receptor-mediated delivery. Intravenously injected L-fucose-bound liposomes carrying Cisplatin were successfully delivered to pancreatic cancer cells, mediating efficient tumor growth inhibition as well as prolonging survival in mouse xenograft models. This modality represents a new strategy for pancreatic cancer cell-targeting therapy.

A randomised phase II trial of the Polo-like kinase inhibitor BI 2536 in chemo-naïve patients with unresectable exocrine adenocarcinoma of the pancreas - a study within the Central European Society Anticancer Drug Research (CESAR) collaborative network

BACKGROUND

BI 2536, a novel Polo-like kinase 1 inhibitor, was assessed in patients with unresectable advanced exocrine adenocarcinoma of the pancreas.

METHODS

The study employed a two-stage design. Randomised first-line patients received BI 2536 200 mg on day 1 (n=43) or 60 mg on days 1-3 (n=43) every 21 days. Recruitment of second-line patients was planned for a second stage dependent on an interim analysis demonstrating ≥ 2 responses in the first 18 evaluable patients following 12 weeks of treatment and/or tumour control ≥ 12 weeks in 5 patients per schedule. Primary end point was objective response rate (ORR).

RESULTS

By independent review, ORR was 2.3% (all partial) and 24.4% had stable disease as confirmed best response. The second stage was not initiated. Median overall and progression-free survivals were 149 (95% confidence interval (CI), 91-307) and 46 days (95% CI, 44-56). Most common drug-related adverse events were neutropenia (37.2%), leukopenia (29.1%), fatigue (29.1%) and nausea (22.1%); most common grade 3/4-related events were neutropenia (36.0%), leukopenia (27.9%) and thrombocytopenia (8.1%).

CONCLUSION

Given the low ORR and poor survival, further development of BI 2536 monotherapy is not warranted in this population.

Resection after neoadjuvant therapy for locally advanced, "unresectable" pancreatic cancer

BACKGROUND

For pancreatic cancer, complete macroscopic resection in combination with chemotherapy is the only potentially curative treatment. Many patients present with locally advanced cancers deemed unresectable. We sought to assess the results of exploration after neoadjuvant therapy for locally advanced possibly unresectable pancreatic cancer.

METHODS

From a prospective database, all consecutive patients undergoing operation from October 2001 to December 2009 after neoadjuvant therapy for locally advanced pancreatic cancer were identified. Main criteria for "unresectability" were infiltration of the celiac axis or superior mesenteric artery. Resection rates, perioperative results, and survival were analyzed.

RESULTS

Of 257 patients, 199 (77.4%) had received neoadjuvant chemoradiation, and 58 (22.6%) chemotherapy only. Of 257 patients, 120 (46.7%) underwent successful resection, whereas 137 patients underwent exploration only; 47 (39.2%) multivisceral and 45 (37.5%) vascular resections (12 arterial reconstructions) were performed. There were 6 (5%) ypT0 neoplasms, 36 (30.0%) R0, 61 (50.8%) R1, and 16 (13.3%) R2 resections. The median follow-up of surviving patients (n = 22) was 22 months. Median postoperative survival was greater after resection (12.7 months) than after exploration alone (8.8 months; P < .0001). Median postoperative survival was 24.6 months after R0, 11.9 months after R1, and 8.9 months after R2 resection. The 3-year survival rate after R0 resection was 24%. To determine survival after start of neoadjuvant therapy, 3.7 months (median) have to be added.

CONCLUSION

In locally advanced, unresectable pancreatic cancer, R0/R1 resections can be achieved in up to 40% of patients who undergo operation after neoadjuvant therapy. In these cases, survival rates are similar to those observed for initially resectable pancreatic cancer.

Therapeutic targeting of pancreatic cancer utilizing sigma-2 ligands

One major barrier in the development of pancreas cancer therapeutics is the selective delivery of the drugs to their cellular targets. We have previously developed several sigma-2 ligands and reported the discovery of a component of the receptor for these ligands. Several sigma-2 ligands have been shown to trigger apoptosis in pancreas cancer cells. More importantly, sigma-2 ligands are internalized rapidly by the cancer cells and are capable of delivering other small-molecule therapeutics. Here we review sigma-2 ligands and conjugates as a potential novel therapy suitable for investigation in patients with pancreatic cancer.

The gamma secretase inhibitor MRK-003 attenuates pancreatic cancer growth in preclinical models

Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignancy, with most patients facing an adverse clinical outcome. Aberrant Notch pathway activation has been implicated in the initiation and progression of PDAC, specifically the aggressive phenotype of the disease. We used a panel of human PDAC cell lines as well as patient-derived PDAC xenografts to determine whether pharmacologic targeting of Notch pathway could inhibit PDAC growth and potentiate gemcitabine sensitivity. MRK-003, a potent and selective γ-secretase inhibitor, treatment resulted in the downregulation of nuclear Notch1 intracellular domain, inhibition of anchorage-independent growth, and reduction of tumor-initiating cells capable of extensive self-renewal. Pretreatment of PDAC cells with MRK-003 in cell culture significantly inhibited the subsequent engraftment in immunocompromised mice. MRK-003 monotherapy significantly blocked tumor growth in 5 of 9 (56%) PDAC xenografts. A combination of MRK-003 and gemcitabine showed enhanced antitumor effects compared with gemcitabine in 4 of 9 (44%) PDAC xenografts, reduced tumor cell proliferation, and induced both apoptosis and intratumoral necrosis. Gene expression analysis of untreated tumors indicated that upregulation of NF-κB pathway components was predictive of sensitivity to MRK-003, whereas upregulation in B-cell receptor signaling and nuclear factor erythroid-derived 2-like 2 pathway correlated with response to the combination of MRK-003 with gemcitabine. Our findings strengthen the rationale for small-molecule inhibition of Notch signaling as a therapeutic strategy in PDAC.

Genetically defined subsets of human pancreatic cancer show unique in vitro chemosensitivity

PURPOSE

Pancreatic cancer is the fourth cause of death from cancer in the western world. Majority of patients present with advanced unresectable disease responding poorly to most chemotherapeutic agents. Chemotherapy for pancreatic cancer might be improved by adjusting it to individual genetic profiles. We attempt to identify genetic predictors of chemosensitivity to broad classes of anticancer drugs.

EXPERIMENTAL DESIGN

Using a panel of genetically defined human pancreatic cancer cell lines, we tested gemcitabine (antimetabolite), docetaxel (antimicrotubule), mitomycin C (MMC; alkylating), irinotecan (topoisomerase I inhibitor), cisplatin (crosslinking), KU0058948 (Parp1 inhibitor), triptolide (terpenoid drug), and artemisinin (control).

RESULTS

All pancreatic cancer cell lines were sensitive to triptolide and docetaxel. Most pancreatic cancer cells were also sensitive to gemcitabine and MMC. The vast majority of pancreatic cancer cell lines were insensitive to cisplatin, irinotecan, and a Parp1 inhibitor. However, individual cell lines were often sensitive to these compounds in unique ways. We found that DPC4/SMAD4 inactivation sensitized pancreatic cancer cells to cisplatin and irinotecan by 2- to 4-fold, but they were modestly less sensitive to gemcitabine. Pancreatic cancer cells were all sensitive to triptolide and 18% were sensitive to the Parp1 inhibitor. P16/CDKN2A-inactivated pancreatic cancer cells were 3- to 4-fold less sensitive to gemcitabine and MMC.

CONCLUSIONS

Chemosensitivity of pancreatic cancer cells correlated with some specific genetic profiles. These results support the hypothesis that genetic subsets of pancreatic cancer exist, and these genetic backgrounds may permit one to personalize the chemotherapy of pancreatic cancer in the future. Further work will need to confirm these responses and determine their magnitude in vivo.