Chemotherapy for pancreatic cancer

The potential role of the glycoprotein osteoactivin/glycoprotein nonmetastatic melanoma protein B in pancreatic cancer

OBJECTIVES

Pancreatic ductal adenocarcinoma is still one of the deadliest solid cancers so the finding of new therapeutic approaches and novel targets are of utmost importance. Glycoprotein nonmetastatic melanoma protein B (GPNMB), initially termed glycoprotein nonmetastatic gene B and also named osteoactivin (OA), is a type 1 transmembrane protein that has been recently found to play a role in cancer cell proliferation, angiogenesis, and invasion. Due to its potential responsibility in cancer aggressiveness, the main objective of this work was to assess the role of GPNMB/OA in human pancreatic cancer.

METHODS

Using the human pancreatic cancer cell line Panc-1 in vitro, the effects of GPNMB on growth, proliferation, and invasion were tested by BrdU uptake, cell cycle and Annexin V-FITC analysis, RT-PCR, protein expression, and invasion chamber assays.

RESULTS

Our results showed that GPNMB/OA protein expression prevents cells from apoptosis-enhancing proliferation and represents a novel modulator of the invasion and metastasis in pancreatic cancer cells.

CONCLUSIONS

Due to its main membrane localization in cancer cells and its role in the aggressiveness of pancreatic cancer, GPNMB/OA could represent a novel targeted therapy for pancreatic cancer being attractive for antibody-based therapies.

Synergistic activity of troxacitabine (Troxatyl) and gemcitabine in pancreatic cancer

Background

Gemcitabine, a deoxycytidine nucleoside analog, is the current standard chemotherapy used as first-line treatment for patients with locally advanced or metastatic cancer of the pancreas, and extends life survival by 5.7 months. Advanced pancreatic cancer thus remains a highly unmet medical need and new therapeutic agents are required for this patient population. Troxacitabine (Troxatyl™) is the first unnatural L-nucleoside analog to show potent preclinical antitumor activity and is currently under clinical investigation. Troxacitabine was recently evaluated as a first-line therapy in 54 patients with advanced adenocarcinoma of the pancreas and gave comparable overall results to those reported with gemcitabine in recently published randomized trials.

Methods

The human pancreatic adenocarcinoma cell lines, AsPC-1, Capan-2, MIA PaCa-2 and Panc-1, were exposed to troxacitabine or gemcitabine alone or in combination, for 72 h, and the effects on cell growth were determined by electronic particle counting. Synergistic efficacy was determined by the isobologram and combination-index methods of Chou and Talalay. Mechanistic studies addressed incorporation of troxacitabine into DNA and intracellular levels of troxacitabine and gemcitabine metabolites. For in vivo studies, we evaluated the effect of both drugs, alone and in combination, on the growth of established human pancreatic (AsPC-1) tumors implanted subcutaneously in nude mice. Statistical analysis was calculated by a one-way ANOVA with Dunnett as a post-test and the two-tailed unpaired t test using GraphPad prism software.

Results

Synergy, evaluated using the CalcuSyn Software, was observed in all four cell-lines at multiple drug concentrations resulting in combination indices under 0.7 at Fa of 0.5 (50% reduction of cell growth). The effects of drug exposures on troxacitabine and gemcitabine nucleotide pools were analyzed, and although gemcitabine reduced phosphorylation of troxacitabine when cells were exposed at equal drug concentrations, there was no effect on phosphorylated pools at drug combinations that were synergistic. The amount of troxacitabine incorporated into DNA was also not affected by the presence of gemcitabine. In vivo testing against a human pancreatic (AsPC-1) xenograft mouse tumor model indicated that both drugs were more than additive at well-tolerated doses and schedule. The biological basis for this synergy is unclear as we did not observe changes in apoptosis, DNA repair, troxacitabine incorporation into DNA or troxacitabine metabolism in the presence of gemcitabine.

Conclusion

These data, together with phase I clinical data showing tolerability of both agents when combined, suggest combination therapy with troxacitabine and gemcitabine warrants further evaluation in advanced pancreatic cancer patients.

A novel retinoid-related molecule inhibits pancreatic cancer cell proliferation by a retinoid receptor independent mechanism via suppression of cell cycle regulatory protein function and induction of caspase-associated apoptosis

Retinoid-related molecules are important potential agents for the treatment of cancer. In the present study, we test the effect of a novel retinoid-related ligand, AGN193198 (4-[3-(1-heptyl-4,4-dimethyl-2-oxo-1,2,3,4-tetrahydroquinolin-6-yl)-3-oxo-prophenyl] benzoic acid), on pancreatic cancer cell proliferation and survival. AGN193198 treatment reduces BxPC-3 cell proliferation more efficiently than high-affinity retinoid acid receptor (RAR)- or retinoid X receptor (RXR)-selective retinoids. Moreover, AGN193198 does not activate transcription from RAR or RXR response elements and its effects on cell survival are not reversed by treatment with RAR- or RXR receptor-selective antagonists. These results suggest that the AGN193198-dependent inhibition of BxPC-3 cell function is not mediated via activation of the classical retinoid receptors. Cell cycle analysis of AGN193198-treated BxPC-3 cells indicates that AGN193198 causes accumulation of cells in G2/M. This change is associated with a marked reduction in regulators of S (cyclin A, cyclin-dependent kinase (cdk)2), G2/M (cyclin B1, cdk1, cdc25c) and G1 (cyclin D1, cyclin E, cdk2, cdk4) phase, and an increase in p21 and p27 level. Kinases assays reveal that cdk1, cdk2 and cdk4 activity are suppressed in AGN193198-treated cells. In addition, reduced cell proliferation is associated with enhanced procaspase (3, 8 and 9) and PARP cleavage. Z-VAD-FMK, a pancaspase inhibitor, inhibits AGN193198-dependent caspase activation and attenuates cell death. Z-VAD-FMK inhibits PARP cleavage, but does not alter the AGN193198-dependent reduction in cell cycle regulatory protein expression and activity, suggesting that caspase activation and suppression of cell cycle regulatory protein levels are independent processes. AGN193198 produces similar responses in other pancreatic cancer cell lines including AsPC-1 and MIA PaCa-2. These studies suggest that AGN193198 may be useful for the treatment of pancreatic cancer.

Retinoic acid enhances the cytotoxic effects of gemcitabine and cisplatin in pancreatic adenocarcinoma cells

INTRODUCTION

Retinoids, which are derivatives of vitamin A, are important factors involved in the control of biologic functions such as cell growth and differentiation, development, and carcinogenesis. We have shown previously that the naturally occurring retinoids all-trans-retinoic acid (ATRA) and 9-cisretinoic acid (9cRA) induce growth inhibition followed by apoptosis in pancreatic adenocarcinoma cells in vitro.

AIM

To evaluate the efficacy of retinoids in combination with the chemotherapeutic drugs gemcitabine and cisplatin.

METHODOLOGY

In vitro growth inhibition and induction of apoptosis by different combinations of retinoids and cytotoxic drugs were studied by using the T3M-4 and BxPc-3 cell lines. For in vivo studies, T3M-4 cells were injected subcutaneously in nude mice.

RESULTS

Pre-treatment of pancreatic adenocarcinoma cells with ATRA or 9cRA before the addition of the drugs resulted in significant reduction in cell number compared with treatment with the drugs alone. Pre-treatment with 9cRA followed by gemcitabine or cisplatin alone also resulted in a strong increase in the percentage of cells undergoing programmed cell death, or apoptosis. Furthermore, there was an indication that the combination of ATRA and gemcitabine caused increased apoptosis in vivo.

CONCLUSION

Our results clearly suggest the need for additional studies exploring the potential role of the combination of retinoids and gemcitabine in the management of pancreatic cancer.

Expression of Bcl-2 and p53 protein in resectable invasive ductal carcinoma of the pancreas: effects on clinical outcome and efficacy of adjuvant chemotherapy

BACKGROUND AND OBJECTIVES

p53 tumor suppressor gene has a dual role as a trigger of apoptosis and as an initiator of DNA repair. The Bcl-2 can work to protect cells from apoptosis, which is induced by p53 gene. These facts suggest the significant role of these genes in the genesis and progression of various tumors. The present study was designed to assess the significance of p53 and Bcl-2 protein (pBcl-2) expression on resectable invasive ductal carcinoma (IDC) of the pancreas.

METHODS

The present study included 63 IDCs, which were resected between 1982 and 1998. pBcl-2 and p53 were stained immunohistochemically with monoclonal antibodies.

RESULTS

pBcl-2 was expressed in 16 (25.4%), and p53 was positively expressed in 32 out of 63 IDCs (50.8%); however, expression of pBcl-2 did not necessarily correlate with that of p53. Although p53 expression did not show any significant influence on the patients' survival, pBcl-2(+) patients showed a higher survival than pBcl-2(-) patients for both p53(+) and p53(-) patients, which suggested that pBcl-2 expression had a more significant effect on the survival of patients than p53 expression. On the other hand, there were no differences in the survival curve between the adjuvant chemotherapy (ACT) group and the surgery alone (SA) group. pBcl-2 expression had no influence on the effect of ACT, the ACT group showed a significantly better survival than the SA group for p53(+) IDC patients.

CONCLUSIONS

pBcl-2 expression is a beneficial prognostic factor for patients with IDC, whereas p53 expression may be beneficial in the prediction of the effects of adjuvant chemotherapy on patients with IDC. J. Surg. Oncol. 2001;76:188-196.

Novel non-operative treatment and treatment strategies in pancreatic cancer

Patients with advanced pancreatic cancer have traditionally been treated with palliative care only. The last decade has seen significant improvements in the surgical treatment of this disease but until the late 1990s there was no effective non-surgical treatment for these tumours. The introduction of gemcitabine has given clinicians treating patients with pancreatic cancer a new option. The published randomised data of gemcitabine in patients with pancreatic cancer has shown both a small survival advantage and significant improvements in quality of life indicators in these patients. These data have stimulated a resurgence of interest in pancreatic tumours and several studies have been or are currently investigating novel treatments or treatment strategies. The explosion in the molecular knowledge of cancer has led to the development of several 'molecular designer drugs' that have been tested in pancreatic cancer. The furthest advanced of these is a matrix metalloproteinase (MMP) inhibitor called marimastat. The first randomised data using this new class of agents is increasing and suggests that marimastat may have a role in the future treatment of patients with pancreatic cancer. Other agents such as gastrimmune, are about to enter Phase III studies and several other molecular treatment strategies are progressing from the in vitro stage towards the clinical arena. Each of these treatments and treatment regimens are discussed along with their current progress.

Transcatheter arterial infusion therapy in the treatment of advanced pancreatic cancer: a feasibility study

PURPOSE

To evaluate the effects of transcatheter arterial infusion (TAI) therapy in 18 patients with advanced pancreatic cancer.

METHODS

The drugs infused were epirubicin 60 mg, mitomycin C 20 mg, and 5-fluorouracil 500 mg. The efficacy of TAI was evaluated by a tumor marker (CA19-9), computed tomography (CT) findings, and postoperative histopathological specimens.

RESULTS

In 10 of 15 cases, the tumor marker level was decreased after TAI therapy. In 6 of 14 cases, CT showed a decrease in the tumor size, and in 1 case, the tumor disappeared completely. In 6 cases the tumor could be resected. Necrosis, fibrosis, and degeneration of cancer cells were seen in 3 of 4 cases for whom a histopathological evaluation was done. The median survival was 11 months. In 17 patients back pain was the chief complaint, and was reduced to a self-controlled level in 10 patients following TAI therapy. No major complications were encountered.

CONCLUSION

TAI appears to be an effective palliative treatment for advanced pancreatic cancer.

A phase II pilot trial of 13-cis retinoic acid and interferon-alpha in patients with advanced pancreatic carcinoma

BACKGROUND

Advanced unresectable pancreatic adenocarcinoma has a dismal prognosis. The authors previously have shown that retinoic acid (RA) and interferon-alpha (IFN-alpha) inhibit growth and induce differentiation in human pancreatic carcinoma cells in vitro and in vivo. The purpose of this trial was to examine the feasibility and tolerability of a combination therapy of 13-cis RA and IFN-alpha in patients with advanced unresectable pancreatic carcinoma.

METHODS

Twenty-two patients (median age, 62 years) with histologically confirmed, unresectable pancreatic adenocarcinoma classified as International Union Against Cancer Stage III (5 patients) or IV (17 patients) were included. Patients received 1 mg/kg body weight 13-cis RA orally and 6 million IU IFN-alpha subcutaneously daily. Restaging by ultrasound, computed tomography scan, and chest X-ray was performed every 2 months.

RESULTS

No complete remission and 1 partial remission (PR) (4.5%) were observed. Fourteen patients (63.6%) demonstrated stable disease with a median duration of 5.0 months (range, 2.3-17.7+ months). Toxicity mainly was related to IFN-alpha and predominantly was hematologic (no toxicity was World Health Organization [WHO] Grade 4 and 13.6% were WHO Grade 3). Nonhematologic toxicities did not exceed Grade 2 (skin and oral mucosa) and mainly were related to 13-cis RA. The median survival of the patients with Stage III disease was 8.7 months (range, 6.8-23.9+ months) and was 7.4 months for patients with Stage IV disease (range, 0.9-19.2+ months), resulting in a median overall survival of 7.7 months (range, 0.9-23.9+ months).

CONCLUSIONS

Combination therapy with 13-cis RA and IFN-alpha is feasible and well tolerated in patients with advanced pancreatic carcinoma. Based on the median survival rates observed in this study this combination should be investigated further in Phase III trials.

Retinoic acid receptor gamma1 expression determines retinoid sensitivity in pancreatic carcinoma cells

BACKGROUND & AIMS

Retinoids inhibit growth and induce differentiation in a variety of pancreatic carcinoma cells. The goal of this study was to examine the molecular mechanisms responsible for retinoid sensitivity.

METHODS

Anchorage-independent growth was examined in AR42J, DSL-6A/C1, and Capan-2 cells using a human tumor clonogenic assay. Retinoid receptors were characterized by a reverse-transcription polymerase chain reaction. Retinoic acid receptor gamma1 (RARgamma1) was stably transfected into AR42J cells using lipofectamin and into DSL-6A/C1 using ballistomagnetic gene transfer. Receptor expression was verified using Southern and Northern blotting as well as electrophoretic mobility shift assays.

RESULTS

Retinoid treatment resulted in a dose-dependent growth inhibition of Capan-2 cells, whereas growth was not affected in AR42J and DSL-6A/C1 cells. A selective loss of RARgamma1 expression was observed in both retinoid-resistant cell lines, whereas all other retinoid receptor subtypes showed an identical expression pattern. Retinoid treatment of three independent RARgamma1-expressing cell clones of AR42J and DSL-6A/C1 cells resulted in pronounced growth inhibition compared with wild-type control cells.

CONCLUSIONS

RARgamma1 expression determines sensitivity of pancreatic carcinoma cells to retinoid-mediated growth inhibition and might therefore serve as a valuable predictive marker for retinoid treatment of pancreatic cancer.

Progress report. A randomized multicenter European study comparing adjuvant radiotherapy, 6-mo chemotherapy, and combination therapy vs no-adjuvant treatment in resectable pancreatic cancer (ESPAC-1)

CONCLUSION

The ESPAC-1 trial is the largest study of its kind in pancreatic cancer and should definitively address the question of the role of conventional methods of adjuvant treatment in pancreatic cancer.

BACKGROUND

At the joint International Association of Pancreatology and the European Pancreatic Club meeting in Mannheim, Germany (June 12-15, 1996) a satellite meeting of the European Study Group for Pancreatic Cancer (ESPAC) met to discuss the progress of the ESPAC-1 trial.

METHODS

A randomized multicenter study to address which, if any, of the following adjuvant treatments are of benefit in patients with resectable pancreatic cancer: radiotherapy (40 Gy with 5-FU as a sensitizing agent), 6 mo of chemotherapy (5-FU and folinic acid), or a combination of these treatments.

RESULTS

From February 1994 to June 1996 (the time of the Mannheim meeting) 221 patients so far have been recruited into the three treatment arms and one control arm.

Adjuvant chemotherapy in pancreatic cancer

There is increasing interest in the use of adjuvant treatment for pancreatic cancer since although postoperative mortality is much improved, median long-term survival is only on the order of 11-15 mo. Despite a proliferation of studies in advanced pancreatic cancer indicating a benefit for chemotherapy, there has only been one small randomized adjuvant trial. A combination of 5-fluorouracil, doxorubicin, and mitomycin-C demonstrated a significantly improved median survival (23 vs 11 mo in controls) but no significant improvement in 5-yr survival (4 vs 8%, respectively). At present there is insufficient evidence to support the routine use of adjuvant chemotherapy (even with radiotherapy) outside of controlled trials. What is required is large randomized trials of adjuvant chemotherapy. A further important question that needs addressing is the role of adjuvant radiotherapy (with concomitant chemotherapy) with or without sequential chemotherapy.

Combined modality treatment with accelerated radiotherapy and chemotherapy in patients with locally advanced inoperable carcinoma of the pancreas: results of a feasibility study

Between July 1990 and September 1993, 32 patients with locally advanced irresectable adenocarcinoma of the pancreas, histologically proven by laparotomy, were involved in our study. Patients were treated with hyperfractionated, accelerated radiotherapy and simultaneous application of 5-fluorouracil and folinic acid. Chemotherapy was given on days 1,2 and 3. Determination of the target volume for radiotherapy was carried out by computerized axial tomography. The total tumour dose of 44.8 Gy was applied relative to the 90% isodose in two daily fractions of 1.6 Gy, resulting in ten fractions per week. On the first three days of radiotherapy, 600 mg m-3 of 5-fluorouracil and 300 mg m-3 of folinic acid were given i.v. According to response, chemotherapy was repeated in 4-week intervals. The median survival time for all patients was 12.7 months, compared with 3-7 months after palliative surgery (historical control). The median progression-free interval was 6.6 months. Toxicity and therapy-induced morbidity were recorded according to WHO criteria. Nausea and vomiting of WHO grade I and II occurred in 72.1% and of grade III and IV in 27.9% of the patients. WHO grade I and II diarrhoea was seen in 11 patients. The overall incidence of leucopenia and thrombocytopenia was 37.4%; severe side-effects (WHO III-IV) occurred in 9.3% of all patients. One patient experienced a severe mucositis (WHO III). This combined modality treatment consisting of accelerated hyperfractionated radiotherapy and chemotherapy turned out to be feasible for patients with locally advanced, irresectable pancreatic cancer. The therapy could be applied in a short period of time, approximately half the time used in conventional therapy schemes.

Intermittent continuous infusion of ifosfamide and 5-fluorouracil in patients with advanced adenocarcinoma of the pancreas

BACKGROUND

In advanced adenocarcinoma of the pancreas treatment with 5-fluorouracil (5-FU) or ifosfamide results in response rates of approximately 20%. Continuous infusion of these drugs is on many grounds theoretically attractive and may therefore offer advantages over bolus or short-term infusion.

PATIENTS AND METHODS

Sixteen patients with advanced adenocarcinoma of the pancreas with progressive measurable disease and no previous chemotherapy entered the study. After implantation of a subcutaneous infusion chamber patients were treated on days 1-12 with ifosfamide (1.0 g/m2/day) and 5-FU (300 mg/m2/day) as a continuous intravenous infusion using a portable infusion pump. Mesna (1.0 g/m2/day) was added as uroprotective agent from day 1-14. Courses were repeated every 4 weeks.

RESULTS

Fifteen of the 16 patients were evaluable for response. One partial response was observed (response rate 7% [95% CI: 0%-32%]). Toxicity occurred in 64% of the courses. Dose limiting toxic effects were grade 3 nausea/vomiting (WHO) in 3 patients, grade 2 mucositis in 1 patient and grade 4 leukopenia in 1 patient.

CONCLUSION

Intermittent continuous infusion with ifosfamide, mesna and 5-FU is feasible on an outpatient basis. Although continuous infusion of ifosfamide may have a more favorable toxicity profile, the combination of 5-FU and ifosfamide in this schedule is no more effective than bolus or short-term infusion.

Retinoids: effects on growth, differentiation, and nuclear receptor expression in human pancreatic carcinoma cell lines

BACKGROUND & AIMS

Advanced pancreatic carcinoma has a dismal prognosis despite extensive chemotherapeutic trials. The aim of this study was to evaluate the role of retinoids as an experimental therapeutic approach for pancreatic cancer.

METHODS

Four ductal and one acinar pancreatic tumor cell lines were investigated. Growth was determined by cell number and a human tumor clonogenic assay. In vivo growth was assessed by xenografts transplanted into nude mice. Differentiation was characterized by immunofluorescence microscopy and carbonic anhydrase II gene expression. Retinoid receptors were characterized by Northern blotting and reverse-transcriptase polymerase chain reaction.

RESULTS

Retinoid treatment results in a time- and dose-dependent growth inhibition in vitro and in vivo of ductal but not acinar pancreatic tumor cells. Retinoid treatment induces a more differentiated phenotype in ductal tumor cells as shown by morphological criteria and increased expression of carbonic anhydrase II. All pancreatic tumor cell lines expressed a broad panel of cellular retinoid binding proteins and nuclear retinoid receptors. Retinoic acid receptor gamma and cellular retinoic acid binding protein II were found in all retinoid-sensitive ductal tumor cell lines but not in the retinoid-resistant acinar cell lines.

CONCLUSIONS

Detailed knowledge of nuclear retinoid receptor expression may provide rational strategies for retinoid treatment of pancreatic cancer.

No standard treatment is available for advanced pancreatic cancer

All randomised trials, published from 1980 to 1993, of treatments in advanced and locally unresectable exocrine pancreatic carcinoma were critically reviewed to identify the most effective therapeutic strategy for use as a control arm in randomised trials for such patients. All the published randomised trials on patients with pancreatic cancer were identified, and the treatment results summarised by means of published methodological guidelines. Twenty-seven reports, including 21 on hormonal or chemotherapy and six on radio/chemotherapy were identified. Very different treatment programmes were used in the trials, without a rationale sequence for testing hypotheses. Furthermore, several methodological drawbacks undermined both the internal and the external validity of these studies. Therefore, no meta-analysis can be conducted, combining the results of the randomised controlled trials in pancreatic cancer published from 1990 to 1993; no standard treatment is currently available for patients with advanced pancreatic cancer; future studies should screen new drugs or new combinations; and an untreated control group should be included in future comparative studies until real advantages in terms of better quality of life or improved survival are demonstrated.

Chemotherapy prolongs survival in inoperable pancreatic carcinoma

Forty-three patients with irresectable advanced pancreatic cancer were randomized to receive chemotherapy using a combination of 5-fluorouracil, Adriamycin and mitomycin or no chemotherapy. Groups were well matched with regard to age, extent of disease and performance status on entry. Chemotherapy was well tolerated and, although common, side-effects were usually mild. Psychological measurements based on the Hospital Anxiety and Depression score were made in 31 patients. These showed significantly less depression but not anxiety in the treated group immediately after randomization and following 2 months of chemotherapy. Median survival in the treated group was 33 (range 9-80) weeks compared with 15 (range 1-62) weeks in the untreated group (P < 0.002). Chemotherapy should be considered in all patients presenting with advanced inoperable pancreatic cancer.