Adjuvant therapy for pancreatic cancer

Multi-disciplinary management of locally advanced pancreatic cancer with irreversible electroporation

The essential diagnosis for LAPC is based on high-quality cross-sectional imaging, which demonstrates tumor invasion into the celiac/superior mesenteric arteries and/or superior mesenteric/portal venous system that is not reconstructable. The optimal management of these patients is evolving quickly with the advent of newer chemotherapeutics, radiation, and non-thermal ablation modalities. This review will present the current status of initial chemotherapy, surgical therapy, ablative therapy, and radiation therapy for patients with nonmetastatic locally advanced unresectable pancreatic cancer.

Minimally invasive ablation treatment for locally advanced pancreatic adenocarcinoma

Pancreatic adenocarcinoma is an aggressive tumour with an extremely poor prognosis, which has not changed significantly during the last 30 years. Prolonged survival is achieved only by R0 resection with macroscopic tumour clearance. However, the majority of the cases are considered inoperable at diagnosis due to local spread or presence of metastatic disease. Chemoradiotherapy is not tolerated by all patients and still fails to prolong survival significantly; neoadjuvant treatment also has limited results on pain control or tumour downstaging. In recent years, there has been a growing interest in the use of ablation therapy for the treatment of nonresectable tumours in various organs. Ablation techniques are based on direct application of chemical, thermal, or electrical energy to a tumour, which leads to cellular necrosis. With ablation, tumour cytoreduction, local control, and relief from symptoms are obtained in the majority of the patients. Inoperable cases of pancreatic adenocarcinoma have been treated by various ablation techniques in the last few years with promising results. The purpose of this review is to present the current status of local ablative therapies in the treatment of pancreatic adenocarcinoma and to investigate on the efficiency and the future trends.

Few genes are associated with the capability of pancreatic ductal adenocarcinoma cells to grow in the liver of nude rats

Owing to aggressiveness and chemoresistance, pancreatic ductal adenocarcinoma (PDAC) is characterised by a poor prognosis. To address this disease-spe-cific dilemma we aimed to establish animal models, which can be used for identifying new specific tumor markers, as well as serving as tools for potential therapeutic approaches. From a panel of sixteen pancreatic cancer cell lines, two human (Suit2-007 and Suit2-013) and a rat (ASML) cell line were selected for their properties to grow in the liver of male RNU rats and mimic liver metastasis of PDAC. For better monitoring of metastatic tumor growth in vivo, all three pancreatic cancer cell lines were stably transfected with eGFP and luciferase marker genes. In addition, the mRNA expression profile of 13 human PDAC cell lines was analyzed by BeadChip array analysis. Only 33 genes and 5 signaling pathways were identified as significantly associated with the ability of the cell lines to grow initially and/or consistently in rat liver. Only a minority of these genes (osteopontin, matrix metalloproteinase-1 and insulin-like growth factor 1) has been intensively studied and shown to be closely related to cancer progression. The function of the remaining 30 genes ranges from moderate to poorly investigated, and their function in cancer progression is still unclear. The ensuing three pancreatic cancer liver metastasis models vary in their aggressiveness and macroscopic growth. They will be used for preclinical evaluation of new therapeutic approaches aiming at the genes identified.

Multicenter phase II trial of adjuvant therapy for resected pancreatic cancer using cisplatin, 5-fluorouracil, and interferon-alfa-2b-based chemoradiation: ACOSOG Trial Z05031

BACKGROUND

The American College of Surgeons Oncology Group sought to confirm the efficacy of a novel interferon-based chemoradiation regimen in a multicenter phase II trial.

PATIENTS AND METHODS

Patients with resected (R0/R1) adenocarcinoma of the pancreatic head were treated with adjuvant interferon-alfa-2b (3 million units s.c. on days 1, 3, and 5 of each week for 5.5 weeks), cisplatin (30 mg/m(2) i.v. weekly for 6 weeks), and continuous infusion 5-fluorouracil (5-FU; 175 mg·m(2)/day for 38 days) concurrently with external-beam radiation (50.4 Gy). Chemoradiation was followed by two 6-week courses of continuous infusion 5-FU (200 mg·m(2)/day). The primary study end point was 18-month overall survival from protocol enrollment (OS18); an OS18 ≥65% was considered a positive study outcome.

RESULTS

Eighty-nine patients were enrolled. Eighty-four patients were assessable for toxicity. The all-cause grade ≥3 toxicity rate was 95% (80 patients) during therapy. No long-term toxicity or toxicity-related deaths were noted. At 36-month median follow-up, the OS18 was 69% [95% confidence interval (CI) 60% to 80%]; the median disease-free survival and overall survival were 14.1 months (95% CI 11.0-20.1 months) and 25.4 months (95% CI 23.4-34.1 months), respectively.

CONCLUSIONS

Notwithstanding promising multi-institutional efficacy results, further development of this regimen will require additional modifications to mitigate toxic effects.

Comparison of CT and PET-CT based planning of radiation therapy in locally advanced pancreatic carcinoma

BACKGROUND

To compare computed tomography (CT) with co-registered positron emission tomography-computed tomography (PET-CT) as the basis for delineating gross tumor volume (GTV) in unresectable, locally advanced pancreatic carcinoma (LAPC).

METHODS

Fourteen patients with unresectable LAPC had both CT and PET images acquired. For each patient, two three-dimensional conformal plans were made using the CT and PET-CT fusion data sets. We analyzed differences in treatment plans and doses of radiation to primary tumors and critical organs.

RESULTS

Changes in GTV delineation were necessary in 5 patients based on PET-CT information. In these patients, the average increase in GTV was 29.7%, due to the incorporation of additional lymph node metastases and extension of the primary tumor beyond that defined by CT. For all patients, the GTVCT versus GTVPET-CT was 92.5 +/- 32.3 cm3 versus 104.5 +/- 32.6 cm3 (p = 0.009). Toxicity analysis revealed no clinically significant differences between two plans with regard to doses to critical organs.

CONCLUSION

Co-registration of PET and CT information in unresectable LAPC may improve the delineation of GTV and theoretically reduce the likelihood of geographic misses.

Locally advanced pancreatic cancer: current therapeutic approach

Even though pancreatic cancer accounts for only 2% of all cancer diagnoses in the U.S., it is the fourth-leading cause of cancer death and one of the most difficult malignancies to manage. Because of the usually late onset of symptoms, only 10%-15% of patients present with resectable disease, whereas the remaining 85%-90% present with locally advanced unresectable or metastatic disease. Despite a lack of consistent evidence from previous clinical trials, chemotherapy in addition to radiation therapy is the most commonly used approach in treating locally advanced pancreatic cancer. The most appropriate chemotherapy in combination with radiation is still debatable between 5-fluorouracil and gemcitabine, and novel trends to prevent resistance and enhance efficacy incorporate biologically targeted agents. This paper reviews the current management options, controversies, and ongoing and future directions for the treatment of locally advanced adenocarcinoma of the pancreas.

Surgical Resection after Radiochemotherapy in Patients with Unresectable Adenocarcinoma of the Pancreas

BACKGROUND

The use of chemoradiotherapy for pancreatic cancer has been advocated for its potential ability to downstage locally advanced tumors. This article reports our experience with chemoradiotherapy for patients with unresectable, locally advanced pancreatic cancer (superior mesenteric artery or celiac axis encasement).

STUDY DESIGN

Since 1998, 61 patients with radiographically unresectable, pathologically confirmed pancreatic adenocarcinoma have received standard fractionation radiation therapy (total dose, 45 Gy at 1.8 Gy, 5 d/wk) with chemotherapy, which included a continuous infusion of fluorouracil (5-FU: 650 mg/m(2)/D1-D5 and D21-D25) and cisplatin (80 mg/m(2)/bolus D2 and D22). Patients with tumor response at restaging CT scan underwent surgical exploration to determine whether the tumor was resectable.

RESULTS

Thirty-eight of 61 (62%) restaged patients demonstrated a disease progression. Twenty-three patients (38%) had an objective response, with, in all cases, persistence of arterial encasement. Twenty-three patients underwent exploratory operations after chemoradiotherapy, and 13 underwent standard Whipple resection. So 13 of 23 (56%) patients who had exploratory operation, or 23 of 61 (21%) patients, underwent surgical resection. With a median followup of 27 months, median survival for the resected patients was 28 months. Median survival was 11 months in the nonresponder group (n = 38) and 20 months in the group who received a palliative procedure (n = 10).

CONCLUSIONS

Locally advanced, unresectable pancreatic adenocarcinoma may be downstaged by chemoradiotherapy to allow for surgical resection. Patients whose cancer becomes resectable have a median survival at least comparable with survival after resection for initially resectable pancreatic adenocarcinoma.

Preoperative locoregional re-evaluation by endoscopic ultrasound in pancreatic ductal adenocarcinoma after neoadjuvant chemoradiation

INTRODUCTION

The accuracy of endoscopic ultrasound (EUS) for the diagnosis and staging of pancreatic ductal adenocarcinoma (PDA) has been confirmed. Chemo-radiotherpay (CRT) induces tumor changes which can limit the accuracy of EUS. The aim of our study was to analyze the efficacy of EUS following neoadjuvant CRT comparing findings with the pathology results.

PATIENTS AND METHODS

From November 1996 to October 2003, 45 patients with histologically proven and EUS-staged PDA were treated with neo-adjuvant CRT and radical surgery. All were restaged before surgery using both EUS and computed tomography. Fifteen patients were found to have developed distant metastases. Thirty patients finally underwent pancreaticoduodenectomy (N=24) or distal pancreatectomy (N=6).

RESULTS

Following CRT, tumor stage was correctly assessed in 12 patients (40%). The most frequent misinterpretation was overestimation of tumor size (N=13, 43.3%). Locoregional vascular invasion of veins was suspected by EUS in 13 patients (43.3%) but surgical findings and the histological examination were both negative. Node status was correctly assessed in 27 patients (90%) but nodal involvement was found on the histological specimen in only 3 patients.

CONCLUSION

Preoperative EUS after neoadjuvant CRT for PDA does not enable reliable definitive selection of patients for surgery, probably due to radiation-induced pancreatic changes.

Detection of recurrent pancreatic cancer: comparison of FDG-PET with CT/MRI

OBJECTIVE

To determine the value of fluorine-18-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) for the detection of recurrent pancreatic cancer in comparison to computed tomography (CT) and magnetic resonance imaging (MRI).

METHODS

Thirty-one patients with suspected recurrence after surgery were included. Inclusion criteria were sudden weight loss, pain or increased CA 19-9 levels. FDG-PET was performed in all patients. After visual analysis, maximal standardized uptake values (SUVmax) were determined by placing regions of interest on the pancreas bed. Additionally, all patients underwent contrast-enhanced multidetector CT (n = 14) or MR (n = 17) imaging. Positive findings at FDG-PET or CT/MRI were compared to follow-up.

RESULTS

All patients relapsed. Of 25 patients with local recurrences upon follow-up, initial imaging suggested relapse in 23 patients. Of these, FDG-PET detected 96% (22/23) and CT/MRI 39% (9/23). Local SUVmax ranged from 2.26 to 16.9 (mean, 6.06). Among 12 liver metastases, FDG-PET detected 42% (5/12). CT/MRI detected 92% (11/12) correctly. Moreover, 7/9 abdominal lesions were malignant upon follow-up of which FDG-PET detected 7/7 and CT/MR detected none. Additionally, FDG-PET detected extra-abdominal metastases in 2 patients.

CONCLUSION

In patients suspected of pancreatic cancer relapse; FDG-PET reliably detected local recurrences, whereas CT/MRI was more sensitive for the detection of hepatic metastases. Furthermore, FDG-PET proved to be advantageous for the detection of nonlocoregional and extra-abdominal recurrences.

Large-scale allelotype of pancreaticobiliary carcinoma provides quantitative estimates of genome-wide allelic loss

Studies of the allelotype of human cancers have provided valuable insights into those chromosomes targeted for genetic inactivation during tumorigenesis. We present the comprehensive allelotype of 82 xenografted pancreatic or biliary cancers using 386 microsatellite markers and spanning the entire genome at an average coverage of 10 cM. Allelic losses were nonrandomly distributed across the genome and most prevalent for chromosome arms 9p, 17p, and 18q (>60%), sites of the known tumor suppressor genes CDKN2A, TP53, and MADH4. Moderate rates of loss (at any one locus) were noted for chromosome arms 3p, 6q, 8p, 17q, 18p, 21q, and 22q (40-60%). A mapping of individual loci of allelic loss revealed 11 "hot spots" of loss of heterozygosity (>30%) in addition to loci near known tumor suppressor genes, corresponding to 3p, 4q, 5q, 6q, 8p, 12q, 14q, 21q, 22q, and the X chromosome. The average genomic fractional allelic loss was 15.3% of all tested markers for the 82 xenografted cancers, with allelic loss affecting as little as 1.5% to as much as 32.1% of tested loci, a remarkable 20-fold range. We determined the chromosome location (in cM) of each of the 386 markers used based on mapping data available from the National Center for Biotechnology Information, and we provide the first distance-based estimates of chromosome material lost in a human epithelial cancer. Specifically, we found that the cumulative size of allelic losses ranged from 58 to 1160 cM, with an average loss of 561.32 cM/tumor. We compared the genomic fractional allelic loss of each xenografted cancer with known clinicopathological features for each patient and found a significant correlation with smoking status (P < 0.01). These findings offer new loci for investigation of the genetic alterations common to pancreaticobiliary cancers and aid the understanding of mechanisms of allelic loss in human carcinogenesis.

Neoadjuvant preoperative chemoradiation in patients with pancreatic cancer

PURPOSE

To assess the toxicity and efficacy of preoperative chemoradiation in pancreatic cancer.

METHODS AND MATERIALS

Between November 1996 and December 2001, 32 patients with biopsy-proven pancreatic adenocarcinoma (28 head; 4 body) were treated by chemoradiation consisting of either split-course therapy (two courses of 15 Gy separated by a 2-week break, n = 10) or standard-fractionation therapy (45 Gy during 5 weeks, n = 22). Concurrent chemotherapy included continuous infusion of 5-fluorouracil and a cisplatin bolus. Pancreatic resection was scheduled for 4-6 weeks after completion of chemoradiation treatment.

RESULTS

All 32 patients completed the chemoradiation protocol. Only 2 cases of Grade 3 toxicity (weight loss, vomiting) and one fatal Grade 4 infection occurred. Of the 32 patients, 19 underwent curative resection. Two patients had a complete pathologic response. One patient died 36 months after diagnosis of late treatment-related toxicity (acute superior mesenteric artery thrombosis) with no evidence of disease. The 2-year overall survival rate for the entire group and the resected patients was 37.3% (95% confidence interval 18.2-56.4%) and 59.3% (95% confidence interval 34.1-84.9%), respectively.

CONCLUSION

Preoperative chemoradiation with 5-fluorouracil and cisplatin is feasible and promising.

Prevention of chemotherapy-related toxic side effects by infection with adeno-associated virus type 2

Drug resistance and toxic side effects are major limiting factors in the clinical use of antineoplastic chemotherapy. Patients with pancreatic cancer generally do not benefit from chemotherapy. The nonpathogenic adeno-associated virus type 2 (AAV-2) has been shown to sensitize human tumor cells to gamma irradiation and chemotherapeutic drugs. In the present study, we characterized the therapeutic role of AAV-2 infection in combination with 5-fluorouracil (5-FU)-based chemotherapy on pancreatic cancer cells in an animal model. In Lewis rats bearing s.c. implants of syngeneic DSL6A pancreatic cancer cells, intratumoral infection with AAV-2 (MOI 10E8 i.u.) in combination with 5-FU (5 or 50 mg/kg body weight) resulted in significantly reduced tumor growth and prolonged survival time compared with 5-FU single therapy. Most surprisingly, AAV-2-infected rats remained in a much better physical condition compared to their noninfected counterparts. While rats treated with 5-FU single therapy lost weight, were sluggish and died within 4 months after tumor implantation, animals infected with AAV showed much better vigilance, with body weight, leukocyte number and hemoglobin levels similar to healthy rats. In particular, 5-FU-related side effects like thrombocytopenia and leukopenia were significantly reduced in animals treated with the combination regimen. By in vitro analysis, human (Capan-1 and DANG) pancreatic cancer cell lines were shown to be sensitized to 5-FU chemotherapy to an extent similar to DSL6A cells. AAV-2 infection enhanced 5-FU-induced apoptosis by a factor of 8 to 14 in both human and rat pancreatic cancer cell lines. The data suggest that infection with the nonpathogenic AAV-2 significantly improves both chemotherapy efficacy and physical appearance and offers a novel strategy in cancer treatment.

Molecular diagnosis of early pancreatic ductal adenocarcinoma in high-risk patients

The prevalence of pancreatic cancer in the general population is too low--even in high-prevalence areas such as Northern Europe and North America (8-12 per 10(5) population)--relative to the diagnostic accuracy of present detection methods to permit primary screening in the asymptomatic adult population. The recognition that the lifetime risk of developing pancreatic cancer for patients with hereditary pancreatitis (HP) is extremely high (20% by the age of 60 years and 40% by the age of 70 years) poses considerable challenges and opportunities for secondary screening in those patients without any clinical features of pancreatic cancer. Even for secondary screening, the detection of cancer at a biological stage that would be amenable to cure by surgery (total pancreatectomy) still requires diagnostic modalities with a very high sensitivity and specificity. Conventional radiological imaging methods such as endoluminal ultrasound and endoscopic retrograde pancreatography, which have proved to be valuable in the early detection of early neoplastic lesions in patients with familial pancreatic cancer, may well be applicable to patients with HP but only in those without gross morphological features of chronic pancreatitis (other than parenchymal atrophy). Unfortunately, most cases of HP also have associated gross features of chronic pancreatitis that are likely to seriously undermine the diagnostic value of these conventional imaging modalities. Pre-malignant molecular changes can be detected in the pancreatic juice of patients. Thus, the application of molecular screening in patients with HP is potentially the most powerful method of detection of early pancreatic cancer. Although mutant (mt) K-ras can be detected in the pancreatic juice of most patients with pancreatic cancer, it is also present in patients with non-inherited chronic pancreatitis who do not progress to pancreatic cancer (at least in the short to medium term), as well as increasingly in the older population without pancreatic disease. Nevertheless, the presence of mt-K-ras may identify a genuinely higher-risk group, enabling additional diagnostic imaging and molecular resources to be focussed on such a group. What is clear is that prospective multi-centre studies, such as that being pursued by the European Registry of Hereditary Pancreatitis and Familial Pancreatic Cancer (EUROPAC), are essential for the development of an effective secondary screening programme for these patients.

A phase II single institutional experience with preoperative radiochemotherapy in pancreatic adenocarcinoma

BACKGROUND

Resection of pancreatic adenocarcinoma has a limited impact on survival. We hypothesized that delivering preoperative radiochemotherapy (RTCT) might enhance local control of the cancer and improve survival.

METHODS

Nineteen patients with localized pancreatic cancer (14 head and 5 body) were treated during the past 4 years with an intramural protocol consisting of continuous infusion of fluorouracile (5-FU: 650 mg/m(2)/D1-D5 and D21-D25 and Cisplatin 80 mg/m(2)/bolus D2 and D22 with preoperative external beam radiotherapy (RT) (30Gy split course RT or 45 Gy standard fractionation RT).

RESULTS

Four patients did not have surgical resection: Three patients were noted to have liver metastases and 1 patient developed peritoneal carcinomatosis. The remaining 15 patients had potentially curative resection (12 Whipple procedure and 3 distal subtotal pancreatectomy). There was no postoperative death. Pathologic findings showed five major responses including 2 patients with complete pathologic response. The overall median survival for the 19 study patients was 20 months. The median disease free and 2-year overall survival for the group with resection were 30 months and 52.3%.

CONCLUSIONS

Preoperative RTCT followed by resection is well-tolerated and safe for patients with localized pancreatic cancer. Major histological response occurred for 25% of patients. This approach could offer improvement in patient survival.

Update on pancreatic cancer

Pancreatic cancer is one of the commonest causes of cancer death worldwide. Patients with pancreatic cancer benefit from resectional surgery (improved quality of life) and adjuvant treatment (enhanced survival). This review covers advances in the understanding of the development of pancreatic cancer, state-of-the-art clinical management and, finally, novel treatment and screening techniques.

Implication of thymidylate synthase in the outcome of patients with invasive ductal carcinoma of the pancreas and efficacy of adjuvant chemotherapy using 5-fluorouracil or its derivatives

Thymidine synthase (TS) is a key enzyme in the synthesis of pyrimidine in the de novo pathway of DNA synthesis and a major target of 5-fluorouracil (5-FU), but the implications of TS regarding human pancreatic cancer have not been reported. We assessed the expression of TS in invasive ductal carcinoma (IDC) of the pancreas by immunostaining and evaluated its clinicopathological significance, especially its implications regarding the efficacy of chemotherapy with 5-FU or its derivatives. The expression of TS in the nuclei of pancreatic cancer cells in 72 primary lesions of resectable IDC and 30 distant metastases of unresectable IDC was examined by immunostaining using anti-TS polyclonal antibody and immunoreactivity was classified into three categories: negative (-), low (+) and high (2+). High TS immunoreactivity was detected in 43% (31 of 72) of the primary lesions of the resectable IDCs and in 47% (18 of 38) of the metastatic lesions of the unresectable IDCs. The high TS in primary lesions showed a significantly inverse correlation with the level of nodal involvement. High TS immunoreactivity had a significant influence on the outcome of patients with resectable IDC and the rate of survival of the high TS immunoreactivity group was significantly higher than that of the negative or low reactivity groups, although high TS immunoreactivity did not have a significant influence on survival of the patients with unresectable IDC. The implications of TS immunoreactivity regarding the efficacy of 5-FU-based adjuvant chemotherapy (ACT) was also assessed. The high TS immunoreactivity group showed significantly better survival in both the patients who received ACT and those who were treated by surgery alone, in the resectable IDC among patients with resectable IDC. In cases of unresectable IDC, there were no differences in survival between the high and low TS groups among the patients who received ACT and those who were treated by surgery. In conclusion, high TS immunoreactivity was found to be cogent in predicting the prognosis of patients with pancreatic IDC, but its implications regarding the efficacy of 5-FU-based ACT are still unclear.

The anti-apoptotic protein BAG-3 is overexpressed in pancreatic cancer and induced by heat stress in pancreatic cancer cell lines

Pancreatic cancer cells are usually resistant to apoptosis mediated by intrinsic or extrinsic factors. BAG-3 (Bis, CAIR), which was identified as a BAG-1-related protein, is a novel modulator of cellular anti-apoptotic activity that functions through its interaction with Bcl-2. In this study we analyzed BAG-3 expression in human pancreatic cancer tissues and cell lines. BAG-3 mRNA was expressed at moderate to high levels in all pancreatic cancer samples, but at low levels in normal pancreas tissues. In situ hybridization and immunohistochemistry analysis revealed that BAG-3 was present in the cancer cells within the pancreatic tumor mass. When BAG-3 mRNA was analyzed in other gastrointestinal cancers (hepatocellular carcinoma; esophageal, stomach and colon cancer), no difference was found from their corresponding normal controls. In pancreatic cancer cells, BAG-3 mRNA expression levels were strongly induced after heat stress, but not in response to members of the tumor necrosis factor (TNF)-alpha family (TNF-alpha, TRAIL, FasL). These findings indicate that in pancreatic cancer, in contrast to other gastrointestinal malignancies, increased levels of BAG-3 might function to block apoptosis. This characteristic of pancreatic cancer might contribute to its more aggressive growth behavior and poor responsiveness to treatment in vivo.

Periampullary cancers: are there differences?

Our review supports the clinical impression that periampullary cancers vary in outcome after resection. Overall survival after pancreaticoduodenectomy is greatest for patients with ampullary and duodenal cancers, intermediate for patients with bile duct cancer, and least for patients with pancreatic cancer. Moreover, survival for each tumor stage is greater for nonpancreatic periampullary cancers than for pancreatic cancers. Invasion of the pancreas by nonpancreatic periampullary cancers is a major factor adversely affecting survival. Recent data suggest that inherent differences in tumor biology rather than embryologic, anatomic, or histologic factors probably account for these differences in survival. Finally, although pancreaticoduodenectomy remains the procedure of choice for resectable periampullary cancers, further increases in survival will likely evolve through more effective neoadjuvant or adjuvant therapies rather than modifications in the surgical approach.

Adjuvant therapy for pancreatic cancer: current treatment approaches and future challenges

The past several decades have witnessed advances in the management of pancreatic cancer; however, much remains to be accomplished. Emerging techniques in the fields of surgery, RT, chemotherapy, and immunotherapy offer hope for greater locoregional control, survival, and quality of life for these patients.

Polyethylenimine-mediated gene transfer into pancreatic tumor dissemination in the murine peritoneal cavity

Although peritoneal dissemination of cancer cells often occurs at the advanced stages of pancreatic, gastric or ovarian cancers, no effective therapy has been established. Cationic lipid-mediated gene transfer into peritoneal dissemination may offer a prospect of safe therapies, but vector improvements are needed with regard to the efficiency and specificity of the gene transfer. In this study, the intraperitoneal injection of plasmid DNA:polyethylenimine (PEI) complexes into mice was evaluated as a gene delivery system for the peritoneal disseminations. The luciferase and beta-galactosidase genes were used as marker genes. PEI was more efficient than the cationic lipids examined in this study in vivo, and the transgene was preferentially expressed in the tumors. Although PCR analysis showed that the injected DNA was delivered to various organs, the distributed DNA became undetectable by 6 months after the gene transfer. Blood chemistry and histological analysis showed no significant toxicity in the injected mice. This study demonstrated that the intraperitoneal injection of DNA:PEI is a promising delivery method to transduce a gene into disseminated cancer nodules in the peritoneal cavity.

Gene therapy for pancreatic cancer--current and prospective strategies

Pancreatic ductal adenocarcinoma is one of the most common causes of cancer death in the developed world. Long-term survival is currently only achieved through surgical resection. Most patients have locally advanced or metastatic disease at the time of diagnosis and are therefore not amenable to resection, whilst chemotherapy and radiotherapy are by and large ineffective. Gene therapy offers an alternative to current adjuvant strategies. With approximately two-thirds of all gene therapy trials worldwide directed at cancer, the gene therapy approaches that are currently being explored for pancreatic cancer are specifically examined. Gene delivery systems, genetic targets, and combined gene delivery with chemotherapy are discussed in the context of pancreatic cancer treatment.