Pancreatic cancer: survival, errors and evidence

Actual Five-year Survival After Upfront Resection for Pancreatic Ductal Adenocarcinoma: Who Beats the Odds?

OBJECTIVE

To determine actual five-year survival (5YS) rates associated with a strategy of upfront surgery and adjuvant therapy in pancreatic ductal adenocarcinoma (PDAC).

BACKGROUND

The rate of actual 5YS in PDAC remains controversial. Available data is restricted to cohorts acquired over several decades and series of resection after patient selection by neoadjuvant therapy.

METHODS

All patients undergoing upfront resection for resectable and borderline-resectable PDAC from 10/2001 to 12/2011 were identified from a prospective database. Actual overall survival was assessed after a follow-up of at least 5 years. Uni- and multivariable logistic regression analyses were performed.

RESULTS

Median survival of 937 patients was 22.1 months. The actual 5YS rate was 17.0% (n = 159) including 89 (9.5%) patients without evidence of disease >5 years after resection. 5YS rates in patients with or without adjuvanttherapy were 18.8% vs. 12.2%, respectively. Tumorgrading, number of positive lymph nodes, a context of intraductal papillary mucinous neoplasia, and vascular resections were independently associated with 5YS. Patient-related parameters and CA 19-9 levels were associated with observed survival up to 3 years, but lost relevance thereafter. The extent of lymph node involvement was the strongest predictor of 5YS. Patients with pN0R0 had a 5YS rate of 38.2%. in patients with exclusively favorable factors the observed 5YS rate was above 50%.

CONCLUSIONS

This is the largest series of long-term survivors with histologically confirmed PDAC. With upfront resection and adjuvant therapy an actual overall 5YS rate of 18.8% can be expected. in favorable subgroups actual 5YS is above 50%.

Cutting off the fuel supply to calcium pumps in pancreatic cancer cells: role of pyruvate kinase-M2 (PKM2)

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) has poor survival and treatment options. PDAC cells shift their metabolism towards glycolysis, which fuels the plasma membrane calcium pump (PMCA), thereby preventing Ca2+-dependent cell death. The ATP-generating pyruvate kinase-M2 (PKM2) is oncogenic and overexpressed in PDAC. This study investigated the PKM2-derived ATP supply to the PMCA as a potential therapeutic locus.

METHODS

PDAC cell growth, migration and death were assessed by using sulforhodamine-B/tetrazolium-based assays, gap closure assay and poly-ADP ribose polymerase (PARP1) cleavage, respectively. Cellular ATP and metabolism were assessed using luciferase/fluorescent-based assays and the Seahorse XFe96 analyzer, respectively. Cell surface biotinylation identified membrane-associated proteins. Fura-2 imaging was used to assess cytosolic Ca2+ overload and in situ Ca2+ clearance. PKM2 knockdown was achieved using siRNA.

RESULTS

The PKM2 inhibitor (shikonin) reduced PDAC cell proliferation, cell migration and induced cell death. This was due to inhibition of glycolysis, ATP depletion, inhibition of PMCA and cytotoxic Ca2+ overload. PKM2 associates with plasma membrane proteins providing a privileged ATP supply to the PMCA. PKM2 knockdown reduced PMCA activity and reduced the sensitivity of shikonin-induced cell death.

CONCLUSIONS

Cutting off the PKM2-derived ATP supply to the PMCA represents a novel therapeutic strategy for the treatment of PDAC.

Incidence, diagnostic, treatment and outcome of patients diagnosed with cancer of the pancreas during 1986-2009: a population-based study

OBJECTIVE

Limited data exist on the changes in the epidemiology of pancreatic cancer and outcomes over the last decades in population-based cohorts. We aimed to compare the incidence of pancreatic cancer, diagnostic, treatment and survival among patients diagnosed over the period 1986-2009.

MATERIALS AND METHODS

A retrospective, nationwide, population-based study. All patients diagnosed with pancreatic cancer in Iceland in two periods, 1986-1997 (P1) and 1998-2009 (P2) were identified through the Icelandic Cancer Registry and relevant clinical information obtained from medical records.

RESULTS

A total of 645 patients were identified, 296 in P1 and 349 in P2 (NS). The incidence during P1 was 6.8 per 100,000 inhabitants and 6.2 during P2 (NS). Among biopsy-proven cancers, adenocarcinoma was diagnosed in 89% of the cases in P1 and in P2 in 93% of the cases. Overall 38 (14%) in P1 underwent resection and 22 (7%) in P2 (p < .0004). Patients diagnosed in P2 had longer survival at 6 months (p = .015, log-rank test) and one year (p = .0206) after diagnosis. A total of 4/296 (1.4%) in P1 survived more than 5 years and 3/349 (0.9%) in P2 (NS).

CONCLUSIONS

The incidence among patients with pancreatic cancer in Iceland did not show major changes during the last 20 years. Diagnostic approach has changed considerably demonstrating more patients that are not 'resectable'. Survival rate at 6 months and one year has improved over the last two decades whereas the 5-year prognosis has not improved.

MicroRNA profiles during galectin-9-induced apoptosis of pancreatic cancer cells

Pancreatic cancer is the eighth-leading cause of cancer-associated mortality in males and the ninth-leading cause in females worldwide. Even when diagnosed early enough to be potentially resectable, the prognosis of invasive pancreatic cancer is poor. Galectin-9 (Gal-9) is a tandem-repeat type galectin that has recently been demonstrated to possess an anti-proliferative effect on cancer cells. Therefore, the present study evaluated the effects of Gal-9 on the proliferation of human pancreatic cancer cells and examined the microRNAs that are associated with the antitumor effects of Gal-9. Gal-9 suppressed the proliferation of multiple pancreatic cancer cell lines. In addition, Gal-9 treatment increased the levels of caspase-cleaved keratin 18 and the expression of cytochrome c in pancreatic cancer cell lines. This data suggests that Gal-9 induces intrinsic apoptosis in pancreatic cancer cell lines through the caspase-dependent and caspase-independent pathways. In addition, Gal-9 reduced the expression levels of phosphorylated epidermal growth factor receptor and numerous receptor tyrosine kinases (RTKs). In conclusion, Gal-9 may suppress the growth of human pancreatic cancer cells in vitro. These findings suggest that Gal-9 may be a new therapeutic agent for the treatment of pancreatic cancer.

Expression of Glut-1 and HK-II in Pancreatic Cancer and Their Impact on Prognosis and FDG Accumulation

OBJECTIVE: The purpose of this article is to analyze the expression of Glut-1 and HK-II, the association between their expression and ¹⁸F-FDG accumulation in pancreatic cancer. METHODS: Fifty patients with histologically proven pancreatic cancer were included in this preliminary study, all of whom received ¹⁸F-FDG PET/CT performance before surgery. Immunohistochemical staining of tumor tissue and adjacent normal tissue was performed for Glut-1 and HK-II. By combining proportions and intensity of immunochemical staining, we obtained the modified immunohistological scores for Glut-1 and HK-II respectively. The relationship between expression of Glut-1, HK-II and series of parameters was analyzed, i.e. clinicopathological characteristics, prognosis of patients and SUV_max of PET-CT. RESULTS: Compared with normal tissue, the Glut-1 and HK-II expression in pancreatic cancer tissue was significantly increased (P < .001). There was no correlation between expression of Glut-1, HK-II and age, gender, tumor size, tumor location, tumor histological type, tumor differentiation, the nerve infiltration, vascular invasion, local infiltration, lymph node metastasis or tumor staging in pancreatic cancer (P > .05). During the follow-up period, the survival curves of low Glut-1 group and high Glut-1 group were statistically different (P = .049). Multivariate analysis (Cox regression) revealed that Glut-1 expression was not associated with mortality (P > .05). No statistical difference was found in the survival curves of negative HK-II group and positive HK-II group (P = .545). There was no correlation between ¹⁸F-FDG uptake and expression of Glut-1 and HK-II(P > .05). CONCLUSION: The Glut-1 and HK-II expression in pancreatic cancer tissue was significantly increased. There was no correlation between expression of Glut-1, HK-II and clinicopathological characteristics, prognosis and ¹⁸F-FDG uptake.

Pancreatic Cancer: 80 Years of Surgery-Percentage and Repetitions

Objective. The incidence of pancreatic cancer is estimated to be 48,960 in 2015 in the US and projected to become the second and third leading causes of cancer-related deaths by 2030. The mean costs in 2015 may be assumed to be $79,800 per patient and for each resection $164,100. Attempt is made to evaluate the results over the last 80 years, the number of survivors, and the overall survival percentage. Methods. Altogether 1230 papers have been found which deal with resections and reveal survival information. Only 621 of these report 5-year survivors. Reservation about surgery was first expressed in 1964 and five-year survival of nonresected survivors is well documented. Results. The survival percentage depends not only on the number of survivors but also on the subset from which it is calculated. Since the 1980s the papers have mainly reported the number of resections and survival as actuarial percentages, with or without the actual number of survivors being reported. The actuarial percentage is on average 2.75 higher. Detailed information on the original group (TN), number of resections, and actual number of survivors is reported in only 10.6% of the papers. Repetition occurs when the patients from a certain year are reported several times from the same institution or include survivors from many institutions or countries. Each 5-year survivor may be reported several times. Conclusion. Assuming a 10% resection rate and correcting for repetitions and the life table percentage the overall actual survival rate is hardly more than 0.3%.

The Antipancreatic Cancer Activity of OSI-027, a Potent and Selective Inhibitor of mTORC1 and mTORC2

In the present study, we investigated the potential activity of OSI-027, a potent and selective mammalian target of rapamycin (mTOR) complex 1/2 (mTORC1/2) dual inhibitor, against pancreatic cancer cells both in vitro and in vivo. We demonstrated that OSI-027 inhibited survival and growth of both primary and transformed (PANC-1 and MIA PaCa-2 lines) human pancreatic cancer cells. Meanwhile, OSI-027 induced caspase-dependent apoptotic death of the pancreatic cancer cells. On the other hand, caspase inhibitors alleviated cytotoxicity by OSI-027. At the molecular level, OSI-027 treatment blocked mTORC1 and mTORC2 activation simultaneously, without affecting ERK-mitogen-activated protein kinase activation. Importantly, OSI-027 activated cytoprotective autophagy in the above cancer cells. Whereas pharmacological blockage of autophagy or siRNA knockdown of Beclin-1 significantly enhanced the OSI-027-induced activity against pancreatic cancer cells. Specifically, a relatively low dose of OSI-027 sensitized gemcitabine-induced pancreatic cancer cell death in vitro. Further, administration of OSI-027 or together with gemcitabine dramatically inhibited PANC-1 xenograft growth in severe combined immunodeficiency mice, leading to significant mice survival improvement. In summary, the preclinical results of this study suggest that targeting mTORC1/2 synchronously by OSI-027 could be further investigated as a valuable treatment for pancreatic cancer.

Long-Term Diabetes Mellitus Is Associated with an Increased Risk of Pancreatic Cancer: A Meta-Analysis

Purpose

Previous studies have shown a bidirectional relationship between diabetes and pancreatic cancer (PC). In particular, new-onset diabetes might be induced by PC, and people with long-term diabetes might be at increased risk for the development of PC. The purpose of our study was to examine whether long-term diabetes represented an independent risk factor for PC development.

Methodology

A literature search was performed by searching electronic databases for studies published before July 1, 2014, and relative risks (RRs) and corresponding 95% confidence intervals (CIs) were calculated. Data pertaining to diabetes were recorded at both individual and study levels, with RRs calculated separately to analyze the relationship between the duration of diabetes and the development of PC.

Results

Forty-four studies were included in this meta-analysis, including 18 studies with a case-control design, 5 with a nested case-control design and 21 with a cohort design. The overall summary estimate for the relationship between the population with a duration of diabetes ≥2 years and PC was 1.64 (1.52-1.78). The pooled RR (95% CI) of PC for the population with a duration of diabetes ≥5 years was 1.58 (1.42-1.75). For the population with a duration of diabetes ≥10 years, the RR (95% CI) of PC was 1.50 (1.28-1.75).

Conclusions

Our study suggests that long-term diabetes mellitus is associated with an increased risk of PC. However, the level of risk is negatively correlated with increasing diabetes mellitus duration.

Polyphenol-rich extract of Salvia chinensis exhibits anticancer activity in different cancer cell lines, and induces cell cycle arrest at the G₀/G₁-phase, apoptosis and loss of mitochondrial membrane potential in pancreatic cancer cells

Pancreatic cancer (PC) is one of the most aggressive types of human malignancy, which has an overall 5-year survival rate of <2%. PC is the fourth most common cause of cancer‑associated mortality in the western world. At present, there is almost no effective treatment available for the treatment of PC. The aim of the present study was to evaluate the anticancer potential of a polyphenol enriched extract obtained from Salvia chinensis, a Chinese medicinal plant. An MTT assay was used to evaluate the cell viability of five cancer cell lines and one normal cell line. In addition, the effects of the extract on apoptotic induction, cell cycle phase distribution, DNA damage and loss of mitochondrial membrane potential (ΛΨm) were evaluated in MiapaCa‑2 human PC cells. The effects of the extract on cell cycle phase distribution and ΛΨm were assessed by flow cytometry, using propidium iodide and rhodamine‑123 DNA‑binding fluorescent dyes, respectively. Fluorescence microscopy, using 4',6‑diamidino‑2‑phenylindole as a staining agent, was performed in order to detect the morphological changes of the MiapaCa‑2 cancer cells and the presence of apoptotic bodies following treatment with the extract. The results of the present study demonstrated that the polyphenol‑rich extract from S. chinensis induced potent cytotoxicity in the MCF‑7 human breast cancer cells, A549 human lung cancer cells, HCT‑116 and COLO 205 human colon cancer cells, and MiapaCa‑2 human PC cells. The Colo 205 and MCF‑7 cancer cell lines were the most susceptible to treatment with the extract, which exhibited increased rate of growth inhibition. Fluorescence microscopy revealed characteristic morphological features of apoptosis and detected the appearance of apoptotic bodies following treatment with the extract in the PC cells. Flow cytometric analysis demonstrated that the extract induced G0/G1 cell cycle arrest in a dose‑dependent manner. In addition, treatment with the extract induced a significant and concentration-dependent reduction in the ΛΨm of the PC cells.

Isoquercitrin inhibits the progression of pancreatic cancer in vivo and in vitro by regulating opioid receptors and the mitogen-activated protein kinase signalling pathway

Pancreatic cancer is a common malignant tumour that affects individuals worldwide. In recent years, the incidence and mortality rates of pancreatic cancer have continuously increased. Currently, the primary clinical treatment methods for pancreatic cancer include surgical resection, chemotherapy and radiotherapy. However, these treatment methods rarely produce satisfactory therapeutic outcomes. Extensive research has also proven that the effective components of several traditional Chinese medicines, particularly flavonoids extracted from plants, have significant antitumour effects. Isoquercitrin, which is one of the flavonoids found in Bidens pilosa extracts, has a significant antitumour effect. However, the antitumour effect of isoquercitrin and its mechanism of action remain unclear. The objective of the present study was to investigate the effect of isoquercitrin on the progression of pancreatic cancer and to further understand the biological characteristics of the participation of isoquercitrin in the progression of pancreatic cancer. In vitro, we found that a therapeutic dose of isoquercitrin significantly inhibited proliferation, promoted apoptosis and induced cell cycle arrest within the G1 phase in pancreatic cancer cells. Isoquercitrin activated caspase-3, -8 and -9 and reduced the mitochondrial membrane potential. In addition, isoquercitrin inhibited the expression level of the δ opioid receptor; however, isoquercitrin had no effect on the κ and µ opioid receptors. Furthermore, isoquercitrin inhibited extracellular signal-regulated kinase (ERK) phosphorylation and promoted c-Jun N-terminal kinase (JNK) phosphorylation. In vivo, we found that a therapeutic dose of isoquercitrin significantly inhibited xenograft growth in nude mice. In summary, the present study demonstrated that isoquercitrin inhibits human pancreatic cancer progression in vivo and in vitro and that its molecular mechanism may be closely related to opioid receptors and to the activation of the mitogen-activated protein kinase (MAPK) signalling pathway.

Critical appraisal of clinical practice guidelines for treating pancreatic cancer based on the global disease burden

OBJECTIVES

To evaluate the quality of pancreatic cancer guidelines with evidence-based methods based on the global burden of disease and to explore its status, distribution, characteristics of theme, and the difference of recommended therapies among various qualities of guidelines, so as to provide a reference for clinical decision.

METHODS

The PubMed, The Cochrane Library (Issue 11, 2013), Chinese Biomedical Database, China National Knowledge Infrastructure, and VIP databases, as well as the website of National Guidelines Clearinghouse, Guidelines International Network, and National Institute for Clinical Excellence were systematically reviewed through November 2013 for pancreatic cancer guidelines. The Appraisal of Guidelines for Research and Evaluation (AGREE II) were applied to assess the methodological quality of the guidelines.

RESULTS

A total of 14 relevant guidelines (including 5 evidence-based ones) were identified, involving four continents (Asia, Europe, North America, and Oceania), seven counties, and four international organizations. There were only two domains, namely 'scope and purpose' and 'clarity of presentations', getting high average scores (more than 60%) among all 14 guidelines. The mean AGREE domain score in guidelines varies among different areas, and the quality of 5 evidence-based guidelines was superior to that established by consensus. According to AGREE II, 11 guidelines were weakly recommended, while 3 were not recommended due to poor methodological quality. Their subjects of 14 guidelines covered six treatment categories, including chemotherapy, surgery, radiotherapy, support therapy, radiotherapy, and interventional therapy.

CONCLUSION

The overall methodological quality of pancreatic cancer guidelines is suboptimal among different countries or regions. The qualities of evidence-based guidelines are significantly superior to consensus. The chemotherapy, surgery, radiotherapy, and support therapy were the predominant choices by guidelines.

Pancreatic cancer incidence and mortality patterns in china, 2009

OBJECTIVE

To estimate the incidence and mortality rates for pancreatic cancer in China.

METHODS

After checking and reviewing the cancer registry data in 2009 from 72 cancer registry centers, we divided cancer registry areas into urban and rural areas. Incidence/mortality rates, age-specific incidence/mortality rates, age- standardized incidence/mortality rates, proportions, and cumulative incidence/mortality rates for pancreatic cancer were calculated.

RESULTS

The total number of newly diagnosed pancreatic cancer cases and deaths in 2009 were 6,220 and 5,650, respectively. The crude incidence rate in all cancer registry areas was 7.28/100,000 (males 8.24, females 6.29). The age-standardized incidence rate by Chinese standard population (ASR) was 3.35/100,000, with ranking at 7th among all cancers. Pancreatic cancer incidence rate was 8.19/100,000 in urban areas whereas it was 5.41/100 000 in rural areas. Cancer mortality rate in all cancer registry areas was 6.61/100,000 (males 7.45; females 5.75), with ranking at 6th among all cancers, and 7.42/100 000 in urban but 4.94/100000 in rural areas.

CONCLUSIONS

Pancreatic cancer incidence and mortality rates have shown a gradual increase in China. Owing to the difficulty of early diagnosis, identification of high-risk population and modification of risk factors are important to reduce the burden of pancreatic cancer.

DNA-PKcs is important for Akt activation and gemcitabine resistance in PANC-1 pancreatic cancer cells

Pancreatic cancer is one of the most aggressive human malignancies with extremely poor prognosis. The moderate activity of the current standard gemcitabine and gemcitabine-based regimens was due to pre-existing or acquired chemo-resistance of pancreatic cancer cells. In this study, we explored the potential role of DNA-dependent protein kinase catalytic subunit (DNA-PKcs) in gemcitabine resistance, and studied the underlying mechanisms. We found that NU-7026 and NU-7441, two DNA-PKcs inhibitors, enhanced gemcitabine-induced cytotoxicity and apoptosis in PANC-1 pancreatic cancer cells. Meanwhile, PANC-1 cells with siRNA-knockdown of DNA-PKcs were more sensitive to gemcitabine than control PANC-1 cells. Through the co-immunoprecipitation (Co-IP) assay, we found that DNA-PKcs formed a complex with SIN1, the latter is an indispensable component of mammalian target of rapamycin (mTOR) complex 2 (mTORC2). DNA-PKcs-SIN1 complexation was required for Akt activation in PANC-1 cells, while inhibition of this complex by siRNA knockdown of DNA-PKcs/SIN1, or by DNA-PKcs inhibitors, prevented Akt phosphorylation in PANC-1 cells. Further, SIN1 siRNA-knockdown also facilitated gemcitabine-induced apoptosis in PANC-1 cells. Finally, DNA-PKcs and p-Akt expression was significantly higher in human pancreatic cancer tissues than surrounding normal tissues. Together, these results show that DNA-PKcs is important for Akt activation and gemcitabine resistance in PANC-1 pancreatic cancer cells.

Gemcitabine-induced pancreatic cancer cell death is associated with MST1/cyclophilin D mitochondrial complexation

The pancreatic adenocarcinoma remains the most aggressive human malignancy with an extremely low 5-year overall survival. Postoperative gemcitabine could significantly delay recurrence after complete resection of pancreatic cancer. However, the underlying mechanisms are not fully understood. The chemo-resistance factors against gemcitabine still need further characterizations. Here we studied the mechanism of gemcitabine-induced pancreatic cancer cell death by focusing on mammalian sterile 20-like kinase 1 (MST1) and cyclophilin D (Cyp-D). We found that MST1 and Cyp-D expressions were significantly lower in gemcitabine-resistant pancreatic cancer tissues and cell lines. In vitro, gemcitabine activated MST1 through reactive oxygen species (ROS) production, which was prevented by antioxidant n-acetyl-cysteine (NAC). We found that gemcitabine-activated MST1 translocated to mitochondria and formed a complex with the local protein Cyp-D. Gemcitabine-induced cell death was alleviated by MST1 or Cyp-D shRNA silencing, but was aggravated by MST1 or Cyp-D over-expression. Further, cyclosporin A (CsA), the Cyp-D inhibitor, prevented gemcitabine-induced MST1/Cyp-D mitochondrial complexation and cancer cell death. We suggest that gemcitabine-induced death of pancreatic cancer cells requires MST1/Cyp-D mitochondrial complexation.

Perifosine inhibits S6K1-Gli1 signaling and enhances gemcitabine-induced anti-pancreatic cancer efficiency

PURPOSE

The pancreatic cancer has extremely low overall 5-year survival, and gemcitabine is the only approved single agent for pancreatic cancer treatment.

METHODS

In the present study, we investigated the potential effect of perifosine, a novel Akt inhibitor on gemcitabine-induced anti-pancreatic cancer effect both in vivo and in vitro.

RESULTS

We showed that sub-cytotoxic low concentration of perifosine dramatically enhanced gemcitabine-induced cytotoxicity in cultured pancreatic cancer cells. Perifosine inhibited Akt-mammalian target of rapamycin and Erk-mitogen-activated protein kinase activation in pancreatic cancer cells. Meanwhile, perifosine suppressed the hedgehog signaling, as it inhibited glioma-associated oncogenes (Gli) 1 activation and decreased its target protein patched 1 (PTCH1) expression. Our data demonstrated that perifosine blocked p70S6K1 (S6K1) activation, thus disrupting S6K1-Gli1 association and subsequent Gli1 activation. The reduction of S6K1 or Gli1 expression by target siRNAs inhibited PTCH1 expression and enhanced gemcitabine-induced cytotoxicity in pancreatic cancer cells. Significantly, perifosine dramatically enhanced gemcitabine-mediated antitumor effect in a PANC-1 xenograft severe combined immunodeficiency mice model.

CONCLUSIONS

In summary, we conclude that perifosine sensitizes gemcitabine-mediated anti-pancreatic cancer efficiency through regulating multiple signaling pathways.

Pancreatoduodenectomy associated complications influence cancer recurrence and time interval to death

BACKGROUND

Resection is the only life-prolonging option for pancreatic or periampullary cancer. Cell-mediated immunity might reduce progression of metastasis or local recurrence likelihood, but surgery associated morbidity can suppress this immunity. The aim of this study was to examine the influence of complications on cancer specific survival after pancreatoduodenectomy (PD) for pancreatic and periampullary cancer.

METHOD

517 consecutive patients who underwent PD for pancreatic or periampullary adenocarcinoma were analysed.

RESULTS

After median follow-up of 24 (14-44) months, 377 (73%) patients had died from progressive disease, 140 (27%) were alive. Median survival for pancreatic adenocarcinoma was 22 (18-25) months following an uncomplicated postoperative course versus 16 (13-19) months for patients with major surgical complications (p = 0.021). Multivariable Cox regression analysis demonstrated that microscopically residual disease (R1), complications, and adjuvant therapy were independent factors for recurrence. Within the R1 group, survival for patients with complications was even more limited, 9.7 (8.3-11.0) versus 18.7 (15.0-22.5) for those without (p < 0.001). For patients with R1 resection complications was the only independent predictor for a shorter time interval to death (hazard ratio 1.96; 95% CI 1.16-3.30). Complications did not influence survival of patients with periampullary adenocarcinoma.

CONCLUSION

Complications after resection are independently related to an impaired survival following PD for pancreatic, but not periampullary cancer. The effect is even more dramatic in patients who had an R1 resection. Although the relation is not causal per se, the findings support the hypothesis of a complication-induced, compromised immunity rendering patients more susceptible for recurrent disease.

Glycolytic ATP fuels the plasma membrane calcium pump critical for pancreatic cancer cell survival

Pancreatic cancer is an aggressive cancer with poor prognosis and limited treatment options. Cancer cells rapidly proliferate and are resistant to cell death due, in part, to a shift from mitochondrial metabolism to glycolysis. We hypothesized that this shift is important in regulating cytosolic Ca²⁺ ([Ca²⁺]_i), as the ATP-dependent plasma membrane Ca²⁺ ATPase (PMCA) is critical for maintaining low [Ca²⁺]_i and thus cell survival. The present study aimed to determine the relative contribution of mitochondrial versus glycolytic ATP in fuelling the PMCA in human pancreatic cancer cells. We report that glycolytic inhibition induced profound ATP depletion, PMCA inhibition, [Ca²⁺]_i overload, and cell death in PANC1 and MIA PaCa-2 cells. Conversely, inhibition of mitochondrial metabolism had no effect, suggesting that glycolytic ATP is critical for [Ca²⁺]_i homeostasis and thus survival. Targeting the glycolytic regulation of the PMCA may, therefore, be an effective strategy for selectively killing pancreatic cancer while sparing healthy cells.

SiRNA-mediated silencing of the RPL31 gene inhibits proliferation of human pancreatic cancer PANC-1 cells

AIM: To investigate the impact of small interfering RNA (siRNA)-mediated RPL31 gene silencing on biological behavior of human pancreatic cancer PANC-1 cells, and to explore the feasibility of using the human RPL31 gene as a therapeutic target for pancreatic cancer.

METHODS: Three RPL31-specific siRNAs were designed and transfected into PANC-1 cells using Lipofectamine^TM 2000. Blank control and negative control groups were run at the same time. After PANC-1 cells were transfected with RPL31-specific siRNA, the levels of RPL31 mRNA and protein were detected by quantitative real-time PCR (qRT-PCR) and Western blot, respectively. Cell proliferation was detected by MTT assay. Cell cycle progression was determined by flow cytometry. Cell migration was determined by Transwell chamber assay. Vascular endothelial growth factor (VEGF) expression in cells was detected by ELISA.

RESULTS: All three RPL31-specific siRNAs could silence the expression of RPL31 at the mRNA and protein levels 48 hours after transfection. MTT assay showed that cell proliferation was significantly inhibited. Flow cytometry analysis revealed that PANC-1 cells transfected with RPL31 siRNA had a more significant cell cycle arrest (G0/G1 phase: 59.85% ± 5.47% vs 45.71% ± 3.44%; S phase: 28.63% ± 4.52% vs 45.13% ± 2.64%, both P < 0.05). RPL31 knockdown significantly suppressed VEGF expression (1563.45 ± 24.95 pg/10⁶ cells/24 h vs 2804.6 ± 40.46 pg/10⁶ cells/24 h, 2791.5 ± 44.77 pg/10⁶ cells/24 h, both P < 0.05) and the migration of PANC-1 cells (178.6 ± 30.3 vs 470.5 ± 22.8, 474.2 ± 20.4, both P < 0.05) compared to the blank control and negative control groups.

CONCLUSION: Transfection of RPL31-specific siRNAs could effectively inhibit RPL31 expression, significantly suppress cell proliferation, and reduce cell migration and VEGF expression. RPL31 might serve as a target for gene therapy of pancreatic cancer.

SiRNA-mediated RPL31 gene silencing inhibits the growth of xenograft tumors derived from human pancreatic cancer BxPC-3 cells in nude mice

AIM: To investigate the effect of siRNA-mediated RPL31 gene silencing on the growth of xenograft tumors derived from human pancreatic cancer cell line BxPC-3 in nude mice, and to explore the potential role of the RPL31 gene in pancreatic cancer.

METHODS: The siRNA sequence targeting to human RPL31 gene was designed. Human pancreatic cancer BxPC-3 cells were subcutaneously inoculated into Balb/c nude mice to develop a transplantation tumor model of human pancreatic cancer. According to the tumor volume, nude mice were randomly divided into three groups: vehicle control group, negative control group and RPL31-siRNA injection group. Mice of the RPL31-siRNA injection group were intratumorally injected with RPL31-siRNA using RNAi-Mate. Tumor volumes were calculated daily. On the 16th day after the first intratumoral injection, all the mice were sacrificed and the tumors were taken out to undergo real-time quantitative PCR (qRT-PCR) and Western blot analyses to detect RPL31 expression. The expression of Ki-67 and CD31 proteins in xenograft tissue was detected by immunohistochemistry. Cell apoptosis in xenograft tumors was detected by TUNEL assay.

RESULTS: Compared with the vehicle control group and negative control group, mice in the RPL31-siRNA injection group exhibited slower tumor growth, significantly smaller tumor volume (P < 0.05), and lower RPL31 expression level (P < 0.05). Immunohistochemistry results showed that the proportions of Ki-67- and CD31-positive cells decreased in xenograft tissue injected with RPL31-siRNA (55.78% ± 4.63%, 51.37% ± 5.05% vs 11.08% ± 1.31%; 56.53% ± 6.03%, 44.84% ± 5.24% vs9.67% ± 1.39%). TUNEL results showed that apoptosis increased in xenograft tissue injected with RPL31-siRNA (2.92% ± 0.54%, 3.85% ± 0.87% vs 39.58% ± 4.02%).

CONCLUSION: Silencing of RPL31 expression could inhibit the growth of subcutaneous xenograft tumors derived from BxPC-3 cell line in nude mice, down-regulate the expression of Ki-67 and CD31, and induce cell apoptosis in the transplantation tumors. The RPL31 gene is a potential target for gene therapy of pancreatic cancer.

Antiproliferative effect of alpinetin in BxPC-3 pancreatic cancer cells

Alpinetin is a novel plant flavonoid derived from Alpinia katsumadai Hayata, found to possess strong anticancer effects. However, the antitumor effect of alpinetin on pancreatic cancer cells and the detailed mechanism remain unclear. The aim of this study was to investigate alpinetin's beneficial effect on pancreatic cancer and the possible molecular mechanism involved. Pancreatic cancer cell lines were treated with alpinetin at various doses and for different times, and the effect of alpinetin on cell growth inhibition, apoptosis and the cell cycle was determined. The expression of Bcl-2, Bcl-xL, XIAP and Bax, the activity of caspases and the levels of cytochrome c released were measured. The results showed that alpinetin inhibited the viability of three pancreatic cancer cell lines and induced apoptosis of BxPC-3 cells in a dose- and time-dependent manner. This was accompanied by regulation of the expression of Bcl-2, Bcl-xL, Bax and XIAP. Furthermore, alpinetin treatment led to the release of cytochrome c and activation of caspases-3, -8 and -9 proteins. Taken together, our studies indicate that alpinetin inhibited the proliferation of pancreatic cancer cells possibly through the regulation of the Bcl-2 family and XIAP expression, release of cytochrome c and the activation of caspases. Alpinetin may serve as a potential agent for the development of pancreatic cancer cell therapies.

Pancreatic cancer; reporting and long-term survival in Sweden

BACKGROUND

The overall completeness of the Swedish Cancer Register is high, although underreporting for certain sites must be acknowledged. The aims of the present study were twofold. Firstly to assess the completeness of reporting of pancreatic cancer to the Swedish Cancer Register, and secondly to identify and characterise long-term survivors based on information from two separate population-based register resources.

MATERIAL AND METHODS

To assess the completeness of the Cancer Register, pancreatic cancer cases registered in the National Patient Register between 1987 and 1999 were compared to cases reported to the Cancer Register. For estimations of long-term survival, the study population was restricted to 4321 cases identified both in the Cancer Register and the Patient Register with a histopathologically confirmed diagnosis of pancreatic ductal adenocarcinoma. A complete follow-up of survival in this group was performed till December 31, 2004.

RESULTS

There was a considerable underreporting of pancreatic cancer to the Cancer Register. During the period under study, a total of 19 745 patients were identified with a diagnosis of pancreatic cancer. Of these, only 73% had been reported to the Cancer Register. The underreporting increased markedly with age at diagnosis and was more pronounced during the second period under study. Only 2.8% of patients with a histopathologically confirmed diagnosis of pancreatic ductal adenocarcinoma survived five years or longer. The likelihood of long-term survival was strongly associated with younger age and surgery. Pancreatic resection was reported in 20.4% of all patients. Median survival among those operated on was 12 months compared to 4.6 months in all patients.

CONCLUSIONS

Underreporting of pancreatic cancer to the Swedish Cancer Register was pronounced and increased with older age. Less than 3% of patients with a record of pancreatic cancer both in the Cancer Register and the Patient Register survived five years or longer.

Advance in understanding the epidemiology and etiology of pancreatic cancer

Pancreatic cancer is a life-threatening digestive system neoplasm with a low rate of surgical resection and poor prognosis. Symptoms of pancreatic cancer are so insidious that it is difficult to identify them at early stage. Due to changes in human lifestyle and diet, the incidence of pancreatic cancer has been increasing worldwide. Both genetic and environmental factors contribute to the pathogenesis of pancreatic cancer. Some hereditary factors, such as genetic mutations and genetic polymorphisms, have been demonstrated to be related to the development of pancreatic cancer. Many risk factors associated with pancreatic cancer, such as smoking, obesity, alcohol consumption, chronic pancreatitis, and diabetes, have also been identified. Here we review the recent advances in understanding the epidemiology and etiology of pancreatic cancer.

Clinical validity of detecting K-ras mutations for the diagnosis of exocrine pancreatic cancer: a prospective study in a clinically-relevant spectrum of patients

The diagnostic utility of detecting K-ras mutations for the diagnosis of exocrine pancreatic cancer (EPC) has not been properly studied, and few reports have analysed a clinically relevant spectrum of patients. The objective was to evaluate the clinical validity of detecting K-ras mutations in the diagnosis of EPC in a large sample of clinically relevant patients. We prospectively identified 374 patients in whom one of the following diagnoses was suspected at hospital admission: EPC, chronic pancreatitis, pancreatic cysts, and cancer of the extrahepatic biliary system. Mutations in the K-ras oncogene were analysed by PCR and artificial RFLP in 212 patients. The sensitivity and specificity of the K-ras mutational status for the diagnosis of EPC were 77.7% (95% CI: 69.2-84.8) and 78.0% (68.1-86.0), respectively. The diagnostic accuracy was hardly modified by sex and age. In patients with either mutated K-ras or CEA > 5 ng/ml, the sensitivity and specificity were 81.0% (72.9-87.6) and 62.6% (72.9-87.6), respectively. In patients with mutated K-ras and CEA > 5 ng/ml the sensitivity was markedly reduced. In comparisons with a variety of non-EPC patient groups sensitivity and specificity were both always greater than 75%. In this clinically relevant sample of patients the sensitivity and specificity of K-ras mutations were not sufficiently high for independent diagnostic use. However, it seems premature to rule out the utility of K-ras analysis in conjunction with other genetic and 'omics' technologies.

Targeting apoptosis pathways in pancreatic cancer

Pancreatic cancer - here in particular pancreatic ductal adenocarcinoma (PDAC) - is still a highly therapy refractory disease. Amongst the mechanisms by which PDAC cells could escape any non-surgical therapy, anti-apoptotic protection seems to be the most relevant one. PDAC cells have acquired resistance to apoptotic stimuli such as death ligands (FasL, TRAIL) or anti-cancer drugs (gemcitabine) by a great number of molecular alterations either disrupting an apoptosis inducing signal or counteracting the execution of apoptosis. Thus, PDAC cells exhibit alterations in the EGFR/MAPK/Ras/raf1-, PI3K/Akt-, TRAIL/TRAF2-, or IKK/NF-κB pathway accompanied by deregulations in the expression of apoptosis regulators such as cIAP, Bcl2, XIAP or survivin. Along with protection against apoptosis, PDAC cells also overexpress histone deacetylases (HDACs) giving rise to epigenetic patterns of chemoresistance and to acetylation of other regulatory proteins, as well. With respect to the multitude of anti-apoptotic pathways, a great number of molecular targets might be of high potential in novel therapy strategies. Thus, natural compounds as well as novel synthetic drugs are considered to be used in single or combined therapy of PDAC. A number of proteasome and HDAC inhibitors or selective inhibitors of IKK, EGFR, Akt and mTOR have been widely explored in preclinical settings and clinical studies. Even though these early studies encouraged an application in a clinical setting, most of the trials have been rather disappointing yet. Thus, new molecular targets and novel concepts of combination therapies need to get access into clinical trials - either in neoadjuvant/adjuvant or in palliative treatments.