Current status and progress of pancreatic cancer in China

Cancer is currently one of the most important public health problems in the world. Pancreatic cancer is a fatal disease with poor prognosis. As in most other countries, the health burden of pancreatic cancer in China is increasing, with annual mortality rates almost equal to incidence rates. The increasing trend of pancreatic cancer incidence is more significant in the rural areas than in the urban areas. Annual diagnoses and deaths of pancreatic cancer in China are now beyond the number of cases in the United States. GLOBOCAN 2012 estimates that cases in China account for 19.45% (65727/337872) of all newly diagnosed pancreatic cancer and 19.27% (63662/330391) of all deaths from pancreatic cancer worldwide. The population's growing socioeconomic status contributes to the rapid increase of China's proportional contribution to global rates. Here, we present an overview of control programs for pancreatic cancer in China focusing on prevention, early diagnosis and treatment. In addition, we describe key epidemiological, demographic, and socioeconomic differences between China and developed countries. Facts including no nationwide screening program for pancreatic cancer, delay in early detection resulting in a late stage at presentation, lack of awareness of pancreatic cancer in the Chinese population, and low investment compared with other cancer types by government have led to backwardness in China's pancreatic cancer diagnosis and treatment. Finally, we suggest measures to improve health outcomes of pancreatic cancer patients in China.

The molecular biology of pancreatic adenocarcinoma: translational challenges and clinical perspectives

Pancreatic cancer is an increasingly common cause of cancer mortality with a tight correspondence between disease mortality and incidence. Furthermore, it is usually diagnosed at an advanced stage with a very dismal prognosis. Due to the high heterogeneity, metabolic reprogramming, and dense stromal environment associated with pancreatic cancer, patients benefit little from current conventional therapy. Recent insight into the biology and genetics of pancreatic cancer has supported its molecular classification, thus expanding clinical therapeutic options. In this review, we summarize how the biological features of pancreatic cancer and its metabolic reprogramming as well as the tumor microenvironment regulate its development and progression. We further discuss potential biomarkers for pancreatic cancer diagnosis, prediction, and surveillance based on novel liquid biopsies. We also outline recent advances in defining pancreatic cancer subtypes and subtype-specific therapeutic responses and current preclinical therapeutic models. Finally, we discuss prospects and challenges in the clinical development of pancreatic cancer therapeutics.

LyP-1-conjugated nanoparticles for targeting drug delivery to lymphatic metastatic tumors

Active tumor targeting by biodegradable nanoparticles has been widely studied for cancer diagnosis and therapy. However, target-specific nanoparticles for drug delivery to lymphatic metastases have not been reported yet due to the lack of specific markers in the tumor lymphatics. Recently, peptide LyP-1 has been recognized for its specific home to tumors and their lymphatics. In this study, we tested the possibility of LyP-1 serving as a target-specific peptide of PEG-PLGA nanoparticles to tumor lymph metastases. LyP-1 was synthesized by using Boc-protected amino acids. The copolymers of maleimide-PEG-PLGA were formed by the conjugation of maleimide-PEG-NH(2) to PLGA-COOH, which were applied to prepare pegylated nanoparticles with mPEG-PLGA by means of double emulsion/solvent evaporation technique. LyP-1 with sulfhydryl group was conjugated to the maleimide function located at the distal end of PEG surrounding the nanoparticle surface. LyP-1-conjugated PEG-PLGA nanoparticle (LyP-1-NPs) had a round and regular shape with a diameter around 90 nm. In vitro, cellular uptake of LyP-1-NPs was about four times of that of PEG-PLGA nanoparticles without LyP-1 (NPs). In vivo, the uptake of LyP-1-NPs in metastasis lymph nodes was about eight times of that of NPs. This study indicates that LyP-1-NP is a promising carrier for target-specific drug delivery to lymphatic metastatic tumors.

Magnetic functionalised carbon nanotubes as drug vehicles for cancer lymph node metastasis treatment

Strategies using carbon-based nanomaterials as carriers for delivering chemotherapeutic drugs to cancers have been described well. Here a novel magnetic lymphatic-targeting drug-delivery system, based on functionalised carbon nanotubes (fCNTs), is presented with the aim of improving the outcome of cancer with lymph node involvement. The potential therapeutic effect of gemcitabine (GEM) loading magnetic multiwalled carbon nanotubes (mMWNTs) was compared with that of GEM loading magnetic-activated carbon particles (mACs) in vitro and in vivo. mMWNTs-GEM and mACs-GEM both had high anti-tumour activity in vitro similar to free drug. Subcutaneous administration of GEM loading magnetic nanoparticles resulted in successful regression and inhibition of lymph node metastasis under the magnetic field, with mMWNTs-GEM superior to mACs-GEM, and more effectively in the high-dose versus low-dose groups. The successful application of intra-lymphatic delivery of chemotherapeutics using mMWNTs highlights the clinical potential of fCNTs for future cancer metastasis treatment with high efficacy and minimum side-effects.

Liposome based delivery systems in pancreatic cancer treatment: from bench to bedside

Despite rapid advances in cancer diagnosis and treatment, pancreatic cancer remains one of the most difficult human malignancies to be treated, with a mortality rate nearly equal to its incidence. Although gemcitabine has been established as the standard first-line treatment for advanced pancreatic cancer, gemcitabine-based combination chemotherapy showed either marginal or no improvement in survival. Developments in liposomal delivery systems have facilitated the targeting of specific agents for cancer treatment. Such systems could be developed as platforms for future multi-functional theranostic nanodevices tailor-made for the combined detection of early cancer and functional drug delivery. We systemically review liposome based drug-delivery systems, which can provide improved pharmacokinetics, reduced side effects and potentially increased tumor uptake, for pancreatic cancer therapy. Novel liposomal formulations allowing for higher tumor targeting efficiencies and used in current clinical trials to treat this challenging disease are emphasized.

Magnetic graphene-based nanotheranostic agent for dual-modality mapping guided photothermal therapy in regional lymph nodal metastasis of pancreatic cancer

Although regional lymph nodes (RLN) dissection remains the only way to cure pancreatic cancer metastasis, it is unavoidably associated with sizable trauma, multiple complications, and low surgical resection rates. Thus, exploring a treatment approach for the ablation of drug-resistant pancreatic cancer is always of great concern. Moreover, reoperative and intraoperative mapping of RLN is also important during treatment, because only a few lymph nodes can be detected by the naked eye. In our study, graphene oxides modified with iron oxide nanoparticles (GO-IONP) as a nanotheranostic agent is firstly developed to diagnose and treat RLN metastasis of pancreatic cancer. The approach was designed based on clinical practice, the GO-IONP agent directly injected into the tumor was transported to RLN via lymphatic vessels. Compared to commercial carbon nanoparticles currently used in the clinic operation, the GO-IONP showed powerful ability of dual-modality mapping of regional lymphatic system by magnetic resonance imaging (MRI), as well as dark color of the agent providing valuable information that was instrumental for surgeon in making the preoperative plan before operation and intraoperatively distinguish RLN from surrounding tissue. Under the guidance of dual-modality mapping, we further demonstrated that metastatic lymph nodes including abdominal nodes could be effectively ablated by near-infrared (NIR) irradiation with an incision operation. The lower systematic toxicity of GO-IONP and satisfying safety of photothermal therapy (PTT) to neighbor tissues have also been clearly illustrated in our animal experiments. Using GO-IONP as a nanotheranostic agent presents an approach for mapping and photothermal ablation of RLN, the later may serve as an alternative to lymph node dissection by invasive surgery.

Carbon nanotubes in cancer diagnosis and therapy

During the past years, great progress has been made in the field of nanomaterials given their great potential in biomedical applications. Carbon nanotubes (CNTs), due to their unique physicochemical properties, have become a popular tool in cancer diagnosis and therapy. They are considered one of the most promising nanomaterials with the capability of both detecting the cancerous cells and delivering drugs or small therapeutic molecules to these cells. Over the last several years, CNTs have been explored in almost every single cancer treatment modality, including drug delivery, lymphatic targeted chemotherapy, thermal therapy, photodynamic therapy, and gene therapy. In this review, we will show how they have been introduced into the diagnosis and treatment of cancer. Novel SWNT-based tumor-targeted drug delivery systems (DDS) will be highlighted. Furthermore, the in vitro and in vivo toxicity of CNTs reported in recent years will be summarized.

Hydrophilic multi-walled carbon nanotubes decorated with magnetite nanoparticles as lymphatic targeted drug delivery vehicles

Hydrophilic multi-walled carbon nanotubes decorated with magnetite nanoparticles were readily taken up into lymph vessels and delivered gemcitabine to lymph nodes with high efficiency under the guidance of a magnetic field.

Benefit from synchronous portal-superior mesenteric vein resection during pancreaticoduodenectomy for cancer: a meta-analysis

BACKGROUND

Pancreaticoduodenectomy combined with portal-superior mesenteric vein synchronous resection for cancer remains a hot debate topic. The present study used meta-analytical technique to provide update information and an evidence-based evaluation on both the perioperative benefit and long-term survival.

METHODS

A meta-analysis was performed to evaluate studies comparing venous resection (VR) versus without venous resection (WVR) groups. 22 retrospective studies including 2890 patients were eligible for an analysis of perioperative morbidity, mortality, and long-term survival. Furthermore, subgroup analysis was made according to histopathology and resection margin status respectively for the purpose of survival assessment.

RESULTS

There was no difference in perioperative morbidity, mortality and 1-year, 3-year survival between two groups, but showed differences in median tumor size (P < 0.001), R0 resection rate (P < 0.001), lymph node metastasis (P = 0.03), pancreatic fistula (P = 0.01), and 5-year survival (P = 0.03). In subgroup analysis, patients in venous resection group received R0 resection had a significantly better survival comparing with who received R1 resection both at 2-year (P < 0.001) and 5-year (P = 0.00002). In histopathology subgroup, patients in venous resection groups who had true tumor infiltration had a significantly bad survival comparing with whom only with inflammation pathology.

CONCLUSION

Pancreaticoduodenectomy combined with venous resection can achieve equal perioperative morbidity and mortality as standard resection. However, in order to obtain an optimal survival outcome, surgeons should make an R0 resection as far as possible, especially in cases need synchronous venous resection.

Solid pseudopapillary tumor of the pancreas: a case series of 26 consecutive patients

OBJECTIVE

Solid pseudopapillary tumor (SPT) of the pancreas, which predominantly affects young women, is a relatively indolent entity with favorable prognosis. The aim of this study is to describe the clinicopathologic features and surgical management of this disease in our institution.

METHODS

A retrospective study of clinical data from 26 consecutive patients with SPT managed in a tertiary academic center between January 2002 and December 2007 was performed. Clinicopathologic factors were compared between benign and malignant cases to determine what features of the tumor could suggest malignant potential.

RESULTS

The 26 cases included 22 female and 4 male patients, and the average age was 32.3 years (range 15 to 64). Clinical symptoms were nonspecific and included upper abdominal pain or discomfort, abdominal distention, and back pain. The neoplasm was localized in the pancreatic head/neck in 14 patients and in the body/tail in 12 patients. The median diameter of these lesions was 6.25 cm (range 2 to 15). All of the tumors-including 8 pancreaticoduodenectomies, 10 distal pancreatectomies, 6 local resections, 1 total pancreatectomy, and 1 central pancreatectomy-were resected successfully. No patient received chemotherapy or radiotherapy after surgery. All of the patients except 1 were alive at a median follow-up of 32.5 months (range 3 to 69). One of the 2 patients with malignant SPT, in whom Ki-67 immunoreactivity was >25%, developed local recurrence with liver metastasis 4 months and died 6 months after surgery. There were no significant associations between clinicopathologic factors and malignancy.

CONCLUSIONS

SPT is a rare neoplasm with low malignant potential. Characteristic computed axial tomography and magnetic resonance imaging scans combined with age and sex profile should be sufficient for the decision to operate. Patients with malignant SPT should have careful follow-up. The high proliferative index assessed by immunohistochemical staining for Ki-67 may predict poor outcome of malignant SPT.

Emerging inorganic nanomaterials for pancreatic cancer diagnosis and treatment

Pancreatic cancer is a devastating disease with incidence increasing at an alarming rate and survival not improved substantially during the past three decades. Although enormous efforts have been made in early detection and comprehensive treatment for this disease, little or no survival improvement was obtained, which necessitates the development of novel strategies. Emerging inorganic nanomaterials, such as carbon nanotubes, quantum dots, mesoporous silica/gold/supermagnetic nanoparticles, have been widely used in biomedical research with great optimism for cancer diagnosis and therapy. Such nanoparticles possess unique optical, electrical, magnetic and/or electrochemical properties. With such properties along with their impressive nano-size, these particles can be targeted to cancer cells, tissues, and ligands efficiently and monitored with extreme precision in real-time. In additional to liposome, dendrimer, and polymeric nanoparticles, they are considered the most promising nanomaterials with the capability of both cancer detection and multimodality treatment. Emerging approaches to harness nanotechnology to optimize the existing diagnostic and therapeutic tools for pancreatic cancer have been extensively explored during the recent years. Future options for early detection, individual therapy and monitoring responses of pancreatic cancer are focused on multifunctional nanomedicine. In this review, we present the recent development of clinically applicable inorganic nanoparticles, with focus on the diagnosis and treatment of pancreatic cancer. Furthermore, their advantages in theranostic nanomedicine, and challenges of translation to clinical practice, are discussed.

Insulin-like growth factor 1-induced enolase 2 deacetylation by HDAC3 promotes metastasis of pancreatic cancer

Enolase 2 (ENO2) is a key glycolytic enzyme in the metabolic process of glycolysis, but its potential function in pancreatic ductal adenocarcinoma (PDAC) is unclear. In this study, we observed a significant overexpression of ENO2 in PDAC tissues, and its expression was correlated with metastasis and poor prognosis in PDAC patients. K394 was identified as a major acetylation site in ENO2 that regulates its enzymatic activity, cell metabolism and PDAC progression. Knockdown of ENO2 suppressed tumor growth and liver metastasis in PDAC. Re-expression of wild-type (WT) ENO2, but not the K394 acetylation mimetic mutant, could reverse the decreased tumor malignancy. We further characterized histone deacetylase 3 (HDAC3) and P300/CBP-associated factor (PCAF) as the potential deacetylase and acetyltransferase for ENO2, respectively. HDAC3-mediated deacetylation was shown to lead to ENO2 activation and enhancement of glycolysis. Importantly, insulin-like growth factor-1 (IGF-1) was found to decrease K394 acetylation and stimulate ENO2 activity in a dose- and time-dependent manner. The PI3K/AKT/mTOR pathway facilitated the phosphorylation of HDAC3 on S424, which promoted K394 deacetylation and activation of ENO2. Linsitinib, an oral small-molecule inhibitor of IGF-1R, could inhibit IGF-1-induced ENO2 deacetylation by HDAC3 and the PI3K/AKT/mTOR pathway. Furthermore, linsitinib showed a different effect on the growth and metastasis of PDAC depending on the overexpression of WT versus K394-mutant ENO2. Our results reveal a novel mechanism by which acetylation negatively regulates ENO2 activity in the metastasis of PDAC by modulating glycolysis. Blockade of IGF-1-induced ENO2 deacetylation represents a promising strategy to prevent the development of PDAC.

Prognostic value of Ki-67 in solid pseudopapillary tumor of the pancreas: Huashan experience and systematic review of the literature

BACKGROUND

Solid pseudopapillary tumor of the pancreas (SPTP) is considered to have a low Ki-67 proliferation index, which may explain the generally good clinical outcome. The aim of our study was to evaluate whether Ki-67 has prognostic value in SPTP.

METHODS

A case series study of patients with SPTP treated in our institution from June 2002 to April 2014 was conducted. Prognostic factors for clinical outcomes were analyzed by the use of clinical decision and survival analysis. In addition, we performed a systematic review and pooled analysis to evaluate our results.

RESULTS

The institutional data included 71 patients (13 male and 58 female) ranging in age from 12 to 64 years (median, 31 years). Three patients developed local recurrence and/or liver metastasis after initial surgery. The 5-year recurrence-free survival rate was 93.6%. One patient died of disease, with the 5-year disease-specific survival rate of 98.5%. Ki-67 index ≥ 4% was found significantly associated with the survival of SPTP. Twenty-six studies comprising 163 patients were included in the pooled analysis based on our inclusion criteria. A total of 15 cases showed a Ki-67 index ≥ 4%. Kaplan-Meier survival analysis confirmed that Ki-67 index ≥ 4% was significantly associated with poorer recurrence-free survival and disease-specific survival (both P < .001).

CONCLUSION

This study highlighted a potential role of Ki-67 in predicting adverse outcome of patients with SPTP and should be considered as part of routine histological reporting of SPTP.

Diagnostic, Therapeutic Predictive, and Prognostic Value of Neutrophil Extracellular Traps in Patients With Gastric Adenocarcinoma

Neutrophils are a significant population of infiltrated immune cells in the tumor microenvironment. Neutrophil extracellular traps (NETs) are implicated in the biological behavior of many malignant tumors. NETs can be degraded into soluble nucleosomes, leading to the release of fragments containing DNA and granule proteins into the peripheral blood (PB). Using human gastric cancer (GC) biopsies and PB samples, we investigated the specific value of NETs in GC from a clinical perspective. In summary, the formation of NETs was discovered in the tissue microenvironment and PB of GC patients. The amounts of NETs and neutrophil accumulation decreased from tumor tissue to paratumor tissue. In addition, the level of NETs in the PB gradually declined through the following patient populations: advanced disease patients, preoperative patients, postoperative patients, benign disease patients, and healthy controls. The levels of NETs in the plasma and serum were significantly correlated. As a serum biomarker, NETs had a better diagnostic value than carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) in GC. The neutrophil count and neutrophil to lymphocyte ratio (NLR) were significantly associated with the level of NETs in the PB. The existence of lymph node metastasis indicated a high level of NETs in the serum. Moreover, the level of NETs in the PB was inversely correlated with short-term efficacy in GC patients who had received advanced first-line treatment. The higher baseline level of NETs in the PB of patients with negative HER2 status was correlated with worse progression-free survival (PFS). And the level of NETs in the PB was a unfavorable independent prognostic factor for PFS in patients with advanced GC who had received first-line treatment. Thus, NETs have novel diagnostic, therapeutic predictive, and prognostic value in GC patients.

Establishment of an orthotopic pancreatic cancer mouse model: cells suspended and injected in Matrigel

AIM

To establish an orthotopic mouse model of pancreatic cancer that mimics the pathological features of exocrine pancreatic adenocarcinoma.

METHODS

Pan02 cells were suspended in low-temperature Matrigel and injected into the parenchyma of pancreatic tails of C57BL/6 mice, with cells suspended in phosphate buffered saline (PBS) serving as a control. Primary and implanted tumors were confirmed pathologically. The rate of tumor formation and intraperitoneal implantation in the two groups were compared at different time points after injection. Leakage and intra-abdominal dispersion of Matrigel and PBS, both dyed with methylene blue, were compared after injection into the parenchyma of the pancreas. We observed adherence and proliferation in Pan02 cells suspended in Matrigel in vitro. We also compared the pathological manifestation of this orthotopic pancreatic cancer model in the head and tails of the pancreas. The characteristics of the origin of epithelial cells and exocrine markers of established orthotopic pancreatic tumors were confirmed using immunohistochemistry.

RESULTS

Diluted Matrigel could form a gel drip in the pancreatic parenchyma, effectively preventing leakage from the injection site and avoiding dispersion in the abdominal cavity. Pan02 cells were able to adhere to a dish, proliferate, and migrate in the gel drip. The tumor formation rate in the Matrigel group was 100% at both 2 and 3 wk after injection, whereas it was 25.0% and 37.5% in the PBS group at 2 and 3 wk, respectively (P < 0.05). The intraperitoneal tumor implantation rate was 75.0% in the PBS group after 3 wk of injection, while it was 12.5% in the Matrigel group (P < 0.05). Hepatoduodenal ligament and duodenal invasions with obstructive jaundice and upper digestive obstruction with mesenteric lymph node metastasis were observed in the pancreatic head group. In the pancreatic tail group, spleen and gastric invasion were dominant, leading to retroperitoneal lymph nodes metastasis. Positive immunohistochemical staining of cytokeratin and negative staining of vimentin and chromogranin A confirmed that the orthotopic pancreatic tumor injected with Pan02 cells suspended in Matrigel was of epithelial origin and expressed exocrine markers of cancer.

CONCLUSION

This method of low-temperature Matrigel suspension and injection is effective for establishing an orthotopic mouse model of pancreatic cancer.

Magnetic lymphatic targeting drug delivery system using carbon nanotubes

By controlling size, nanoparticles can be effectively taken up into lymphatics. On this basis, various nanoparticles have been investigated for transporters of chemotherapeutic pharmaceuticals, but only a few were retained in the draining lymph node. Here, we present a technology using a magnetic carbon nanotubes (MNTs) delivery system, and it may be possible to facilitate the targeted delivery of drugs in the lymphatic tissue more effectively. Chemotherapeutic agents were incorporated into the pores of functionalized MNTs synthesized with a layer of magnetite nanoparticles on the inner surface of the nanotubes. To improve drug delivery to cancer cells in the lymph nodes, individualized MNTs were noncovalently functionalized by folic acid (FA). By using an externally placed magnet to guide the drug matrix to the regional targeted lymph nodes, the MNTs can be retained in the draining targeted lymph nodes for several days and continuously release chemotherapeutic drugs. Selective killing of tumor cells overexpressing the folate receptors (FRs) in the lymph nodes can be achieved, as FR is overexpressed across a broad spectrum of human tumors.

Utility of PET/CT in diagnosis, staging, assessment of resectability and metabolic response of pancreatic cancer

Pancreatic cancer is one of the most common gastrointestinal tumors, with its incidence staying at a high level in both the United States and China. However, the overall 5-year survival rate of pancreatic cancer is still extremely low. Surgery remains the only potential chance for long-term survival. Early diagnosis and precise staging are crucial to make proper clinical decision for surgery candidates. Despite advances in diagnostic technology such as computed tomography (CT) and endoscopic ultrasound, diagnosis, staging and monitoring of the metabolic response remain a challenge for this devastating disease. Positron emission tomography/CT (PET/CT), a relatively novel modality, combines metabolic detection with anatomic information. It has been widely used in oncology and achieves good results in breast cancer, lung cancer and lymphoma. Its utilization in pancreatic cancer has also been widely accepted. However, the value of PET/CT in pancreatic disease is still controversial. Will PET/CT change the treatment strategy for potential surgery candidates? What kind of patients benefits most from this exam? In this review, we focus on the utility of PET/CT in diagnosis, staging, and assessment of resectability of pancreatic cancer. In addition, its ability to monitor metabolic response and recurrence after treatment will be emphasis of discussion. We hope to provide answers to the questions above, which clinicians care most about.

Elevated expression of tumor miR-222 in pancreatic cancer is associated with Ki67 and poor prognosis

Pancreatic cancer is known for its bad prognosis. Micro-RNAs mis-expressions are associated with various human cancers and offer new candidate targets for diagnostic and therapeutic strategies. Micro-RNA-222 has been shown to play a crucial role in cancer cell proliferation in recent studies. However, its correlations with the clinicopathological characters of pancreatic cancer still remain unclear. Through a prospective study of 60 pairs of pancreatic cancer tissues, adjacent normal tissues were examined by quantitative reverse-transcription polymerase chain reaction. The correlation between the expression of micro-RNA-222 and clinico-pathological characters was performed using the two-sample Student's t test. The survival correlations were analyzed by the Kaplan-Meier method and the Cox's proportional hazards model. Results showed that the expression levels of micro-RNA-222 were significantly elevated in the pancreatic cancer tissue compared with that in adjacent normal tissue. In addition, the overexpression of the tissue micro-RNA-222 strongly related to the expression level of Ki67. Finally, Cox's proportional hazards model analysis confirmed that micro-RNA-222 high expression level was an independent predictor of poor prognosis. This study provides the first evidence of a potential link between Ki67 and micro-RNA-222, which are both relevant to cell proliferation. Our data suggest the potential of micro-RNA-222 as a prognostic biomarker for the pancreatic cancer.

Clinical experiences of solid pseudopapillary tumors of the pancreas in China

AIMS

To discuss the clinical experiences of solid pseudopapillary tumors (SPTs) of the pancreas by summarizing clinical information of patients with this disease in China.

METHODS

Chinese literature concerning SPTs of the pancreas published between January 1996 and October 2006 were retrospectively reviewed and analyzed.

RESULTS

A total of 390 cases had been reported, among which 47 were men, with a female to male ratio of 7.30:1. Mean age of the patients was 25.3 years old, more than 50 per cent were between 10 and 24 years. The mean diameter of the tumor was 8.4 cm (range, 2 cm-25 cm). There was no significant difference in patient age and tumor size between male and female. Major clinical presentations included abdominal pain or discomfort, and palpable abdominal masses, however, nearly one third of all patients were asymptomatic. The rate of pre-operative misdiagnosis was rather high. Those who tested positive to metastases or invasions, 14.4% of the patients were diagnosed as malignant SPTs. Sex, age, symptoms, tumor size and tumor markers were not significant clinical factors to predict SPTs with malignant potential. Surgical procedures mainly included pancreatoduodenectomy, distal pancreatectomy and local resection. Three patients developed local recurrence, and one patient developed hepatic metastasis, all within four years after tumor resection. Five patients with malignant SPTs died due to tumor progression within 25 months after surgery.

CONCLUSIONS

Surgical resection is the most effective means for curing this rare tumor. Despite metastasis, a good satisfactory effect could be achieved by surgical debulking. At least 4-yearly follow-up is mandatory for all patients undergoing surgical resection.

Pilot study of targeting magnetic carbon nanotubes to lymph nodes

AIM

The lymphatic distribution of magnetic carbon nanotubes was studied in vivo and compared with magnetic-activated carbon particles, which were selectively taken up in the lymphatic channels and delivered to the regional lymph nodes.

MATERIAL & METHODS

Magnetic multiwalled carbon nanotubes functionalized with poly(acrylic acid) (mMWNTs) and magnetic-activated carbon particles were subcutaneously injected in mice. The draining lymph nodes were harvested at different times postadministration to examine the lymphatic distribution of these particles. The short-term accumulation and toxicity of mMWNTs in the major organs were studied.

RESULTS

mMWNTs had the same properties of lymph node mapping as magnetic-activated carbon particles in mice independent of lymph node metastasis. The degree of black staining of lymph nodes and concentration of mMWNTs had a dose-response relationship. Aggregation of magnetic particles was found around the metastatic foci within the lymph nodes. Footpad injection of mMWNTs did not cause any obvious local or systemic toxicities, and no particle agglomerates were found in the major organs.

CONCLUSION

The feasibility of targeting magnetic carbon nanotubes to lymph nodes was demonstrated and the results support further studies for their potential use in diagnosing and treating cancer.

RNA interference of MBD1 in BxPC-3 human pancreatic cancer cells delivered by PLGA-poloxamer nanoparticles

Methyl-CpG binding domain protein 1 (MBD1) is a transcriptional regulator that binds methylated CpG islands of tumor suppressor genes and represses their transcription. In a former study, we found high expression of MBD1 in pancreatic cancer cell lines and tissues which may play an important role in the development of pancreatic cancer. In the present study, we incorporated the siRNA sequence of MBD1 plasmid into a PLGA-poloxamer carrier to test the therapeutic effect of this compound on BxPC-3 human pancreatic cancer cells. We found that an MBD1 siRNA plasmid can be successfully transfected into tumor cells and the MBD1 nanoparticle compound can inhibit cell growth and induce apoptosis. The MBD1 nanoparticle is a promising candidate for gene therapy of pancreatic cancer in vitro.

Duodenal gastrointestinal stromal tumor: clinicopathological characteristics, surgical outcomes, long term survival and predictors for adverse outcomes

BACKGROUND

Gastrointestinal stromal tumors (GISTs) occur rarely in the duodenum. Because of their low incidence, data on long-term survival and prognostic factors are limited. The aims of this study were to present the authors' experiences in the diagnosis and treatment of this disease and to evaluate long-term surgical outcomes.

METHODS

Clinical data from 22 consecutive patients with duodenal GISTs surgically managed from May 1999 to August 2011 were retrospectively studied. A pooled analysis was done by systematically reviewing other case series reported in the English literature. Recurrence-free survival and independent predictors of adverse outcomes were analyzed using the Kaplan-Meier method and multivariate Cox regression.

RESULTS

Duodenal GISTs had a mild male predominance (68.2%), occurring primarily in older adults (median age, 58 years), with a frequency of 7.49% among all GISTs. Clinical presentations were nonspecific, with gastrointestinal bleeding and abdominal pain or discomfort being the most common symptoms. The tumors were located mainly in the second portion of the duodenum, in 14 patients (63.6%), with a median size of 3.75 cm (range, 1.4 to 14). All patients underwent curative surgical resection, including 9 pancreaticoduodenectomy, 3 segmental duodenectomy, and 10 local resection. Eighteen patients were alive without evidence of recurrence after a median follow-up period of 67.5 months (range, 3 to 118). The 1-year, 2-year, and 3-year rates of recurrence-free survival were 95%, 89.5%, and 86.7%, respectively. Kaplan-Meier analysis and log-rank tests showed that surgical pattern, mitosis, and risk grade were significantly associated with recurrence-free survival (P < .05 for all). However, only high mitosis was a significant predictive factor for adverse outcomes on multivariate analysis (hazard ratio, 16.414; 95% confidence interval, 1.914 to 140.756; P = .011).

CONCLUSIONS

Duodenal GIST is an unusual neoplasm with favorable survival after curative resection. Mitotic activity was more influential than tumor size and risk grade in predicting adverse outcomes. All patients with duodenal GISTs require long-term follow-up, because late relapse can occur even if the tumor has low malignant potential.

FOXP3+ lymphocyte density in pancreatic cancer correlates with lymph node metastasis

OBJECTIVE

To determine if the density of FOXP3+ lymphocytes in primary tumors and lymph nodes in pancreatic cancer correlates with the presence of lymph node metastases.

METHODS

FOXP3+ lymphocyte density in primary pancreatic cancer tissue and draining lymph nodes was measured using immunohistochemistry. We analyzed the clinical and pathological aspects associated with the accumulation of FOXP3+ lymphocytes in pancreatic cancer. We also analyzed the correlation of density of FOXP3+ lymphocytes in lymph nodes with the nodal status and distance from the primary tumor.

RESULTS

FOXP3+ lymphocyte density in pancreatic cancer was significantly higher than in paratumoral pancreatic tissue. The density of FOXP3+ lymphocytes in local tumor tissue correlated significantly with the histological grade and overall lymph node status. Furthermore, FOXP3+ lymphocyte density was significantly higher in positive lymph nodes than in negative ones, while it had no correlation with the distance of the lymph node from the primary tumor.

CONCLUSION

FOXP3+ lymphocyte density in primary tumor tissue in patients with pancreatic cancer correlates with lymph node metastasis. Lymph nodes containing metastases having higher FOXP3+ lymphocyte densities than do negative lymph nodes.