Pancreatic cancer screening: state of the art

Combined ultrasound endoscopy-guided fine-needle aspiration with DNA methylation of SHOX2 and RASSF1A genes to enhance the auxiliary diagnostic precision of pancreatic cancer

The purpose of this study was to assess the influence and the clinical effectiveness of the short stature homeobox 2 (SHOX2) and ras association domain family 1A (RASSF1A) genes by tissue sampling through ultrasound endoscopy-guided fine-needle aspiration (EUS-FNA) as auxiliary diagnostic tools for pancreatic cancer (PC). Methylation markers were detected in 96 patients using real-time fluorescence quantitative PCR (qPCR), and the performance of this diagnostic assay was compared with CA19-9, CEA, and puncture fluid-based exfoliative cytology using receiver operating characteristic curve (ROC) analysis. The PC group exhibited higher methylation rates for SHOX2, RASSF1A, and the combined assay of both genes compared to the control group (95.7 % vs. 54.0 %, 78.3 % vs. 36.0 %, and 73.9 % vs. 16.0 %, P < 0.05). The areas under the ROC curve (AUC) for CA19-9, CEA, liquid-based exfoliative cytology, SHOX2, RASSF1A, the combination of SHOX2 and RASSF1A, the combination assay with CEA, CA19-9, and liquid-based exfoliative cytology were 0.827, 0.692, 0.767, 0.770, 0.732, 0.870, 0.870, 0.933, and 0.900, respectively. Therefore, the methylation assay based on the combined SHOX2 and RASSF1A genes in EUS-FNA puncture fluid is more effective than using a single gene, liquid-based exfoliative cytology, or intravenous tumor markers for diagnosing PC. Combining the conventional marker CA19-9 enhances the diagnostic value, making it a promising approach to complement histology and cytology.

Pancreatic Cancer: A Review of Risk Factors, Diagnosis, and Treatment

This review aims to summarize the latest knowledge on factors, diagnosis, and treatment of pancreatic cancer, and aims to promote further research on this under-studied malignant tumor. At present, we urgently need to identify high-risk patients with precancerous diseases through screening approaches, so that medical professionals and the general public may better understand prevention strategies or early detection measures. Pancreatic cancer is a highly invasive malignant tumor with a fatal risk, mainly seen in men and older adults (60-85 years old). Pancreatic cancer is now increasingly observed in young patients. Because the disease has no early symptoms and can quickly invade surrounding tissues and organs, it is one of the deadliest cancers. With a view to identify the important factors for the development of pancreatic cancer, previous studies have found that smoking, alcohol, and chronic pancreatitis are considered high-risk factors. Recent studies have shown that abnormal metabolism of human microorganisms, blood type, and glucose and lipid levels are also important factors in the development of pancreatic cancer. Identifying early diagnosis options is an important way to improve detection and survival rates of pancreatic cancer. None of the many tumor markers associated with pancreatic cancer are highly specific, which also indicates further research is required to improve the early detection rate. Future directions in terms of treatment evaluating the relationship between the microbiology-free system and immunotherapy will bring a major breakthrough and is expected to bring exciting clinical applications in improving the life-cycle of pancreatic cancer patients.

Quantitative parameters of intravoxel incoherent motion diffusion weighted imaging (IVIM-DWI): potential application in predicting pathological grades of pancreatic ductal adenocarcinoma

Background

The aim of this study was to compare intravoxel incoherent motion diffusion weighted imaging (IVIM-DWI) parameters such as standard apparent diffusion coefficient (ADC_standard), pure diffusion coefficient (D_slow), pseudodiffusion coefficient (D_fast) and perfusion fraction (ƒ) for differentiating pancreatic ductal adenocarcinoma (PDAC) with different pathological grades.

Methods

Institutional Review Board of our hospital approved this study protocol. Subjects comprised 38 PDACs confirmed by pathology. Pancreatic multiple b values DWI with 15 b values of 0, 10, 20, 40, 60, 80, 100, 150, 200, 400, 800, 1,000, 1200, 1,500, and 2,000 s/mm² was performed using GE Discovery MR750 3.0T scanner. ADC_standard, D_slow, D_fast and ƒ values of all PDACs were calculated using mono- and bi-exponential models. Parameters of well/moderately differentiated and poorly differentiated PDAC were compared using Independent Sample t-test. P values <0.05 were considered significant.

Results

Mean D_slow value of well/moderately differentiated PDAC was significantly lower than that of poorly differentiated PDAC (0.540×10^-3vs. 0.676×10^-3 mm²/s, P<0.001). Mean ƒ value of well/moderately differentiated PDAC was significantly higher than that of poorly differentiated PDAC (60.3% vs. 38.4%, P<0.001). The area under curve value of ƒ in differentiating well/moderately differentiated PDAC from poorly differentiated PDAC was slightly higher than that of D_slow (0.894>0.865). When the D_slow value was less than or equal to 0.599×10^-3 mm²/s, the sensitivity and specificity were 100% and 84.6% respectively. When ƒ value was greater than 49.6%, the sensitivity and specificity were 92.0% and 84.6% respectively.

Conclusions

D_slow and ƒ derived from IVIM-DWI model can be used to distinguish well/moderately differentiated PDAC from poorly differentiated PDAC. And to serve this purpose, D_slow and ƒ have high diagnostic performance. IVIM-DWI is a promising and non-invasive tool for predicting pathological grade of PDAC.

Comparing the diagnostic accuracy of five common tumour biomarkers and CA19-9 for pancreatic cancer: a protocol for a network meta-analysis of diagnostic test accuracy

INTRODUCTION

Surgical resection is the only curative treatment for patients with resectable pancreatic cancer. Unfortunately, 80%-85% of patients present with locally advanced or metastatic unresectable pancreatic cancer at the time of diagnosis. Detection of pancreatic cancer at early stages remains a great challenge due to lack of accurate detection tests. Recommendations in existing clinical practice guidelines on early diagnosis of pancreatic cancer are inconsistent and based on limited evidence. Most of them endorse measuring serum CA19-9 as a complementary test, but also state that it is not recommended for diagnosing early pancreatic cancer. There are currently no other tumour-specific markers recommended for diagnosing early pancreatic cancer. This study aims to evaluate and compare the accuracy of five common tumour biomarkers (CA242,carcino-embryonic antigen (CEA)), CA125, microRNAs and K-ras gene mutation) and CA19-9 and their combinations for diagnosing pancreatic cancer using network meta-analysis method, and to rank these tests using a superiority index.

METHODS AND ANALYSIS

PubMed, EMBASE and the Cochrane Central Register of Controlled Trials will be searched from inception to April 2017. The search will include the above-mentioned tumour biomarkers for diagnosing pancreatic cancer, including CA19-9. The risk of bias for each study will be independently assessed as low, moderate or high using criteria adapted from the Quality Assessment of Diagnostic Accuracy Studies 2. Network meta-analysis will be performed using STATA V.12.0 and R software V.3.4.1. The competing diagnostic tests will be ranked by a superiority index.

ETHICS AND DISSEMINATION

Ethical approval and patient consent are not required since this study is a network meta-analysis based on published studies. The results of this network meta-analysis will be submitted to a peer-reviewed journal for publication.

PROSPERO REGISTRATION NUMBER

CRD42017064627.

Screening for Pancreatic Cancer: Current Status and Future Directions

Pancreatic ductal adenocarcinoma is a lethal disease for a multitude of reasons, including difficulty of early detection, early metastatic spread, and absence of more effective therapies. Even with the advent of newer systemic therapies, the 1-year survival for metastatic disease ranges from 17–23% and 5-year survival is <5%. This necessitates an urgent need for the development of more effective modalities for early detection, particularly due to the long latent period between the genomic cellular changes and the development of metastatic disease. Currently available biochemical and molecular markers have significant potential; however, they require further clinical validation. Endoscopic ultrasound is one of the most sensitive modalities used to both screen and sample lesions, but is limited to use in high-risk patients due to its invasive nature and associated risks. Although clinically meaningful progress has been made in screening the high-risk cohorts in terms of detection of pancreatic ductal adenocarcinoma, intraductal papillary mucinous neoplasms, and mucinous cystic neoplasms, leading to early diagnosis and treatment, nonselective population-based screening is not yet available for widespread use. Currently there is no consensus on the most appropriate screening protocol for early pancreatic cancer detection. In this review, we focus on understanding the potential role of molecular and radiogenomic markers in the early detection of pancreatic cancer.

Epidemiology of pancreatic cancer

Cancer of the pancreas remains one of the deadliest cancer types. Based on the GLOBOCAN 2012 estimates, pancreatic cancer causes more than 331000 deaths per year, ranking as the seventh leading cause of cancer death in both sexes together. Globally, about 338000 people had pancreatic cancer in 2012, making it the 11th most common cancer. The highest incidence and mortality rates of pancreatic cancer are found in developed countries. Trends for pancreatic cancer incidence and mortality varied considerably in the world. A known cause of pancreatic cancer is tobacco smoking. This risk factor is likely to explain some of the international variations and gender differences. The overall five-year survival rate is about 6% (ranges from 2% to 9%), but this vary very small between developed and developing countries. To date, the causes of pancreatic cancer are still insufficiently known, although certain risk factors have been identified, such as smoking, obesity, genetics, diabetes, diet, inactivity. There are no current screening recommendations for pancreatic cancer, so primary prevention is of utmost importance. A better understanding of the etiology and identifying the risk factors is essential for the primary prevention of this disease.

Combining in Vitro Diagnostics with in Vivo Imaging for Earlier Detection of Pancreatic Ductal Adenocarcinoma: Challenges and Solutions

Pancreatic ductal adenocarcinoma (PDAC) is the fourth-leading cause of cancer-related death in the United States and is associated with a dismal prognosis, particularly when diagnosed at an advanced stage. Overall survival is significantly improved if PDAC is detected at an early stage prior to the onset of symptoms. At present, there is no suitable screening strategy for the general population. Available diagnostic serum markers are not sensitive or specific enough, and clinically available imaging modalities are inadequate for visualizing early-stage lesions. In this article, the role of currently available blood biomarkers and imaging tests for the early detection of PDAC will be reviewed. Also, the emerging biomarkers and molecularly targeted imaging agents being developed to improve the specificity of current imaging modalities for PDAC will be discussed. A strategy incorporating blood biomarkers and molecularly targeted imaging agents could lead to improved screening and earlier detection of PDAC in the future. (©) RSNA, 2015.

The promise of methylation on beads for cancer detection and treatment

Despite numerous technical hurdles, the realization of true personalized medicine is becoming a progressive reality for the future of patient care. With the development of new techniques and tools to measure the genetic signature of tumors, biomarkers are increasingly being used to detect occult tumors, determine the choice of treatment and predict outcomes. Methylation of CpG islands at the promoter region of genes is a particularly exciting biomarker as it is cancer-specific. Older methods to detect methylation were cumbersome, operator-dependent and required large amounts of DNA. However, a newer technique called methylation on beads has resulted in a more uniform, streamlined and efficient assay. Furthermore, methylation on beads permits the extraction and processing of miniscule amounts of methylated tumor DNA in the peripheral blood. Such a technique may aid in the clinical detection and treatment of cancers in the future.

How early can pancreatic cancer be recognized? A case report and review of the literature

The early symptoms of pancreatic cancer are often very vague. They may precede the diagnosis by years and go unrecognized. This makes pancreatic cancer one of the cancers with the worst survival rates. The progression rate of the early phase might be slower than previously thought. Here, we report a case where symptoms, including thromboembolism and new-onset diabetes mellitus, preceded the diagnosis of pancreatic cancer by 6 years or longer. The awareness of the early symptoms of pancreatic cancer is required for being vigilant and further diagnostic tests. A simple clinical model utilizing certain risk factors and symptoms for pancreatic cancer will help stratify the patients for further screening tests.

Endoscopic ultrasonography for surveillance of individuals at high risk for pancreatic cancer

Pancreatic cancer is a highly lethal disease with a genetic susceptibility and familial aggregation found in 3%-16% of patients. Early diagnosis remains the only hope for curative treatment and improvement of prognosis. This can be reached by the implementation of an intensive screening program, actually recommended for individuals at high-risk for pancreatic cancer development. The aim of this strategy is to identify pre-malignant precursors or asymptomatic pancreatic cancer lesions, curable by surgery. Endoscopic ultrasound (EUS) with or without fine needle aspiration (FNA) seems to be the most promising technique for early detection of pancreatic cancer. It has been described as a highly sensitive and accurate tool, especially for small and cystic lesions. Pancreatic intraepithelial neoplasia, a precursor lesion which is highly represented in high-risk individuals, seems to have characteristics chronic pancreatitis-like changes well detected by EUS. Many screening protocols have demonstrated high diagnostic yields for pancreatic pre-malignant lesions, allowing prophylactic pancreatectomies. However, it shows a high interobserver variety even among experienced endosonographers and a low sensitivity in case of chronic pancreatitis. Some new techniques such as contrast-enhanced harmonic EUS, computer-aided diagnostic techniques, confocal laser endomicroscopy miniprobe and the detection of DNA abnormalities or protein markers by FNA, promise improvement of the diagnostic yield of EUS. As the resolution of imaging improves and as our knowledge of precursor lesions grows, we believe that EUS could become the most suitable method to detect curable pancreatic neoplasms in correctly identified asymptomatic at-risk patients.

Follow-up of patients with pseudotumoral chronic pancreatitis: Outcome and surveillance

AIM: To follow up patients with pseudotumoral chronic pancreatitis (PCP) to assess their outcome and identify an optimal surveillance interval.

METHODS: Data obtained prospectively were analyzed in a retrospective manner. Patients with clinical evidence of chronic pancreatitis (abdominal pain in the epigastrium, steatorrhea, and diabetes mellitus), endoscopic ultrasound (EUS) criteria > 4, and EUS-fine needle aspiration (FNA) were included. A pseudotumor was defined as a non-neoplastic space-occupying lesion, a cause of chronic pancreatitis that may mimic changes typical of pancreatic cancer on CT or endoscopic ultrasound but without histological evidence. A real tumor was defined as a neoplastic space-occupying lesion because of pancreatic cancer confirmed by histology.

RESULTS: Thirty-five patients with chronic pancreatitis were included, 26 (74.2%) of whom were men. Nine (25.7%) patients were diagnosed with pseudotumoral chronic pancreatitis and two (2/35; 5.7%) patients with pseudotumoral chronic pancreatitis were diagnosed with pancreatic cancer on follow-up. The time between the diagnosis of pseudotumoral chronic pancreatitis and pancreatic adenocarcinoma was 35 and 30 d in the two patients. Definitive diagnosis of pancreatic adenocarcinoma was made by surgery. In the remaining six patients with pseudotumoral chronic pancreatitis, the median of follow-up was 11 mo (range 1-22 mo) and they showed no evidence of malignancy on surveillance. In the follow-up of patients without pseudotumoral chronic pancreatitis but with chronic pancreatitis, none were diagnosed with pancreatic cancer. According to our data, older patients with chronic pancreatitis are at risk of pseudotumoral chronic pancreatitis.

CONCLUSION: According to characteristics of patient, detection of PCP should lead a surveillance program for pancreatic cancer with EUS-FNA in < 1 mo or directly to surgical resection.

Novel methylation biomarker panel for the early detection of pancreatic cancer

PURPOSE

Pancreatic cancer is the fourth leading cause of cancer deaths and there currently is no reliable modality for the early detection of this disease. Here, we identify cancer-specific promoter DNA methylation of BNC1 and ADAMTS1 as a promising biomarker detection strategy meriting investigation in pancreatic cancer.

EXPERIMENTAL DESIGN

We used a genome-wide pharmacologic transcriptome approach to identify novel cancer-specific DNA methylation alterations in pancreatic cancer cell lines. Of eight promising genes, we focused our studies on BNC1 and ADAMTS1 for further downstream analysis, including methylation and expression. We used a nanoparticle-enabled methylation on beads (MOB) technology to detect early-stage pancreatic cancers by analyzing DNA methylation in patient serum.

RESULTS

We identified two novel genes, BNC1 (92%) and ADAMTS1 (68%), that showed a high frequency of methylation in pancreatic cancers (n = 143), up to 100% in PanIN-3 and 97% in stage I invasive cancers. Using the nanoparticle-enabled MOB technology, these alterations could be detected in serum samples (n = 42) from patients with pancreatic cancer, with a sensitivity for BNC1 of 79% [95% confidence interval (CI), 66%-91%] and for ADAMTS1 of 48% (95% CI, 33%-63%), whereas specificity was 89% for BNC1 (95% CI, 76%-100%) and 92% for ADAMTS1 (95% CI, 82%-100%). Overall sensitivity using both markers is 81% (95% CI, 69%-93%) and specificity is 85% (95% CI, 71%-99%).

CONCLUSIONS

Promoter DNA methylation of BNC1 and ADAMTS1 is a potential biomarker to detect early-stage pancreatic cancers. Assaying the promoter methylation status of these genes in circulating DNA from serum is a promising strategy for early detection of pancreatic cancer and has the potential to improve mortality from this disease.

Multiple target-specific molecular agents for detection and image analysis of breast cancer characteristics in mice

Breast cancer is a heterogenetic tumor at the cellular level with multiple factors and components. The inconsistent expression of molecular markers during disease progression reduces the accuracy of diagnosis and efficacy of target-specific therapy. Single target-specific imaging agents can only provide limited tumor information at one time point. In contrast, multiple target-specific imaging agents can increase the accuracy of diagnosis. The aim of this study was to demonstrate the ability of multi-agent imaging to discriminate such differences in single tumor. Mice bearing human cancer cell xenografts were tested to determine individual differences under optimal experimental conditions. Neovasculature agent (RGD peptide), tumor stromal agent (matrix metalloproteinase), and tumor cell markers (epidermal growth factor, Her-2, interleukin 11) imaging agents were labeled with reporters. 18F-Fluorodeoxyglucose was used to evaluate the tumor glucose status. Optical, X-ray, positron emission tomography, and computer tomography imaging modalities were used to determine tumor characteristics. Tumor size and imaging data demonstrated that individual differences exist under optimal experimental conditions. The target-specific agents used in the study bind to human breast cancer cell lines in vitro and xenografts in vivo. The pattern of binding corresponds to that of tumor markers. Multi-agent imaging had complementary effects in tumor detection. Multiple noninvasive imaging agents and modalities are complementary in the interrogation of unique biological information from each individual tumor. Such multi-agent approaches provide methods to study several disease components simultaneously. In addition, the imaging results provide information on disease status at the molecular level.

CA19-9 and CA242 as tumor markers for the diagnosis of pancreatic cancer: a meta-analysis

Pancreatic cancer has the worst prognosis of any gastrointestinal cancer, with the mortality approaching the incidence. Early detection is crucial for improving patient prognosis. We therefore performed a meta-analysis to evaluate and compare the sensitivity and specificity of CA19-9 and CA242 in pancreatic cancer. We searched PubMed, EMBASE, and the Cochrane Library for studies that evaluated the diagnostic validity of CA19-9 and CA242 between January 1966 and March 2011. Meta-analysis methods were used to pool sensitivity and specificity and to construct a summary receiver-operating characteristic (SROC) curve. A total of 11 studies that included 2,316 patients who fulfilled all of the inclusion criteria were considered for analysis. The pooled sensitivities for CA242 and CA19-9 were 0.719 (95 % confidence interval [CI] 0.690-0.746) and 0.803 (95 % CI 0.777-0.826), respectively. The pooled specificities of CA242 and CA19-9 were 0.868 (95 % CI 0.849-0.885) and 0.802 (95 % CI 0.780-0.823), respectively. The diagnostic odds ratio (DOR) estimate was significantly higher for CA242 (16.261) than for CA19-9 (15.637). Our meta-analysis showed that CA242 and CA19-9 could play different roles in the diagnosis of pancreatic cancer. Although the sensitivity of CA242 is lower than that of CA19-9, its specificity is greater.

Percutaneous fine needle biopsy in pancreatic tumors: a study of 42 cases

The technological progress within the range of methods of pancreas imaging and their more common accessibility selects a group of patients requiring a microscopic diagnosis. Percutaneous fine needle aspiration biopsy under the control of ultrasonography (PCFNA/USG) is the method commonly used in determining the character of a focal pancreatic lesion. Aim of the Work. An assessment of the accessibility of PCFNA biopsy in the assessment of solid and cystic changes in a pancreas and the correlation of the results of imaging examination, cytological smear and concentration of a serous marker CA19-9. Material and Methodology. In our material we analysed 43 cases of tumors of the pancreas among the patients who were at the average age of 59 ± 10.4 (14 women, 28 men) diagnosed by PCFNA biopsy. Results. In a group we are 23 cases of cancer, 12 cases of inflammation and 7 cases of cellular atypia for which 2 cases of IPMN were included. The sensitivity of the method was 92.5% but specificity was 68%. In our opinion PCFNA/USG is a method of the comparable sensitivity and specificity with fine needle aspiration biopsy with EUS control and its efficiency depends to a considerable degree on experience and interdisciplinary collaboration.

Individuals at high-risk for pancreatic cancer development: management options and the role of surgery

Pancreatic cancer (PC) is a highly lethal disease. Despite advances regarding the safety and long-term results of pancreatectomies, early diagnosis remains the only hope for cure. This necessitates the implementation of an intensive screening program (based mainly on modern imaging), which - given the incidence of PC - is not cost effective for the general population. However, this screening program is recommended for individuals at high-risk for PC development. Indications for screening include the following three clinical settings: hereditary cancer predisposition syndromes associated with PC, hereditary pancreatitis and familial pancreatic cancer syndrome. The aim of this strategy is to identify pre-invasive (precursor) lesions, which are curable. Surgery is recommended in the presence of recognizable lesion on imaging lesions. Partial (anatomic) pancreatectomy - depending on the location of the suspicious lesion - is the most widely accepted type of surgical intervention in this setting; occasionally, however, total pancreatectomy may be required, in carefully selected patients. Despite that experience still remains limited, there is evidence that this aggressive strategy allows early detection of neoplastic lesions, thereby improving the effectiveness of surgery and prognosis.

Target-specific agents imaging ectopic and orthotopic human pancreatic cancer xenografts

OBJECTIVES

This study aimed to develop target-specific binding agents for in vitro and in vivo imaging of human pancreatic cancer.

METHODS

A monoclonal neutrophil gelatinase-associated lipocalin (NGAL)-specific antibody and a peptide specific for matrix metalloproteinase (MMP) were labeled with a near-infrared dye for in vitro and in vivo imaging studies. Fluorescence or confocal microscopy was used to determine antibody or peptide binding and internalization of agents into human AsPC-1, Panc-1, and MiaPaCa pancreatic cancer cell lines and in mice bearing ectopic or orthotopic pancreatic tumor transplants.

RESULTS

Both the NGAL-specific antibody and MMP peptide bound to pancreatic cancer cells with high specificity; most NGAL-specific antibody localized to the cytosol. In vivo imaging results demonstrated high signal intensity of both agents bound to the tumor. The average tumortr-to-background ratio of antibody and peptide was 1.29 and 2.86, respectively. Signal was also detectable in the liver, kidneys, and bladder.

CONCLUSIONS

Both NGAL-specific antibody and MMP peptide bound to cancer cells, and the labeled antibody was internalized. These results demonstrate that both agents can be used to enhance detection of human pancreatic cancer xenografts. However, the biodistribution patterns of these agents might limit their use in research and clinical practice.

Intravoxel incoherent motion MRI for the differentiation between mass forming chronic pancreatitis and pancreatic carcinoma

PURPOSE

To determine which of the quantitative parameters obtained from intravoxel incoherent motion diffusion weighted imaging (DWI) is the most significant for the differentiation between pancreatic carcinoma and mass-forming chronic pancreatitis.

MATERIALS AND METHODS

Twenty-nine patients with pancreatic masses were included, 9 proved to have a mass-forming pancreatitis and 20 had a pancreatic carcinoma. The patients were studied using intravoxel incoherent motion DWI with 11 b-values and the apparent diffusion coefficient (ADC), the true diffusion constant (D) and the perfusion fraction (f) were calculated. The diagnostic strength of the parameters was evaluated using receiver operating characteristic analysis.

RESULTS

The ADC in chronic pancreatitis was higher than in pancreatic carcinoma with significant differences at b = 50, 75, 100, 150, 200, 300 s/mm (ADC50 = 3.17 ± 0.67 vs. 2.55 ± 1.09, ADC75 = 2.46 ± 0.4 vs. 1.93 ± 0.52, ADC100 = 2.28 ± 0.48 vs. 1.73 ± 0.45, ADC150 = 1.97 ± 0.26 vs. 1.63 ± 0.40, ADC200 = 1.98 ± 0.24 vs. 1.53 ± 0.28, and ADC300 = 1.76 ± 0.19 vs. 1.46 ± 0.31 × 10(-3) mm2/s). No significant differences were found at b = 25, 400, 600, and 800 s/mm (ADC25 = 4.69 ± 0.65 vs. 4.04 ± 1.35, ADC400 = 1.57 ± 0.21 vs. 1.37 ± 0.30, ADC600 = 1.38 ± 0.18 vs. 1.24 ± 0.25, and ADC800 = 1.27 ± 0.10 vs. 1.18 ± 0.19 × 10(-3) mm2/s) nor using ADCtot (1.42 ± 0.23 vs. 1.28 ± 0.12 × 10(-3) mm2/s). The perfusion fraction f was significantly higher in pancreatitis compared with pancreatic carcinoma (16.3% ± 5.30% vs. 8.2% ± 4.00%, P = 0.0001). There was no significant difference between groups for D (1.07 ± 0.224 × 10(-3) mm2/s for chronic pancreatitis and 1.09 ± 0.3 × 10(-3) mm2/s for pancreatic carcinoma, P = 0.66). For f, the highest area under the curve (0.894) and combined sensitivity (80%) and specificity (89.9%) were found.

CONCLUSIONS

There were significant differences in ADC50-300 between chronic pancreatitis and pancreatic carcinoma. Because D is not significantly different between groups, differences in ADC can be attributed mainly to differences in perfusion. The perfusion fraction f proved to be the superior DWI-derived parameter for differentiation of mass-forming pancreatitis and pancreatic carcinoma.

Incidence of pancreatic cancer in chinese patients with chronic pancreatitis

BACKGROUND AND AIM

It is suggested that patients with chronic pancreatitis (CP) have a markedly increased risk of pancreatic cancer compared with the general population. This study was designed to determine the rate of pancreatic cancer in CP patients in China.

METHODS

This was a semiprospective, single-center study including 420 consecutive CP patients (285 males and 135 females, median age at onset 39.5 years), with the median follow-up time being 102.3 months (range 24-419 months). We calculated the standardized incidence ratio (SIR) based on the pancreatic cancer incidence in the general population of China.

RESULTS

Four cases of pancreatic cancer (0.9% of patients) were observed in 3,591 patient-years (expected number of cases 0.15; SIR 27.2, 95% CI 7.4-69.6). Similar results were seen in alcoholics and non-alcoholics, and in smokers and non-smokers. When patients lost to follow-up were considered to be followed up until the end point without having developed pancreatic cancer (4,280 patient-years), SIR was 22.8 (CI 6.2-58.4). Based on the Cox model, with inserting factors being sex, age at the time of CP clinical onset, type of pancreatitis, and presence or absence of diabetes, calcification, alcohol use and smoking status, only age was found to correlate positively with the occurrence of pancreatic cancer (>50 years, hazard ratio, 1.8 ± 0.5; p = 0.044).

CONCLUSION

The risk of pancreatic cancer is markedly increased in CP patients in China compared with the general population, especially in older patients. and IAP.

Differentiation of pancreas carcinoma from healthy pancreatic tissue using multiple b-values: comparison of apparent diffusion coefficient and intravoxel incoherent motion derived parameters

OBJECTIVES

To evaluate in detail the diagnostic performance of diffusion-weighted imaging (DWI) to differentiate pancreas carcinoma from healthy pancreas using the apparent diffusion coefficient (ADC) and parameters derived from the intravoxel incoherent motion (IVIM) theory.

MATERIALS AND METHODS

Twenty-three patients with pancreas carcinoma and 14 volunteers with healthy pancreas were examined at 1.5 Tesla using a single-shot echo-planar imaging DWI pulse sequence. Eleven b-values ranging from 0 to 800 s/mm2 were used. The acquisition was separated into blocks (b0, b25), (b0, b50),...(b0, b800) and each block was acquired in a single expirational breath-hold (TA = 26 seconds) to avoid motion artifacts. The ADC was calculated for all b-values using linear regression yielding ADC(tot). By applying the IVIM model, which allows for the estimation of perfusion effects in DWI, the perfusion fraction f and the perfusion free diffusion parameter D were calculated. The diagnostic performance of ADC, f and D as a measure for the differentiation between healthy pancreas and pancreatic carcinoma was evaluated with receiver operating characteristics analysis.

RESULTS

In the healthy control group, the ADC(tot) ranged from 1.53 to 2.01 microm2/ms with a mean value of 1.71 +/- 0.19 microm2/ms, the perfusion fraction f ranged from 18.5% to 40.4% with a mean value of 25.0 +/- 6.2%, and the diffusion coefficient D from 0.94 to 1.28 microm2/ms with a mean value of 1.13 +/- 0.15 microm2/ms. In patients with pancreas carcinoma, the ADC(tot) ranged from 0.98 to 1.81 microm2/ms with a mean value of 1.31 +/- 0.24 microm2/ms, the perfusion fraction f ranged from 0% to 20.4% with a mean value of 8.59 +/- 4.6% and the diffusion coefficient D from 0.74 to 1.60 microm2/ms with a mean value of 1.15 +/- 0.22 microm2/ms. In comparison to healthy pancreatic tissue, a significant reduction of the perfusion fraction f and of ADC(tot) was found in pancreatic carcinoma (P < 0.00001, 0.0002, respectively). The f value showed more than a 10-fold higher significance level in distinguishing cancerous from normal tissue when compared with the ADC(tot) value. No significant difference in the diffusion coefficient D was observed between the 2 groups (P > 0.5). In the receiver operating characteristic-analyses, the area under curve for f was 0.991 and significantly larger than ADC(tot) (P < 0.05). f had the highest sensitivity, specificity, negative predictive value, and positive predictive value with 95.7%, 100%, 93.3%, and 100%, respectively.

CONCLUSIONS

Using the IVIM-approach, the f value proved to be the best parameter for the differentiation between healthy pancreas and pancreatic cancer. The acquisition of several b-values strongly improved the stability of the parameter estimation thus increasing the sensitivity and specificity to 95.7% and 100% respectively. The proposed method may hold great promise for the non invasive, noncontrast-enhanced imaging of pancreas lesions and may eventually become a screening tool for pancreatic cancer.

Using genetics and genomics strategies to personalize therapy for cancer: focus on melanoma

Individualizing therapeutic selection for patients is a major goal in cancer treatment today. This goal is best facilitated by understanding both an individual's inherited genetic variation and the somatic genetic changes arising during cancer development. Clinical decision making based on inherited genetic variation is done for those patients with cancer susceptibility syndromes and more generally to personalize drug dosing. Personalized medicine based on genetic and genomic changes within tumors is being applied more widely, with increased use of therapies targeted to somatic mutations and amplifications. Somatic mutations associated with resistance also are being used to select against therapies. Somatic point mutation testing being used clinically includes direct sequencing, short sequencing and single nucleotide interrogation. Single amplifications are commonly assessed using FISH or CISH; high throughput assessment of amplifications and deletions is done mainly on a research basis. Melanomas contain complex mutational profiles that allow them to be sub-grouped by their genetic and genomic profile, each of which then can be evaluated pre-clinically to determine their response to targeted therapies. BRAF V600E mutations are the most common found in melanoma; specific inhibitors of mutant BRAF have been developed and are currently in clinical trials. In addition, other melanoma sub-groups have been identified genetically, which respond to other inhibitors. These studies focus on somatic genetic changes in cancer, which can be targeted directly by therapies. However in the future, personalized medicine will use a combination of inherited and somatic genetics to select the optimal tailored therapy for each patient.

Limitations in improving detection of pancreatic adenocarcinoma

OBJECTIVE

To review the current trends in pancreatic cancer research and propose alternatives for an earlier diagnosis.

METHOD

A search was conducted using the PubMed and Scielo electronic databases to find statistics related to the incidence of pancreatic cancer.

RESULTS

Pancreatic cancer is the fourth most common cause of cancer mortality in the USA; in Colombia the incidence of this neoplasia is 4.5 per 100,000 individuals; and in Peru, amongst digestive diseases, it is the fifth most common cause. In Brazil and Chile this cancer has increased in incidence, while in Mexico, it has decreased in terms of the relative percentage of gastrointestinal cancers from 1976 to 2003. Chronic pancreatitis, cigarette smoking, diabetes, obesity and dietary mutagen exposure are the most consistent risk factors implicated in the development of pancreatic cancer; however, the genetic and molecular changes underlying the epidemiological association between these factors and pancreatic cancer remain largely unknown, and only 5-10% are hereditary in nature.

CONCLUSION

The prognosis for pancreatic cancer has not changed substantially for at least the last 20 years. The most useful tumor marker for pancreatic adenocarcinoma is still the carbohydrate antigen 19-9 (CA19-9). Currently, a multimodal-screening approach of endoscopic ultrasound, computed tomography and endoscopic retrograde cholangiopancreatography are the most effective methods to detect pancreatic cancer in high-risk patients. Future options for early detection of this malignancy are focused on new molecular markers, telomerase enzyme, receptor-targeted imaging using multifunctional nanoparticles, detection of glycan changes and epigenetics.