Pancreatic head cancer: accuracy of CT in determination of resectability

Imaging Techniques and Biochemical Biomarkers: New Insights into Diagnosis of Pancreatic Cancer

Pancreatic cancer (PaC) incidence is increasing, but our current screening and diagnostic strategies are not very effective. However, screening could be helpful in the case of PaC, as recent evidence shows that the disease progresses gradually. Unfortunately, there is no ideal screening method or program for detecting PaC in its early stages. Conventional imaging techniques, such as abdominal ultrasound, CT, MRI, and EUS, have not been successful in detecting early-stage PaC. On the other hand, biomarkers may be a more effective screening tool for PaC and have greater potential for further evaluation compared to imaging. Recent studies on biomarkers and artificial intelligence (AI)-enhanced imaging have shown promising results in the early diagnosis of PaC. In addition to proteins, non-coding RNAs are also being studied as potential biomarkers for PaC. This review consolidates the current literature on PaC screening modalities to provide an organized framework for future studies. While conventional imaging techniques have not been effective in detecting early-stage PaC, biomarkers and AI-enhanced imaging are promising avenues of research. Further studies on the use of biomarkers, particularly non-coding RNAs, in combination with imaging modalities may improve the accuracy of PaC screening and lead to earlier detection of this deadly disease.

Alteration in DNA methylation patterns: Epigenetic signatures in gastrointestinal cancers

Abnormalities in epigenetic modifications can cause malignant transformations in cells, leading to cancers of the gastrointestinal (GI) tract, which accounts for 20% of all cancers worldwide. Among the epigenetic alterations, DNA hypomethylation is associated with genomic instability. In addition, CpG methylation and promoter hypermethylation have been recognized as biomarkers for different malignancies. In GI cancers, epigenetic alterations affect genes responsible for cell cycle control, DNA repair, apoptosis, and tumorigenic-specific signaling pathways. Understanding the pattern of alterations in DNA methylation in GI cancers could help scientists discover new molecular-based pharmaceutical treatments. This study highlights alterations in DNA methylation in GI cancers. Understanding epigenetic differences among GI cancers may improve targeted therapies and lead to the discovery of new diagnostic biomarkers.

Survey of Denoising, Segmentation and Classification of Pancreatic Cancer Imaging

BACKGROUND

Pancreatic cancer is one of the most serious problems that has taken many lives worldwide. The diagnostic procedure using the traditional approaches was manual by visually analyzing the large volumes of the dataset, making it time-consuming and prone to subjective errors. Hence the need for the computer-aided diagnosis system (CADs) emerged that comprises the machine and deep learning approaches for denoising, segmentation and classification of pancreatic cancer.

INTRODUCTION

There are different modalities used for the diagnosis of pancreatic cancer, such as Positron Emission Tomography/Computed Tomography (PET/CT), Magnetic Resonance Imaging (MRI), Multiparametric-MRI (Mp-MRI), Radiomics and Radio-genomics. Although these modalities gave remarkable results in diagnosis on the basis of different criteria. CT is the most commonly used modality that produces detailed and fine contrast images of internal organs of the body. However, it may also contain a certain amount of gaussian and rician noise that is necessary to be preprocessed before segmentation of the required region of interest (ROI) from the images and classification of cancer.

METHOD

This paper analyzes different methodologies used for the complete diagnosis of pancreatic cancer, including the denoising, segmentation and classification, along with the challenges and future scope for the diagnosis of pancreatic cancer.

RESULT

Various filters are used for denoising and image smoothening and filters as gaussian scale mixture process, non-local means, median filter, adaptive filter and average filter have been used more for better results.

CONCLUSION

In terms of segmentation, atlas based region-growing method proved to give better results as compared to the state of the art whereas, for the classification, deep learning approaches outperformed other methodologies to classify the images as cancerous and non- cancerous. These methodologies have proved that CAD systems have become a better solution to the ongoing research proposals for the detection of pancreatic cancer worldwide.

Rim Enhancement and Peripancreatic Fat Stranding in Preoperative MDCT as Predictors for Occult Metastasis in PDAC Patients

RATIONALE AND OBJECTIVE

To identify the radiological features and clinical biomarkers that could predict the occult metastasis (OM) of pancreatic ductal adenocarcinoma (PDAC).

MATERIALS AND METHODS

This retrospective study included PDAC patients who were radiologically diagnosed resectable (R) or borderline resectable (BR) and underwent surgical exploration from January 2018 to December 2021. Depending on whether distant metastases were found during the exploration, patients were divided into OM and non-OM groups. Univariate and multivariable logistic regression analyses were performed to determine the radiological and clinical predictive factors for occult metastasis. Model performance was determined by discrimination and calibration.

RESULTS

A total of 502 patients (median age, 64 years; interquartile range, 57-70 years; 294 men) were enrolled, among which 68 (13.5%) patients were found with distant metastases, with 45 liver-only, 19 peritoneal-only, four patients had both liver and peritoneal metastases. Rim enhancement and peripancreatic fat stranding were more frequent in the OM group than in the non-OM group. Tumor size (p = 0.028), tumor resectability (p = 0.031), rim enhancement (p < 0.001), peripancreatic fat stranding (p < 0.001) and level of CA125 (p = 0.021) were independent predictors of occult metastasis according to the multivariable analyses, and the areas under the curve (AUCs) of these characteristics were 0.703, 0.594, 0.638, 0.655, 0.631, respectively. The combined model showed the highest AUC of 0.823.

CONCLUSIONS

Rim enhancement, peripancreatic fat stranding, tumor size, tumor resectability and level of CA125 are risk factors for OM of PDAC. The combined model of radiological and clinical features may help the preoperative prediction of OM in PDAC.

Determination of arterial invasion in pancreatic ductal adenocarcinoma: what is the best diagnostic criterion on CT?

OBJECTIVES

To investigate the diagnostic performance and interobserver variability in the determination of arterial invasion in pancreatic ductal adenocarcinoma (PDAC) and determine the best CT imaging criterion.

METHODS

We retrospectively evaluated 128 patients with PDAC (73 men and 55 women) who underwent preoperative contrast-enhanced CT. Five board-certified radiologists (expert) and four fellows (non-expert]) independently assessed the arterial invasion (celiac, superior mesenteric, splenic, and common hepatic arteries) using a 6-point score: 1, no tumor contact; 2, hazy attenuation ≤ 180°; 3, hazy attenuation > 180°; 4, solid soft tissue contact ≤ 180°; 5, solid soft tissue contact > 180°; and 6, contour irregularity. ROC analysis was performed to evaluate the diagnostic performance and determine the best diagnostic criterion for arterial invasion, with pathological or surgical findings as references. Interobserver variability was assessed using Fleiss's ĸ statistics.

RESULTS

Among the 128 patients, 35.2% (n = 45/128) received neoadjuvant treatment (NTx). Solid soft tissue contact ≤ 180° was the best diagnostic criterion for arterial invasion as defined by the Youden Index both in patients who did and did not receive NTx (sensitivity, 100% vs. 100%; specificity, 90% vs. 93%; and AUC, 0.96 vs. 0.98, respectively). Interobserver variability among the non-expert was not inferior to that among the expert (ĸ = 0.61 vs 0.61; p = .39 and ĸ = 0.59 vs 0.51; p < .001 in patients treated with and without NTx, respectively).

CONCLUSIONS

Solid soft tissue contact ≤ 180° was the best diagnostic criterion for the determination of arterial invasion in PDAC. Considerable interobserver variability was seen among the radiologists.

KEY POINTS

• Solid soft tissue contact ≤ 180° was the best diagnostic criterion for the determination of arterial invasion in pancreatic ductal adenocarcinoma. • Interobserver agreement among non-expert radiologists was almost comparable to that among expert radiologists.

RNA-sequencing for transcriptional profiling of whole blood in early stage and metastatic pancreatic cancer patients

We investigated the transcriptional profile of whole blood in early and metastatic stages of pancreatic cancer (PaC) patients to identify potential diagnostic factors for early diagnosis. Blood samples from 18 participants (6 healthy individuals, 6 patients in early stage (I/II) PaC, and 6 patients in metastatic PaC) were analyzed by RNA-sequencing. The expression levels of identified genes were subsequently compared with their expression in pancreatic tumor tissues based on TCGA data reported in UALCAN and GEPIA2 databases. Overall, 331 and 724 genes were identified as differentially expressed genes in early and metastatic stages, respectively. Of these, 146 genes were shared by early and metastatic stages. Upregulation of PTCD3 and UBA52 genes and downregulation of A2M and ARID1B genes in PaC patients were observed from early stage to metastasis. TCGA database showed increasing trend in expression levels of these genes from stage I to IV in pancreatic tumor tissue. Finally, we found that low expression of PTCD3, A2M, and ARID1B genes and high expression of UBA52 gene were positively correlated with PaC patients survival. We identified a four-gene set (PTCD3, UBA52, A2M, and ARID1B) expressed in peripheral blood of early stage and metastatic PaC patients that may be useful for PaC early diagnosis.

Prediction of residual tumor and overall survival after first-line surgery in patients with pancreatic ductal adenocarcinoma using preoperative magnetic resonance imaging findings

BACKGROUND

Complete resection is the only potentially curative treatment in patients with pancreatic ductal adenocarcinoma (PDA) and is associated with a longer overall survival (OS) than incomplete resection of tumor. Hence, prediction of the resection status after surgery would help predict the prognosis of patients with PDA.

PURPOSE

To predict residual tumor (R) classification and OS in patients who underwent first-line surgery for PDA using preoperative magnetic resonance imaging (MRI).

MATERIAL AND METHODS

In this study, 210 patients with PDA who underwent MRI and first-line surgery were randomly categorized into a test group (n=150) and a validation group (n=60). The R classification was divided into R0 (no residual tumor) and R1/R2 (microscopic/macroscopic residual tumor). Preoperative MRI findings associated with R classification and OS were assessed by using logistic regression and Cox proportional hazard models. In addition, the prediction models for the R classification and OS were validated using calibration plots and C statistics.

RESULTS

On preoperative MRI, portal vein encasement (odds ratio 4.755) was an independent predictor for R1/R2 resection (P=0.040). Tumor size measured on MRI (hazard ratio [HR] per centimeter 1.539) was a predictor of OS, along with pathologic N1 and N2 stage (HR 1.944 and 3.243, respectively), R1/R2 resection (HR 3.273), and adjuvant chemoradiation therapy (HR 0.250) (P<0.050). Calibration plots demonstrated satisfactory predictive performance.

CONCLUSION

Preoperative MRI was valuable for predicting R1/R2 resection using portal vein encasement. Tumor size measured on MRI was useful for the prediction of OS after first-line surgery for PDA.

Prognostic Role of Carbohydrate Antigen 19 to 9 in Predicting Survival of Patients With Pancreatic Cancer: A Meta-Analysis

This study evaluates the prognostic role of carbohydrate antigen 19 to 9 (CA19-9) in predicting survival of pancreatic cancer patients. Literature search was conducted in electronic databases (Google Scholar, Ovid, PubMed, and Science Direct) and study selection was based on precise eligibility criteria. Random-effects meta-analyses were performed to achieve overall estimates of median survival and hazard ratios (HRs) of survival with cutoff defined lower and higher CA19-9 levels before and after surgery or chemotherapy (CT)/radiotherapy (RT) and the changes in CA19-9 levels after any treatment. A total of 41 studies (6519 patients; 42% females; age 63.3 years [95% confidence interval [CI]: 62.2, 64.4]) were included. A pooled HR of 1.79 with a narrow 95% CI (1.58, 2.01) showed that higher CA19-9 levels or less decrease in CA19-9 levels after treatment predicted shorter survival. Median survival in patients with lower and higher preoperative CA19-9 levels was 23.2 months [95% CI: 17.2, 29.2] and 14.0 months [95% CI: 10.9, 17.2], respectively, whereas median survival with lower and higher postoperative CA19-9 levels was 25.0 months [95% CI: 21.9, 28.0] and 13.0 months [95% CI: 10.9, 15.0] respectively. Median survival with lower and higher pre-CT/RT CA19-9 levels was 11.9 months [95% CI: 10.2, 13.6] and 7.7 months [95% CI: 6.2, 9.2], respectively, whereas median survival with lower and higher post-CT/RT CA19-9 levels was 15.1 months [95% CI: 13.2, 17.0] and 10.7 months [95% CI: 7.3, 14.0] respectively. A decrease in CA19-9 levels after treatment was also associated with longer survival. Thus, both pretreatment and posttreatment CA19-9 levels or their changes after treatment have good prognostic value in determining the survival of pancreatic cancer patients.

Current controversies and advances in the management of pancreatic adenocarcinoma

Pancreatic adenocarcinoma is a lethal disease with a mortality rate that has not significantly improved over decades. This is likely due to several challenges unique to pancreatic cancer. Most patients with pancreatic cancer are diagnosed at a late stage of disease due to the lack of specific symptoms prompting an early investigation. A small subset of patients who are diagnosed at an early stage have a better chance at survival with curative surgical resection, but most patients still succumb to the disease in a few years. The dismal overall prognosis is due to suspected micro-metastasis at an early stage. Due to this reason, there is a recent interest in treating all patients with pancreatic cancers with systemic therapy upfront (including the ones that are surgically resectable). This approach is still not the standard of care due to the lack of robust prospective data available. Recent advancements in treatment regimens of chemotherapy, radiation and immunotherapy have improved the overall short-term survival but the long-term survival still remains poor. Novel approaches in diagnosis and treatment have shown promise in clinical studies but long-term clinical data is lacking. The following manuscript presents an overview of the epidemiology, diagnosis, staging, recent advances, novel approaches and controversies in the management of pancreatic adenocarcinoma.

Use of volumetric CT scanning to predict tumor staging and survival in pancreatic cancer patients that are to be administered curative resection

BACKGROUND

This study evaluates the achievability of CT volumetry of pancreatic cancer and its correlation with pTNM stage and survival.

METHODS

Tumor volume was measured from contrast enhanced CT images of 58 patients who undergo curative resection for pancreatic cancer using the Segment Editor module implemented in 3D-Slicer-a free open source software platform. Receiver operating characteristic (ROC) analysis was used to evaluate correlation between Tvol and pTNM staging.

RESULTS

The preoperative images of 58 pancreatic adenocarcinoma patients were included. The mean Tvol of pancreatic cancer is an increasing trend with T stage (The mean T1vol = 1.75 cm³ , the mean T2vol = 11.43 cm³ , the mean T3vol = 14.98 cm³ , the mean T4vol = 19.6 cm³ ). There were statistical differences between volumes (p = .000). On ROC analysis, the area under the ROC curve (Az) of Tvol to differentiate T1 stage from ≥T2 stage was 0.966 (p = .000). At a cut-off value of 3.050 cm³ , sensitivity of 92.3%, and specificity of 83.3% were achieved. Az value of Tvol to differentiate ≤T2 from ≥T3 stage was 0.750 (p = .010). At a cut-off value of 10.250 cm³ , sensitivity of 72.7% and specificity of 66% were achieved. In addition Az value of Tvol to differentiate ≤T3 from ≥T4 stage was 0.652 and was not significant (p = .380). At a cut-off value of 11.2 cm³ , sensitivity of 66.7% and specificity of 63.6% were achieved.

CONCLUSION

CT volumetry in pancreatic cancer is feasible with excellent reproducibility. It is one of the prognostic factors affecting survival in operated patients with pancreatic cancer.

Girdin interaction with vimentin induces EMT and promotes the growth and metastasis of pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a highly malignant cancer of the digestive tract that has a high potential for metastasis and a poor prognosis. Girdin was first reported in 2005 as an actin-binding protein and was designated as Akt-phosphorylation enhancer (APE); thus, Girdin has been revealed to have an important role in regulating cancer development. There is additional evidence indicating that Girdin is associated with cell proliferation, migration, invasion and survival in certain cancers. However, the potential mechanisms involving Girdin and mobility in pancreatic cancer have not been elucidated. In the present study, it was revealed that Girdin was highly expressed in pancreatic cancer tissue and was associated with tumor grade. The present study, to the best of our knowledge, is the first aimed at investigating the unknown role of Girdin in PDAC metastasis. A short hairpin RNA for Girdin (sh-Girdin) was successfully constructed with recombinant adenoviral vectors to suppress the expression of Girdin in pancreatic cancer cell lines (PANC-1 and BXPC-3). The silencing efficiency of the Girdin shRNA was determined by RT-qPCR and western blot analysis, and decreased Girdin expression in the cytoplasm was revealed by immunofluorescence detection. Then, sulforhodamine B (SRB) and colony formation assays were used to confirm that the knockdown of Girdin inhibited proliferation in vitro, and Transwell assays were used to examine the influence of Girdin knockdown on cellular mobility. Animal experiments also confirmed that silencing the expression of Girdin in pancreatic cancer cells inhibited the growth and metastasis of pancreatic cancer in vivo. Transforming growth factor-β (TGF-β) is a common inducer of epithelial-mesenchymal transition (EMT) and can effectively induce EMT in PDAC. Notably, TGF-β-treated cells exhibited changes in the classic biological markers of EMT. The expression of E-cadherin, a marker of the epithelial phenotype, increased, and the expression of N-cadherin and vimentin, markers of the interstitial phenotype, decreased in response to sh-Girdin. According to these experiments, Girdin may affect pancreatic cancer progression and development by interacting with vimentin. Therefore, there is evidence indicating that Girdin could be designated as a prognostic biological indicator and a candidate therapeutic target for pancreatic cancer.

Imaging diagnosis and staging of pancreatic ductal adenocarcinoma: a comprehensive review

Pancreatic ductal adenocarcinoma (PDAC) has continued to have a poor prognosis for the last few decades in spite of recent advances in different imaging modalities mainly due to difficulty in early diagnosis and aggressive biological behavior. Early PDAC can be missed on CT due to similar attenuation relative to the normal pancreas, small size, or hidden location in the uncinate process. Tumor resectability and its contingency on the vascular invasion most commonly assessed with multi-phasic thin-slice CT is a continuously changing concept, particularly in the era of frequent neoadjuvant therapy. Coexistent celiac artery stenosis may affect the surgical plan in patients undergoing pancreaticoduodenectomy. In this review, we discuss the challenges related to the imaging of PDAC. These include radiological and clinical subtleties of the tumor, evolving imaging criteria for tumor resectability, preoperative diagnosis of accompanying celiac artery stenosis, and post-neoadjuvant therapy imaging. For each category, the key imaging features and potential pitfalls on cross-sectional imaging will be discussed. Also, we will describe the imaging discriminators of potential mimickers of PDAC.

Cell-Free DNA Methylation: The New Frontiers of Pancreatic Cancer Biomarkers' Discovery

Pancreatic ductal adenocarcinoma (PDAC) is among the most lethal cancer types world-wide. Its high mortality is related to the difficulty in the diagnosis, which often occurs when the disease is already advanced. As of today, no early diagnostic tests are available, while only a limited number of prognostic tests have reached clinical practice. The main reason is the lack of reliable biomarkers that are able to capture the early development or the progression of the disease. Hence, the discovery of biomarkers for early diagnosis or prognosis of PDAC remains, de facto, an unmet need. An increasing number of studies has shown that cell-free DNA (cfDNA) methylation analysis represents a promising non-invasive approach for the discovery of biomarkers with diagnostic or prognostic potential. In particular, cfDNA methylation could be utilized for the identification of disease-specific signatures in pre-neoplastic lesions or chronic pancreatitis (CP), representing a sensitive and non-invasive method of early diagnosis of PDAC. In this review, we will discuss the advantages and pitfalls of cfDNA methylation studies. Further, we will present the current advances in the discovery of pancreatic cancer biomarkers with early diagnostic or prognostic potential, focusing on pancreas-specific (e.g., CUX2 or REG1A) or abnormal (e.g., ADAMTS1 or BNC1) cfDNA methylation signatures in high risk pre-neoplastic conditions and PDAC.

Prognostic Predicting Role of Contrast-Enhanced Computed Tomography for Locally Advanced Pancreatic Adenocarcinoma

INTRODUCTION

Contrast-enhanced computed tomography (CECT) imaging is commonly used to assess pancreatic adenocarcinoma (PAC). However, the value of semiquantitative and quantitative assessments of CECT parameters used to predict survival in PAC remains unknown. This study aims to investigate the prognostic role of pretreatment CECT imaging in patients with locally advanced pancreatic adenocarcinoma (LAPAC).

MATERIALS AND METHODS

From June 2013 to May 2017, eighty-six newly diagnosed patients with pathologically and radiologically confirmed LAPAC were retrospectively recruited. All patients were evaluated by CECT and experienced gemcitabine-based chemotherapy. The relationship between overall survival (OS) and clinical factors including age, sex, serum carbohydrate antigen 19-9 value, and CECT findings (including tumour location, tumour volume, peripancreatic involvement, blood vessel involvement, tumour enhanced rate, and distance liver metastasis) was determined using Cox proportional hazard regression models, and a nomogram was constructed for the prediction of 1- and 1.5-year survival rates of patients with LAPAC.

RESULTS

On univariate analysis, patients who had a tumour enhanced rate (TER) less than 80.465% and those who had a TER ≥ 80.465% are with a 3.587-fold increase in OS (p < 0.001). After multivariate Cox regression, a nomogram was established based on a new model containing the predictive variables of high Ca19-9 level, higher clinical stages, larger tumour volume, the presence of peripancreatic involvement, and liver metastases. The model displayed good accuracy in predicting OS with a C-index of 0.614. The calibration plots also showed a good discrimination and calibration of the nomogram between the predicted and observed survival probabilities.

CONCLUSION

Our results showed that TER can be used to predict survival in LAPAC, and we developed a nomogram for determining the prognosis of patients with LAPAC. However, the purposed nomogram still requires external data verification in future applications.

CTC phenotyping for a preoperative assessment of tumor metastasis and overall survival of pancreatic ductal adenocarcinoma patients

BACKGROUND

The evaluation for surgical resectability of pancreatic ductal adenocarcinoma (PDAC) patients is not only imaging-based but highly subjective. An objective method is urgently needed. We report on the clinical value of a phenotypic circulating tumor cell (CTC)-based blood test for a preoperative prognostic assessment of tumor metastasis and overall survival (OS) of PDAC patients.

METHODS

Venous blood samples from 46 pathologically confirmed PDAC patients were collected prospectively before surgery and immunoassayed using a specially designed TU-chip™. Captured CTCs were differentiated into epithelial (E), mesenchymal and hybrid (H) phenotypes. A further 45 non-neoplastic healthy donors provided blood for cell line validation study and CTC false positive quantification.

FINDINGS

A validated multivariable model consisting of disjunctively combined CTC phenotypes: "H-CTC≥15.0 CTCs/2ml OR E-CTC≥11.0 CTCs/2ml" generated an optimal prediction of metastasis with a sensitivity of 1.000 (95% CI 0.889-1.000) and specificity of 0.886 (95% CI 0.765-0.972). The adjusted Kaplan-Meier median OS constructed using Cox proportional-hazard models and stratified for E-CTC < 11.0 CTCs/2 ml was 16.5 months and for E-CTC ≥ 11.0 CTCs/2 ml was 5.5 months (HR = 0.050, 95% CI 0.004-0.578, P = .016). These OS results were consistent with the outcome of the metastatic analysis.

INTERPRETATION

Our work suggested that H-CTC is a better predictor of metastasis and E-CTC is a significant independent predictor of OS. The CTC phenotyping model has the potential to be developed into a reliable and accurate blood test for metastatic and OS assessments of PDAC patients. FUND: National Natural Science Foundation of China; Zhejiang Province Science and Technology Program; China Scholarship Council.

Pancreatic ductal adenocarcinoma and paraaortic lymph nodes metastases: The accuracy of intraoperative frozen section

BACKGROUND

Pancreatoduodenectomy for pancreatic ductal adenocarcinoma (PDAC) with paraaortic lymph nodes metastases (PALN +) is associated with poor survival. Still, there are no current guidelines advocating systematic detection of PALN+.

METHODS

All consecutive patients who underwent surgical exploration/resection with concurrent paraaortic (group 16) lymphadenectomy for PDAC between 2009 and 2016 were considered for inclusion. Resection was systematically aborted in case of intraoperative PALN + detection. Diagnostic performance of preoperative imaging upon blind review and intraoperative PALN dissection with frozen section (FS) for PALN detection were evaluated. Additionally, the prognostic significance of PALN + on overall survival (OS) was analyzed.

RESULTS

Over the study period, among 129 patients undergoing surgery for PDAC, 113 had intraoperative PALN dissection with FS analysis. Median number of resected PALN was 3 (range, 1-15). Overall, PALN+ was found in 19 patients (16.8%). Upon blind review, preoperative imaging performed poorly for PALN + detection with a low agreement between imaging and final pathology (Kappa-Cohen index<0.2). In contrast, PALN FS showed high detection performances and strong agreement with final pathology (Kappa-Cohen index = 0.783, 95%CI 0.779-0.867, p < 0.001). Regarding survival outcomes, there was no difference between patients with PALN+ and patients not resected in the setting of liver metastases or locally unresectable disease found at exploration (p = 0.708).

CONCLUSIONS

Before PD for PDAC, intraoperative PALN dissection and FS analysis yields accurate PALN assessment and allows appropriate patient selection. This should be routinely performed and aborting resection should be strongly considered in case of PALN+.

Preoperative contrast-enhanced computed tomographic characterisation of pancreatic cystic lesions: A prospective study

Background

Characterisation of pancreatic cystic lesions has a direct role in their management and computed tomography is the mainstay of investigation for diagnosing and characterising them.

Objectives

The aim of this study was to prospectively assess the diagnostic accuracy of contrast-enhanced computed tomography (CECT) in preoperative characterisation of pancreatic cystic lesions with histopathology as the reference standard.

Method

A total of 38 patients with cystic pancreatic lesions diagnosed after clinical, laboratory and sonographic evaluation, irrespective of age, were preoperatively evaluated with CECT. Images were reviewed for the general characteristics of the lesions on pre-contrast and portal venous phase images and overall diagnostic accuracy calculated. Imaging findings were compared with histopathology, or cytology and/or intra-operative findings.

Results

Serous cystadenoma (SCA) was the most common cystic pancreatic lesion found in 31.6% of patients followed by mucinous cystadenoma (MCA) (26.3%), solid pseudo-papillary tumour (SPT) (21.1%) and intra-ductal papillary mucinous neoplasm (IPMN) (10.5%). Three patients (7.9%) had simple cysts and one patient (2.6%) had a lymphangioma. The diagnostic accuracy of CECT for pancreatic cystic lesions was found to be 72.5.

Conclusion

The diagnostic accuracy of computed tomography (CT) was high for SCA, IPMN and pancreatic cysts, and low for MCA and SPT. Combination of a multiloculated cystic lesion with locule size of less than 20 mm, septal enhancement with relative lack of wall enhancement, central scar and lobulated outline are highly specific for SCA. Unilocular or macro-cystic pattern with locule size of more than 20 mm, female gender and wall enhancement with smooth external contour are pointers towards MCA. Solid cystic pancreatic head lesions in young females may be suggestive of SPT. A dilated main pancreatic duct in a cystic lesion with internal septations may point towards IPMN. Fluid attenuation lesions with imperceptible non-enhancing wall indicate pancreatic cysts. Lastly, pseudocysts and neuroendocrine tumours with cystic components are great mimickers of pancreatic cystic lesions, and a history of pancreatitis and hormonal profile of patients should always be sought.

Promoter methylation of ADAMTS1 and BNC1 as potential biomarkers for early detection of pancreatic cancer in blood

BACKGROUND

Despite improvements in cancer management, most pancreatic cancers are still diagnosed at an advanced stage. We have recently identified promoter DNA methylation of the genes ADAMTS1 and BNC1 as potential blood biomarkers of pancreas cancer. In this study, we validate this biomarker panel in peripheral cell-free tumor DNA of patients with pancreatic cancer.

RESULTS

Sensitivity and specificity for each gene are as follows: ADAMTS1 87.2% and 95.8% (AUC = 0.91; 95% CI 0.71-0.86) and BNC1 64.1% and 93.7% (AUC = 0.79; 95% CI 0.63-0.78). When using methylation of either gene as a combination panel, sensitivity increases to 97.3% and specificity to 91.6% (AUC = 0.95; 95% CI 0.77-0.90). Adding pre-operative CA 19-9 values to the combined two-gene methylation panel did not improve sensitivity. Methylation of ADAMTS1 was found to be positive in 87.5% (7/8) of stage I, 77.8% (7/9) of stage IIA, and 90% (18/20) of stage IIB disease. Similarly, BNC1 was positive in 62.5% (5/8) of stage I patients, 55.6% (5/9) of stage IIA, and 65% (13/20) of patients with stage IIB disease. The two-gene panel (ADAMTS1 and/or BNC1) was positive in 100% (8/8) of stage I, 88.9% (8/9) of stage IIA, and 100% (20/20) of stage IIB disease. The sensitivity and specificity of the two-gene panel for localized pancreatic cancer (stages I and II), where the cancer is eligible for surgical resection with curative potential, was 94.8% and 91.6% respectively. Additionally, the two-gene panel exhibited an AUC of 0.95 (95% CI 0.90-0.98) compared to 57.1% for CA 19-9 alone.

CONCLUSION

The methylation status of ADAMTS1 and BNC1 in cfDNA shows promise for detecting pancreatic cancer during the early stages when curative resection of the tumor is still possible. This minimally invasive blood-based biomarker panel could be used as a promising tool for diagnosis and screening in a select subset of high-risk populations.

MDCT findings predicting post-operative residual tumor and survival in patients with pancreatic cancer

OBJECTIVES

To predict residual tumor (R) classification and overall survival (OS) on preoperative MDCT in patients who underwent first-line surgery for pancreatic ductal adenocarcinoma (PDA).

METHODS

Three hundred sixteen patients with PDA who underwent MDCT and first-line surgery were included. Patients were divided into a test (n = 216) and a validation group (n = 100). The R classification was categorized into R0 (no residual tumor) and R1/R2 (microscopic/macroscopic residual tumor). We assessed the correlation between the MDCT findings and the R classification. For survival analysis, we used the Kaplan-Meier estimation and Cox proportional hazard model to determine the prognostic factors for OS. Validation of the prediction models for the R classification and OS was performed using C statistics and calibration plot.

RESULTS

Peritumoral fat stranding (odds ratio (OR) 3.826), suspicious distant metastasis (OR 2.916), portal vein involvement (OR 2.795), and tumor size (OR 1.045) were independent predictors for residual tumor (p < .05). On survival analysis, common hepatic artery involvement (hazard ratio (HR) 5.656), R1/R2 stage (HR 2.476), and N1 stage (HR 1.745) were predictors of poor OS (p < .05). C statistics for prediction models for R classification and OS were 0.816 and 0.662, respectively. Calibration plots showed good predictive performance in a high probability of the R1/R2 stage or poor OS.

CONCLUSION

Preoperative MDCT is useful for predicting the R classification using the tumor size, peritumoral fat stranding, portal vein involvement, and suspicious distant metastasis, as well as for anticipating poor OS using the N1 stage, common hepatic artery involvement, and R1/R2 stage in patients with PDA.

KEY POINTS

• Thorough assessment of the involvement of common hepatic artery or portal vein and peritumoral fat stranding is warranted for predicting prognosis in patients with pancreatic ductal adenocarcinoma. • Not only encasement but also abutment of common hepatic artery or portal vein by tumor predicts poor prognosis after upfront surgery. • If residual tumor or poor overall survival is anticipated on preoperative MDCT, neoadjuvant treatment can be performed.

Risk factors related to metastasis of para-aortic lymph nodes in pancreatic ductal adenocarcinoma: A retrospective observational study

This study was designed to explore the risk factors related to metastasis of para-aortic lymph node (PALN).Clinicopathologic data of 241 patients with resectable or borderline resectable pancreatic cancer who underwent pancreaticoduodenectomy with extended lymphadenectomy between January 2008 and December 2015 were collected, potential factors related to metastasis of PALN were analyzed.Positive rate of PALN was 19.5% (47/241). Univariate analysis showed that back pain (P = .028), preoperative CA19-9 level (P < .001), tumor size (P < .001), portal vein (PV)/superior mesenteric vein (SMV) invasion (P < .001), superior mesenteric artery (SMA) invasion (P < .001), and diameter > 1.0 cm were in correlation with PALN involvement, multivariate analysis revealed that preoperative CA19-9 level, PV/SMV invasion, SMA invasion and diameter > 1.0 cm were independent risk factors to metastasis of PALN. Patients with LN8+ had a higher positive rate of PALN than with LN8- (38.1% vs 15.6%, P = .001), similar results could be found when LN12+ (35.8% vs 13.2%, P < .001) and LN14+ (41.2% vs 11.0%, P < .001), multivariate analysis showed that LN8+ and LN14+ were closely in correlation with PALN metastasis.Several factors were related to the status of PALN, preoperative CA19-9 level, PV/SMV invasion, SMA invasion and diameter > 1.0 cm were 4 independent risk factors to PALN metastasis. LN8+ and LN14+ were 2 strong predictors of PALN metastasis. A comprehensive analysis covering all possible risk factors related to metastasis of PALN should be given before design of treatment plan whenever involvement of PALN was suspected.

PET/MRI for Gastrointestinal Imaging: Current Clinical Status and Future Prospects

Positron emission tomography (PET)/computed tomography (CT) with 2-deoxy-2-[¹⁸F]fluoro-d-glucose (FDG) has become the standard of care for the initial staging and subsequent treatment response assessment for numerous gastrointestinal malignancies. However, it is often supplemented by magnetic resonance imaging (MRI) for local tumor staging. Hybrid PET/MRI scanners, which acquire PET data and MRI data simultaneously, have the potential to provide accurate whole-body staging in a single examination. Furthermore, to address certain limitations of FDG, many new PET tracers have been developed to probe distinctive aspects of tumor biology.

Improving prediction of surgical resectability over current staging guidelines in patients with pancreatic cancer who receive stereotactic body radiation therapy

Purpose

For patients with localized pancreatic cancer (PC) with vascular involvement, prediction of resectability is critical to define optimal treatment. However, the current definitions of borderline resectable (BR) and locally advanced (LA) disease leave considerable heterogeneity in outcomes within these classifications. Moreover, factors beyond vascular involvement likely affect the ability to undergo resection. Herein, we share our experience developing a model that incorporates detailed radiologic, patient, and treatment factors to predict surgical resectability in patients with BR and LA PC who undergo stereotactic body radiation therapy (SBRT).

Methods and materials

Patients with BR or LA PC who were treated with SBRT between 2010 and 2016 were included. The primary endpoint was margin negative resection, and predictors included age, sex, race, treatment year, performance status, initial staging, tumor volume and location, baseline and pre-SBRT carbohydrate antigen 19-9 levels, chemotherapy regimen and duration, and radiation dose. In addition, we characterized the relationship between tumors and key arteries (superior mesenteric, celiac, and common hepatic arteries), using overlap volume histograms derived from computed tomography data. A classification and regression tree was built, and leave-one-out cross-validation was performed. Prediction of surgical resection was compared between our model and staging in accordance with the National Comprehensive Care Network guidelines using McNemar's test.

Results

A total of 191 patients were identified (128 patients with LA and 63 with BR), of which 87 patients (46%) underwent margin negative resection. The median total dose was 33 Gy. Predictors included the chemotherapy regimen, amount of arterial involvement, and age. Importantly, radiation dose that covers 95% of gross tumor volume (GTV D95), was a key predictor of resectability in certain subpopulations, and the model showed improved accuracy in the prediction of margin negative resection compared with National Comprehensive Care Network guideline staging (75% vs 63%; P < .05).

Conclusions

We demonstrate the ability to improve prediction of surgical resectabiliy beyond the current staging guidelines, which highlights the value of assessing vascular involvement in a continuous manner. In addition, we show an association between radiation dose and resectability, which suggests the potential importance of radiation to allow for resection in certain populations. External data are needed for validation and to increase the robustness of the model.

Glycoprotein biomarkers for the detection of pancreatic ductal adenocarcinoma

Pancreatic cancer (PaC) shows a clear tendency to increase in the next years and therefore represents an important health and social challenge. Currently, there is an important need to find biomarkers for PaC early detection because the existing ones are not useful for that purpose. Recent studies have indicated that there is a large window of time for PaC early detection, which opens the possibility to find early biomarkers that could greatly improve the dismal prognosis of this tumor. The present manuscript reviews the state of the art of the existing PaC biomarkers. It focuses on the anomalous glycosylation process and its role in PaC. Glycan structures of glycoconjugates such as glycoproteins are modified in tumors and these modifications can be detected in biological fluids of the cancer patients. Several studies have found serum glycoproteins with altered glycan chains in PaC patients, but they have not shown enough specificity for PaC. To find more specific cancer glycoproteins we propose to analyze the glycan moieties of a battery of glycoproteins that have been reported to increase in PaC tissues and that can also be found in serum. The combination of these new candidate glycoproteins with their aberrant glycosylation together with the existing biomarkers could result in a panel, which would expect to give better results as a new tool for early diagnosis of PaC and to monitor the disease.

Liquid biopsy in pancreatic cancer: the beginning of a new era

With dismal survival rate pancreatic cancer remains one of the most aggressive and devastating malignancy. Predominantly, due to the absence of a dependable methodology for early identification and limited therapeutic options for advanced disease. However, it takes over 17 years to develop pancreatic cancer from initiation of mutation to metastatic cancer; therefore, if diagnosed early; it may increase overall survival dramatically, thus, providing a window of opportunity for early detection. Recently, genomic expression analysis defined 4 subtypes of pancreatic cancer based on mutated genes. Hence, we need simple and standard, minimally invasive test that can monitor those altered genes or their associated pathways in time for the success of precision medicine, and liquid biopsy seems to be one answer to all these questions. Again, liquid biopsy has an ability to pair with genomic tests. Additionally, liquid biopsy based development of circulating tumor cells derived xenografts, 3D organoids system, real-time monitoring of genetic mutations by circulating tumor DNA and exosome as the targeted drug delivery vehicle holds lots of potential for the treatment and cure of pancreatic cancer. At present, diagnosis of pancreatic cancer is frantically done on the premise of CA19-9 and radiological features only, which doesn't give a picture of genetic mutations and epigenetic alteration involved. In this manner, the current diagnostic paradigm for pancreatic cancer diagnosis experiences low diagnostic accuracy. This review article discusses the current state of liquid biopsy in pancreatic cancer as diagnostic and therapeutic tools and future perspectives of research in the light of circulating tumor cells, circulating tumor DNA and exosomes.

Pancreatic Adenocarcinoma Staging in the Era of Preoperative Chemotherapy and Radiation Therapy

Pancreatic ductal adenocarcinoma (PDA) remains among the most challenging malignancies to treat. At diagnosis, the tumor often already extends beyond the confines of the pancreas, spreading to an extent such that primary surgery with curative intent is very rarely feasible. Considerable momentum is now being given to a treatment strategy involving neoadjuvant chemotherapy or chemotherapy and radiation therapy in patients with nonmetastatic PDA. The main advantage of this strategy is better selection of patients likely to benefit from curative-intent surgery through the achievement of negative resection margins. Patients with rapidly progressive disease are identified and are spared ineffective surgery with its attendant morbidity. Neoadjuvant therapy can downstage tumors classified as locally advanced at initial imaging studies to resectable tumors. However, the imaging study evaluation of the response to neoadjuvant therapy is extremely complex. Thus, the diagnostic performance of imaging studies is not sufficient to ensure the accurate selection of patients in whom negative-margin resection is likely to be achieved. More specifically, standard criteria for predicting vascular invasion, based on the amount of tumor-vessel contact, are not valid after neoadjuvant therapy. ^©RSNA, 2018.

Nonhypervascular pancreatic neuroendocrine tumors: Spectrum of MDCT imaging findings and differentiation from pancreatic ductal adenocarcinoma

PURPOSE

The purpose of our study was to determine contrast-enhanced MDCT features to differentiate nonhypervascular pancreatic neuroendocrine tumors (PNETs) from pancreatic ductal adenocarcinomas (PDACs).

METHODS

and materials: We included 74 patients with PNETs and 80 patients with PDACs who underwent preoperative MDCT. Two radiologists evaluated the morphologic characteristic and enhancement patterns of the tumors. Quantitative and qualitative analysis was performed, including evaluation of tumor size, homogeneity, contrast enhancement pattern, presence of pancreatic duct dilatation and tumor invasion to the adjacent vessels and peripancreatic infiltration. Tumor-to-pancreas enhancement ratio was defined as the Hounsfield units (HU) value of the tumor divided by the HU value of the pancreas. the first group was hypervascular PNETs showing hyperenhancement on arterial phase images and nonhypervascular PNETs, showing iso- or hypoenhancement on arterial phase images. After that, two radiologists estimated the possibilities of PNET or PDAC were for nonhypervascular PNETs.

RESULTS

On the basis of arterial enhancement, 43 PNETs were hypervascular and 31 were nonhypervascular. When compared to PDAC, nonhypervascular PNETs more frequently had well-defined tumor margins, intratumoral cystic components, calcifications and blood vessels and less frequently had main pancreatic duct dilatation, peripancreatic infiltration and vascular invasion (p < 0.01 for all). Nonhypervascular PNETs had higher tumor-to-pancreas enhancement ratio in venous phase (1.02 vs. 0.78, p = 0.012). Nonhypervascular PNETs more often had portal-venous hyperenhancement or persistent isoenhancement, while PDAC more often had persistent hypoenhancement or gradual delayed enhancement (p < 0.001). The absence of pancreatic duct dilatation and portal-venous hyperenhancement or persistent isoenhancement were the independent predictors for nonhypervascular PNETs. (The most accurate MDCT-findings to predict nonhypervascular PNET were the absence of pancreatic duct dilatation and peripancreatic infiltration (79% and 92% accuracy), portal-venous phase hyperenhancement or persistent isoenhancement (77%), the presence of intratumoral blood vessels (77%) and relative enhancement intensity in venous phase >0.9 (76%). Using these criteria, the area under curve for differentiation of PNET from PDAC was 0.906-0.846.

CONCLUSION

Combined assessment of the enhancement and morphologic characteristics can improve the differentiation between nonhypervascular PNETs and PDAC at contrast-enhanced MDCT.

Pancreatic Cancer Diagnosis and Management: Has the Time Come to Prick the Bubble?

Pancreatic cancer (PC) is associated with poor prognosis and very dismal survival rates. The most effective possibility of cure is tumor resection, which is only possible in about 15% of patients diagnosed at early stages of disease progression. Recent whole-genome sequencing studies pointed genetic alterations in 12 core signaling pathways in PC. These observations hint at the possibility that the initial mutation in PC might appear nearly 20 years before any symptoms occur, suggesting that a large window of opportunity may exist for early detection. Biomarkers with the potential to identify pre-neoplastic disease or very early stages of cancer are of great promise to improve patient survival. The concept of liquid biopsy refers to a minimally invasive sampling and analysis of liquid biomarkers that can be isolated from body fluids, primarily blood, urine and saliva. A myriad of circulating molecules may be useful as tumor markers, including cell-free DNA (cfDNA), cell-free RNA (cfRNA), circulating tumor cells (CTC), circulating tumor proteins, and extracellular vesicles, more specifically exosomes. In this review, we discuss with more detail the potential role of exosomes in several aspects related to PC, from initiation to tumor progression and its applicability in early detection and treatment. Exosomes are small circulating extracellular vesicles of 50-150 nm in diameter released from the plasma membrane by almost all cells and exhibit some advantages over other biomarkers. Exosomes are central players of intercellular communication and they have been implicated in a series of biological process, including tumorigenesis, migration and metastasis. Several exosomal microRNAs and proteins have been observed to distinguish PC from benign pancreatic diseases and healthy controls. Besides their possible role in diagnosis, understanding exosomes functions in cancer has clarified the importance of microenvironment in PC progression as well as its influence in proliferation, metastasis and resistance to chemotherapy. Increasing knowledge on cancer exosomes provides valuable insights on new therapeutic targets and can potentially open new strategies to treat this disease. Continuous research is needed to ascertain the reliability of using exosomes and their content as potential biomarkers, so that, hopefully, in the near future, they will provide the opportunity for early diagnosis, treatment intervention and increase survival of PC patients.

Contrast-enhanced CT in determining resectability in patients with pancreatic carcinoma: a meta-analysis of the positive predictive values of CT

OBJECTIVE

To obtain a summary positive predictive value (sPPV) of contrast-enhanced CT in determining resectability.

METHODS

The MEDLINE and EMBASE databases from JAN2005 to DEC2015 were searched and checked for inclusion criteria. Data on study design, patient characteristics, imaging techniques, image evaluation, reference standard, time interval between CT and reference standard, and data on resectability/unresectablity were extracted by two reviewers. We used a fixed-effects or random-effects approach to obtain sPPV for resectability. Several subgroups were defined: 1) bolus-triggering versus fixed-timing; 2) pancreatic and portal phases versus portal phase alone; 3) all criteria (liver metastases/lymphnode involvement/local advanced/vascular invasion) versus only vascular invasion as criteria for unresectability.

RESULTS

Twenty-nine articles were included (2171 patients). Most studies were performed in multicentre settings, initiated by the department of radiology and retrospectively performed. The I2-value was 68%, indicating heterogeneity of data. The sPPV was 81% (95%CI: 75-86%). False positives were mostly liver, peritoneal, or lymphnode metastases. Bolus-triggering had a slightly higher sPPV compared to fixed-timing, 87% (95%CI: 81-91%) versus 78% (95%CI: 66-86%) (p = 0.077). No differences were observed in other subgroups.

CONCLUSIONS

This meta-analysis showed a sPPV of 81% for predicting resectability by CT, meaning that 19% of patients falsely undergo surgical exploration.

KEY POINTS

• Predicting resectability of pancreatic cancer by CT is 81% (95%CI: 75-86%). • The percentage of patients falsely undergoing surgical exploration is 19%. • The false positives are liver metastases, peritoneal metastases, or lymph node metastases.

[The role of 3D-CT in surgery for pancreatic ductal adenocarcinoma: post-processing and tissue volume calculation]

AIM

To define the indications for pancreatoduodenectomy using 3D CT-imaging, to calculate the volume of damaged and intact tissues and to determine type of surgery depending on severity of disease in case of ductal pancreatic adenocarcinoma.

MATERIAL AND METHODS

Retrospective analysis of CT-scans of 30 patients with ductal pancreatic adenocarcinoma was performed. In groups 1 and 2 by 15 patients total pancreatectomy and pancreatoduodenectomy were made respectively. All patients underwent contrast-enhanced CT examination (Brilliance iCT, Phillips) followed post-processing on Brilliance Workspace Portal platform. All data were assessed by two reviewers.

RESULTS

In group 1 CT volume of the tumor was 24±19 cm3 (32% of total pancreas), in group 2 - 9.8±6 cm3 (16% of total pancreas). CT-volume of celiacomesenteric arteries and portal system was 25.8±10 mm/59.5±18.9 mm and 23.3±6/49.9±14.7 mm in groups 1 and 2 respectively. Greater volume of tumor was significantly associated with increased portal system (p<0.03). Sensitivity, specificity and accuracy of determining of tumor location were increased up to 94%, 50% and 80% respectively in group 1. There were no cases of wrong localization in group 2. Data of both reviewers were similar.

CONCLUSION

Total pancreatectomy is advisable for pancreatic adenocarcinoma if its volume is over 31.8% of total pancreas according to 3D CT-scans. 3D-modeling improves preoperative assessment of resectability, accuracy of determining of tumor localization and identifying vascular invasion.

Definition and Management of Borderline Resectable Pancreatic Cancer

Patients with localized pancreatic ductal adenocarcinoma seek potentially curative treatment, but this group represents a spectrum of disease. Patients with borderline resectable primary tumors are a unique subset whose successful therapy requires a care team with expertise in medical care, imaging, surgery, medical oncology, and radiation oncology. This team must identify patients with borderline tumors then carefully prescribe and execute a combined treatment strategy with the highest possibility of cure. This article addresses the issues of clinical evaluation, imaging techniques, and criteria, as well as multidisciplinary treatment of patients with borderline resectable pancreatic ductal adenocarcinoma.

Biomarkers in pancreatic adenocarcinoma: current perspectives

Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis, with a 5-year survival rate of 7.7%. Most patients are diagnosed at an advanced stage not amenable to potentially curative resection. A substantial portion of this review is dedicated to reviewing the current literature on carbohydrate antigen (CA 19-9), which is currently the only guideline-recommended biomarker for PDAC. It provides valuable prognostic information, can predict resectability, and is useful in decision making about neoadjuvant therapy. We also discuss carcinoembryonic antigen (CEA), CA 125, serum biomarker panels, circulating tumor cells, and cell-free nucleic acids. Although many biomarkers have now been studied in relation to PDAC, significant work still needs to be done to validate their usefulness in the early detection of PDAC and management of patients with PDAC.

Endoscopic ultrasound of pancreatic tumors

Computed tomography (CT) and endoscopic ultrasound (EUS) are the two most effective techniques for the assessment of pancreatic cancers. CT has revolutionized the field of tumor imaging in pancreatic cancer and is now a well-established imaging technique for diagnosis and staging. However, EUS still plays an important role in several situations, especially when the diagnosis is uncertain or when histopathological confirmation of the lesion is needed. Similarly, regarding cystic lesions, magnetic resonance imaging and CT have very good performances but are often inadequate because the diagnosis can be difficult to establish, while the consequences for the patient are major. New biopsy needles, the use of elastography and ultrasonographic contrast agents, and confocal laser endomicroscopy can also provide additional and essential information to improve diagnosis confidence of pancreatic lesions with EUS.

A wait-and-see strategy with subsequent self-expanding metal stent on demand is superior to prophylactic bypass surgery for unresectable periampullary cancer

BACKGROUND

A patient with unresectable periampullary malignancy found at laparotomy has traditionally received a prophylactic double bypass (biliary and duodenal), associated with considerable morbidity. With modern endoscopic treatments, surgical bypass has become questionable. This study aims to compare the two strategies. Sahlgrenska University Hospital (SU) performs a double bypass (DoB) routinely, and Skåne University Hospital Lund (SUL) secures biliary drainage endoscopically and treats only symptomatic duodenal obstruction (Wait and See, WaS).

METHOD

Between 2004 and 2013, 73 patients from SU and 70 from SUL were retrospectively identified. Demographics, tumour-related factors and postoperative outcomes during the remaining lifetime were noted.

RESULTS

The DoB group had significantly more complications (67% vs. 31%, p = 0.00002) and longer hospital stay (14 vs. 8 days, p = 0.001) than the WaS-group. The two groups had similar proportion of patients in need of readmission. The DoB patients and the WaS patients with metallic biliary stents were comparable regarding their need of re-interventions and hospitalisation due to biliary obstruction. Surgical duodenal bypass did not prevent future duodenal obstructions.

CONCLUSION

Patients with unresectable periampullary malignancies can safely be managed with endoscopic drainage on demand and with lower morbidity and shorter hospital stay than with surgical prophylactic bypass.

HIFU for Palliative Treatment of Pancreatic Cancer

Pancreatic cancer is one of the deadliest malignancies, with only a 6 % 5-year survival rate and over 50 % of patients being diagnosed at the advanced stage. Current therapies are ineffective, and the treatment of patients with advanced disease is palliative. In the past decade, HIFU ablation has emerged as a modality for palliative treatment of pancreatic tumors. Multiple preclinical and non-randomized clinical trials have been performed to evaluate the safety and efficacy of this procedure. Substantial tumor-related pain reduction was achieved in most cases after HIFU treatment and few significant side effects were observed. In addition, some studies indicate that combination of HIFU ablation with chemotherapy may provide a survival benefit. This chapter summarizes the pre-clinical and clinical experience obtained to date in HIFU treatment of pancreatic tumors and discusses the challenges, limitations and new approaches in this modality.

The role of endoscopic ultrasound in pancreatic cancer screening

Pancreatic cancer (PC) is a highly lethal cancer. Despite a significant advancement in cancer treatment, the mortality rate of PC is nearly identical to the incidence rates. Early detection of tumor or its precursor lesions with dysplasia may be the most effective approach to improve survival. Screening strategies should include identification of the population at high risk of developing PC, and an intense application of screening tools with adequate sensitivity to detect PC at an early curable stage. Endoscopic ultrasound (EUS) and magnetic resonance imaging (MRI) seem to be the most promising modalities for PC screening based on the data so far. EUS had an additional advantage over MRI by being able to obtain tissue sample during the same examination. Several questions remain unanswered at this time regarding the age to begin screening, frequency of screening, management of asymptomatic pancreatic lesions detected on screening, timing of resection, and extent of surgery and impact of screening on survival. Novel techniques such as needle-based confocal laser endomicroscopy (nCLE), along with biomarkers, may be helpful to identify pancreatic lesions with more aggressive malignant potential. Further studies will hopefully lead to the development of strategies combining EUS with other technological/biological advancements that will be cost-effective and have an impact on survival.

A wait-and-see strategy with subsequent self-expanding metal stent on demand is superior to prophylactic bypass surgery for unresectable periampullary cancer

BACKGROUND

A patient with unresectable periampullary malignancy found at laparotomy has traditionally received a prophylactic double bypass (biliary and duodenal), associated with considerable morbidity. With modern endoscopic treatments, a surgical bypass has become questionable. This study aims to compare the two strategies. Sahlgrenska University Hospital (SU) performs a double bypass (DoB) routinely, and Skåne University Hospital Lund (SUL) secures biliary drainage endoscopically and treats only symptomatic duodenal obstruction (Wait and See, WaS).

METHOD

Between 2004 and 2013, 73 patients from SU and 70 from SUL were retrospectively identified. Demographics, tumour-related factors and post-operative outcomes during the remaining lifetime of the patients were noted.

RESULTS

The DoB group had significantly more complications (67% versus 31%, P = 0.00002) and a longer hospital stay (14 versus 8 days, P = 0.001) than the WaS group. The two groups had a similar proportion of patients in need of readmission. The DoB patients and the WaS patients with metallic biliary stents were comparable regarding their need of re-interventions and hospitalization as a result of biliary obstruction. A surgical duodenal bypass did not prevent future duodenal obstructions.

CONCLUSION

Patients with unresectable periampullary malignancies can safely be managed with endoscopic drainage on demand and with a lower morbidity and a shorter hospital stay than with a surgical prophylactic bypass.

Imaging of pancreatic neoplasms

Ductal adenocarcinoma accounts for 85% to 90% of all solid pancreatic neoplasms, is increasing in incidence, and is the fourth leading cause of cancer-related deaths. There are currently no screening tests available for the detection of ductal adenocarcinoma. The only chance for cure in pancreatic adenocarcinoma is surgery. Imaging has a crucial role in the identification of the primary tumor, vascular variants, identification of metastases, disease response assessment to treatment, and prediction of respectability. Pancreatic neuroendocrine neoplasms can have a distinctive appearance and pattern of spread, which should be recognized on imaging for appropriate management of these patients.

Pancreatectomy with Para-Aortic Lymph Node Dissection for Pancreatic Head Adenocarcinoma: Pattern of Nodal Metastasis Spread and Analysis of Prognostic Factors

BACKGROUND

This study investigated the prognostic impact of the exact location of nodal metastases in a subgroup of patients who underwent pancreatectomy with extended lymphadenectomy for head adenocarcinoma, with a special focus on station 16b1.

METHODS

Clinical, pathologic, and follow-up details were extracted from our database and analyzed retrospectively. Survival analysis was performed using univariate and multivariate models. We also performed a matched case-control analysis with resected patients who did not receive extended lymphadenectomy and with locally advanced patients.

RESULTS

The study population consisted of 67 patients. The rate of station 16b1 metastases was 20.9%. Station 14a-b metastases (OR = 4.28), G3 tumors (OR = 4.03), and number of PLN ≥ 8 (OR = 4.46) were independently associated with station 16b1 involvement. Among pN1 patients, station 14a-b (HR = 2.60) and station 16b1 metastases (HR = 2.40) were predictors of survival. The median disease-specific survival of 16b1+ patients was 17 months (95% CI 8.47-25.52). In the matched case-control analysis, the survival rates of resected 16b1+ patients was in between pN1/16b1- patients and locally advanced patients.

CONCLUSIONS

Metastases to station 16b1 are associated with a decreased survival in comparison with pN1/16b1- patients, yet longer than in matched locally advanced patients. Station 14 can be considered as a "junctional node" to station 16b1.

Extent of lymphadenectomy to associate with pancreaticoduodenectomy in patients with pancreatic head cancer for better tumor staging

OBJECTIVES

To define the extent of lymphadenectomy to associate with surgery for pancreatic head cancer.

BACKGROUND

Pancreaticoduodenectomy with extended lymphadenectomy fails to prolong patient survival.

METHODS

Prospective randomized and nonrandomized controlled trials (RCTs and NRCTs), meta-analyses, retrospective reviews, consensus conferences and pre- and intraoperative diagnoses of lymph node (LN) metastases were retrieved. Standard and extended lymphadenectomies were reviewed, including their effects on postoperative complications, mortality rate and long-term survival. The minimum total number of LN examined (TNLE) for adequate tumor staging, and the incidence of metastasis to each LN station were also considered. A pros and cons analysis was performed on the removal of each LN station.

RESULTS

Eleven retrospective studies (2514 patients), five prospective NRCTs (545 patients), and five prospective RCTs (586 patients) described different lymphadenectomies, which obtained similar long-term results. Five meta-analyses showed they did not influence long-term survival. However, N status is an important component of tumor staging. The recommended minimum TNLE is 15. The percent incidence of metastasis to each LN station was calculated considering at least 385 and up to 3725 patients. Preoperative imaging and intraoperative exploration frequently fail to identify metastatic nodes. A pros and cons analysis suggests that lymph node status is better established removing the following LN stations: 6, 8a-p, 12a-b-c, 13a-b, 14a-b-c-d, 16b1, 17a-b. Metastasis to 16b1 LNs significantly worsens prognosis. Their removal and frozen section examination, before proceeding with resection, may contraindicate resection.

CONCLUSION

A standard lymphadenectomy demands an adequate TNLE and removal of the LN stations metastasizing more frequently, without increasing the surgical risk.

Diagnosis and Management of Borderline Resectable Pancreatic Adenocarcinoma

Borderline resectable pancreatic cancer represents a subcategory of advanced cancer that is typically defined by limited involvement of the major mesenteric vasculature. Such involvement is associated with a high likelihood of microscopically incomplete resection if surgery is used as the primary therapeutic modality. Increasing data support the role of neoadjuvant therapy as part of multimodality management but there is no uniformly accepted standard of care. This review discusses, based on recent literature and the experience of the Pancreatic Tumor Study Group at The University of Texas MD Anderson Cancer Center, the classification, definition, diagnosis, and management of borderline resectable pancreatic cancer.

Update on the management of pancreatic cancer: Surgery is not enough

Pancreatic ductal adenocarcinoma (PDAC) represents the fourth cause of death in cancer and has a 5-year survival of < 5%. Only about 15% of the patients present with a resectable PDAC with potential to undergo “curative” surgery. After surgery, local and systemic recurrence, is though very common. The median survival of resected patients with adjuvant chemotherapy after surgery is only 20-23 mo. This underscores the significant need to improve PDAC management strategies. Increased survival rate is dependent on new breakthroughs in our understanding of not at least tumor biology. The aim of this review is to update and comment on recent knowledge concerning PDAC biology and new diagnostics and treatment modalities. One fundamental approach to improve survival rates is by earlier and improved diagnosis of the disease. In recent years, novel blood-based biomarkers have emerged based on genetic, epigenetic and protein changes in PDAC with very promising results. For biomarkers to enter clinical practice they need to have been developed using adequate control groups and provide high sensitivity and specificity and by this identify patients at risk already in a pre-symptomatic stage. Another way to improve outcomes, is by employing neoadjuvant treatments thereby increasing the number of resectable cases. Novel systemic treatment regimes like FOLFIRINOX and nab-paclitaxel have demonstrated improvements in prolonging survival in advanced cases, but long-term survival is still scarce. The future improved understanding of PDAC biology will inevitably render new treatment options directed against both the cancer cells and the surrounding microenvironment.

Impact of the time interval between MDCT imaging and surgery on the accuracy of identifying metastatic disease in patients with pancreatic cancer

OBJECTIVE

Pancreatic adenocarcinoma is a rapidly progressive malignancy characterized by its tendency for early metastatic spread. MDCT is the primary diagnostic modality for the preoperative staging of patients with pancreatic cancer, with an accuracy established in multiple studies. However, for a variety of reasons, there is often a prolonged interval between staging MDCT and the surgical intervention. This study examines the relationship between the interval between imaging and surgery and the accuracy of MDCT in determining the presence or absence of metastatic disease at surgery in patients with pancreatic cancer.

MATERIALS AND METHODS

Patients were identified who had undergone surgery for pancreatic cancer at our institution with a dedicated preoperative pancreas-protocol MDCT performed in our department. Findings from the preoperative MDCT report were correlated with the operative findings, as well as the time between imaging and surgery.

RESULTS

Two hundred ninety-two MDCT scans were performed on 256 patients who underwent exploration for pancreatic adenocarcinoma. The patients had a median age of 67 years (range, 30-95 years), and 51.6% (132/256) were male. The median time between MDCT and surgical exploration was 15.5 days (range, 1-198 days). MDCT correctly predicted the absence of metastatic disease at surgery in 233 of 274 (85.0%) studies. MDCT was more accurate in predicting the absence of metastatic disease if the study was performed within 25 days of surgery than it was if the study was performed within more than 25 days of surgery (89.3% vs 77.0%; p = 0.0097). Furthermore, regression models showed that the negative predictive value of a given MDCT significantly decreased after approximately 4 weeks.

CONCLUSION

MDCT is an accurate method to stage patients with pancreatic cancer, but its accuracy in excluding distant metastatic disease depreciates over time. Patients should undergo a repeat MDCT within 25 days of any planned definitive operative intervention for pancreatic cancer to avoid unexpectedly finding metastatic disease at surgery.