Prognostic implications of routine, immunohistochemical, and molecular staging in resectable pancreatic adenocarcinoma

Ultrasensitive and High-Resolution Protein Spatially Decoding Framework for Tumor Extracellular Vesicles

Proteins localized on the surface or within the lumen of tumor-derived extracellular vesicles (EVs) play distinct roles in cancer progression. However, quantifying both populations of proteins within EVs has been hampered due to the limited sensitivity of the existing protein detection methods and inefficient EV isolation techniques. In this study, the eSimoa framework, an innovative approach enabling spatial decoding of EV protein biomarkers with unmatched sensitivity and specificity is presented. Using the luminal eSimoa pipeline, the absolute concentration of luminal RAS or KRASG12D proteins is released and measured, uncovering their prevalence in pancreatic tumor-derived EVs. The pulldown eSimoa pipeline measured absolute protein concentrations from low-abundance EV subpopulations. The eSimoa assays detected EVs in both PBS and plasma samples, confirming their applicability across diverse clinical sample types. Overall, the eSimoa framework offers a valuable tool to (1) detect EVs at concentrations as low as 105 EV mL-1 in plasma, (2) quantify absolute EV protein concentrations as low as fM, and (3) decode the spatial distribution of EV proteins. This study highlights the potential of eSimoa in identifying disease-specific EV protein biomarkers in clinical samples with minimal pre-purification, thereby driving advancements in clinical translation.

Role of oncogenic KRAS in the diagnosis, prognosis and treatment of pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is predicted to be the second most common cause of death within the next 10 years. The prognosis for this disease is poor despite diagnostic progress and new chemotherapeutic regimens. The oncogenic KRAS mutation is the major event in pancreatic cancer; it confers permanent activation of the KRAS protein, which acts as a molecular switch to activate various intracellular signalling pathways and transcription factors inducing cell proliferation, migration, transformation and survival. Several laboratory methods have been developed to detect KRAS mutations in biological samples, including digital droplet PCR (which displays high sensitivity). Clinical studies have revealed that a KRAS mutation assay in fine-needle aspiration material combined with cytopathology increases the sensitivity, accuracy and negative predictive value of cytopathology for a positive diagnosis of pancreatic cancer. In addition, the presence of KRAS mutations in serum and plasma (liquid biopsies) correlates with a worse prognosis. The presence of mutated KRAS can also have therapeutic implications, whether at the gene level per se, during its post-translational maturation, interaction with nucleotides and after activation of the various oncogenic signals. Further pharmacokinetic and toxicological studies on new molecules are required, especially small synthetic molecules, before they can be used in the therapeutic arsenal for pancreatic ductal adenocarcinoma.

A quarter century of EUS-FNA: Progress, milestones, and future directions

Tissue acquisition using EUS has considerably evolved since the first EUS-FNA was reported 25 years ago. Its introduction was an important breakthrough in the endoscopic field. EUS-FNA has now become a part of the diagnostic and staging algorithm for the evaluation of benign and malignant diseases of the gastrointestinal tract and of the organs in its proximity, including lung diseases. This review aims to present the history of EUS-FNA development and to provide a perspective on the recent developments in procedural techniques and needle technologies that have significantly extended the role of EUS and its clinical applications. There is a bright future ahead for EUS-FNA in the years to come as extensive research is conducted in this field and various technologies are continuously implemented into clinical practice.

Systematic review of the clinical significance of lymph node micrometastases of pancreatic adenocarcinoma following surgical resection

OBJECTIVES

The aim of this study is to perform a systematic review of the clinical impact of lymph node micrometastasis in pancreatic adenocarcinoma following surgical resection.

METHODS

A systematic review was conducted and published literature were searched using "pancreas or pancreatic" and "cancer or carcinoma or neoplasm", and "micrometastasis or micrometastses" in the PubMed, EMBAE, and Web of Science.

RESULTS

Thirteen publications with 726 patients and 3701 lymph nodes were included in this systematic review. The detection method was immunohistochemical stains or polymerase chain reaction. The pooled proportion of patients with positive lymph node micrometastasis was 43.1% (95% Confidence interval (CI) 0.254-0.628). The pooled proportion of positive lymph node micrometastasis (number of positive lymph node micrometastasis/total number of lymph nodes examined) was 10.8% (95% CI 4.8-22.6). Among the conventional H &E negative patients, the reported 5-year survival rates of the patients without lymph node micrometastases vs. those with lymph node micrometastases in the ranged from 50% to 61% and from 0% to 36%, respectively Patients with lymph node micrometastasis showed poorer survival (Hazard ratio 4.29, 95% CI 1.27-14.41).

CONCLUSIONS

The presence of lymph node micrometastasis is associated with poorer survival. Lymph node micrometastasis is applicable to stratify the risk of recurrence and the need for adjuvant therapy of post-resection patients with pancreatic adenocarcinoma in the conventional H & E lymph node negative patients.

K-Ras mutation detection in liquid biopsy and tumor tissue as prognostic biomarker in patients with pancreatic cancer: a systematic review with meta-analysis

K-Ras gene mutations have been found in most pancreatic cancers; however, conflicting data on the prognostic value of K-Ras mutations in pancreatic cancer have been published. We conducted a meta-analysis to assess its prognostic significance. Literature searches of PubMed, EMBASE, Cochrane Library, Web of Science and Google Scholar were performed through December 2015 to identify publications exploring the association of K-Ras mutation with overall survival. Forty eligible studies involving 3427 patients with pancreatic cancer were included in the present meta-analysis. Our analysis showed a hazard ratio (HR) of negative association with survival of 1.61 [95 % confidence interval (CI) 1.36-1.90; p < 0.01] in K-Ras mutant pancreatic cancer patients. In subgroup analyses, K-Ras mutations detected in tumor tissues and in liquid biopsies had HRs of 1.37 (95 % CI 1.20-1.57; p < 0.01) and 3.16 (95 % CI 2.1-4.71; p < 0.01), respectively. In addition, the HR was higher when K-Ras mutations were detected in fresh frozen samples (HR = 2.01, 95 % CI 1.28-3.16, p = 0.002) than in formalin-fixed, paraffin-embedded (FFPE) samples (HR = 1.29, 95 % CI 1.12-1.49, p < 0.01). Though K-Ras alterations are more frequent among non-East Asian individuals than East Asian individuals, there were no significant differences in HRs of survival between the two ethnic subgroups. In conclusion, this meta-analysis suggests that K-Ras mutations are associated with a worse overall survival in pancreatic cancer patients, especially when mutations are detected in liquid biopsies or fresh frozen tumor tissue samples.

K-ras mutational status in cytohistological tissue as a molecular marker for the diagnosis of pancreatic cancer: a systematic review and meta-analysis

Background. More clinically meaningful diagnostic tests are needed in pancreatic cancer (PC). K-ras mutations are the most frequently acquired genetic alteration. Methods. Original research articles involving the diagnostic accuracy of K-ras mutation detection in PC were selected. Data were presented as forest plots and summary receiver operating characteristic (SROC) curve analysis was used to summarize the overall test performance. Results. We assessed 19 studies from 16 published articles. The reports were divided into three groups according to the process used to obtain the test material. The summary estimates for detecting K-ras status using an invasive method (fine needle aspiration (FNA), endoscopic retrograde cholangiopancreatography (ERCP), or surgery) were better than cytology: the pooled sensitivity was 77% (95% confidence interval (CI): 74–80%) versus 54% (95% CI: 47–61%); specificity was 88% (95% CI: 85–91%) versus 91% (95% CI: 83–96%); and diagnostic odds ratio (DOR) was 20.26 (11.40–36.03) versus 7.52 (95% CI: 2.80–20.18), respectively. When two procedures were combined, the diagnostic accuracy was markedly improved. Conclusions. The analysis of K-ras mutations in pancreatic tissue has a promising diagnostic significance in PC. Further valuable studies are needed.

Comparison of four target volume definitions for pancreatic cancer. Guidelines for treatment of the lymphatics and the primary tumor

BACKGROUND AND PURPOSE

Target volume definitions for radiotherapy in pancreatic ductal adenocarcinoma (PDAC) vary substantially. Some groups aim to treat the primary tumor only, whereas others include elective lymph nodes (eLNs). eLNs close to the primary tumor are often included unintentionally within the treatment volume, depending on the respective treatment philosophies. We aimed to measure the percentages of anatomical coverage of eLNs by comparing four different contouring guidelines.

PATIENTS AND METHODS

Planning target volumes (PTVs) were contoured using planning computed tomography (CT) scans of 11 patients with PDAC based on the Oxford, RTOG (Radiation Therapy Oncology Group), Michigan, and SCALOP (Selective Chemoradiation in Advanced Localised Pancreatic Cancer trial) guidelines. Clinical target volumes (CTVs) included the peripancreatic, para-aortic, paracaval, celiac trunk, superior mesenteric, and portal vein lymph node areas. Volumetric comparisons of the coverage of all eLN regions were conducted to illustrate the differences between the four contouring strategies.

RESULTS

The PTV sizes of the RTOG and Oxford guidelines were comparable. The SCALOP and Michigan PTV sizes were similar to each other and significantly smaller than the RTOG and Oxford PTVs. A large variability of eLN coverage was found for the various subregions according to the respective contouring strategies.

CONCLUSION

This is the first study to directly compare the percentage of anatomical coverage of eLNs according to four PTVs in the same patient cohort. Potential practical consequences are discussed in detail.

Clinical significance of lymph node micrometastasis in gastric cancer

Recently, the existence of lymph node micrometastasis (LNM), including isolated tumor cells, has been focused on during the development of molecular diagnostic tools for lymph node metastasis in various malignant neoplasms. In particular, immunohistochemistry and reverse transcription-polymerase chain reaction have been reported to be available for the detection of LNM in gastric cancer. However, at present, the clinical significance of LNM remains unclear in patients with gastric cancer. Therefore, we cannot strategically make light of this issue in clinical management. Currently, minimally invasive treatments, such as endoscopic submucosal dissection and laparoscopic surgery with personalized lymphadenectomy, are widely performed in consideration of postsurgical quality of life (QOL). However, it is important to maintain the balance between QOL and curability when selecting surgical treatments for patients with gastric cancer. If minimally invasive surgery based on LNM status was established for patients with early gastric cancer, it could be performed safely. We reviewed the clinical significance of LNM as an important strategic target in patients with gastric cancer.

The role of tobacco-derived carcinogens in pancreas cancer

The extremely poor outcome from pancreas cancer is well known. However, its aetiology less well appreciated, and the molecular mechanisms underlying this are poorly understood. Tobacco usage is one of the strongest risk factors for this disease, and this is a completely avoidable hazard. In addition, there are well described hereditary diseases which predispose, and familial pancreas cancer. We have sought here to summarise the role of tobacco-derived carcinogens and the mode of their tumorigenic action on the pancreas. There is compelling evidence from animal and human studies (laboratory including cell line studies and epidemiologic) that tobacco derived carcinogens cause pancreas cancer. However, the manner in which they do so is not entirely apparent. There is also compelling evidence that synergism with genetic and other life-style factors-like diet obesity-results in a multifactorial causation of the disease. Ascertaining the role of tobacco carcinogens in the development of this cancer and their interaction with other risk factors will enable novel therapeutic and preventative strategies to improve outcome from this appalling malignancy.

Surgical implication of micrometastasis for pancreatic cancer

OBJECTIVES

The clinical significance of micrometastasis to regional lymph nodes for pancreas cancer is controversial in patients who underwent curative resection.

METHODS

Nine of 42 patients who underwent macroscopically curative resection of pancreatic head cancer were found to have pN(-) by routine examination. Complete serial section examination of the resected specimens was done to detect micrometastasis in these 9 patients.

RESULTS

A total of 16,505 sections were examined by immunohistochemistry or hematoxylin and eosin staining. Micrometastases were identified in 7 (78%) of 9 patients and 17 (3.6%) of 474 lymph nodes. All micrometastases were found in the pancreas head area. However, the frequency of micrometastases around the superior mesenteric artery was 44%. There were no micrometastases to the para-aortic nodes. There was a tendency that the patients with micrometastases showed better survival than those with overt nodal involvement (P = 0.053). Micrometastasis did not provide the poor prognostic factor in patients who underwent optimal regional lymphadenectomy.

CONCLUSIONS

Even in overtly pN(-) pancreatic cancer, micrometastases occur high frequently (78%) and widely, including the nodes around the superior mesenteric artery. These results provide important pathological information when we consider the preoperative, perioperative, and postoperative strategies, even when patients seem to have no nodal involvement by preoperative examinations.

CD74 is a novel prognostic factor for patients with pancreatic cancer receiving multimodal therapy

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is still one of the most fatal cancers, although its prognosis has improved recently with the introduction of multimodal therapy. To further develop effective treatment for PDAC, establishment of prognostic indicators for patients receiving multimodal therapy is essential.

METHODS

Sixty-eight patients receiving curative extended resection combined with preoperative chemoradiation and postoperative chemotherapy for primary PDAC were selected. Immunohistochemistry using anti-CD74 antibody on paraffin-embedded tissue samples was performed, and cases were divided into two groups according to the ratio of CD74-positive cells: expression level I, CD74-positive cells <70%; level II, CD74-positive cells >or=70%. The correlation of CD74 expression level with clinicopathological features and overall survival was evaluated.

RESULTS

Forty-seven (69.1%) and 21 (30.9%) patients showed level I and II CD74 expression, respectively. Patients with level II CD74 expression showed a higher rate of lymphatic permeation (P = 0.04) and perineural invasion (P = 0.01) compared with those with level I expression. Patients with level I CD74 expression had a significantly better survival rate than those with level II (P = 0.003). Among the patients with pathological tumor-node-metastasis stages I and II, those with level I CD74 expression showed a significantly better prognosis than those with level II (P = 0.006). Multivariate analysis revealed CD74 expression level and vascular permeation of carcinoma as independent prognostic indicators.

CONCLUSIONS

CD74 expression proved as a useful prognostic indicator for PDAC treated with multimodal therapy.

Selected combination therapy with sorafenib: a review of clinical data and perspectives in advanced solid tumors

The development of targeted therapies has provided new options for the management of patients with advanced solid tumors. There has been particular interest in agents that target the mitogen-activated protein kinase pathway, which controls tumor growth and survival and promotes angiogenesis. Sorafenib is an oral multikinase inhibitor that has been proven effective as a single-agent therapy in renal cell carcinoma, and there is a strong rationale for investigating its use in combination with other agents. In particular, targeting multiple Raf isoforms with sorafenib may help to overcome resistance to other agents, while the ability of sorafenib to induce apoptosis may increase the cytotoxicity of chemotherapeutic agents. Based on positive results in preclinical studies, further investigation in phase I and II studies has shown potential antitumor activity when sorafenib is combined with cytotoxic agents in different solid tumors, including hepatocellular carcinoma and melanoma. Promising results have been reported in phase I and II studies of sorafenib combined with paclitaxel and carboplatin, with oxaliplatin in gastric and colorectal cancer, with docetaxel in breast cancer, with gemcitabine in ovarian cancer, and with capecitabine in different solid tumors. Phase II and III studies are currently investigating the use of sorafenib in combination with different agents in a variety of solid tumors. The primary objective of this review is to summarize the early clinical studies of sorafenib with cytotoxic agents and discuss future perspectives of these combinations in different tumor types.

Proteomics of pancreatic cancer

Pancreatic cancer is a devastating disease, with a mortality rate almost identical with its incidence. Late diagnosis and limited therapeutic options make early detection of pancreatic cancer a pressing clinical problem. In this context, the investigation of the pancreatic cancer proteome has recently gained considerable attention because profiles of proteins may be able to more accurately identify disease states, such as cancer. Recent pancreatic cancer proteome studies may be categorized into basic studies cataloguing the pancreatic proteome, studies investigating differential protein expression patterns, and studies searching for proteome-based biomarkers for early cancer detection and differentiation. Although these studies clearly demonstrate that a range of biological samples are suitable for proteomic analyses, comparison of different studies is problematic due to the diversity of methodologies, sample sources, and characterization of patient populations. Reproducibility between studies has rarely been investigated, and no investigation has compared the different methods of proteomic research. The results of this review have shown that more stringent requirements concerning the design and the analysis of future studies should be implemented. These include an adequate patient number, obligatory histological examination of tissues, appropriate control groups, identification of proteins and peaks, validation of differential expression using independent cohorts and/or a second methodology, and, finally, demonstration of result reproducibility. This will hopefully lead to the discovery of prognostic and predictive biomarkers that help to improve prognosis of pancreatic cancer patients.

Comparison of CT and MRI for presurgical characterization of paraaortic lymph nodes in patients with pancreatico-biliary carcinoma

AIM: To determine the accuracy of computed tomography (CT) and magnetic resonance (MR) for presurgical characterization of paraaortic lymph nodes in patients with pancreatico-biliary carcinoma.

METHODS: Two radiologists independently evaluated CT and MR imaging of 31 patients who had undergone lymphadenectomy (9 metastatic and 22 non-metastatic paraaortic nodes). Receiver operating characteristic (ROC) curve analysis was performed using a five point scale to compare CT with MRI. To re-define the morphologic features of metastatic nodes, we evaluated CT scans from 70 patients with 23 metastatic paraaortic nodes and 47 non-metastatic ones. The short axis diameter, ratio of the short to long axis, shape, and presence of necrosis were compared between metastatic and non-metastatic nodes by independent samples t-test and Fisher’s exact test. P < 0.05 was considered statistically significant.

RESULTS: The mean area under the ROC curve for CT (0.732 and 0.646, respectively) was slightly higher than that for MRI (0.725 and 0.598, respectively) without statistical significance (P = 0.940 and 0.716, respectively). The short axis diameter of the metastatic lymph nodes (mean = 9.2 mm) was significantly larger than that of non-metastatic ones (mean = 5.17 mm, P < 0.05). Metastatic nodes had more irregular margins (44.4%) and central necrosis (22.2%) than non-metastatic ones (9% and 0%, respectively), with statistical significance (P < 0.05).

CONCLUSION: The accuracy of CT scan for the characterization of paraaortic nodes is not different from that of MRI. A short axis-diameter (> 5.3 mm), irregular margin, and presence of central necrosis are the suggestive morphologic features of metastatic paraaortic nodes.

Surgical management of carcinoma of the head of pancreas: extended lymphadenectomy or modified en bloc resection?

Pancreatoduodenectomy for the treatment of periampullary cancer was described over 70 years ago. The technique has evolved in an attempt to improve the dismal prognosis for patients with pancreatic cancers. Radical regional resection has been proposed to decrease the incidence of local recurrence as well as to improve survival. These extended resections have failed to show a significant survival benefit in prospective randomized controlled studies. Furthermore, extended pancreatic resections may be associated with increased morbidity. The concept of modified en bloc resection has been advocated and is soundly based on anatomical and pathological principals. This procedure is a modification of the radical regional resection previously described. It involves resection of the peripancreatic retroperitoneal tissue and lymph nodes en bloc with the head of pancreas, in order to achieve an R0 resection but without the morbidity associated with an extended lymphadenectomy. Conceptually, this procedure may be the most appropriate technique for the management of pancreatic head cancers although the ultimate effect on long-term survival can only be judged after further clinical studies.

Pancreatic cancer--low survival rates

INTRODUCTION

Cancers of the pancreas are identified in 11 800 to 13 500 patients each year in Germany. Epidemiological studies prove smoking and chronic alcohol consumption as causes of about 30% of pancreatic cancers.

METHODS

Selective literature review.

RESULTS

Only patients within TNM stage I and II have after oncologic tumor extirpation a chance for long term survival. Controlled prospective clinical trials demonstrated adjuvant chemotherapy yielding an additional significant survival benefit. The 3- and 5-year-survival after R0-resection and adjuvant chemotherapy are about 30% and below 15% respectively. Using the criteria of observed 5-year-survival less than 2% of all pancreatic cancer patients are alive. After R0-resection the median survival time is between 17 and 28 months, after R1/2-resection between 8 and 22 months.

DISCUSSION

Pancreatic cancer is even today for more than 95% of the patients incurable. Strategies to prevent pancreatic cancer are intended to stop smoking and chronic alcohol consumption and early surgical extirpation of cystic neoplastic lesions. For patients with established pancreatic cancer risk a follow-up protocol is discussed.

Pancreatic cancer: a generalized disease--prognostic impact of cancer cell dissemination

BACKGROUND

Pancreatic ductal adenocarcinoma is the fifth leading cause of death among all malignancies, leading to approximately 40,000 deaths each year in Europe. The annual incidence rate for all types of pancreatic cancer is approximately nine new cases per 100,000 people, ranking it as the 11th among all cancers. Stage, grade and resection margin status are currently accepted as the most accurate pathologic variables predicting survival. All classification systems fail prognostically to distinguish between different stages. Even in patients with seemingly early tumours (T1, N0), the likelihood of relapse is high. This reflects the shortcomings of the pathologic staging to sufficiently discriminate patients with a high risk to develop tumour recurrence from those that carry a lower risk.

RESULTS

On the other hand, none of the currently used systems includes or takes into consideration the role of disseminated tumour cells neither in the lymph nodes nor in the bone marrow. Occult residual tumour disease is suggested when either bone marrow or lymph nodes, from which tumour relapse may originate, are affected by micrometastatic lesions undetectable by conventional histopathology. For detection, antibodies against tumour-associated targets can be used to detect individual epithelial tumour cells both in lymph nodes and in bone marrow. The clinical significance of these immunohistochemical analyses is still controversial. Various monoclonal antibodies are still in use for micrometastatic detection, thus contributing to the incongruity of data and validity of results. These assays have been rarely used in patients with pancreatic carcinoma.

CONCLUSION

The presence or absence of lymph-node metastases can predict the likelihood of survival for most, if not all, patients with pancreatic ductal adenocancer and the likelihood that metastases will develop at distant sites.

New advances in pancreatic surgery

PURPOSE OF REVIEW

New understanding of the dynamic of acute pancreatitis, the clinical impact of local pathology in chronic pancreatitis and cystic neoplastic lesions bearing high potential for malignant transformation has changed the management of pancreatic diseases.

RECENT FINDINGS

In acute pancreatitis, risk factors independently determining outcome in severe acute pancreatitis are early and persistent multiorgan failure, infected necrosis and extended sterile necrosis. The management of severe acute pancreatitis is based on early intensive-care treatment and late surgical debridement. In chronic pancreatitis, recent data from randomized controlled clinical trials have demonstrated duodenum-preserving pancreatic head resection with an inflammatory mass of the head as superior to pylorus-preserving Whipple resection. Cystic neoplasms are local lesions of the pancreas with high malignant potential. Local organ-preserving resection techniques have been applied with low morbidity and mortality, replacing a Whipple-type resection. Resection of pancreatic cancer is ineffective to cure patients. After an R0-resection, a significant survival benefit has been achieved when adjuvant chemotherapy has additionally been applied.

SUMMARY

New knowledge about the nature of inflammatory diseases, cystic neoplastic lesions and malignant pancreatic tumours has changed the indication for surgical treatment and the application of organ-preserving surgical techniques.

Accurate discrimination of pancreatic ductal adenocarcinoma and chronic pancreatitis using multimarker expression data and samples obtained by minimally invasive fine needle aspiration

To augment cytological diagnosis of pancreatic ductal adenocarcinoma (PDAC) in tissue samples obtained by minimally invasive endoscopic ultrasound-guided fine needle aspiration, we investigated whether a small set of molecular markers could accurately distinguish PDAC from chronic pancreatitis (CP). Expression levels of 29 genes were first determined by quantitative real-time RT-PCR in a training set of tissues in which the final diagnosis was PDAC (n=20) or CP (n=10). Using receiver operator characteristic curve analysis, we determined that the single gene with the highest diagnostic accuracy for discrimination of CP vs. PDAC in the training study was urokinase plasminogen activator receptor (UPAR; AUC value = 0.895, 95% CI=0.728-0.976). In the set of test tissues (n=14), the accuracy of UPAR decreased to 79%. However, we observed that the addition of 6 genes (EPCAM2, MAL2, CEA5, CEA6, MSLN and TRIM29; referred to as the 6-gene classifier) to UPAR resulted in high accuracy in both training and testing sets. Excluding 3 samples (out of 44; 7%) for which results of the UPAR/6-gene classifier were "undefined," the accuracy of the UPAR/6-gene classifier was 100% in training samples (n=29), 92% in 12 test samples (p=0.004 that results were randomly generated; p=0.046 that the UPAR/6-gene classifier was comparable to UPAR alone; chi2 test), 100% in 3 samples for which the initial cytological diagnosis was "suspicious" and 98% (40/41) overall. Our results provide evidence that molecular marker expression data can be used to augment cytological analysis.

Primary resection versus neoadjuvant chemoradiation followed by resection for locally resectable or potentially resectable pancreatic carcinoma without distant metastasis. A multi-centre prospectively randomised phase II-study of the Interdisciplinary Working Group Gastrointestinal Tumours (AIO, ARO, and CAO)

Background

The disappointing results of surgical therapy alone of ductal pancreatic cancer can only be improved using multimodal approaches. In contrast to adjuvant therapy, neoadjuvant chemoradiation is able to facilitate resectability with free margins and to lower lymphatic spread. Another advantage is better tolerability which consecutively allows applying multimodal treatment in a higher number of patients. Furthermore, the synopsis of the overall survival results of neoadjuvant trials suggests a higher rate compared to adjuvant trials.

Methods/Design

As there are no prospectively randomised studies for neoadjuvant therapy, the Interdisciplinary Study Group of Gastrointestinal Tumours of the German Cancer Aid has started such a trial. The study investigates the effect of neoadjuvant chemoradiation in locally resectable or probably resectable cancer of the pancreatic head without distant metastasis on median overall survival time compared to primary surgery. Adjuvant chemotherapy is integrated into both arms.

Discussion

The protocol of the study is presented in condensed form after an introducing survey on adjuvant and neoadjuvant therapy in pancreatic cancer.

Impact of Lymph Node Micrometastasis in Patients with Pancreatic Head Cancer

PURPOSE

The purpose of this study was to investigate the clinical significance of nodal micrometastasis in patients who underwent a curative operation for pancreatic cancer.

EXPERIMENTAL DESIGN

Fifty-eight patients underwent a macroscopically curative resection with extended lymph node dissection for pancreatic cancer. The total number of resected lymph nodes was 1,058, and 944 histologically negative lymph nodes were subjected to immunohistochemical staining to detect occult micrometastases.

RESULTS

Nodal micrometastases were detected immunohistochemically in 147 out of 944 resected histologically negative lymph nodes (15.6%). Forty-four of all 58 patients (75.9%) and 13 of the 23 histologically node-negative patients (56.5%) had nodal micrometastases. Nodal micrometastases existed in the N1 lymph node area most frequently, followed by the N2 and N3 lymph node areas. The distribution was similar to that of histologically metastatic lymph nodes. Ten out of 16 patients (62.5%) with histological N1, and 5 out of 16 patients (31.3%) with histological N2 had nodal micrometastases beyond the histological lymph node status. Three and 5-year survival rates of pN0 patients without lymph node nodal micrometastases were both 60.0%, while those with nodal micrometastases were 19.2% and 0%, respectively. There was statistically significant difference between the both groups (P = 0.041).

CONCLUSIONS

Nodal micrometastasis in pancreatic cancer existed in wider and more distant areas than histological lymph node status, and it was an unfavorable predictive factor, even in N0 patients.

Impact of Interferon-α in Combined Chemoradioimmunotherapy for Pancreatic Adenocarcinoma (CapRI): First Data From the Immunomonitoring

Data from a phase II trial combining chemoradiotherapy with IFN-alpha (CapRI scheme) for adjuvant treatment of pancreatic carcinoma are very encouraging. Therefore, a phase III trial comparing chemotherapy with the chemoradiotherapy with IFN-alpha scheme has been initiated in August 2004. Translational research with a focus on immunomodulation is performed in parallel to the study. Blood and serum samples are taken at various time points. Patients in arm A (chemoradioimmunotherapy) receive a single low-dose-Interferon injection before therapy to investigate the direct effect of IFN-alpha. So far samples from 44 patients have been investigated for surface molecule expression, cytokine levels, natural killer cell cytotoxicity, and antigen-specific Granzyme B release. Patients in arm A showed 1 day after IFN-alpha injection a significant increase in spontaneous cytotoxicity; this effect was fading after repeated injections. Furthermore, cells releasing Granzyme B after stimulation with CA 19.9 and MUC-1 protein increased under therapy. Five days after the first IFN-alpha injection, IL-12 and TNF-alpha serum levels peak. We observed significant increases of monocytes, peripheral dendritic cells, CD40 cells, central and effector memory T cells, and CD8 cells, CD4 cells decreased during therapy. All these effects were only observed in arm A patients and none of them in arm B patients. In conclusion, in a translational research project accompanying a challenging multimodality treatment trial including IFN-alpha, we observed an immediate activation of antigen-presenting cells and natural killer cells followed later on by antigen-specific activation. It will be most interesting if the immunologic data will show a correlation with the clinical course of the patients.

Large topographic variability of upper abdominal lymphatics and the consequences for radiation treatment planning

BACKGROUND AND PURPOSE

Inclusion of regional lymph nodes usually is indicated when treating upper gastrointestinal malignancies. Lymphatics follow the large vessels of this region. Vascular variability with consequences for planning treatment volume (PTV) was studied.

MATERIALS AND METHODS

Upper abdominal metric relationship of the vascular origins was analysed in CT scans in 104 patients to estimate its influence on PTV variability. PTV volumes were calculated based on these. Additionally, the PTV size of 3D plans of 34 patients with pancreatic adenocarcinoma (PDAC) was analysed depending on different PTV definitions.

RESULTS

Vascular origin varied most for the inferior mesenteric artery (IMA) with substantial PTV size differences. Volumetric variability was analysed for PDAC (IMA versus renal hilum as caudal margin). Additional PTV for IMA was < 100 cc (median) but ranged up to 350 cc in CT (100-199 ml in 14/34 and > 200 ml in 3/34 patients). Data from treatment planning confirmed this observation.

CONCLUSIONS

Considerable vascular and lymphatic variability obliges to base PTV on the individual vascular anatomy. For most patients the caudal PTV margin for PDAC can safely be set at the IMA. But PTV should be restricted when the additional volume would lead to a significant increase to avoid haematotoxicity from concomitant gemcitabine which is proportional with PTV size. The risk of kidney toxicity is also subject to PTV expansion in the caudal direction.

Immunohistochemically demonstrated lymph node micrometastasis and prognosis in patients with gallbladder carcinoma

OBJECTIVE

To investigate whether immunohistochemically demonstrated lymph node micrometastasis has a survival impact in patients with advanced gallbladder carcinoma (pT2-4 tumors).

SUMMARY BACKGROUND DATA

The clinical significance of immunohistochemically detected lymph node micrometastasis recently has been evaluated in various tumors. However, few reports have addressed this issue with regard to gallbladder carcinoma.

METHODS

A total of 1476 lymph nodes from 67 patients with gallbladder carcinoma (pN0, n = 40; pN1, n = 27) who underwent curative resection were immunostained with monoclonal antibody against cytokeratins 8 and 18. The results were correlated with clinical and pathologic features and with patient survival.

RESULTS

Lymph node micrometastases were detected immunohistochemically in 23 (34.3%) of the 67 patients and in 37 (2.5%) of the 1476 nodes examined. Of the 37 nodal micrometastases, 21 (56.8%) were single-cell events, and the remaining 16 were clusters. Five micrometastases were detected in the paraaortic nodes. Clinicopathologic features showed no significant associations with the presence of lymph node micrometastases. Survival was worse in the 27 patients with pN1 disease than in the 40 with pN0 disease (5-year survival; 22.2% vs. 52.6%, P = 0.0038). Similarly, survival was worse in the 23 patients with micrometastasis than in the 44 without micrometastasis (5-year survival; 17.4% vs. 52.7%, P = 0.0027). Twenty-eight patients without any lymph node involvement had the best prognosis, whereas survival for the 11 patients with both types of metastasis was dismal. The grade of micrometastasis (single-cell or cluster) had no effect on survival. The Cox proportional hazard model identified perineural invasion, lymph node micrometastasis, and microscopic venous invasion as significant independent prognostic factors.

CONCLUSIONS

Lymph node micrometastasis has a significant survival impact in patients with pN0 or pN1 gallbladder carcinoma who underwent macroscopically curative resection. Extensive lymph node sectioning with keratin immunostaining is recommended for accurate prognostic evaluation for patients with gallbladder carcinoma.

Impact of disseminated tumor cells in gastrointestinal cancer

The detection of epithelial cells by sensitive immunological and molecular methods in blood, lymph nodes or bone marrow of gastrointestinal cancer patients may open a new approach to clinical metastasis research. The phenotypic and genomic characterization of these cells is of great value in the prediction of the further course of the disease and the monitoring of response to treatment. In addition, the role of ultrastaging in blood, lymph nodes and bone marrow of cancer patients for the indication of multimodal therapy is discussed in this review. The impact of prognostic or predictive factors for new treatment protocols in patients with gastrointestinal cancer was evaluated as well as the correlation with clinical factors.

[Significance of occult lymphatic tumor spread in pancreatic cancer]

PURPOSE

The aim of this study was to determine the frequency and effect on prognosis of occult tumor cells in regional lymph nodes judged to be tumor-free in conventional histopathology of pancreatic cancer patients.

PATIENTS AND METHODS

Among 115 patients who underwent pancreatic resection for pancreatic (n=84) or distal common bile duct malignancy (n=12) or carcinoma of the papilla (n=19), 48 (42%) were staged pN0. Archival paraffin blocks of 271 resected regional lymph nodes of 41 pN0 patients were reevaluated for occult tumor cells using monoclonal antibody Ber-EP4. Cases with or without isolated tumor cells were compared regarding the distribution of various clinicopathological factors.

RESULTS

Of 41 pN0 patients, 16 (39%) exhibited single Ber-Ep4 immunoreactive cells or small cell clusters in at least one lymph node. The occurrence of occult tumor cells was not dependent on other clinicopathological factors such as pT stage, grading, or curative resection. However, those cells were encountered more frequently in common bile duct carcinomas (100%) than in pancreatic (36%) or papilla (20%) carcinomas (P=0.009). Occult tumor cells impaired prognosis significantly in uni- and multivariate analyses (estimated 5-year survival 53% for pN0((i-)) vs 10% for pN0((i+)) and 9% for pN1/N2; P=0.0047).

CONCLUSION

Occult tumor cells are frequent in apparently tumor-free lymph nodes of pancreatic cancer patients and often overlooked in conventional histopathology. They are encountered even in limited stages of disease and they impair prognosis, which is comparable to that of patients with true lymphatic metastases. Occult tumor cells in lymph nodes of pancreatic cancer patients could be used to stratify adjuvant therapy.

Differences in survival by histologic type of pancreatic cancer

OBJECTIVE

Although pancreatic cancer has an extremely high case fatality rate, little is known about differences in mortality by histologic types. We examined median survival and risk of mortality for endocrine pancreatic tumors and two types of exocrine tumors, adenocarcinomas, and mucinous tumors.

METHOD

This analysis included 35,276 pancreatic cancer cases reported to the nine population-based cancer registries participating in the Surveillance, Epidemiology, and End Results program from 1973 to 2000. Survival among cases with pancreatic adenocarcinomas, mucinous tumors, and endocrine tumors were compared using Kaplan-Meier plots. Comparative risks of mortality were evaluated using multivariate adjusted Cox regression models.

RESULTS

Endocrine pancreatic cancer cases had a median survival of 27 months compared with a median survival of 4 months for adenocarcinoma and mucinous tumor cases. Compared with adenocarcinoma cases, endocrine tumor cases had a 0.28-fold lower risk of mortality [95% confidence interval (95% CI), 0.26-0.30], and mucinous tumor cases had a 0.88-fold lower risk (95% CI, 0.84-0.91). These results were similar for men and women. Within histologic types, advanced tumor stage, older diagnosis age, surgery, and Black race were associated with increased risks of mortality, whereas female sex and more recent year of diagnosis were associated with decreased risks.

CONCLUSION

This study confirms the clinical observation that patients with endocrine pancreatic cancer survive longer than patients with exocrine tumors. A better understanding of these differences could contribute to identifying the underlying causes of pancreatic cancer and to improving survival rates across all histologic types.

Detection of tumor cell dissemination in pancreatic ductal carcinoma patients by CK 20 RT-PCR indicates poor survival

PURPOSE

This prospective study evaluates the diagnostic potential of Cytokeratin 20 (CK 20) RT-PCR for the detection of disseminated tumor cells in bone marrow and blood of a large cohort of patients with ductal adenocarcinoma of the pancreas and the prognostic value on overall survival prediction.

METHODS

Between 1994 and 2003, 172 patients (83 male, 89 female; 13-82 years) with pancreatic ductal adenocarcinoma underwent surgery. Bone marrow samples and venous blood were taken preoperatively and analyzed for disseminated tumor cells by nested CK 20 RT-PCR.

RESULTS

Disseminated tumor cells were detected in 81 (47.1%) of the 172 patients in the bone marrow and/or the venous blood. Overall, in 45 of the 135 (33.3%) bone marrow samples and in 52 of the 154 (33.8%) blood samples, CK 20 positive cells were detected. Detection rates increased with the UICC-tumor stage. According to Kaplan-Meier, univariate survival analysis of all 172 patients (n = 78 R0-; n = 18 R1- and n = 5 R2-resected; n = 71 palliative surgery) showed a statistically significant relationship of overall survival to radicality of the operation (P < 0.0001), the UICC-stage of the tumors (P = 0.0011) and the detection of disseminated tumor cells in bone marrow and/or venous blood (P = 0.05). Patients with well- and moderately- differentiated tumors (G1 and G2) had a significantly longer survival (P = 0.045) than patients suffering from poorly differentiated tumors (G3). A positive CK 20 status in the bone marrow and/or blood within the group of patients with G1 and G2 tumors had a significantly negative prognostic impact on their survival (P = 0.046).

CONCLUSIONS

Disseminated tumor cells can be detected in patients with pancreatic ductal adenocarcinoma by CK 20 RT-PCR. Detection rates are stage dependent, and survival analysis demonstrated statistically relevant data. From a clinical point of view, this finding is especially noteworthy for the group of well- and moderately-differentiated tumors.

Definition of elective lymphatic target volume in ductal carcinoma of the pancreatic head based on histopathologic analysis

PURPOSE

In chemoradiation for pancreatic carcinoma three-dimensional target volume definitions could maximize tolerability and therapeutic effect at the same time because toxicity correlates with treatment volume. We aimed to define guidelines for elective treatment of nodal areas based on pathologic nodal involvement to optimize treatment volume for this tumor.

METHODS AND MATERIALS

Pathologic patterns of regional nodal spread in 175 patients who underwent primary pancreatoduodenectomy with > or =10 assessed nodes and literature data on para-aortic spread were the base of the definition of the target volume. Significant correlations between spread to lymphatic areas and tumor characteristics were determined using Fisher's exact test. Computed tomography scans and a Pinnacle3 (Philips, Best, The Netherlands) system were used for treatment planning.

RESULTS

Among 175 resected tumors without pretreatment, 76% had regional nodal metastasis and 22% had spread to distant nodes. High-risk lymphatic areas were identified and selected for elective treatment. A standardized planning procedure was derived and tested under treatment conditions.

CONCLUSIONS

Histopathologic data allowed us to develop recommendations for standardized treatment planning for ductal carcinoma of the pancreatic head. These are proposed for quality assurance in multicenter studies and routine use.

Clinical significance of K-ras and c-erbB-2 mutations in pancreatic adenocarcinoma and chronic pancreatitis

BACKGROUND

The differentiation of chronic pancreatitis (CP) from pancreatic adenocarcinoma (PA) remains the great challenge for clinicians. The purpose of this study was to compare the prevalence of K-ras and c-erbB-2 mutations in PA and CP in order to evaluate their usefulness in differential diagnosis of those diseases.

METHODS

The study included 49 patients who underwent Whipple resection or distal pancreatectomy for pancreatic adenocarcinoma (26 subjects) or chronic pancreatitis (23 subjects). DNA from pancreatic tissue was analyzed for K-ras codon 12 and c-erbB-2 mutations with PCR amplifications.

RESULTS

The K-ras gene mutation has been shown in 20 (76.9%) PA cases and in 8 (34.8%) CP cases (p<0.01). Prevalence of c-erbB-2 amplification in patients with PA was 17 (65.3%), which was not different from CP, 16 (56.5%) (p=0.58). There was a significant correlation between K-ras mutation and lymph node metastases (p=0.025) as well as between K-ras mutation and G3 tumor differentiation (p=0.037). Overall median survival in patients with PA was 9.5 mo. There was no relationship between presence of K-ras (p=0.58) or c-erbB-2 (p=0.17) mutation and survival time in PA patients.

CONCLUSION

Those results may indicate that both K-ras and c-erbB-2 play a role in pancreatic carcinogenesis, however only K-ras may provide an additional tool in differential diagnosis of CP and PC.

Clinical significance of K-ras and c-erbB-2 mutations in pancreatic adenocarcinoma and chronic pancreatitis

BACKGROUND

The differentiation of chronic pancreatitis (CP) from pancreatic adenocarcinoma (PA) remains the great challenge for clinicians. The purpose of this study was to compare the prevalence of K-ras and c-erbB-2 mutations in PA and CP in order to evaluate their usefulness in differential diagnosis of those diseases.

METHODS

The study included 49 patients who underwent Whipple resection or distal pancreatectomy for pancreatic adenocarcinoma (26 subjects) or chronic pancreatitis (23 subjects). DNA from pancreatic tissue was analyzed for K-ras codon 12 and c-erbB-2 mutations with PCR amplifications.

RESULTS

The K-ras gene mutation has been shown in 20 (76.9%) PA cases and in 8 (34.8%) CP cases (p<0.01). Prevalence of c-erbB-2 amplification in patients with PA was 17 (65.3%), which was not different from CP, 16 (56.5%) (p=0.58). There was a significant correlation between K-ras mutation and lymph node metastases (p=0.025) as well as between K-ras mutation and G3 tumor differentiation (p=0.037). Overall median survival in patients with PA was 9.5 mo. There was no relationship between presence of K-ras (p=0.58) or c-erbB-2 (p=0.17) mutation and survival time in PA patients.

CONCLUSION

Those results may indicate that both K-ras and c-erbB-2 play a role in pancreatic carcinogenesis, however only K-ras may provide an additional tool in differential diagnosis of CP and PC.

Detection and clinical implications of minimal residual disease in gastro-intestinal cancer

INTRODUCTION

Metastatic dissemination is an important factor for the prognosis of patients with gastro-intestinal cancer. Exact staging is crucial to determine appropriate multimodal therapeutic strategies. At present, the sensitivity of routinely performed diagnostic techniques is suboptimal for the detection of minimal residual disease (MRD) and occult metastases since the number of disseminated tumour cells (DTCs) is mostly marginal. To amend the verification of DTCs, immunohistochemical and molecular methods were applied to retrieve epithelial cell-specific proteins in non-epithelial tissue of different body compartments or fluids. Many groups have eagerly focussed on the identification of new markers and novel tests, yet specificity and sensitivity of these methods as well as robustness in the clinical setting are frequently missing.

MATERIALS AND METHODS

This review critically evaluates the prognostic impact of MRD in patients with pancreatic, colorectal and gastric cancer by outlining those studies showing diagnostic results of DTC detection in lymph nodes, bone marrow, venous blood and peritoneal lavage, some of which present novel strategies.

CONCLUSION

The analysed data concerning MRD in gastro-intestinal cancers reveal that results are undesirably heterogeneous. From a critical point of view, many clinical studies missed their chance because of small cohort size; moreover, methodological standardisation is generally lacking. On the other hand, the very encouraging results achieved so far, together with the comprehensive analyses of a few research groups, foster the prediction that DTC/MRD issues will soon expand the standard TNM classification.

Cytokeratin is a superior marker for detection of micrometastatic biliary tract carcinoma

BACKGROUND

The incidence of lymph node micrometastases in patients with biliary tract carcinoma is unknown. We evaluated the utility of three antibodies for immunohistochemical (IHC) detection of micrometastatic disease in patients with gallbladder and bile duct carcinoma.

MATERIALS AND METHODS

Surgical specimens from 35 patients with biliary tract carcinoma were evaluated. Histologically involved tissues were stained with the following antibodies using standard IHC techniques: cytokeratin (AE1:AE3), CEA (carcinoembryonic antigen), and EMA (epithelial membrane antigen). The antibodies with the greatest degree of positive staining were then used to evaluate the lymph nodes of patients with histologically negative lymph nodes. Micrometastatic disease was defined as clustered atypical cells <2 mm in size detected only with the use of IHC.

RESULTS

All of the primary tumors and histologically positive lymph nodes demonstrated staining with cytokeratin and CEA antibodies, whereas only 83% were positive for EMA. Therefore, cytokeratin and CEA antibodies were used to evaluate histologically negative lymph nodes. Anti-cytokeratin immunostaining detected micrometastatic disease in two patients. Staining with anti-CEA was negative in all specimens. Overall, two of 15 patients with histologically node negative biliary tract carcinoma had occult micrometastases.

CONCLUSION

Cytokeratin immunostaining enables detection of micrometastases in histologically negative lymph nodes in patients with biliary tract carcinoma. Prospective protocols incorporating cytokeratin staining of the lymph nodes may help determine the incidence and clinical significance of occult micrometastatic disease in these patients.

Immunohistochemical Studies in the Identification of Lymph Node Micrometastases in Patients with Squamous Cell Carcinoma of the Head and Neck

In the prediction of likely disease-free and overall survival intervals in patients with squamous carcinomas of the head and neck, cervical lymph node status assumes a prime role, and patients with cervical node metastases have diminished survivals, as a group, compared with patients whose cervical nodes are reported as negative for metastatic carcinoma. Conventional means of pathologic examination of cervical node biopsy specimens include examination of a single section through each individual node identified on gross examination, a process which, of necessity, leaves a significant portion of the node unexamined by microscopy. Recently, it has become apparent that more exhaustive pathologic sampling techniques, such as examining multiple sections of each lymph node, or staining each lymph node with antibodies to keratin via immunohistochemistry, will reliably yield a greater incidence of positive cervical lymph nodes ("micrometastases") than do conventional pathologic techniques. This suggests that the next line of inquiry should answer this question: just because micrometastases can be detected, should they be? Does the identification of (otherwise likely to be overlooked) tiny microscopic foci of spread of tumor in regional nodes by more sophisticated techniques yield additional data of real import to the patients, or is such information of lesser value? Should a role be defined in the care of head and neck cancer patients for the use of such advanced inquiries in the structuring of therapies, then the best approach to finding such elusive micrometastases (intraoperative immunohistochemistry? immunohistochemistry using routinely fixed tissues? polymerase chain reaction?) may subsequently be established.

Sensitive and specific detection of K-ras mutations in colon tumors by short oligonucleotide mass analysis

Short oligonucleotide mass analysis (SOMA) is a technique by which small sequences of mutated and wild-type DNA, produced by PCR amplification and restriction digestion, are characterized by HPLC-electrospray ionization tandem mass spectrometry. We have adapted the method to specifically detect two common point mutations at codon 12 of the c-K-ras gene. Mutations in DNA from 121 colon tumor samples were identified by SOMA and validated by comparison with sequencing. SOMA correctly identified 26 samples containing the 12GAT mutation and four samples containing the 12AGT mutation. Sequencing did not reveal mutant DNA in three samples out of the 26 samples shown by SOMA to contain the 12GAT mutation. In these three samples, the presence of mutant DNA was confirmed by SOMA analysis after selective PCR amplification in the presence of BstN1 restriction enzyme. Additional mutations in codons 12 and 13 were revealed by sequencing in 24 additional samples, and their presence did not interfere with the correct identification of G to A or G to T mutations in codon 12. These results provide the basis for a sensitive and specific method to detect c-K-ras codon 12-mutated DNA at levels below 10-12% of wild-type DNA.