Friedrich Hubertus Schmitz-Winnenthal

Risk of Malignancy in Serous Cystic Neoplasms of the Pancreas

Background: In contrast to mucinous cystic neoplasms of the pancreas, which are known to have considerable malignant potential, the serous variant is generally thought to be benign. There are, however, several reports of malignancy in serous cystic neoplasms of the pancreas. Aims: To assess the risk of malignancy of serous cystic tumors of the pancreas and to investigate specific clinical and histological features. Methods: Clinical and pathological characteristics of benign and malignant serous cystic neoplasms of the pancreas were investigated by a review of the literature and documented by a case of a serous cystadenocarcinoma and immunohistochemical analysis of a series of serous cystadenomas. Reviewing the literature prevalence, age and sex distribution of serous cystic neoplasms were analyzed. Results: The prevalence of cancer among serous cystic neoplasms reported since 1989 was 3%. Serous cystadenoma of the pancreas present at an earlier age (61 years) than serous cystadenocarcinoma (66 years; p = 0.056) and are symptomatic in the majority of patients.Pathological examination of the primary tumor was not able to distinguish cystadenoma from cystadenocarcinoma in 38% of cases. In 25% the diagnosis of cancer was established only after growth of metachronous metastases. In the present case, nuclear atypia, papillary structures, proliferation marker Ki-67 and p53 protein were increased in the primary tumor and/or metachronous metastasis. Conclusion: Serous cystic neoplasms of the pancreas do have malignant potential with a risk of malignancy of 3% and should be surgically treated if the operative risk is acceptable. Routine analysis of genetic and proliferation markers may improve diagnosis of malignancy in these tumors.

Colocalization of the Tetraspanins, CO-029 and CD151, with Integrins in Human Pancreatic Adenocarcinoma: Impact on Cell Motility

Purpose: Patients with pancreatic adenocarcinoma have a poor prognosis due to the extraordinary high invasive capacity of this tumor. Altered integrin and tetraspanin expression is suggested to be an important factor. We recently reported that after protein kinase C activation, colocalization of α6β4 with the tetraspanin CO-029 strongly supports migration of a rat pancreatic adenocarcinoma. The finding led us to explore whether and which integrin-tetraspanin complexes influence the motility of human pancreatic tumors. Experimental Design: Integrin and tetraspanin expression of pancreatic and colorectal adenocarcinoma was evaluated with emphasis on colocalization and the impact of integrin-tetraspanin associations on tumor cell motility. Results: The majority of pancreatic and colorectal tumors expressed the α2, α3, α6, β1, and β4 integrins and the tetraspanins CD9, CD63, CD81, CD151, and CO-029. Expression of α6β4 and CO-029 was restricted to tumor cells, whereas α1, α2, α3, α6, β1, and CD9, CD81, CD151 were also expressed by the surrounding stroma. CD63, CD81, and β1 expression was observed at comparably high levels in healthy pancreatic tissue. α3β1 frequently colocalized and coimmunoprecipitated with CD9, CD81, and CD151, whereas α6β4 colocalized and coimmunoprecipitated mostly with CD151 and CO-029. Notably, protein kinase C activation strengthened only the colocalization of CD151 and CO-029 with β4 and was accompanied by internalization of the integrin-tetraspanin complex, decreased laminin 5 adhesion, and increased cell migration. Conclusion: α6β4 is selectively up-regulated in pancreatic and colorectal cancer. The association of α6β4 with CD151 and CO-029 correlates with increased tumor cell motility.

Tumor Infiltrating T Lymphocytes in Colorectal Cancer: Tumor-Selective Activation and Cytotoxic Activity In Situ

Objective:To examine whether tumor-selective infiltration, activation, and cytotoxic activity of tumor infiltrating T lymphocytes (TIL) can be demonstrated in situ in colorectal cancer samples. Summary Background Data:Recent studies indicated a correlation between the presence of TIL and an improved prognosis in colorectal cancer. However, tumor-selective activation and cytotoxic activity of CD8+ TIL in situ in colorectal cancer patients have not yet been examined. Methods:Tumor samples from 49 patients and corresponding normal mucosa samples from 23 patients with colorectal cancer (UICC stages II–IV) were examined for TIL. Two-color fluorescence immunohistochemistry and multicolor flowcytometric (FACS) analysis were used for quantification of CD8+ T cells and measurement of their activation status (CD69-expression) and cytotoxic activity (CD107a-expression) in situ. Presence of tumor antigen-reactive T cells in tumor, blood, and bone marrow was evaluated by IFN-γ Elispot analysis. Results:While absolute numbers of CD8+ T cells were similar, CD4+ T helper cells were significantly increased in tumor tissue compared with normal mucosa. There was a significantly higher proportion of activated and cytotoxically active CD8+ TIL in colorectal cancer compared with normal mucosa. Increased activation, cytotoxic activity, and functional reactivity of TIL were correlated with the presence of functional tumor antigen-reactive T cells in the blood and bone marrow. The proportion of activated TIL decreased significantly with higher tumor stage. Conclusions:Tumor-selective activation and cytotoxic activity of CD8+ TIL and tumor-selective migration of CD4+ T helper cells were demonstrated in colorectal cancer for the first time. Our data support the immunogenicity of colorectal cancer and suggest clinical significance of tumor-specific immune responses.

Double-blind, placebo-controlled first in human study to investigate an oral vaccine aimed to elicit an immune reaction against the VEGF-Receptor 2 in patients with stage IV and locally advanced pancreatic cancer

BackgroundThe investigational oral DNA vaccine VXM01 targets the vascular endothelial growth factor receptor 2 (VEGFR-2) and uses Salmonella typhi Ty21a as a vector. The immune reaction elicited by VXM01 is expected to disrupt the tumor neovasculature and, consequently, inhibit tumor growth. VXM01 potentially combines the advantages of anti-angiogenic therapy and active immunotherapy.Methods/DesignThis phase I trial examines the safety, tolerability, and immunological and clinical responses to VXM01. The randomized, placebo-controlled, double blind dose-escalation study includes up to 45 patients with locally advanced and stage IV pancreatic cancer. The patients will receive four doses of VXM01 or placebo in addition to gemcitabine as standard of care. Doses from 106 cfu up to 1010 cfu of VXM01 will be evaluated in the study. An independent data safety monitoring board (DSMB) will be involved in the dose-escalation decisions. In addition to safety as primary endpoint, the VXM01-specific immune reaction, as well as clinical response parameters will be evaluated.DiscussionThe results of this study shall provide the first data regarding the safety and immunogenicity of the oral anti-VEGFR-2 vaccine VXM01 in cancer patients. They will also define the recommended dose for phase II and provide the basis for further clinical evaluation, which may also include additional cancer indications.Trial registrationEudraCT No.: 2011-000222-29, NCT01486329, ISRCTN68809279

Influence of two different resection techniques (conventional liver resection versus anterior approach) of liver metastases from colorectal cancer on hematogenous tumor cell dissemination - prospective randomized multicenter trial.

BackgroundSurgical hepatic resection remains the treatment of choice for patients with liver metastases from colorectal cancer despite the use of alternative therapeutic strategies. Although this procedure provides long-term survival in a significant number of patients, 50–75% of the patients develop intra- and/or extrahepatic recurrence. One possible reason for tumor recurrence may be intraoperative hematogenous tumor cell dissemination due to mechanical manipulation of the tumor during hepatic resection. Surgical technique may have an influence on hematogenous tumor cell spread. We hypothesize that hematogenous tumor cell dissemination may be reduced by using the anterior approach technique compared to conventional liver resection.Methods/DesignThis is a multi-centre prospective randomized controlled, superiority trial to compare two liver resection techniques of liver metastases from colorectal cancer. 150 patients will be included and randomized intraoperatively after surgical exploration just prior to resection. The primary objective is to compare the anterior approach with the conventional liver resection technique with regard to intraoperative haematogenous tumor cell dissemination. As secondary objectives we examine five year survival rates (OS and DFS), blood loss, duration of operation, requirement of blood transfusions, morbidity rate, prognostic relevance of tumor cell detection in blood and bone marrow and the comparison of tumor cell detection by different detection methods.ConclusionThis trial will answer the question whether there is an advantage for the anterior approach technique compared to the conventional resection group with regard to tumor cell dissemination. It will also add further information about prognostic differences, safety, advantages and disadvantages of each technique.Trial registrationCurrent controlled trials – ISRCTN45066244

Anti-angiogenic activity of VXM01, an oral T-cell vaccine against VEGF receptor 2, in patients with advanced pancreatic cancer: A randomized, placebo-controlled, phase 1 trial.

VEGFR-2 is expressed on tumor vasculature and a target for anti-angiogenic intervention. VXM01 is a first in kind orally applied tumor vaccine based on live, attenuated Salmonella bacteria carrying an expression plasmid, encoding VEGFR-2. We here studied the safety, tolerability, T effector (Teff), T regulatory (Treg) and humoral responses to VEGFR2 and anti-angiogenic effects in advanced pancreatic cancer patients in a randomized, dose escalation phase I clinical trial. Results of the first 3 mo observation period are reported. Locally advanced or metastatic, pancreatic cancer patients were enrolled. In five escalating dose groups, 30 patients received VXM01 and 15 placebo on days 1, 3, 5, and 7. Treatment was well tolerated at all dose levels. No dose-limiting toxicities were observed. Salmonella excretion and salmonella-specific humoral immune responses occurred in the two highest dose groups. VEGFR2 specific Teff, but not Treg responses were overall increased in vaccinated patients. We furthermore observed a significant reduction of tumor perfusion after 38 d in vaccinated patients together with increased levels of serum biomarkers indicative of anti-angiogenic activity, VEGF-A, and collagen IV. Vaccine specific Teff responses significantly correlated with reductions of tumor perfusion and high levels of preexisting VEGFR2-specific Teff while those showing no antiangiogenic activity had low levels of preexisting VEGFR2 specific Teff, showed a transient early increase of VEGFR2-specific Treg and reduced levels of VEGFR2-specific Teff at later time points – pointing to the possibility that early anti-angiogenic activity might be based at least in part on specific reactivation of preexisting memory T cells.

Detection of Disseminated Tumor Cells in Liver Biopsies of Colorectal Cancer Patients Is not Associated with a Worse Prognosis

BackgroundLiver metastases occur frequently in colorectal cancer and are probably caused by disseminated tumor cells having been trapped in the liver. The prognostic significance of hematogenous tumor cell dissemination has already been demonstrated for blood and bone marrow of patients with colorectal cancer. The aim of this study was to investigate the frequency and prognostic significance of disseminated tumor cells in liver biopsies of colorectal cancer patients.MethodsLiver biopsies from 100 patients with UICC stage I–III colorectal cancer were taken prospectively during resection of the primary tumor. Liver biopsies obtained from 16 patients with benign gastrointestinal diseases served as negative controls. Liver samples from seven patients with liver cirrhosis were additionally taken. Liver biopsies were examined using a reverse transcriptase (RT)-PCR assay to amplify cytokeratin (CK) 20 transcripts. The median follow-up of the patients was 55 months.ResultsDisseminated tumor cells were detected in liver samples of 10/100 (10%) patients with UICC stage I–III colorectal cancer. Liver specimens from all seven patients with liver cirrhosis were CK 20-positive, whereas 16 patients with other benign gastrointestinal diseases were all CK 20-negative. There was no correlation between tumor cell detection in liver biopsies and survival of the patients. The only significant prognostic factor on uni- and multivariate analysis was the UICC stage.ConclusionsThis study demonstrates that detection of disseminated tumor cells in liver samples from patients with UICC stage I–III colorectal cancer has no prognostic influence. UICC classification was the strongest prognostic factor in this patient series.

Detection and prognostic relevance of cytokeratin 20 in differentiated and anaplastic thyroid carcinomas by RT-PCR

BACKGROUND Metastatic disease in epithelial cancer results from tumor cell dissemination. We investigated an expression of cytokeratin 20 (CK20) by reverse transcriptase-polymerase chain reaction (RT-PCR) in differentiated (DTC) and anaplastic thyroid carcinomas (ATC) and correlated the results with TNM categories and the clinical follow-up. METHODS Tissue and blood samples of 32 patients with papillary (PTC), 17 patients with follicular (FTC), and 7 patients with ATC were obtained during operation and subjected to CK20 RT-PCR. RESULTS An expression of CK20 transcripts was detected in 47% of the tissue samples of PTC, 71% of the FTC, and 14% of the ATC. Patients with CK20-positive FTC had a significantly better outcome than patients with CK20-negative FTCs (P=.0016). Disseminated tumor cells were found in 9 of 22 (41%) blood samples of patients with CK20-positive carcinomas. The detection of CK20 transcripts in peripheral blood correlated with tumor categories. Four of 8 (50%) patients with DTC and circulating tumor cells developed local or distant recurrence compared with 3 of 13 (23%) patients with CK20-positive carcinomas and CK20-negative blood samples. CONCLUSION Our results suggest that CK20 might be a suitable differentiation marker in thyroid carcinomas. In patients with CK20-positive tumors, those with CK20-positive blood samples had a poorer prognosis. We suggest that patients with thyroid cancer with positive CK20 blood samples should be evaluated for further adjuvant therapies after surgery.

Tumorspezifische zytotoxische T-Zellen im Knochenmark: therapeutisches Potential bei Pankreaskarzinompatienten?

Memory T-cells specifically reactive to tumor antigens should be an ideal source to generate therapeutic effector cells against pancreatic cancer.