Uta Reichelt

Direct Genetic Analysis of Single Disseminated Cancer Cells for Prediction of Outcome and Therapy Selection in Esophageal Cancer

The increasing use of primary tumors as surrogate markers for prognosis and therapeutic decisions neglects evolutionary aspects of cancer progression. To address this problem, we studied the precursor cells of metastases directly for the identification of prognostic and therapeutic markers and prospectively analyzed single disseminated cancer cells from lymph nodes and bone marrow of 107 consecutive esophageal cancer patients. Whole-genome screening revealed that primary tumors and lymphatically and hematogenously disseminated cancer cells diverged for most genetic aberrations. However, we identified chromosome 17q12-21, the region comprising HER2, as the most frequent gain in disseminated tumor cells that were isolated from both ectopic sites. Survival analysis demonstrated that HER2 gain in a single disseminated tumor cell but not in primary tumors conferred high risk for early death.

Frequent homogeneous HER-2 amplification in primary and metastatic adenocarcinoma of the esophagus

HER-2 is the target for antibody based treatment of breast cancer (Herceptin®). In order to evaluate the potential role of such a treatment in esophageal cancers, HER-2 amplification and overexpression was investigated in primary and metastatic cancers of the esophagus. A tissue microarray was constructed from 255 primary esophageal cancers (110 adenocarcinomas and 145 squamous cell carcinomas), 89 nodal and 33 distant metastases. Slides were analyzed by immunohistochemistry (HercepTest™; DAKO) and fluorescence in situ hybridization (FISH; PathVysion™; Vysis-Abbott) for HER-2 amplification and overexpression. Amplification was seen in 16/110 (15%) adenocarcinomas and in 7/145 (5%) squamous cell carcinomas. There was a strong association between HER-2 amplification and overexpression, especially in adenocarcinomas (P<0.0001, log rank). There was a 100% concordance of the HER-2 results in primary tumor and corresponding metastases in 84 analyzed pairs. Amplification was typically high-level with more than 10–15 HER-2 copies per tumor cell. Amplification was unrelated to survival, grading, pT, pN, pM or UICC stage. We conclude that esophageal adenocarcinomas belong to those cancer types with relevant frequency high-level HER-2 gene amplification clinical trials or individual case studies investigating the response of metastatic HER-2-positive esophageal cancers to Herceptin® should be undertaken. The strong concordance of the HER-2 status in primary and metastatic cancers argues for a possible response of metastases from patients with HER-2-positive primary tumors to Herceptin®.

Aggressive surgery improves long-term survival in neuroendocrine pancreatic tumors: an institutional experience.

Objective:To evaluate surgical strategies for neuroendocrine pancreatic tumors (NEPT) in the light of the new WHO classification from 2004 and to draw conclusions for future surgical concepts. Background:The extent of surgical resection in primary and recurrent NEPT is unclear. Methods:Between 1987 and 2004, 62 patients with sporadic NEPT were treated at our institution and sections from biopsy and resection specimen were histopathologically reclassified. Clinical presentation, surgery, metastases, and pattern of recurrence were related to survival. Results:Fifteen well-differentiated tumors (WDT, 24%), 39 low-grade carcinomas (LGC, 63%), and 8 high-grade carcinomas (HGC, 13%) were identified. Median observation time was 30.5 months; 48 of 62 patients (78%) were surgically resected, and in 45 patients R0/R1 status was achieved. Overall 2- and 5-year survival in the latter group was 80% and 64%, respectively. Retrospective WHO classification revealed that organ-preserving segmental resections had been performed in 10 LGC and 1 HGC. These patients showed equal outcome as radically resected counterparts (n = 19). Liver and other organ metastases were present in 19 of 62 patients (31%), and resection was accomplished in 7 of 19 patients, which conferred better overall survival (P = 0.026, log-rank test); 21 of 45 R0/R1-resected patients (47%) suffered from recurrence, and reoperation was accomplished in 9 patients, which resulted in better overall survival (P = 0.066). Conclusion:Organ-preserving resections offer sufficient local control in LGC; therefore, radical resections do not seem to be justified. On the other hand, radical resection is indicated even in metastasized patients or in case of loco-regional recurrence. The silent and slow course of the disease facilitates long-term surgical control.

L1 is associated with micrometastatic spread and poor outcome in colorectal cancer

L1 is a cell adhesion molecule expressed at the invasive front of colorectal tumors with an important role in metastasis. The aim of the present study was to determine L1 protein expression in a large cohort of colorectal cancer patients and its impact on early metastatic spread and survival. A total of 375 patients that underwent surgical treatment for colorectal cancer were chosen retrospectively. A tissue microarray was constructed of 576 tissue samples from these patients and analyzed by immunohistochemistry with a monoclonal antibody against human L1 (UJ127). Lymph node and bone marrow micrometastasis were assessed with monoclonal antibodies Ber-EP4 and pancytokeratin A45-B/B3, respectively. Associations between L1 expression and lymph node, bone marrow micrometastasis and survival were investigated with Fishers, log-rank test and Cox multivariate analysis. All statistical tests were two-sided. L1 was detected in a subset of 48 (13%) of 375 patients examined. Analysis of L1 expression and survival revealed a significantly worse outcome for L1-positive patients by log-rank test (P<0.05). Multivariate Cox regression analysis showed the strongest independent prognostic impact of L1 expression (P<0.05). Fishers test revealed a significant association of L1 expression and presence of disseminated tumor cells in lymph nodes and bone marrow (P<0.05). L1 is a powerful prognostic marker for patients that undergo complete surgical resection. It may have a role in early metastatic spread, as L1 is associated with micrometastases to both the lymph nodes and bone marrow. Thus, L1 should be explored further as a target for adjuvant therapy for micrometastatic disease.

Interleukin-6 and C-reactive protein serum levels in sepsis-related fatalities during the early postmortem period

Postmortem interleukin-6 (IL-6) and C-reactive protein (CRP) serum levels were investigated prospectively in sepsis-related fatalities and non-septic fatalities by using a linear regression model. At least three blood samples were collected between 0.3 and 139 h postmortem from sepsis-related fatalities (n=8) and non-septic fatalities (n=16). In addition, one antemortem blood sample was collected shortly before death from the septic patients. Antemortem and postmortem IL-6 and CRP levels were highly elevated in all individuals included in the sepsis group. An excessive postmortem increase of IL-6 serum levels associated with progressive time after death was observed in five out of the eight septic patients. Both, IL-6 and CRP serum concentrations seem to be suitable biochemical postmortem markers of sepsis. The determination of IL-6 serum levels above 1500 pg/ml in peripheral venous blood obtained in the early postmortem interval can be considered as a diagnostic hint towards an underlying septic condition. A more precise postmortem discrimination between sepsis and non-septic underlying causes of death is provided by the postmortem measurement of serum CRP in peripheral venous blood: on condition that at least two postmortem CRP values have been determined at different time points postmortem, the CRP level of a deceased at the time of death can be calculated by using linear regression analysis. When assessing postmortem IL-6 and CRP concentrations as biochemical postmortem markers of sepsis, various clinical conditions, such as a preceding trauma or burn injury going along with elevated IL-6 and/or CRP levels prior to death as a result of the systemic inflammatory response syndrome (SIRS) should be taken into consideration, thus adding relevant information for the practical interpretation of the results.

Expression of the Stem Cell Markers Nestin and CD133 on Circulating Melanoma Cells

Different molecular markers have been identified for melanoma-initiating cells including CD133 and nestin. Assuming that metastasis requires a dissemination of tumor-initiating cells, presence of circulating tumor-initiating cells should be associated with worse patient outcome. In this study, 20 ml blood was collected from 32 consecutive patients affected by metastatic melanoma and blood was enriched for circulating melanoma cells (CMCs) by CD45 depletion of the non-melanoma cell fraction. Multiparameter cytometry was carried out to co-stain with combinations of CD133 and nestin (NES). Six tissue samples from metastatic lesions of six different patients were stained with the same antibodies by immunohistochemistry. Percentage of NES-positive CMCs correlated with tumor burden and number of metastatic sites. Cox regression analysis revealed levels of lactate dehydrogenase (LDH; hazard ratio: 12.8 (1.35-121.5); P=0.02), number of metastatic sites (hazard ratio 3.87 (1.66-9.03); P=0.02), tumor burden (hazard ratio 5.72 (1.57-20.9); P=0.01), and percentage of NES-expressing CMCs ≥ 35% (hazard ratio 5.73 (1.66-19.7); P=0.006) to be factors related to shorter overall survival. CD133- and NES-expression profiles on CMCs were similar to matched metastatic tissue. These findings show that CMCs expressed stem cell-associated markers NES and CD133. Higher expression of NES on CMCs might represent an index of poor prognosis.

Serum procalcitonin (PCT): a valuable biochemical parameter for the post-mortem diagnosis of sepsis

Abstract The aim of this prospective study was to investigate whether serum procalcitonin (PCT) can be used as a post-mortem marker of sepsis and to determine whether this biochemical parameter can be employed in the forensic elucidation of death due to sepsis. At least three blood samples were collected between 0.3 and 139 h post-mortem from sepsis-related fatalities (n = 8) and control individuals (n = 53, where death was due to various natural and unnatural causes). Additionally one ante-mortem blood sample was collected shortly before death from the patients in the sepsis group. In the sepsis group, serum PCT concentrations, determined by using an immunoluminometric assay, were elevated in all patients for the whole observation period, whereas in the control group serum PCT was not detectable in 94% of the cases. Measurement of PCT levels seems reasonable until at least approximately 140 h postmortem, depending on the ante-mortem levels. A linear regression model is presented that allows the serum PCT concentration of an individual at the time of death to be estimated on condition that at least two positive post-mortem PCT values have been determined. Ante-mortem PCT values correlated well with the predicted PCT values at the time of death in the sepsis group using the standardized PCT logarithms. According to the results of the present study, PCT is a valuable biochemical parameter for the post-mortem discrimination between sepsis and underlying non-septic causes of death.

L1 (CD171) is highly expressed in gastrointestinal stromal tumors

The treatment strategy for mesenchymal tumors of the gastrointestinal tract is based upon typing of the tumor. Especially differential diagnosis of gastrointestinal stromal tumors (GISTs) to leiomyomas is crucial for determining radicality of surgery. L1 cell adhesion molecule (CD171) plays an essential role in tumor progression. The aim of this study was to determine expression of L1 in GISTs, smooth muscle tumors, desmoid-type fibromatosis and peripheral nerve sheath tumors (PNSTs). We retrospectively analyzed a total of 129 surgically resected primary tumors or metastases of 72 GISTs, 29 smooth muscle tumors, seven PNSTs and 21 desmoid-type fibromatosis by immunohistochemistry for c-kit, CD34, smooth muscle actin, desmin, vimentin, S-100 and L1 expression. L1 expression was detected in 53 (74%) of 72 GISTs but in none of 29 smooth muscle tumors or 21 desmoid-type fibromatosis (P<0.01 by Fishers test). In all, four (57%) of seven peripheral nerve sheath tumors were L1-positive. Survival analysis of 55 surgically completely resected GISTs presenting without metastasis at initial diagnosis revealed no tumor-specific death among L1-negative patients (P=0.13 by log-rank test; median follow-up time 41 months) and one recurrence was observed (P=0.12). Interestingly high levels of L1 were seen in tumor vascular endothelial cells of smooth muscle tumors and PNSTs, but not in GISTs. Our data show that L1 is highly expressed in GISTs but not in smooth muscle tumors and desmoid-type fibromatosis being important differential diagnoses. The trend towards a reduced survival of L1-positive patients in this study has to be further evaluated in future trials with higher patient numbers.

Determination of Microvessel Density by Quantitative Real-time PCR in Esophageal Cancer: Correlation with Histologic Methods, Angiogenic Growth Factor Expression, and Lymph Node Metastasis

Purpose: Angiogenesis and lymphangiogenesis are important steps in tumor growth and dissemination and are of prognostic importance in solid tumors. The determination of microvessel density (MVD) by immunohistology is subject to considerable variability between different laboratories and observers. We compared MVD determination by immunohistology and quantitative real-time PCR and correlated the results with clinical variables. Experimental Design: The expression of endothelial antigens vascular endothelial cadherin (CD144), P1H12 (CD146), tie-2, and VEGFR-2, and lymphatic endothelial markers VEGFR-3, Prox, and LYVE was assessed by quantitative PCR (qPCR) in primary surgical samples. The expression of angiogenetic growth factors VEGF-A, VEGF-C, VEGF-D, angiopoietin-1, and angiopoietin-2 was quantified by PCR and correlated with MVD and clinical variables. Results: The expression of endothelial antigens vascular endothelial cadherin (CD144), P1H12 (CD146), tie-2, and VEGFR-2 correlated with each other in 54 samples of primary esophageal cancer (P < 0.0001 for all comparisons). MVD determined immunohistologically by CD31 staining in a subgroup of 35 patients correlated significantly with the qPCR method. The expression of angiogenetic growth factors VEGF-A, VEGF-C, VEGF-D, angiopoietin-1, and angiopoietin-2 was significantly associated with MVD (P < 0.0001 for all comparisons). Analysis of the expression of lymphendothelial markers VEGFR-3, Prox, and LYVE revealed concordant results, indicating that quantification of lymphendothelial cells is possible by qPCR. The presence of lymph node metastasis on surgical specimens was significantly correlated with MVD (P < 0.003), VEGFR-2 (P < 0.048), and VEGF-C (P < 0.042) expression. Conclusions: These results indicate that quantification of MVD by qPCR in surgical samples of esophageal carcinoma yields similar results with immunohistology. Interestingly, the extent of angiogenesis and lymphangiogenesis was not related in individual tumor samples. Lymph node metastases could be predicted by MVD and VEGF-C expression.

Prognostic Implications of Netrin-1 Expression and Its Receptors in Patients with Adenocarcinoma of the Pancreas

BackgroundTo assess the interaction between the expression of netrin-1 or of its receptors to the prognosis of ductal adenocarcinoma of the pancreas.MethodsIn 82 patients with resectable pancreatic adenocarcinoma who underwent curative operation, the expression patterns of netrin-1, deleted in colorectal carcinomas (DCC), UNC5H3, and neogenin were determined by immunohistochemical staining. Kaplan-Meier analysis was performed to assess the prognostic relevance of the examined expression patterns.ResultsMedian follow-up was 15 ± 19.9 months (range, 4–108 months). Patients suffering from tumors with no or little expression of netrin-1 (n = 67) had a median recurrence-free survival of 10 months (95% CI, 7–13 months), while a middle to strong expression (n = 15) was associated with a significantly worse median recurrence-free survival of only four months (95% CI, three to five months, p = 0.0165). Overall and recurrence-free survival showed no significant differences between the different expression patterns of DCC, UNC5H3 or neogenin. Netrin-1 expression had significant impact (p = 0.001) on overall survival of patients suffering from poorly differentiated tumors. Stratification according to the nodal status revealed significant influence (p = 0.007) of UNC5H3 expression on the overall survival of patients with pN1 status.ConclusionExpression of netrin-1 has significant impact on time to tumor relapse in adenocarcinoma of the pancreas. Netrin-1 expression is associated with worse outcome in poorly differentiated pancreatic adenocarcinomas. Risk-stratification according to the UNC5H3 receptor expression pattern shows that node positive patients (pN1) with no to little UNC5H3 expression carry a significantly worse prognosis than those with middle to strong UNC5H3 expression.