Frozen section diagnosis in donor liver biopsies: observer variation of semiquantitative and quantitative steatosis assessment.

Donor livers are not generally accepted for liver transplantation if intraoperative frozen section histology on wedge biopsies provides evidence for more severe steatosis. In this reliability study, assessment of steatosis in donor liver biopsies by different approaches (frozen sections vs. paraffin sections; macrovesicular steatosis vs. microvesicular steatosis), different observers, and different evaluation methods (conventional microscopy vs. point grid analysis on digital microphotographs) was compared. One hundred twenty consecutive donor liver biopsies were investigated. Intraoperative diagnosis was made on hematoxylin and eosin (H&E)-stained frozen sections. The residual portion of each biopsy was analyzed later on H&E-, diastase-resistant PAS-, and Elastica van Gieson-stained paraffin sections. Microvesicular steatosis and macrovesicular steatosis were classified semiquantitatively into 5 % steps. Additionally, point grid counting was applied on ten digital microphotographs per slide. The values for steatosis revealed a wide range of data between 0 and 70 or 85 % (mean values, 12.0-18.3 %), considering all types of specimens. The results of the two observers were highly correlated for macrovesicular steatosis (r ≥ 0.925) and for microvesicular steatosis (r ≥ 0.880). The values for macrovesicular and microvesicular steatosis, however, showed poor correlation (r ≤ 0.581). The rate of agreement between the two observers ranged between 84.2 and 95.8 % (κ, 0.763-0.937), depending on the threshold setting. For point grid analysis, significantly lower mean values and ranges for both types of steatosis compared to conventional histopathology were found (p < 0.001). Comparing the results of point grid analysis with those of conventional histopathology, a relatively loose correlation was found (r, 0.581-0.779). Intraoperative histology remains a reliable and highly relevant method for the assessment of steatosis in liver donor grafts. It represents one important component in the decision-finding whether or not a donor liver should be accepted and should possibly be combined with results of preoperative computed tomography imaging. Considering our data, macrovesicular and microvesicular steatosis should be analyzed separately due to the limited correlation between them.

CT-guided percutaneous core needle biopsy in oncology outpatients: sensitivity, specificity, complications.

BACKGROUND: Inpatient CT-guided core needle biopsies are an integral diagnostic method to obtain a histology from lesions of unknown dignity in oncology. The purpose of this study was to evaluate feasibility, sensitivity, specificity, and complication rate of diagnostic CT-guided percutaneous core needle biopsies in oncology outpatients. PATIENTS AND METHODS: We retrospectively analyzed data of all oncology outpatients who received CT-guided core needle biopsies between August 2001 and March 2005. RESULTS: 432 outpatients received 465 CT-guided core needle biopsies using a 14-, 16-, or 18-gauge coaxial cutting needle. 174 patients (37%) were biopsied for intra-abdominal lesions, 130 (28%) for intrathoracic lesions, 55 (12%) for bone lesions, 40 (9%) for peripheral tumors, 36 (8%) for peripheral lymph nodes, and 30 (7%) for central lymph nodes. 249 (53%) biopsies were performed in local anesthesia, 216 (47%) in general anesthesia. Sensitivity was 94%, specificity 92%, and effective accuracy 92%. Complications occurred after 23 biopsies (4.9%). A pneumothorax occurred after 17 thorax biopsies (13%). 7 patients (1.5%) had to be hospitalized after the biopsy. No patient died due to the procedure. CONCLUSION: CT-guided core needle biopsies are feasible and safe in oncology outpatients. The technique shows a high diagnostic sensitivity and specificity with a low complication rate in routine care.

Primary human coculture model of alveolo-capillary unit to study mechanisms of injury to peripheral lung.

In order to delineate individual pathomechanisms in acute lung injury and pulmonary toxicology, we developed a primary coculture system to simulate the human alveolo-capillary barrier. Human pulmonary microvascular endothelial cells (HPMEC) were cocultivated with primary isolated human type II alveolar epithelial cells (HATII) on opposite sides of a permeable filter support, thereby constituting a bilayer. Within 7-11 days of coculture, the HATII cells partly transdifferentiated to type-I-like (HATI-like) cells, as demonstrated by morphological changes from a cuboidal to a flattened morphology, the loss of HATII-cell-specific organelles and the increase of HATI-cell-related markers (caveolin-1, aquaporin-5, receptor for advanced glycation end-products). Immunofluorescent analysis detected type-II-like and type-I-like alveolar epithelial cells mimicking the heterocellular composition of alveolar epithelium in vivo. The heterocellular epithelial monolayer showed a circumferential staining of tight-junctional (ZO-1, occludin) and adherens-junctional (E-cadherin, beta-catenin) proteins. HPMEC on the opposite side also developed tight and adherens junctions (VE-cadherin, beta-catenin). Under integral barrier properties, exposure to the proinflammatory cytokine tumour necrosis factor-alpha from either the endothelial (basolateral) or the epithelial (apical) side caused a largely compartmentalized release of the chemokines interleukin-8 and monocyte chemoattractant protein-1. Thus, the established coculture provides a suitable in vitro model to examine barrier function at the distal lung, including the interaction of microvascular endothelial cells with ATII-like and ATI-like epithelial cells. The compartmentalization of the barrier-forming bilayer also allows mechanisms of lung injury to be studied in both the epithelial (intra-alveolar) and the endothelial (intravascular) compartments.

TA-MUC1 epitope in non-small cell lung cancer.

MUC1 (CD227), an established tumor marker, is expressed on glandular epithelia and on epithelial tumors. Tumor MUC1 differs from normal MUC1 by modified glycan side chains. Recently, a novel carbohydrate-induced conformational tumor-associated MUC1 epitope (TA-MUC1) was described, whose clinical relevance in lung cancer is not known. Eighty-five paraffin embedded tissue sections of non-small cell lung cancer (NSCLC) patients (73% male; mean age 64+/-9 years) were stained with the monoclonal antibody PankoMab (against TA-MUC1) and compared with the established antibodies E29 and 214D4 regarding prognostic relevance. TA-MUC1 is virtually absent in bronchial epithelium. As shown by multivariate analysis, only staining with PankoMab, but not with E29 or 214D4, was correlated with patients' survival (p=0.029). Moreover, when regarding interactions of MUC1 antibody staining results and clinico-pathological parameters, patients with lymph node metastasis lacking PankoMab staining were attributed the highest risk by far (Hazard ratio=4.6, 95% CI: 2.1-9.7, p=0.000). In summary, the presence of TA-MUC1 is a favorable prognostic factor in this cohort of NSCLC patients, in particular if lymph node metastases are present. This is in contrast to the results for E29 and 214D4, which recognize less or not glycosylation dependent epitopes. As this is the first report on a well-defined MUC1 epitope associated with improved survival in NSCLC, a more differentiated view on MUC1 may be mandatory.

C-kit and its ligand stem cell factor: potential contribution to prostate cancer bone metastasis.

The tyrosine kinase receptor c-kit and its ligand stem cell factor (SCF) have not been explored in prostate cancer (PC) bone metastasis. Herein, we found that three human PC cell lines and bone marrow stromal cells express a membrane-bound SCF isoform and release a soluble SCF. Bone marrow stromal cells revealed strong expression of c-kit, whereas PC cells showed very low levels of the receptor or did not express it all. Using an experimental model of PC bone metastasis, we found that intraosseous bone tumors formed by otherwise c-kit-negative PC3 cells strongly expressed c-kit, as demonstrated using immunohistochemical and Western blot analyses. Subcutaneous PC3 tumors were, however, c-kit-negative. Both bone and subcutaneous PC3 tumors were positive for SCF. Immunohistochemical analysis of human specimens revealed that the expression frequency of c-kit in epithelial cells was of 5% in benign prostatic hyperplasia, 14% in primary PC, and 40% in PC bone metastases, suggesting an overall trend of increased c-kit expression in clinical PC progression. Stem cell factor expression frequency was more than 80% in all the cases. Our data suggest that the bone microenvironment up-regulates c-kit expression on PC cells, favoring their intraosseous expansion.

Frequent chromosomal gains in recurrent juvenile nasopharyngeal angiofibroma.

Juvenile nasopharyngeal angiofibroma (JNA) is a rare benign tumor, mostly affecting adolescent males. Some patients develop recurrences after surgery independently of completeness of removal. Only very limited data concerning underlying chromosomal changes are available. We therefore analyzed samples of 22 JNAs, including six recurrences, with comparative genomic hybridization (CGH). Additionally, quantitative image cytometry was used for measurement of DNA aneuploidy in representative samples. Of the 13 primary JNAs without later recurrence, DNA gains were identified on autosomes in only two samples. Four patients with one or two recurrences were included in the study; for one of these, no material of the primary tumor was available for analysis. Looking at autosomes, two of the three available primaries displayed multiple gains; in one of those, two additional losses were observed. Multiple gains were detected in two of the four first recurrences, but none in the two second recurrences. Across all 22 samples, gains occurred in more than one sample on chromosomes arms 1p, 9q, 10q, 12q, 16p, 16q, 17q, 19p, 19q, 20q, and 22q. Losses were found in a single case exclusively on chromosome 4. Sex chromosomes were frequently affected in both primary tumors and recurrences. There was no correlation among tumor staging, age, and DNA amplification. No DNA aneuploidy was detected, a finding in accordance with the generally benign characteristics of JNAs. Our observations suggest that in JNA the activation of oncogenes is more likely than the inactivation of tumor suppressor genes. Autosomal gains in the primary tumor should be further evaluated as markers for a potentially increased risk of recurrence after surgical removal in this entity.

Dysfunction of the non-neuronal cholinergic system in the airways and blood cells of patients with cystic fibrosis.

The non-neuronal cholinergic system is widely expressed in human airways, skin and immune cells. Choline acetyltransferase (ChAT), acetylcholine and nicotine/muscarine receptors are demonstrated in epithelial surface cells, submucosal glands, airway smooth muscle fibres and immune cells. Moreover, acetylcholine is involved in the regulation of cell functions like proliferation, differentiation, migration, organization of the cytoskeleton, cell-cell contact, secretion and transport of ions and water. Cystic fibrosis (CF), the most frequent genetic disorder, is known to be caused by a mutation of the CF-gene coding for the cystic fibrosis transmembrane regulator protein (CFTR). CFTR represents a regulating transport protein for ion channels and processes involving endo- and exocytosis. Despite the identification of the genetic mutation knowledge of the underlying cellular pathways is limited. In the present experiments the cholinergic system was investigated in the peripheral blood and in the lung of CF patients undergoing lung transplantation (n=7). Acetylcholine content in bronchi and lung parenchyma of CF was reduced by 70% compared to controls (tumor-free tissue obtained from patients with lung tumor; n=13). In contrast, ChAT activity was elevated to some extent (p>0.05) in CF, and esterase activity did not differ from control. Acetylcholine content extracted from peripheral leucocytes (30 ml) was also reduced by 70% in CF (n=13) compared to healthy volunteers (n=9). Double labelling experiments with anti-CF antibodies and anti-ChAT antibodies showed a co-localization in peripheral lymphocytes, giving first evidence that CFTR may be linked with the intracellular storage/transport of non-neuronal acetylcholine. It is concluded that the non-neuronal cholinergic system is involved in the pathogenesis of CF. A reduced content of non-neuronal acetylcholine could contribute to the deleterious changes of epithelial ion and water movements in CF, because acetylcholine stimulates apical Cl(-) secretion, inhibits apical Na(+) and water absorption and therewith facilitates mucociliary clearance.

D2-40 labeling in lymphangiomyoma/lymphangiomyomatosis of the soft tissue: further evidence of lymphangiogenic tumor histogenesis.

We examined ten cases of extrapulmonary lymphangioleiomyoma/lymphangioleiomyomatosis (LAM; all patients female; median age 46.5 years) for immunohistochemical labeling with a monoclonal antibody against podoplanin (D2-40), which is specific for lymphatic endothelial lining. We found positive staining in thin-wall branching vessels reflecting the lymphatic nature of tumor vessels in all cases tested. In contrast, perivascular (HMB-45 positive) myoid cells were not detected by D2-40. The D2-40 labeling confirms the current concept of lymphangiogenic origin of the tumor vessels in LAM. In addition, this study makes a further contribution to the immunohistochemical mapping of this antibody in vascular tumors. Finally, the use of this commercially available antibody provides an additional help in the differential diagnosis of LAM from other soft tissue tumors.

The prognostic impact of blood group-related antigen Lewis Y and the ABH blood groups in resected non-small cell lung cancer.

The blood group antigen Lewis Y is expressed on epithelial tumors of the respiratory, digestive and reproductive system. Despite being regarded as an attractive target for immunotherapy, its function is still not well defined and its prognostic value remains a subject of discussion. Eighty-three paraffin-embedded tissue sections of non-small cell lung cancer (NSCLC) patients in stage I-IIIa, who underwent surgical resection of the primary tumor (73% male; 43% adenocarcinoma), were stained with a new, highly specific monoclonal antibody against Lewis Y (clone A70-C/C8). A positive Lewis Y expression was observed in 51% of patients; adenocarcinomas were favorably stained (67%). Multivariate analysis identified stage I, blood group A or AB and Lewis Y expression on tumor cells to be independent markers for improved survival after tumor resection (p = 0.024, 0.043, 0.003, respectively). In summary, unlike in several previous studies the presence of Lewis Y on tumor cells is a favorable prognostic factor in this cohort of resected NSCLC patients. Coexisting blood group antigen A may be of additional positive prognostic impact. We hypothesize that related blood group antigens both on tumor cells and in peripheral blood may have an underestimated function for progression in resected NSCLC.

Response to transarterial chemoembolization as a biological selection criterion for liver transplantation in hepatocellular carcinoma.

Criteria to select patients with hepatocellular carcinoma (HCC) for liver transplantation (LT) are based on tumor size and number of nodules rather than on tumor biology. The present study was undertaken to assess the role of transarterial chemoembolization (TACE) in selecting patients with tumors suitable for LT. Ninety-six consecutive patients with HCC were treated by repeatedly performed TACE, 62 of them exceeding the Milan criteria. Patients meeting the Milan criteria were immediately listed, and patients beyond the listing criteria were listed upon downstaging of the tumor following successful TACE. Fifty patients were finally transplanted. Of these 50 patients, 34 exceeded the Milan criteria. In these 96 patients, overall 5-year survival was 51.9%. However, it was 80.9% for patients undergoing LT and 0% for patients without transplantation (P < 0.0001). Tumor recurrence was primarily influenced by the control of the disease through continued TACE during the waiting time. Freedom from recurrence after 5 years was 94.5% in patients (n = 39) with progress-free TACE during the waiting time. Tumor recurrence was significantly higher in patients (n = 11) who after initial response to TACE progressed again before LT (freedom from recurrence 35.4%; P = 0.0017). Progress-free course of TACE during the waiting time (P = 0.006; risk ratio, 8.95), and a limited number of tumor nodules as assessed in the surgical specimen (P = 0.025; risk ratio, 0.116) proved to be significant predictors for freedom from recurrence in the multivariate analysis. Milan criteria were without impact on recurrence. Our data suggest that sustained response to TACE is a better selection criterion for LT than the initial assessment of tumor size or number.

Hilar cholangiocarcinoma: resectability and radicality after routine diagnostic imaging.

BACKGROUND/PURPOSE: En-bloc resection has contributed to the improvement of long-term survival in patients with hilar cholangiocarcinoma. In addition, attenuation of intraoperative traumatization of the tumor may decrease tumor spread. The objective of this study was to assess the importance of a routine diagnostic workup for the surgical strategy, radicality, and results in patients with hilar cholangiocarcinoma. METHODS: Between September 1997 and December 2002, 82 patients with hilar cholangiocarcinoma were treated at our department. Preoperative diagnostic workup included endoscopic retrograde cholangiography (ERC), percutaneous transhepatic cholangiography (PTC), computed tomography (CT), and magnetic resonance imaging (MRI). The results of preoperative and retrospective (blinded) assessment of diagnostic data concerning the tumor growth along the bile ducts were compared with the results of surgery. RESULTS: The resection rate was 75%, and the hospital mortality, 7%. The prospective assessment of the resection to be performed was correct in 81% of cases. In ERC, magnetic resonance cholangiography (MRC), and PTC, tumor assessment was precise in 29%, 36%, and 53%, of cases, respectively. Overestimation occurred more frequently than underestimation. The 3-year survival of patients with formally curative or palliative en-bloc resection was 61% and 15%, respectively. For the 9 patients with hilar resection, the 3-year survival was 25%. Survival of patients was comparable, regardless of whether their tumor had been correctly assessed or over- or underestimated. In the multivariate analysis, R0 resection was the only significant prognostic factor ( P = 0.011). CONCLUSIONS: Our routine diagnostic approach led to high resection and survival rates. Obviously a sophisticated diagnostic workup is not an absolute prerequisite for adequate surgery.

c-kit expression in adenocarcinomas of the lung.

The tyrosine-kinase receptor c-kit (CD117) and its ligand stem cell factor are considered to be co-expressed in various solid tumors, including adenocarcinomas of the lung. The frequency of c-kit expression and its association with clinical parameters has not yet been evaluated in a larger population of lung adenocarcinomas. Therefore, tumor tissue of 95 consecutive patients with adenocarcinoma of the lung was stained using a polyclonal c-kit antibody. c-kit expression was correlated with relevant clinical parameters obtained by chart review. Positive c-kit expression in tumor tissue was observed in 61 of 95 patients (64%). Univariate analysis showed a significant effect of T (p = 0.003), N (p = 0.001) and M stage (p < 0.001) as well as of performance status (p = 0.001), surgical resection (p < 0.001), and LDH serum levels (p = 0.016) on survival. In contrast, c-kit protein expression was non- significant (p = 0.913). However, multivariate Cox regression with the influential parameters revealed a significant effect of c-kit expression on survival. Forward stepwise selection showed a 1.77-fold increased risk to die (hazard ratio, HR; 95% confidence interval, CI: 1.00-3.14, p = 0.047) for patients with c-kit-positive tumors. Similar data for c-kit expression were obtained by backward stepwise selection (HR: 1.78; 95% CI: 1.00-3.16; p = 0.044). In conclusion, the receptor tyrosine kinase c-kit is frequently expressed in adenocarcinomas of the lung and has a relevant effect on patient survival. The results of this study support clinical trials targeting the c-kit receptor with specific c-kit inhibitors (e.g. imatinib).

Effects of sex hormones, forskolin, and nicotine on choline acetyltransferase activity in human isolated placenta.

The activity of choline acetyltransferase (ChAT) was investigated in the human placenta before and after long-term incubation (24 h) to test the effects of sex hormones, nicotine and forskolin. ChAT activity differed considerably between the amnion (0.03 micromol/mg protein/h) and the villus (0.56). After long-term incubation, ChAT activity persisted in the latter but declined in the amnion. Neither sex hormones (beta-estradiol, testosterone, progesterone; 10 or 100 nM each) nor follicle stimulating hormone and luteinizing hormone (FSH/LH; 8.4 U/ml each) modified ChAT activity. Also nicotine (1 nM-100 microM) did not affect ChAT activity. Forskolin, an activitor of adenylyl cyclase, reduced ChAT activity in the villus but not in amnion. The present model offers the possibility to investigate ChAT regulation in intact tissue under long-term incubation. The risks of maternal smoking during pregnancy cannot be attributed to an effect of nicotine on placental ChAT activity. Differences in the regulation of ChAT appear to exist between neuronal and nonneuronal cells.

Proliferative effect of acetylcholine on rat trachea epithelial cells is mediated by nicotinic receptors and muscarinic receptors of the M1-subtype.

Acetylcholine (ACh), synthesized in mammalian non-neuronal cells such as epithelial cells of the airways, digestive tract and skin, is involved in the regulation of basic cell functions (so-called non-neuronal cholinergic system). In the present experiments rat trachea epithelial cells have been cultured to study the proliferative effect of applied ACh by [3H]thymidine incorporation. ACh (exposure time 24 h) caused a concentration-dependent increase in cell proliferation with a doubling of the [3H]thymidine incorporation at a concentration of 0.1 microM. This effect was partly reduced by 30 microM tubocurarine and completely abolished by the additional application of 1 microM atropine. The stimulatory effect of acetylcholine, remaining in the presence of tubocurarine, was prevented by 1 microM pirenzepine (preferentially acting at M1-receptors), but neither by 1 microM AFDX 116 (preferentially acting at M2-receptors) nor by 1 microM hexahydrosiladifenidol (preferentially acting at M3-receptors). The combination of tubocurarine and pirenzepine halved the basal [3H]thymidine incorporation. In conclusion, ACh produces a proliferative effect in rat trachea epithelial cells, the effect being mediated by both nicotinic receptors and muscarinic receptors of the M1-subtype.

Expression and function of the non-neuronal cholinergic system in endothelial cells.

Increasing evidence has shown the expression of the non-neuronal cholinergic system in endothelial cells. In the present experiments the expression of choline acetyltransferase (ChAT) was investigated in human endothelial cells by anti-ChAT immunohistochemistry and anti-ChAT immunofluorescence. Positive ChAT immunoreactivity was found in cultures of human umbilical endothelial cells (HUVEC) and a human angiosarcoma cell line (HAEND). In HUVEC and HAEND choline acetyltransferase activity and small amounts of acetylcholine were also detected. Positive ChAT-immunoreactivity was demonstrated in situ in endothelial cells of the human umbilical cord. In addition, in experiments with confocal laser scanning microscopy positive anti-ChAT immunoreactivity was found in situ in endothelial cells of human skin blood vessels. In the first functional experiments with HUVEC acetylcholine appeared to mediate a small facilitatory effect on the expression of intracellular adhesion molecule-1. The present experiments demonstrate the wide existence of ChAT in human endothelial cells. Further experiments are addressed to elucidate the biological role of acetylcholine in the endothelium and possible differences between the different subtypes of endothelial cells.

Increased acetylcholine levels in skin biopsies of patients with atopic dermatitis.

Recent experimental evidence indicates that non-neuronal acetylcholine is involved in the regulation of basic cell functions. Here we investigated the cholinergic system in the skin of healthy volunteers and patients with atopic dermatitis (AD). The synthesizing enzyme, choline-acetyltransferase (ChAT), was studied by anti-ChAT immunohistochemistry and enzyme assay. Skin biopsies taken from healthy volunteers and from AD patients were separated into the 2 mm superfical (epidermis and upper dermis) and 3 mm underlying portion (deeper dermis and subcutis). ChAT enzyme activity was detected in homogenized skin and subcutaneous fat (about 13 nmol/mg protein/h). ChAT immunoreactivity was expressed in keratinocytes, hair papilla, sebaceous and eccrine sweat glands, endothelial cells and mast cells. In healthy volunteers the superficial and underlying portion of skin biopsies contained 130 +/- 30 and 550 +/- 170 pmol/g acetylcholine (n = 12), respectively. In AD patients (n = 7) acetylcholine was increased 14-fold in the superficial and 3-fold in the underlying biopsy portion. The present study demonstrates the widespread expression of ChAT protein in the vast majority of human skin cells. Tissue levels of acetylcholine are greatly (14-fold) enhanced in the superficial 2 mm skin of AD patients.

Characterization of c-kit expression in small cell lung cancer: prognostic and therapeutic implications.

PURPOSE: The tyrosine-kinase receptor c-kit and its ligand stem cell factor are coexpressed in many small cell lung cancer (SCLC) cell lines, leading to the hypothesis that this coexpression constitutes an autocrine growth loop. To further evaluate the frequency and pathogenic relevance of c-kit expression, tumor tissue together with the corresponding clinical data of SCLC patients was analyzed. EXPERIMENTAL DESIGN: Tumor tissue of 102 consecutive SCLC cancer patients was analyzed immunohistochemically using an affinity-purified polyclonal c-kit antibody. Immunostaining data were correlated with survival and other relevant clinical parameters. RESULTS: A positive c-kit expression was observed in 37% of patients. c-kit expression was associated with decreased survival in the likelihood-ratio-forward selection model of the Cox regression including clinically relevant risk factors (c-kit expression, age, gender, stage, tumor stage, node stage, metastasis stage, weight loss, performance status, response to chemotherapy, lactate dehydrogenase, neuronspecific enolase, hemoglobin). Only c-kit expression [hazard ratio, 2.00; confidence interval (CI), 1.17-3.41; P = 0.012], response to chemotherapy (hazard ratio, 4.49; CI, 2.36-8.55; P < 0.001), and tumor stage (hazard ratio, 2.11; CI, 1.18-3.74; P = 0.008) were explanatory prognostic factors. These factors and all possible interactions between them were further analyzed in a second Cox regression model. As expected, response to chemotherapy had the highest impact on survival (hazard ratio, 3.06; CI, 1.69-5.54; P < 0.001). In patients with extensive disease, minor response to chemotherapy, and positive c-kit expression, the risk to die increased to 8.4 (hazard ratio, 2.74; CI, 1.52-4.91; P = 0.002). In a Kaplan-Meier analysis median survival of patients with minor response to chemotherapy and extensive stage was 288 days (CI, 255-321 days) when c-kit expression was negative compared with only 71 days (CI, 0-237 days) for c-kit-positive patients (log rank test: P = 0.003). CONCLUSIONS: c-kit represents a new prognostic factor in SCLC. c-kit expression is of particular clinical relevance in patients with advanced disease and poor response to chemotherapy. Given the very limited therapeutic options and unfavorable prognosis of these patients, clinical studies aimed at targeting c-kit (e.g., STI571) are clearly warranted.

Establishment and characterization of an angiosarcoma-derived cell line, AS-M.

A novel human endothelial cell line, AS-M, has been established from a cutaneous angiosarcoma on the scalp. The cells expressing platelet endothelial cell adhesion molecule-1 (CD31) were isolated using magnetic beads and subsequently cultured for a year. To date, the cells have undergone more than 100 population doublings (PDs). The AS-M cells manifested endothelial characteristics, such as active uptake of acetylated low-density lipoprotein labeled with 1,1'-dioctadecyl 3,3,3',3'-tetramethylindocarbocyanine perchlorate (Dil-Ac-LDL), capacity to bind the Ulex europeaus agglutin-I (UEA-I), and expression of von Willebrand factor (vWF) and CD31. The single cell-derived clone, AS-M.5, showed a constitutive expression of CD31, vWF, angiotensin-converting enzyme (ACE), endoglin (CD105), and the endothelial cell receptor tyrosine kinases KDR and Tie-1. Similarly to freshly isolated endothelial cells, the AS-M.5 responded to induction by bacterial lipopolysaccharide (LPS) by increased transcription of cell adhesion molecules and cytokines. The AS-M.5 cultures required endothelial growth supplements for optimal growth and long-term propagation in vitro. However, in contrast to normal endothelial cells, p53 gene products were detected in nuclei of AS-M.5 cells. Cytogenetic analyses consistently revealed a hypodiploid karyotype with complete loss of one homologue of several chromosomes and a homogeneous pattern of distinct karyotypic changes. Although the AS-M.5 presented characteristics suggestive of tumor cells, they did not develop into tumors when inoculated subcutaneously into nude mice. The cell line AS-M.5 could be a useful model system to study endothelial pathobiology in vitro.

Staging small cell lung cancer: Veterans Administration Lung Study Group versus International Association for the Study of Lung Cancer--what limits limited disease?

Small cell lung cancer (SCLC) is usually classified into a two-stage system, limited (LD) and extensive disease (ED). However, the criteria for these two categories remain controversial. The widely used Veterans Administration Lung Study Group (VALG) definition of LD includes patients with primary tumor and nodal involvement limited to one hemithorax. In contrast, the International Association for the Study of Lung Cancer (IASLC) recommends that LD should additionally include all patients without distant metastasis. As a consequence, since treatment modalities for LD and ED could be different, individual clinical outcome of SCLC patients may be influenced by the staging system chosen. Among 109 consecutive SCLC patients treated in our clinic between 1989 and 1999 (mean age 68+/-9.1 years, 81% male) 23 patients (21%) could be either classified as LD or ED (LD-ED), depending on the staging system used. The prognosis of this overlapping group (LD-ED: median survival 291 days) was not statistically different from patients with limited disease defined by VALG criteria (LD-VALG: 385 days, log-rank test P = 0.42). On the other hand the survival difference between LD-ED patients and the ED-IASLC population was relevant (ED-IASLC: 208 days, P = 0.05), indicating that LD-ED patients should rather be included in the LD category. This is further supported by the results of a multivariate Cox regression analysis with all clinically relevant data. Only stage as defined by IASLC criteria was an independent prognostic factor in the likelihood-ratio-forward (hazard ratio = 1.94, CI = 1.26-2.99; P = 0.005) and backward model (hazard ratio = 1.76, CI: 1.12-2.76; P = 0.012), confirming the higher discriminatory power of the IASLC definition. In conclusion, the IASLC staging criteria for SCLC patients have a higher prognostic impact and are therefore preferable in clinical practice and future therapeutic trials.