Biomedical subjects

Andreas Faldum

Publications and source records attributed to Andreas Faldum.

22 records · Page 2Linked to original sources

PubMed2003

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.

Aged↗

PubMed2002

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.

Aged↗

PubMed2002

Melatonin secretion and increased daytime sleepiness in childhood craniopharyngioma patients.

Craniopharyngioma is a rare dysontogenetic benign tumor. Patients frequently suffer from endocrine deficiencies, sleep disturbances, and obesity due to pituitary and hypothalamic lesions. A self-assessment daytime sleepiness questionnaire (German version of the Epworth Sleepiness Scale) was used to evaluate 79 patients with childhood craniopharyngioma. Because hypothalamic lesions may explain daytime sleepiness in craniopharyngioma patients, salivary melatonin and cortisol concentrations were examined in obese and nonobese craniopharyngioma patients (n = 79), patients with hypothalamic pilocytic astrocytoma (n = 19), and control subjects (n = 30). Using a general linear model procedure analyzing the influence of body mass index (BMI) and tumor diagnosis on diurnal salivary melatonin, we found that morning salivary melatonin levels were related to BMI (by F test, P = 0.004) and tumor diagnosis (by F test, P = 0.032). Also for nighttime salivary melatonin levels significant relations with BMI (by F test, P < 0.001) and tumor diagnosis (by F test, P = 0.025) were detectable. Melatonin concentrations in saliva of craniopharyngioma patients collected at night or in the morning showed a negative correlation (night: Spearman's rho = -0.42; P = 0.001; morning: Spearman's rho = -0.31; P = 0.020) with the patient's Epworth Sleepiness Scale score. Severely obese craniopharyngioma patients and severely obese hypothalamic tumor patients had similar patterns of melatonin secretion. Differences in terms of diurnal salivary cortisol concentrations were not detectable when patient groups and controls were compared. We speculate that hypothalamic lesions might be responsible for both obesity and daytime sleepiness. As decreased nocturnal melatonin levels were associated with increased daytime sleepiness, BMI, and hypothalamic tumor diagnosis, further studies on the beneficial effects of melatonin substitution on daytime sleepiness and weight control in these patients are warranted.

Adolescent↗

PubMedDate not supplied

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).

Adenocarcinoma↗