To analyze the outcome of Wilms' tumor patients with primary lung metastases. Radiotherapy and/or surgery are used for local control of primary pulmonary Wilms' tumor metastases. A widely accepted treatment standardization is still lacking. Data for 210 patients with Wilms' tumor and primary lung metastases from the collaborative multicenter trials SIOP 93-01/GPOH and SIOP 2001/GPOH of the German Society of Pediatric Oncology and Hematology were reviewed. Analyses included patient data, tumor characteristics, local treatment, outcome and possible prognostic factors. Five-year overall survival (OS) was 83.3% and 5-year event free survival (EFS) was 72.3% for all children. Survival was significantly poorer in children with high risk primary tumor histology (OS 44.4%) compared to low risk (OS 100.0%) and intermediate risk histology (OS 89.2%, P < 0.001). Within the high risk group, tumors of the blastemal subtype (OS 56.5%) were associated with a significantly better outcome than those presenting with diffuse anaplasia (OS 22.2%, P = 0.02). Further, prognostic markers were lacking response to chemotherapy (P = 0.011), persistence of metastases after local treatment (P = 0.007), and vitality of metastases (P = 0.01). The prognosis of children with primary Wilms' tumor lung metastases mainly depends on the biology of primary tumors and metastases and is excellent with adequate treatment. Pulmonary metastasectomy is indicated if complete remission can be achieved to avoid lung irradiation. In the future a standardized local approach to nonresponding lung metastases (metastasectomy, irradiation, or both) will have to be prospectively evaluated regarding outcome, acute toxicity, and late effects.

Expression profiling of tumor tissue allows a systematic search for targeted therapies and offers relevant prognostic information. Molecular studies on rhabdomyosarcoma (RMS) revealed a more differentiated classification than the histological subgrouping into embryonal (RME) and alveolar (RMA) rhabdomyosarcoma, and reflected the chromosomal aberrations found in RMS. We addressed biological processes like cell migration and emerging drug resistance by expression profiling to identify mechanisms of metastasic invasion and differential response to chemotherapy in RMS. Gene expression analysis was performed in 19 RMS samples using the Affymetrix U133 Plus2 array. Validation of target genes was performed by qRT-PCR. Data were analyzed using Pathway analysis software. Involvement of these genes in invasion processes was evaluated in knock-down experiments using specific interference RNA and Matrigel(TM) invasion assay. In RMA tissues 211 of 534 genes were overexpressed, in RME tissues 323 genes were overexpressed. Pathway analysis software identified a group of genes involved in cell growth, morphology and motility. In patients with distant metastases especially transcription factors such as FOXF1 and LMO4 showed a high expression, which were described as determinants of tumor cell migration. Down-regulation of these factors inhibited the invasion of RMS cells >10-fold. Microarray technology is a powerful method not only to classify RMS samples, but also to identify major regulatory processes. Functional evaluation of LMO4 and FOXF1 identified targets of a molecular network for preventing metastatic invasion in RMS.

During recent years minimally invasive surgery (MIS) has become the standard approach for various operations in infants and children. This also holds true for surgery in children with solid tumors. Meanwhile, more and more oncological biopsies and resections are being performed laparoscopically or thoracoscopically. Despite its increasing role in pediatric tumor surgery, the different national and international multicenter trial groups have not yet implemented MIS within guidelines and recommendations in most of the current treatment protocols. An increasing number of reports describe a potential role of MIS in the different entities of pediatric surgical oncology. Over the time, there has been a diverse development of this approach with regard to the different neoplasms. The aim of this article is to give an overview and to describe the current state of the art of MIS in pediatric solid tumors.