A long duration of the prediagnostic symptomatic interval is not associated with an unfavourable prognosis in childhood medulloblastoma.

BACKGROUND: Due to the lacking specificity of symptoms making a correct diagnosis can be a challenge in children with medulloblastoma. This can lead to prediagnostic symptomatic intervals (PSIs) of several weeks to months. It is unknown whether the length of the PSI is associated with an inferior survival outcome in this population. METHODS: To study the association of PSI with disease stage at diagnosis, tumour control and survival in children with medulloblastoma, prospectively collected data on PSI, clinical, and biological features were analysed in 224 patients diagnosed at the age of 3-18 years and treated within the prospective randomised multicentre trial HIT'91. RESULTS: Patients with lower-stage disease tended towards a longer median PSI than those with higher-stage disease (M0 stage, 2.0 months; M1 stage, 2.0 months; M2/M3 stage, 1 month; p = 0.094. M0/1 stage versus M2/3 stage; p = 0.025). The patient group with the longest PSI had the best survival outcome (PSI ≥ 4.0 months: 10-year overall survival rate (OS), 71%; PSI < 4.0 months, 10-year OS, 61%; p = 0.056). Age at diagnosis was positively correlated with PSI (p = 0.027). No associations were found between PSI and sex histological subtype, presence of postoperative residual tumour, or c-myc and TrkC mRNA expression. CONCLUSION: Contrary to a common belief that a longer PSI may adversely affect prognosis, a longer PSI was associated with a trend towards lower metastatic stage and better survival probabilities. Nevertheless these findings do not obviate the importance of a timely diagnosis in paediatric patients with medulloblastoma.

Long-term outcome and clinical prognostic factors in children with medulloblastoma treated in the prospective randomised multicentre trial HIT'91.

PURPOSE: To analyse long-term outcome and clinical prognostic factors in medulloblastoma. METHODS: We analysed 280 patients with medulloblastoma (3-18 years) included from 1991 to 1997 in the randomised multicentre trial HIT'91 comparing pre-('sandwich') and postradiation ('maintenance') chemotherapy (median follow-up of survivors for 10 years). RESULTS: In 187 patients with complete staging, overall survival (OS) was higher after maintenance compared to sandwich treatment for M0 (10-year OS 91% and 62%, p=0.001) and M1 patients (10-year OS 70% and 34%, p=0.020). In M2/3 disease, 10-year OS was 42% and 45%. Incomplete staging, metastases, younger age and sandwich chemotherapy were independent adverse risk factors. Twelve percent of all relapses (13 of 107) occurred after more than five years, and 12 patients had secondary neoplasms. CONCLUSIONS: After maintenance therapy, long-term survival was excellent in fully assessable patients with localised medulloblastoma, and favourable for M1 patients. Patients should be followed longer for late relapses and secondary tumours.

Prognostic relevance of clinical and biological risk factors in childhood medulloblastoma: results of patients treated in the prospective multicenter trial HIT'91.

PURPOSE: To identify better risk stratification systems in childhood medulloblastoma based on clinical factors and analysis of routinely processed formalin-fixed tumor material. EXPERIMENTAL DESIGN: Formalin-fixed paraffin-embedded tumor samples from well-documented patients treated within the prospective randomized multicenter trial HIT'91 were analyzed for DNA amplification of c-myc and N-myc (n=133) and mRNA expression of c-myc and trkC (n=104; compared with human cerebellum) using validated methods of quantitative PCR and reverse transcription-PCR. Results were related to clinical data and outcome. RESULTS: TrkC and c-myc mRNA expression were identified as independent prognostic factors by multivariate analysis. Three risk groups were identified. (a) Favorable risk group: all 8 patients (2 metastatic) with high trkC (>1x human cerebellum) and low c-myc mRNA expression (

Childhood pineoblastoma: experiences from the prospective multicenter trials HIT-SKK87, HIT-SKK92 and HIT91.

OBJECTIVE: To analyze the outcome of children with pineoblastoma (PB), treated within the prospective multicenter trials HIT-SKK87, HIT-SKK92 and HIT91 of German-speaking countries. PATIENTS: We report on 11 children suffering from PB. Five children younger than 3 years of age received chemotherapy after surgery until eligible for radiotherapy (HIT-SKK87 and HIT-SKK92). Five of six children older than 3 years were treated after surgery with immediate chemotherapy and craniospinal irradiation, and one child received maintenance chemotherapy after postoperative radiotherapy (HIT91). RESULTS: Five of the six older children are still alive in continuous complete remission (CCR) with a median overall survival (OS) and progression free survival (PFS) of 7.9 years. Five of these six HIT91 patients responded to postoperative chemotherapy and radiotherapy. The only patient with tumor progression during initial chemotherapy achieved complete remission with radiotherapy and is alive. In contrast, all five young children died of tumor progression after a median OS of 0.9 years (PFS 0.6 years). They had either metastatic disease (M1) and/or postoperative residual tumor. Response to postoperative chemotherapy was lower than in the older age group, and only one of these children received radiotherapy. CONCLUSIONS: Combined chemotherapy and radiotherapy were feasible and effective in the older age group, leading to prolonged remissions in five of six children. Tumor biology may be more aggressive in younger children with PB, who presented more frequently with high-risk features at diagnosis and had poorer response rates to neoadjuvant postoperative chemotherapy. More intensified treatment regimens may be needed for young children with PB.

Insulin-like growth factor-binding protein 4 in children with acute lymphoblastic leukemia.

Insulin-like growth factor-binding protein 4 (IGFBP-4) is a potent inhibitor of IGF-mediated cell proliferation. To investigate the functional relevance of IGFBP-4 in leukemia, we measured plasma IGFBP-4 levels and messenger RNA expression in leukemic cell clones of patients with acute lymphoblastic leukemia (ALL) and in control subjects. The IGFBP-4 levels of ALL patients at diagnosis were significantly lower than the levels of healthy control subjects. We evaluated the patients at diagnosis and after 33 days of chemotherapy and found plasma IGFBP-4 levels at day 33 to be significantly lower than the levels at diagnosis. There was no correlation of plasma IGFBP-4 level with age, sex, immunophenotype, or ALL risk group, and there was no correlation of IGFBP-4 level with plasma IGF-I, IGF-II, IGFBP-1, IGFBP-2, and IGFBP-3 levels. Gene expression analysis of the leukemic blast population at diagnosis revealed that the leukemic clones did not significantly contribute to systemic IGFBP-4 levels. The decrease in plasma IGFBP-4 levels during chemotherapy represents an indirect effect, probably caused by the chemotherapeutic effects on IGFBP-4-expressing cells of the liver and other organs. In addition, IGFBP-4 gene expression was investigated in 13 human immune cell-related cell lines by reverse transcription-polymerase chain reaction analysis. IGFBP-4 was exclusively expressed in cell lines derived either from B-cells or from myelomonocytic cells, whereas IGFBP-4 was not expressed in T-cell lines.

Insulin-like growth factor binding protein-2 at diagnosis of childhood acute lymphoblastic leukemia and the prediction of relapse risk.

Despite remarkable advances in the clinical outcome of most children with acute lymphoblastic leukemia, a substantial number of patients ultimately relapse or suffer from side effects of treatment. In the present study, we investigated components of the IGF system for their predictive value to identify patients with an increased risk of relapse. Serum levels of IGF-I, IGF-II, IGF binding protein (IGFBP)-1, IGFBP-2, and IGFBP-3 were measured in 162 children with acute lymphoblastic leukemia treated by the Berlin Frankfurt Munster Study Group. At diagnosis we found elevated IGFBP-2, low IGFBP-3, low IGF-I, and low normal IGF-II, but normal IGFBP-1 levels. Highly elevated IGFBP-2 and low IGFBP-3 at the time of diagnosis correlated with a higher risk of an event such as lack of remission or a relapse. Serum IGFBP-2 was identified as an independent factor that adds additional information for the prediction of events (relapse or treatment failure) to the conventional prognostic factors such as white blood cell count and platelet count at diagnosis.

Chronic natural killer cell lymphocytosis is associated with elevated cytotoxic activity of natural killer cells.

The authors describe a 16-year-old girl who has suffered from chronic natural killer cell lymphocytosis (CNKL) for 12 years. From age 4 years, she has shown a persistent lymphadenopathy and lymphocytosis. Clinically, she developed allergic skin involvement, thrombocytopenia, and peripheral polyneuropathy. Annual flow cytometry analyses of lymphocyte subsets revealed persistently elevated NK cell levels (55-75% of the lymphocyte fraction and 0.7-10 x 10(3) NK cells per microliter of blood). Furthermore, IgE serum concentrations were markedly increased. Based on CD16, CD161, and CD94 surface antigen expression, the NK cell population was characterized as mature NK cells. Functional analysis of these cells showed a 2-fold increase of intrinsic cytotoxic activity toward K-562 cells compared with NK cells from healthy controls. The authors present a clinical case of rare CNKL. The patient's NK cells possess significantly increased cytotoxic activity. These findings are discussed in context with elevated IgE concentrations.

Loss of imprinting of IGF-II gene in children with acute lymphoblastic leukemia.

Insulin-like growth factor-II (IGF-II) is known to be involved in the regulation of growth, differentiation and cell death in normal human tissues. In a variety of human tumors, the IGF-II gene is overexpressed and considered to be a stimulator for tumor growth through autocrine and paracrine mechanisms. The IGF-II gene is normally parental imprinted, only the paternal allele being expressed in most tissues. Several reports about biallelic expression (loss of imprinting (LOI)) of the IGF-II gene in different tumors suggest a role of dysregulation of IGF-II imprinting in tumorigenesis. However, biallelic expression of IGF-II gene has also been reported in different tissues of a significant number of normal controls, indicating either a normal phenomenon or an elevated cancer risk in this group of persons. Although LOI of IGF-II presumably promotes tumorigenesis by increasing IGF-II expression, elevated IGF-II levels in those patients have not been reported. We studied IGF-II gene expression in malignant lymphoblasts of 124 children suffering from acute lymphoblastic leukemia, 196 cord blood samples from healthy newborns and mononuclear cells (MNC) from 50 healthy age matched children. The ApaI polymorphism in exon 9 of the IGF-II gene and allele-specific exon-connection RT-PCR was used for determination of the imprinting status. From 44 informative ALL-patients, 24 (54%) showed LOI of the IGF-II gene. Twenty percent of the informative cord blood samples (N=56) and 14% of the informative MNC samples from healthy controls (N=22) showed biallelic expression of IGF-II. In the ALL-patients, no statistical significant correlation between LOI patients and relapse rate, surviving rate and risk groups could be detected. We conclude that LOI of IGF-II occurs in malignant lymphoblasts of children suffering from acute lymphoblastic leukemia in more than 50% of the patients. In MNC from cord blood and peripheral MNC from healthy controls, biallelic expression could be detected in up to 20% of all cases. The importance of LOI in ALL-patients needs to be further evaluated to determine its impact in leukemogenesis.

Plasma leptin and leptin receptor expression in childhood acute lymphoblastic leukemia.

Recently, leptin has been shown to play a regulatory role for differentiation within the myeloid and erythroid cell lineage, whereas results of its regulatory effects on lymphocytes and related tumor cells have been contradictory. To investigate whether leptin plays a role in acute lymphoblastic leukemia (ALL), we investigated the levels of leptin in plasma with enzyme-linked immunosorbent assays and the expression of the leptin receptor on malignant lymphoblasts with reverse transcriptase polymerase chain reaction (RT-PCR). At diagnosis, the leptin levels of bone marrow-derived plasma in children with ALL were found to be significantly lower than the levels of healthy control subjects (0.92 +/- 0.79 ng/mL versus 3.01 +/- 2.27 ng/mL, respectively). Notably, at complete hematologic remission (at day 33 of chemotherapy), leptin levels had normalized to 2.6 +/- 2.4 ng/mL. To elucidate the underlying mechanism of this phenomenon, we analyzed the expression of the leptin receptor on the mononuclear cell populations of the patients. RT-PCR analysis revealed gene expression rates of 33% at diagnosis versus 71% at remission, compared with 100% for healthy control subjects. Results of immunohistochemical staining supported these findings by showing that the tumor clones themselves do not express the leptin receptor. Finally, some hypotheses that might explain the decrease of leptin levels in the presence of the tumor clone are discussed.