Multimodal analysis of cell-free DNA whole-genome sequencing for pediatric cancers with low mutational burden

Sequencing of cell-free DNA in the blood of cancer patients (liquid biopsy) provides attractive opportunities for early diagnosis, assessment of treatment response, and minimally invasive disease monitoring. To unlock liquid biopsy analysis for pediatric tumors with few genetic aberrations, we introduce an integrated genetic/epigenetic analysis method and demonstrate its utility on 241 deep whole-genome sequencing profiles of 95 patients with Ewing sarcoma and 31 patients with other pediatric sarcomas. Our method achieves sensitive detection and classification of circulating tumor DNA in peripheral blood independent of any genetic alterations. Moreover, we benchmark different metrics for cell-free DNA fragmentation analysis, and we introduce the LIQUORICE algorithm for detecting circulating tumor DNA based on cancer-specific chromatin signatures. Finally, we combine several fragmentation-based metrics into an integrated machine learning classifier for liquid biopsy analysis that exploits widespread epigenetic deregulation and is tailored to cancers with low mutation rates. Clinical associations highlight the potential value of cfDNA fragmentation patterns as prognostic biomarkers in Ewing sarcoma. In summary, our study provides a comprehensive analysis of circulating tumor DNA beyond recurrent genetic aberrations, and it renders the benefits of liquid biopsy more readily accessible for childhood cancers.

Common Ewing sarcoma-associated antigens fail to induce natural T cell responses in both patients and healthy individuals

Disseminated or relapsed Ewing sarcoma (EwS) has remained fatal in the majority of patients. A promising approach to preventing relapse after conventional therapy is to establish tumor antigen-specific immune control. Efficient and specific T cell memory against the tumor depends on the expansion of rare T cells with native specificity against target antigens overexpressed by the tumor. Candidate antigens in EwS include six-transmembrane epithelial antigen of the prostate-1 (STEAP1), and the human cancer/testis antigens X-antigen family member 1 (XAGE1) and preferentially expressed antigen in melanoma (PRAME). Here, we screened normal donors and EwS patients for the presence of circulating T cells reactive with overlapping peptide libraries of these antigens by IFN-γ Elispot analysis. The majority of 22 healthy donors lacked detectable memory T cell responses against STEAP1, XAGE1 and PRAME. Moreover, ex vivo detection of T cells specific for these antigens in both blood and bone marrow were limited to a minority of EwS patients and required nonspecific T cell prestimulation. Cytotoxic T cells specific for the tumor-associated antigens were efficiently and reliably generated by in vitro priming using professional antigen-presenting cells and optimized cytokine stimulation; however, these T cells failed to interact with native antigen processed by target cells and with EwS cells expressing the antigen. We conclude that EwS-associated antigens fail to induce efficient T cell receptor (TCR)-mediated antitumor immune responses even under optimized conditions. Strategies based on TCR engineering could provide a more effective means to manipulating T cell immunity toward targeted elimination of tumor cells.

Gene expression profiling of peripheral blood cells: new insights into Ewing sarcoma biology and clinical applications

Ewing sarcoma (ES) is a group of highly aggressive small round cell tumors of bone or soft tissue with high metastatic potential and low cure rate. ES tumors are associated with a rapid osteolysis and necrosis. The currently accepted clinical prognostic parameters do not accurately predict survival of high-risk patients. Moreover, neither the subtype of EWS-FLI1/ERG in the tumor, nor the detection of fusion transcripts in the peripheral blood (PB) samples, has prognostic value in ES patients. We evaluated the prevalence of circulating tumor cells (CTCs) in 34 adult ES patients. Since CTCs were confirmed in only small subset of patients, we further explored the expression profiles of PB leukocytes using a panel of genes associated with immune system status and increased tumor invasiveness. Moreover, we analyzed the alterations of the routine blood tests in the examined cohort of patients and correlated our findings with the clinical outcome. A uniform decrease in ZAP70 expression in PB cells among all ES patients, as compared to healthy individuals, was observed. Monocytosis and the abnormal expression of CDH2 and CDT2 genes in the PB cells significantly correlated with poor prognosis in ES patients. Our study supports the previously proposed hypothesis of systemic nature of ES. Based on the PB cell expression profiles, we propose a mechanism by which immune system may be involved in intensification of osteoclastogenesis and disease progression in ES patients. Moreover, we demonstrate the prognostic value of molecular PB testing at the time of routine histopathological diagnosis.

Investigation of the insulin-like growth factor-1 signaling pathway in localized Ewing sarcoma: a report from the Children's Oncology Group

BACKGROUND

The insulin-like growth factor-1 (IGF-1) signaling pathway plays an important role in the pathology of Ewing sarcoma (ES). Retrospective studies have suggested that levels of IGF-1 and IGF binding protein 3 (IGFBP-3) are correlated with the outcome of patients with ES.

METHODS

The IGF-1 signaling pathway was investigated prospectively in 269 patients who had localized, previously untreated ES. Serum samples were obtained at diagnosis, and concentrations of IGF-1 and IGFBP-3 were determined by enzyme-linked immunosorbent assays. In addition, immunohistochemistry (IHC) was performed to assay for phosphorylated p70S6 kinase, protein kinase B (Akt), and forkhead box protein O1 (FOXO1) and to determine the presence of protein tyrosine phosphatase-L1 (PTPL1). IHC findings along with IGF-1 and IGFBP-3 concentrations were correlated with age, tumor location, sex, event-free survival, and overall survival.

RESULTS

Patients aged >18 years tended to have higher levels of IGF-1 (P = .10), lower levels of IGFBP-3 (P = .16), and decreased IGFBP-3:IGF-1 ratios (P = .01). No correlations were observed between sex, tumor location, or outcomes and concentrations of IGF-1 or IGFBP-3. Phosphorylation of p70S6 kinase, Akt, and FOXO1 was detected in the majority of patient tissues but was not associated with age, sex, or tumor location. PTPL1 was present in >80% of tumors and also was not correlated with age, sex, or tumor location. There was no difference in survival with respect to the presence of phosphorylated p70S6 kinase, phosphorylated FOXO1, phosphorylated Akt, or PTPL1.

CONCLUSIONS

The baseline IGFBP-3:IGF-1 ratio was correlated with age but did not affect the outcomes of patients with ES. The authors concluded that additional investigation of the IGF-1 pathway is warranted in patients with ES, and especially in those who have received treatment with IGF-1 receptor antibody inhibitors.

Serum metallothionein in newly diagnosed patients with childhood solid tumours

Tumour markers are substances produced by malignant cells or by the organism as a response to cancer development. Determination of their levels can, therefore, be used to monitor the risk, presence and prognosis of a cancer disease or to monitor the therapeutic response or early detection of residual disease. Time-consuming imaging methods, examination of cerebrospinal fluid or tumour tissue and assays for hormones and tumour markers have been used for cancer diagnosis. However, no specific marker for diagnosis of childhood solid tumours has been discovered yet. In this study, metallothionein (MT) was evaluated as a prospective marker for such diseases. Serum metallothionein levels of patients with childhood solid tumours were determined using differential pulse voltammetry - Brdicka reaction. A more than 5-fold increase in the amount of metallothionein was found in sera of patients suffering from cancer disease, compared with those in sera of healthy donors. The average metallothionein level in the sera of healthy volunteers was 0.5 ± 0.2 μmol · dm⁻³ and was significantly different (p<0.05, determined using the Schefe test) from the average MT level found in serum samples of patients suffering from childhood solid tumours (3.4 ± 0.8 μmol · dm⁻³). Results found in this work indicate that the MT level in blood serum can be considered as a promising marker for diagnostics, prognosis and estimation of therapy efficiency of childhood tumours.

Thromboembolism in children with sarcoma

BACKGROUND

Thromboembolism (TE) is a common complication and cause of death in adults with cancer. Cancer has been identified as a major risk factor in children with TE. However, the information regarding the epidemiology of TE in children with cancer, especially in association with childhood solid tumors, is scant.

OBJECTIVE

To define the prevalence and epidemiology of TE in children with sarcoma.

PROCEDURE

Hospital records of children </=18 years of age with sarcoma diagnosed and treated at McMaster Children's Hospital during January 1990 to December 2005 were reviewed for demographic details, details of diagnosis and therapy for sarcoma, and details of diagnosis and management of TE. Statistical analysis was performed using Fisher's exact t-test.

RESULTS

Ten of 70 (14.3%; 95% CI; 7.1, 24.7) patients with sarcoma developed symptomatic TE. Patients with CVL-dysfunction (n = 9) were at significantly higher risk for symptomatic TE compared to those without CVL dysfunction (n = 61) (55.5 vs. 8.2%; P = 0.002, 95% CI; 14.2, 80.5). Patients with pulmonary disease (n = 23) had higher prevalence of TE compared to those without pulmonary disease (n = 47) (26 vs.8.5%; P = 0.07, 95% CI; -2.06, 37.2). Older patients, patients with metastatic disease and those with Ewing sarcoma had higher prevalence of TE.

CONCLUSIONS

TE is a significant complication in children with sarcoma. Over 50% of patients with CVL dysfunction had symptomatic TE; such patients may warrant careful evaluation for associated TE. Large prospective studies are needed to define the epidemiology and identify risk factors predisposing to TE in children with sarcoma.

Early lymphocyte recovery as a prognostic indicator for high-risk Ewing sarcoma

BACKGROUND

Increasing evidence suggests that lymphocyte recovery plays a major part in tumor control. Facilitating immune reconstitution might be a novel direction of cancer therapy. The purpose of this study was to determine if early lymphocyte recovery is an independent prognostic indicator for high-risk Ewing sarcoma outcome.

RESULTS

Data of 24 Ewing sarcoma patients were analyzed (age, 3 to 50 y; median, 16.5; male to female, 16:8). The 5-year overall survival (OS) of the total population was 47.9% [10.6 standard error (SE)]. Patients were separated into 2 groups: prolonged lymphopenia versus early lymphocyte recovery, using a threshold absolute lymphocyte count (ALC) of > or =500 cells/microL on day 15. The majority (67%; n=16) of the patients had an ALC > or =500 cells/microL, and of these 10/16 are alive with a 5-year OS of 58.7% (13.2 SE). In contrast, 33% (n=8) of patients had an ALC <500 cells/microL on day 15 and only 2/8 are alive with a 5-year OS of 25% (15.3 SE). This difference was significant (P=0.007 using the log rank test). When comparing patients with metastatic disease, patients with an ALC-15 < 500 cells/microL had a median survival of 13 months, whereas patients with an ALC-15 > or =500 cells/microL had a median survival of 29.5 months. All patients had an ALC before chemotherapy of >1000 cells/microL. The difference was significant (P value=0.001 using the log rank test). Univariate analysis of platelet counts, age, sex, and absolute neutrophil count showed no statistically significant association with OS.

CONCLUSIONS

The data demonstrate that an ALC > or =500 cells/microL on day 15 of the first course of chemotherapy is an independent prognostic factor associated with superior OS in high-risk Ewing sarcoma.

Are serum levels of CD44 relevant in children with pediatric sarcomas?

BACKGROUND

Variation in serum levels of CD44, which acts as an adhesion receptor involved in lymphocyte migration and binding, have been reported in some malignancies. The aim of this study is to compare serum levels of CD44 in children with sarcomas with those in healthy children.

PROCEDURE

CD44 levels were measured by enzyme-linked immunosorbent assay (ELISA) in serum samples taken at diagnosis from 55 children with sarcomas and from 27 healthy children of similar age, sex, and socioeconomic status.

RESULTS

There was no statistically significant difference between CD44 serum levels of children with sarcomas and those of healthy children. No significant difference was observed between CD44 serum levels of each patient group and those of control group (P > 0.05). There was no significant difference among CD44 serum levels of patient groups according to stage or outcome.

CONCLUSIONS

In this study, serum CD44 levels were not found to be of value in the diagnosis or prognosis in children with sarcomas.

Changes in thyroid hormone state in children receiving chemotherapy

OBJECTIVE

The concentrations of thyroid function determinants may change during severe illness. Our goal was to quantify their changes in children with cancer during chemotherapy, and to correlate them to clinical condition and type of drugs.

DESIGN

During a 3-month period all patients admitted for chemotherapy to the paediatric oncology ward were evaluated for inclusion. Patients with brain tumours, neuroblastoma (cranio)spinal irradiation and use of dexamethasone before the first blood sample were excluded.

MEASUREMENTS

Plasma concentrations of T4, T3, rT3, thyroxine-binding globulin (TBG), thyroglobulin (Tg), TSH, IGF-1, cortisol, PRL and physical well-being by means of questionnaires were measured before and during chemotherapy.

RESULTS

In 19 children, 46 courses of chemotherapy and 123 plasma samples were analysed. During chemotherapy, mean concentrations of TSH, T3, Tg and cortisol decreased to 53, 67, 69 and 15% of the baseline value, respectively. Mean plasma rT3 increased to 217% of baseline. In 87% of all courses, one or more thyroid parameter(s) was aberrant. Furthermore, in 23 samples (19%) from 10 patients (53%), the concentration of IGF-1 was below the reference value (adjusted for sex and age). Small changes were seen in scores for clinical condition but none was related to a change in thyroid function determinant. Most changes in thyroid hormones could be attributed to using dexamethasone.

CONCLUSIONS

These results demonstrate that, in children, thyroid hormone state changes significantly during chemotherapy, apparently not related to physical well-being but to the drugs administered. Future investigations should focus on the impact for patient care and possibilities of (preventive) intervention.

Soluble p185(HER-2) in patients with malignant bone tumours

BACKGROUND

This study was initiated to test the hypothesis that soluble p185(HER-2) could be of value as a diagnostic or predictive marker for patients with malignant bone tumours.

PROCEDURE

Sera of 35 patients with high-grade malignant osteosarcoma (n = 27) and Ewing Sarcoma (n = 8) were tested at the time of diagnosis by ELISA and compared with sera of controls (n = 38) and clinical data.

RESULTS

In patients with osteosarcoma and Ewing Sarcoma, levels of sp185(HER-2) did not differ significantly from levels in controls. These results were irrespective of the type of tumour, survival chemotherapy or other clinical variables.

CONCLUSION

p185(HER-2) serum levels do not appear to be of diagnostic or predictive value for differentiation of high-grade osteosarcoma and Ewing Sarcoma.

Procholecystokinin as Marker of Human Ewing Sarcomas

PURPOSE

Ewing sarcoma is a rapidly growing mesenchymal tumor in young adults. Although it was shown previously to express the cholecystokinin (CCK) gene, it is unknown whether CCK gene expression is detectable at protein level in Ewing sarcoma tumor cell lines, in tumor tissue, and in plasma from Ewing sarcoma patients, and, if so, whether CCK peptides might play a role as tumor markers.

EXPERIMENTAL DESIGN

CCK gene expression was evaluated with in situ hybridization or reverse transcription-PCR in tumor tissue. CCK precursors and bioactive CCK were measured with specific RIAs in tumor tissue, in cell culture medium, and in plasma of Ewing sarcoma patients before and after chemotherapy as well as after tumor recurrence.

RESULTS

CCK mRNA was identified in 12 Ewing sarcoma biopsies sampled in two series and in four Ewing sarcoma cell lines but not in unrelated neoplasia. Immunoreactive proCCK was identified in the culturing medium of all Ewing sarcoma cell lines but not in the media from unrelated tumor cell lines. Moreover, in plasma from Ewing sarcoma patients, precursors and mature forms of CCK, in particular proCCK, were detected; several fold elevation of the total proCCK product was found in plasma from patients before treatment and after tumor recurrence, whereas successful chemotherapy reduced proCCK to basal concentrations. Plasma concentrations of proCCK paralleled the respective tumor size.

CONCLUSIONS

This is the first study that consistently documents an altered CCK metabolism in human cancer; Ewing sarcomas synthesize and secrete proCCK that can be identified in plasma as circulating tumor marker.

Cytokine and cytokine receptor serum levels in adult bone sarcoma patients: Correlations with local tumor extent and prognosis

BACKGROUND AND OBJECTIVES

We analyzed the correlations between pretreatment serum levels of 11 cytokines and soluble cytokine receptors (interleukin 6 (IL-6); interleukin 8 (IL-8); interleukin 10 (IL-10); vascular endothelial growth factor (VEGF); basic fibroblast growth factor (bFGF); macrophage colony-stimulating factor (M-CSF); granulocyte colony-stimulating factor (G-CSF); interleukin 1 receptor antagonist (IL-1ra); sIL-2Ralpha; tumor necrosis factor receptor I (TNF RI), and TNF RII) with clinico-pathological features and survival of patients with bone sarcomas.

METHODS

Altogether, 72 patients with bone sarcomas without distant metastases before treatment (26 osteosarcomas-36%, 23 chondrosarcomas-32%, 13 Ewing's sarcomas/PNET-18%, 10 giant-cell tumors-14%), 22 patients with benign non-inflammatory bone tumors and 50 age-matched healthy controls were included into this prospective study.

RESULTS

Median serum levels of 9/11 cytokines, with the exception of sIL-2Ralpha and G-CSF, were significantly higher in sarcoma patients than in controls. Median serum levels of IL-6, IL-8, IL-1ra, TNF RI, and M-CSF were significantly higher in patients with bone sarcoma as compared to patients with benign bone tumors. In 45.9% of sarcoma patients, six or more cytokines and cytokine receptors, including those that are involved in bone destruction (e.g., IL-6 and IL-8) and bone formation (e.g., IL-1ra and TNFRI and TNFRII), were elevated in parallel. Serum levels of IL-6, IL-8, TNF RI, TNF RII, and VEGF correlated significantly with tumor size (<10 cm vs. >or=10 cm in diameter) and serum levels of IL-6, IL-8, TNF RI, and IL-1ra correlated significantly with local tumor extent (E2/4 vs. E5/6 according to the classification proposed by Spanier et al. 46). Moreover, serum levels of IL-1ra and IL-6 were significantly higher in patients with small tumors (<5 cm in diameter) infiltrating structures adjacent to the periosteum (E5/6) than in large tumors (>10 cm in diameter) but confined to the bone and periosteum (E < 4). The lowest median serum levels of 8/11 cytokines/cytokine receptors were found in patients with giant-cell tumors. In an univariate analysis, increased serum levels of IL-1ra, IL-6, IL-8, IL-10, sIL-2Ralpha, M-CSF, TNF RI, and TNF RII, the number of cytokines elevated, higher tumor grade, larger tumor size, greater local extent (E) and patients' age >35 years correlated with poor overall survival (OS) (P < 0.05). Similarly, high serum levels of IL-1ra, IL-6, TNF RI and TNF RII, tumor grade, tumor size, and tumor local extent (E) (P < 0.05) affected disease free survival (DFS) in univariate analysis. Multivariate analysis using Cox's proportional hazards model showed that high serum levels of IL-1ra (P = 0.039) and TNF RI (P = 0.048), the number of serum cytokines above normal cut-off values (0-1 vs. 2-5 vs. >or=6; P = 0.029), greater tumor local extent E (E2/4 vs. E5/6; P = 0.02) correlated significantly with shorter OS. Only E was found as an independent prognostic factor for DFS (P = 0.04).

CONCLUSIONS

These findings indicate that cytokines and soluble cytokine receptors, both physiologically involved in bone destruction and bone formation, have an essential role in the progression of malignant bone tumors.

Serum concentrations of sCD30 and sCD40L in patients with malignant bone tumours

The aim of this study was to evaluate serum levels of both soluble CD30 (sCD30) and soluble CD40 ligand (sCD40L) in patients with malignant bone tumours and to determine their ability to serve as serum markers. Sera of 31 patients were taken at the time of diagnosis, analysed by ELISA, and the results were correlated with clinical features and compared with healthy controls. Soluble CD30 and sCD40L levels were significantly higher in all patient groups than in the healthy controls. Soluble CD30 levels showed statistically significant differences between high malignant osteosarcoma and Ewing sarcoma (P = 0.015), whereas no statistically significant correlation was seen between different types of tumours and sCD40L levels. Soluble CD30 and sCD40L seem to be of diagnostic value in osteosarcoma and Ewing sarcoma.

Serum levels of TNF-beta and sTNF-R in patients with malignant bone tumours

OBJECTIVE

To determine serum levels of TNF-beta and soluble TNF-R in patients with primary highly malignant bone tumours.

PATIENTS AND METHODS

Sera of 27 patients with highly malignant osteosarcoma and Ewing sarcoma were taken at the time of diagnosis and analysed by ELISA.

RESULTS

Both TNF-beta and sTNF-R levels were lower in sera from osteosarcoma patients as compared to those from Ewing sarcoma. In patients with high-grade osteosarcoma, but not Ewing sarcoma, high levels of TNF-beta correlated with bad response to neoadjuvant chemotherapy.

CONCLUSION

In patients with high-grade osteosarcoma TNF-beta levels seem to be of predictive value and both TNF-beta and sTNF-R seem to be of diagnostic value for differentiation between high-grade osteosarcoma and Ewing sarcoma.

Measurement and analysis of the chemotherapy-induced genetic instability in pediatric cancer patients

Bleomycin sensitivity has been proven to be a useful biomarker for environmental carcinogenesis and tumor genetic instability. We have previously reported a significant increase in the chromosomal aberrations induced by chemotherapy regimens. This study aimed to test whether there is an inherent increased genetic instability in cancer patients at diagnosis, to determine the increase and time course of the chemotherapy-induced instability and to test whether bleomycin sensitivity can be used as a predictor of tumor evolution or relapse. The analysis included 99 pediatric cancer patients with four different tumor types (Ewing's sarcoma, osteosarcoma, lymphoma and CNS tumors) and 25 controls. Blood samples (n = 171) were obtained before and at the end of treatment, during clinical remission and at relapse and bleomycin tests on lymphocyte cultures were performed. We detected a significant increase (P = 0.004) in mutagen sensitivity in patients at the end of treatment compared with untreated patients, regardless of the tumor type. In both the longitudinal and cross-sectional analyses maximal and similar values of mutagen sensitivity were found in patients during treatment (1.84 +/- 0.82) and at relapse (1.78 +/- 0.52); minimum and similar values were found in controls (0.93 +/- 0.23), untreated patients (1.15 +/- 0.65) and in those who had fulfilled the chemotherapy protocols for at least 2 years before their sample was collected (1.09 +/- 0.53). From this preliminary data we can conclude that cytostatic drugs induce a transient increase in chromosomal instability in pediatric cancer patients that can be monitored by bleomycin-induced sensitivity tests and that the genetic instability indices should be further investigated as predictors of relapse.

Incidence of anemia in children with solid tumors or Hodgkin disease

Anemia is a hematologic abnormality commonly discussed during the treatment of childhood cancer, but its incidence has not been previously reported. As the basis for determining the incidence of anemia, this retrospective review of medical records combined databases containing the records of all patients 1 to 18 years of age with newly diagnosed neuroblastoma, rhabdomyosarcoma, Hodgkin disease, Ewing sarcoma, or osteosarcoma from two pediatric oncology centers. Data from 405 patients were included in the analysis of hemoglobin at the time of diagnosis. Across diagnoses, 51% to 74% of patients were anemic using the Centers for Disease Control and Prevention age- and sex-specific values to define anemia. The long-term complications of anemia in children with cancer are unknown. Further investigation of the clinical significance of anemia, including its impact on quality of life, is warranted.

Insulin-like growth factor type 1 (IGF-1) and IGF binding protein-3 in patients with Ewing sarcoma family of tumors

BACKGROUND

Ewing sarcoma family of tumors (ESFTs) are the second most common bone tumor, that most often affects persons ages 3-40 years. The ESFTs rely on signaling through the insulin-like growth factor-1 receptor (IGF-1R) for growth and transformation. The current studies were performed to determine the levels of IGF-1 and IGF binding protein-3 (IGFBP-3) in patients with ESFT. The authors then performed an exploratory analysis to evaluate whether IGF parameters could differentiate event free or overall survival in ESFT patients.

METHODS

The authors measured serum levels of IGF-1 and IGFBP-3 by using a radioimmunoassay from 111 patients with ESFT with a median follow-up of 13 years from diagnosis.

RESULTS

The IGF-1 levels were lower among patients with metastatic disease to the bones or the bone marrow compared with patients without metastasis to these sites (p2 = 0.021 and 0.0038, respectively). IGFBP-3 is known to sequester IGF-1; the ratios of IGFBP-3 to IGF-1 were evaluated. Patients with metastatic disease to any site had higher IGFBP-3 to IGF-1 ratios than patients with localized disease (p2 = 0.0067). There was a trend toward increased survival in patients with localized disease who had high IGFBP-3 to IGF-1 levels. Metastatic patients showed a similar trend.

CONCLUSIONS

Levels of IGF-1 and IGFBP-3 in ESFT patients can identify patients with the most widespread disease. The IGFBP-3 to IGF-1 ratio in patients with either localized or metastatic disease identified patients with a trend toward increased survival. Further prospective evaluation with higher patient numbers might show a prognostic role for the IGFBP-3 to IGF-1 ratio in patients with ESFT.

Blood thiols following amifostine and mesna infusions, a pediatric oncology group study

The Pediatric Oncology Group study for metastatic Ewing's sarcoma used amifostine and mesna with the alkylating agents. To determine the fate of combined drug thiols, we measured thiol levels in plasma, red blood cells (RBC), and peripheral blood mononuclear cells (PBMC) of four patients. We also conducted analogous measurements on two patients who received mesna alone and a volunteer's blood following in vitro treatment. Thiols were labeled with monobromobimane, separated on high-pressure liquid chromatography, and detected by fluorescence. Incubation of a volunteer's blood with mesna, WR-1065, or both revealed that cellular uptake of total reducible drug was approximately 10% of plasma level for mesna but approximately 60% for WR-1065. Cellular drugs were mainly the thiol form, whereas half of the plasma drugs were disulfides. Combined incubation with both thiols did not change the extent or form of uptake. WR-1065 and mesna prevented glutathione depletion by 4-hydroperoxycyclophosphamide. Results from patients were similar. WR-1065 and mesna appeared in the cells by the end of the drug infusions, although WR-1065 uptake was more efficient than mesna. The concentration-time profiles of mesna in RBC paralleled those in plasma. Amifostine administration during mesna infusion caused transient increase in mesna levels. Both agents increased blood cysteine and decreased total reducible cysteine. Mesna alone and mesna plus amifostine prevented cellular glutathione depletion. In conclusion, mesna is imported by RBC and PBMC, but less efficiently than WR-1065. When present at equal levels, these thiols do not influence each other's uptake. Adequate dosing of either drug is necessary for protecting the cells from toxic effects of alkylating agents.

Concentration of vascular endothelial growth factor (VEGF) in the serum of patients with malignant bone tumors

BACKGROUND

Vascular endothelial growth factor (VEGF) is recognized as an important stimulator of angiogenesis. Formation of new blood vessels by angiogenic factors occurs in many biological processes, both physiological and pathological, among others in growth of primary solid malignant tumors and metastasis. This implies that the inhibition of angiogenic factors like VEGF would result in a suppression of tumor growth and metastasis formation. The aim of the present study was to compare preoperative serum VEGF levels of patients having malignant bone tumors with healthy controls to identify serum VEGF levels as a tumor marker.

PROCEDURE

Blood sera from patients with high-grade osteosarcoma (n = 17), chondrosarcoma (n = 4) and Ewing sarcoma (n = 6) were taken at the time of diagnosis before biopsy and compared with sera from 129 healthy persons. To measure VEGF levels in serum, a commercially available ELISA was used (Quantikine Human VEGF Immunoassay; R&D Systems).

RESULTS

The observed geometric mean VEGF levels and 95% confidence intervals are 232.0 pg ml(-1) (168.9-318.5) for patients with high-grade osteosarcoma, 325.5 pg ml(-1) (169.3-625.8) for patients with chondrosarcoma, 484.3 pg ml(-1) (284.0-826.0) for patients with Ewing sarcoma, as compared to 216.2 pg ml(-1) (192.8-242.5) for healthy individuals.

CONCLUSIONS

While the sample means for the three groups of sarcoma patients were higher than the respective mean for the healthy controls, only the mean for the group with Ewing sarcoma is statistically significantly higher than the mean for the healthy controls. Despite the significant difference, VEGF levels are not suitable as a marker for Ewing sarcoma.

Nonclonal chromosomal aberrations induced by anti-tumoral regimens in childhood cancer: relationship with cancer-related genes and fragile sites

Cytogenetic studies were performed on 80 pediatric cancer patients to observe the chromosomal damage, both quantitative and qualitative, induced by chemotherapy. Peripheral blood lymphocytes (PBL) (n = 127) were obtained at diagnosis, during treatment, at remission, and at relapse, and chromosome analysis performed utilizing G-banding standard procedures. The results show a significant increase in the number of altered karyotypes (P = 0.03) in the samples during treatment, returning to values that were similar to those at diagnosis at 2-year remission. Most of the chromosomal aberrations (CA) detected during the chemotherapy regimens were nonclonal, unbalanced (75%), and involved chromosomes 1, 3, 5, 6, 11, 12, 16, and 17 most frequently. There was also a marked increase of CA in samples at relapse with very similar features (type and distribution) to those detected during treatment. There was a good correlation between the chromosomal breakpoints in our series and fragile sites (58%), oncogene (75%), and tumor suppressor gene (33%) loci described in the literature. The results obtained suggest that cytostatic drugs induce a transient increase in chromosome fragility occurring at several cancer-associated breakpoints.

Vascular endothelium growth factor and angiogenin in the serum of patients with osteosarcoma and Ewing's tumor

The concentrations of vascular endothelium growth factor and angiogenin were measured by enzyme immunoassay in the sera of healthy subjects and patients with osteosarcoma and Ewing's tumor with consideration for the main clinical and morphological characteristics of the diseases. The studied angiogenic factors were characterized by high individual variability in both healthy subjects and age- and sex-matched patients with primary bone sarcomas. The level of endothelial growth factor was higher in control women than in men. The highest concentration of endothelial growth factor was detected in male patients with Ewing's tumor. Possible involvement of vascular endothelium growth factor and angiogenin in the pathogenesis of osteosarcoma and Ewing's tumor is discussed.

Hematologic abnormalities and acute myeloid leukemia in children and adolescents administered intensified chemotherapy for the Ewing sarcoma family of tumors

PURPOSE

Current treatment of the Ewing sarcoma family of tumors (ESFT) includes intensive multiagent chemotherapy with topoisomerase II inhibitors, alkylating agents, and granulocyte colony-stimulating factor (G-CSF). This treatment approach has been associated with myelodysplasia and acute myeloid leukemia. Because macrocytosis and thrombocytopenia are distinctive features of myelodysplasia, the authors evaluated a cohort of patients treated for ESFT to determine the degree and duration of macrocytosis and thrombocytopenia and their relation with the development of therapy-related hematologic malignancies.

PATIENTS AND METHODS

The study group consisted of 73 patients with ESFT treated on two consecutive protocols (EW92 and EW87). Both chemotherapy regimens incorporated the same agents but differed in cumulative drug dose, dose per course, and the use of G-CSF. Platelet counts and the mean corpuscular volume (MCV) of erythrocytes were determined at diagnosis and during follow-up visits after completion of treatment.

RESULTS

Patients in the EW92 group had significantly greater MCVs after treatment than did the less intensively treated EW87 group. These changes persisted throughout the 40-month observation period. Patients in the EW92 group also had lesser mean platelet counts after treatment than those in the EW87 group. MCV differences (from baseline) were inversely related to platelet counts. The cumulative incidence of treatment-related acute myeloid leukemia was 7.8%+/-4.7% at 4 years in the EW92 group and zero in the EW87 group.

CONCLUSION

Patients treated for ESFT with intensive chemotherapy that includes large doses of alkylators, topoisomerase II inhibitors, and G-CSF characteristically have persistently elevated MCVs and decreased platelet counts after completion of therapy. These hematologic abnormalities may represent stem cell damage, predisposing patients to myelodysplasia and acute myeloid leukemia, but further study is needed to establish this relation.

Immunomagnetic selection of CD34+ cells: factors influencing component purity and yield

BACKGROUND

In immunomagnetic selection of CD34+ cells from HPC transplants, not all factors that affect yield and purity of CD34+ cells are known.

METHODS

Forty-three consecutive procedures of immunomagnetic selection of CD34+ cells from peripheral blood HPCs and bone marrow harvests (autologous harvests, n = 27; allogeneic harvests; n=16) were performed by use of a cell selection system (Isolex 300i, Baxter Immunotherapy). The composition of the starting component and the subsets of CD34+ cells were analyzed for correlation with the yield and purity of the final component.

RESULTS

The mean purity of the final components was 84.3 percent (range, 27-99%), and the mean yield was 51.4 percent (range, 9.4-80. 4%). Partial regression analysis showed that, among the factors correlating with purity and/or yield, the RBC volume in the starting fraction had the highest predictive impact on the purity and yield of CD34+ cells, even after the exclusion of procedures using bone marrow harvests as an HPC source (beta coefficient, -0.704; p = 0. 001).

CONCLUSION

The use of the Isolex 300i system allows efficient recovery of CD34+ cells in routine selection procedures. The volume of RBCs in the starting component should be minimized to ensure a high yield and purity of the final component.

Serum antibodies against the heat shock protein 60 are elevated in patients with osteosarcoma

Osteosarcoma is the most frequent malignant bone tumor, mainly occurring in the second and third decade of life. Diagnosis is limited to clinical symptoms, radiology and histology, but so far no diagnostic laboratory tests are available. Heat shock proteins (hsp), highly conserved proteins performing vital intracellular chaperoning functions and preventing cells from death, have been shown to be involved in tumor immunity. We analyzed 75 sera from 23 patients with high-grade osteosarcoma, 8 patients with chondrosarcoma, 10 patients with Ewing's sarcoma, 5 patients with soft tissue sarcoma, 11 patients with benign bone tumors at the time of diagnosis and from 18 healthy controls with an indirect one-site enzyme linked immunosorbent assay (ELISA) for the presence of anti-hsp60 and 70 antibodies. In these assays 10/23 osteosarcoma patients (43%) had anti-hsp60 antibodies with a mean +/- S.D. titer of 0.382 +/- 0.243 U/ml. Only one of the 18 healthy controls (1/18, 5.6%; titer 0.22 U/ml), two of the Ewing's sarcoma patients (2/10, 20%; titer 0.2 +/- 0.09 U/ml), two of the patients with a benign bone tumor (2/11, 18%; titer 0.22 +/- 0.16 U/ml) and one of the chondrosarcoma patients (1/8, 12.5%; titer 0.14 U/ml) were positive, whereas all others, including all soft tissue sarcomas were negative throughout. Anti-hsp60 antibodies in patients with osteosarcoma are therefore significantly increased (p < 0.05). 19/23 (83%) of osteosarcoma biopsy specimens expressed hsp60 immunohistochemically and all specimens from patients with a positive anti-hsp60 serum titer expressed hsp60. The level of the anti-hsp60 antibodies did not correlate with clinical parameters such as response to preoperative chemotherapy, duration of symptoms, age, gender, tumor size, serum alkaline-phosphatase levels and metastases. Although no difference in anti-hsp70 antibodies could be observed between sera from patients and healthy controls, a positive correlation was found for the presence of anti-hsp70 serum antibodies and lung metastases at the time of diagnosis in osteosarcoma patients. These data suggest an increase of anti-hsp60 antibodies at the time of first diagnosis of osteosarcoma. These findings should therefore give rise to further investigations on a group of new markers for the diagnosis of osteosarcoma.

The course of fibrinolytic proteins in children with malignant bone tumours

To evaluate the role of fibrinolytic and proteolytic proteins in children and adolescents suffering from Ewing sarcoma or osteosarcoma with respect to postoperative complications and late outcome, a prospective two-arm two-centre study was conducted. Plasminogen, plasminogen activator inhibitor (PAI)-1, tissue-type plasminogen activator (t-PA) and urokinase plasminogen activator (u-PA) were investigated in the pre-surgical period and in the postoperative follow-up period in children suffering from Ewing sarcoma (ES; n = 36) or osteosarcoma (OS; n = 39). In addition, the factor V mutation (FV) Q506, protein C, protein S, antithrombin and lipoprotein (a) were determined. All children received LMWH (EnoxaparinR) 1 mg/kg s.c. once daily over a period of 6 weeks to 3 months. Besides a short-lasting increase of PAI-1 in patients with OS on day 1 and in children with Es on day 14, a small and significant but clinically irrelevant difference was found on days 7-10 for plasminogen, t-PA and u-PA. No thromboembolic complications occurred in patients treated with LMWH and having a prothrombotic genetic risk factor. Within one year of surgery 7 out of 36 patients with ES and 5 out of 39 children with OS showed a relapse of their disease. Prior to the first local tumour therapy, 5 out of 7 children with ES and relapse had elevated u-PA concentrations compared with 2 out of 5 children in the OS group. No such differences were found for PAI-1- or t-PA antigen.

CONCLUSION

The role of u-PA as a possible follow-up marker for a poorer outcome in children with ES should be evaluated in a prospective multicentre study.

WR-2721 (amifostine) infusion in patients with Ewing's sarcoma receiving ifosfamide and cyclophosphamide with mesna: drug and thiol levels in plasma and blood cells, a Pediatric Oncology Group study

PURPOSE

Previous WR-2721 human pharmacokinetic studies were limited to plasma levels in patients receiving platinum-based compounds, and none includes the effects of WR-2721 on endogenous thiols. In the present study (Pediatric Oncology Group study no. 9457), we measured the levels of WR-2721, its active metabolites, as well as cysteine and glutathione in whole blood, plasma, and blood cells in patients receiving high-dose alkylating agents with mesna.

METHODS

WR-2721 was administered (15 min intravenous infusion of 825 mg/m(2) per dose x2) to five patients with metastatic Ewing's sarcoma receiving ifosfamide and cyclophosphamide with mesna. Intracellular and extracellular blood thiols were labeled with monobromobimane (mBBr) at the time of collection, and the low molecular weight (LMW) thiols were subsequently separated by HPLC and detected by fluorescence.

RESULTS

The active metabolite of the drug, WR-1065, peaked at 100 microM in plasma and blood cells at the end of WR-2721 infusion and decayed with a rapid initial half-life. Detectable levels of WR-1065 and its LMW disulfides were present in plasma and blood cells at approximately 1 h after the WR-2721 infusion. By the end of the first WR-2721 infusion (prior to mesna infusion), the mean cysteine level more than doubled and the mean Cys-SS-LMW (cystine and the mixed LMW disulfides) level decreased by approximately 50% in both plasma and blood cells. In four of five patients, reduced glutathione levels in blood cells increased by the end of the first WR-2721 infusions, the average increment being approximately 36%.

CONCLUSIONS

(1) WR-1065 is rapidly formed from WR-2721 and equilibrates between plasma and blood cells; (2) WR-1065 decays in plasma and blood cells with similar rapid initial half-lives of approximately 16 min; (3) WR-2721 treatment increases cysteine in plasma and blood cells, an effect similar to that of mesna; (4) WR-2721 treatment appears to increase glutathione levels in blood cells; (5) Mesna does not have a substantial effect on the fate of WR-2721 in patients.

Detection of EWS chimeric transcripts by nested RT-PCR to allow reinfusion of uncontaminated peripheral blood stem cells in high-risk Ewing's tumor in childhood

BACKGROUND AND OBJECTIVE

Ewing's tumors (ET) are primary malignancies of bone and soft tissues characterized in at least 96% of cases by specific fusion transcripts originating from recurrent chromosomal translocations. Clinical protocols for high-risk metastatic ETs include high-dose radiation/chemotherapy followed by autologous peripheral blood stem cell (PBSC) reinfusion. We used nested reverse transcriptase polymerase chain reaction (RT-PCR) to search for the presence of ET-specific transcripts in PBSC collections from patients with high-risk ET in order to collect harvests free from neoplastic cells but still sufficient to obtain early stable engraftment.

DESIGN AND METHODS

Thirty-seven harvest samples from 15 ET patients treated with mobilizing chemotherapy were analyzed. Nested RT-PCR was performed to detect ET-specific transcripts in RNA extracted from the PBSC collections.

RESULTS

A total of 30 harvests was performed. On average, 2 harvests (range 1-4) were sufficient to collect the minimum required number of mononuclear cells (2.5

RT-PCR evaluation of peripheral blood, bone marrow and peripheral blood stem cells in children and adolescents undergoing VACIME chemotherapy for Ewing's sarcoma and alveolar rhabdomyosarcoma

Peripheral blood stem cell support allows dose intensification of multiple cycle chemotherapy for metastatic tumors, including pediatric sarcomas. The VACIME protocol (vincristine, adriamycin, cyclophosphamide, ifosfamide, mesna and etoposide) utilizes peripheral blood stem cells (PBSC) collected following the treatment cycle as support for subsequent dose- and time-intensive chemotherapy. A critical assumption is that PBSC collected in this manner will be purged of residual tumor cells in vivo. We tested this assumption using sensitive reverse-transcriptase polymerase chain reaction (RT-PCR) to assess the presence of the characteristic translocations of the Ewing's sarcoma family of tumors (ESFT) and alveolar rhabdomyosarcoma (ARMS), t(11;22), and t(2;13), respectively. We used RT-PCR to evaluate 122 samples of peripheral blood (PB), bone marrow (BM) and PBSC collected from 12 pediatric patients with metastatic ESFT and ARMS. The samples included pre-therapy BM and PB, as well as BM, PB, and PBSC collections at various times in the VACIME treatment course. Molecular evidence of tumor contamination was detected in 1/40 PBSC collections from 12 patients. In all patients, we documented clearance of disease by RT-PCR in peripheral blood and bone marrow by week 9 of the VACIME protocol. In vivo purging in combination with the intensive VACIME regime appears to be effective in removing tumor cells from PBSC, bone marrow, and peripheral blood as detected by RT-PCR.

Prognostic significance of serum LDH in Ewing's sarcoma of bone

The pretreatment serum lactic dehydrogenase (SLDH) levels of 618 patients with Ewing's sarcoma of the extremities (136 metastatic at presentation and 482 localized) were analyzed to evaluate whether the enzyme level had a clinical value in predicting the course of the disease. The percentage of patients with increased SLDH was significantly higher in the metastatic group than in the group of patients with localized disease (68% vs 32%; P<0.0001). In the latter group treated with neoadjuvant chemotherapy the 5-year disease-free survival rate was significantly higher in patients with normal pretreatment SLDH than in those with high levels (65% vs 41%; P<0.0001). The time to relapse was significantly shorter for patients with elevated SLDH than in patients with normal values of the enzyme. The site of the tumor was significantly related with the stage of the disease, and for patients with localized disease, with the disease survival rate, at the multivariate analyses site of the tumor and SLDH levels were independently related with the stage of disease and with prognosis. These data demonstrate that in Ewing's sarcoma of bone pretreatment SLDH have a prognostic value and should be considered in the comparison of the results achieved with different therapies and in planning new randomized clinical therapeutic trials.

Measurement of DNA cross-linking in patients on ifosfamide therapy using the single cell gel electrophoresis (comet) assay

The single cell gel electrophoresis comet assay has become established as a sensitive technique for measuring DNA strand breaks. The technique has been modified to allow the sensitive detection and quantitation of DNA interstrand cross-linking at the single cell level. Cells are irradiated immediately before analysis to deliver a fixed level of random strand breakage. After embedding of cells in agarose and lysis, the presence of cross-links retards the electrophoretic mobility of the alkaline denatured cellular DNA. Cross-links are, therefore, quantitated as the decrease in the comet tail moment compared with irradiated controls. Using this method, a linear response of cross-linking versus dose of chlorambucil over a wide dose range was demonstrated in human lymphocytes after drug treatment ex vivo. The method was also sensitive enough to determine cross-linking in clinical samples after chemotherapy. For example, crosslinking was observed in the lymphocytes of patients receiving ifosfamide (3 g/m2/day) as a continuous infusion for 3-5 days or as a 3-h infusion daily for 3 days. Cross-links were detected in all patients within 3 h, with no evidence of DNA single strand break formation. In patients receiving continuous infusion, a plateau of cross-linking was reached by 24 h. In the patients receiving ifosfamide over 3 h, a clear decrease in the peak level of cross-linking was observed before subsequent infusions.

Prognostic value of clinicopathologic characteristics including neuroectodermal differentiation in osseous Ewing's sarcoma family of tumors in children

AIMS AND BACKGROUND

The aim of the present study was to determine the relationship between clinico-pathologic parameters, including neuroectodermal differentiation, and their impact on survival in a series of pediatric patients with osseous tumors of the Ewing's sarcoma family admitted to the Pediatric Department of the Istituto Nazionale Tumori of Milan.

METHODS

Seventy-three patients were enrolled. The variables analyzed were sex, age, site of primary tumor, serum lactate dehydrogenase (LDH) level at diagnosis, involvement of periosseous soft tissues by primary tumor, presence of metastatic disease, status of disease after the treatment plan, as well as the presence of mitoses, morphologic and immunocytochemical neural markers, and neuroendocrine markers in the primary tumor.

RESULTS

Neural and neuroendocrine markers were not significantly associated with any of the other parameters. In the univariate analysis, significant risk factors related to unfavorable outcome were elevated LDH, metastatic disease, lack of complete remission after treatment, presence of mitoses and of morphological neural markers; immunocytochemical neural and neuroendocrine markers lacked prognostic value. In the multivariate analysis, only LDH levels and the status of disease following the treatment were retained.

CONCLUSIONS

LDH level at diagnosis might be a useful marker to identify different risk levels; neuroectodermal differentiation might have no clear-cut impact on the clinical management of osseous Ewing's sarcoma family of tumors.

Ewing family tumors: potential prognostic value of reverse-transcriptase polymerase chain reaction detection of minimal residual disease in peripheral blood samples

In more than 95% of patients, the Ewing family of tumors (ET) has chimeric transcripts caused by fusion of the EWS gene to either FLI1 or ERG. The presence of specific EWS-FLI1 or EWS-ERG transcripts in peripheral blood (PB) samples of patients being treated for ET was prospectively evaluated, and these data were correlated to their clinical status. The authors studied 113 PB samples from 28 patients with ET. Treatment included chemotherapy, radiotherapy, and surgical excision of tumor after induction therapy. PB samples were taken prospectively at least 2 weeks after resection of tumor. Nested reverse-transcriptase polymerase chain reaction (RT-PCR) followed by Southern blot was performed in all samples. Resected tumors were reviewed for the degree of response to chemotherapy and volume. Seventy-seven PB samples from 28 patients had EWS-FLI1/ERG transcripts. In 11 patients, PB samples became negative with treatment, and, in 5 of them, the samples remained negative throughout the study. Samples taken during progression were always positive and, in 4 patients, became positive before progression was clinically evident. All patients with transcripts other than EWS-FLI1 type 1 (n = 3) died from tumor progression. This is a sensitive assay to monitor circulating tumor cells in Ewing tumors. The preliminary data suggest that progression is preceded by positive samples and may be related to specific transcript types.

Presence of tumor cells in bone marrow but not in blood is associated with adverse prognosis in patients with Ewing's tumor. Société Française d'Oncologie Pédiatrique

PURPOSE

Gene fusions that result from the chromosome translocations observed in Ewing's tumor (ET) provide tumor-specific markers that can be used to detect the presence of tumor cells in peripheral blood (PB), bone marrow (BM), and stem cell collection (SCC). These markers were used to evaluate, at diagnosis, a series of 67 ET patients.

PATIENTS AND METHODS

RNA was extracted from nucleated cells from PB and BM and a nested reverse-transcriptase polymerase chain reaction (RT-PCR) was performed to search for EWS-FLI-1 or EWS-ERG fusion transcripts that resulted from the t(11;22) or t(21;22) translocations, respectively.

RESULTS

At diagnosis, 16 of 62 (26%) patients had circulating tumor cells. This was not correlated with any clinical parameter. In contrast, Ewing's cells were detected by RT-PCR in BM in 14 of 43 (33%) patients and were associated with the presence of clinically detectable metastases and a statistically significant unfavorable outcome in univariate analysis. There was no correlation between the RT-PCR results in PB and in BM.

CONCLUSION

These results suggested that the monitoring of BM but not of PB by RT-PCR might constitute an important criterion for the staging, at diagnosis, of patients with ET. Further studies should appreciate the relationship or independence of this marker toward other classical prognostic factors in ET, particularly to the presence of clinically detectable metastases.

Long-term results from the first UKCCSG Ewing's Tumour Study (ET-1). United Kingdom Children's Cancer Study Group (UKCCSG) and the Medical Research Council Bone Sarcoma Working Party

The aim of this study was to evaluate multimodal chemotherapy and radiotherapy in patients with Ewing's sarcoma. 142 (74 male, 68 female) patients were entered into the ET-1 study between 1978 and 1986. They were treated with vincristine, doxorubicin, actinomycin D, and cyclophosphamide with radiotherapy plus or minus surgery to the primary tumour. Of the 120 who had no metastases at diagnosis, 45 remain alive with a median follow-up of 11.2 years. Only 2 of those with metastases at diagnosis remain alive. The major prognostic factor was site of disease, but age and serum lactic dehydrogenase at diagnosis also had an influence on outcome. 45 of the 61 patients who survived 4 years or more had late effects documented. The type and extent were dependent on tumour site, type of local therapy, volume and dose of radiotherapy. 4 patients had second malignancies. Prospects for long-term survival have improved in patients treated for Ewing's sarcoma. However, late sequelae are present in the majority of patients.

Pharmacokinetics of high-dose intravenous melphalan in patients undergoing peripheral blood hematopoietic progenitor-cell transplantation

The pharmacokinetics of melphalan following high-dose (140 mg/m2) i.v. administration were determined in 20 patients with advanced malignancies undergoing peripheral blood hematopoietic progenitor-cell transplantation. Melphalan was assayed in plasma by a specific HPLC method with UV detection. Plasma levels of melphalan declined in a biexponential fashion with a mean terminal half-life of 83 minutes (range 52-168 minutes). Estimated peak plasma concentrations ranged from 1.65 to 14.5 micrograms/ml. Plasma levels were lower than the limit of quantitation of the method used (20 ng/ml) 24 hours after drug administration. The average volume of distribution and total clearance were 317 ml/min/m2 (range 127-797 ml/min/m2) and 37.9 l/m2 (range 15.4-108 l/m2), respectively. These parameters are similar to those reported in the literature. A weak correlation was found between total clearance of melphalan and creatinine clearance (p < 0.05). No relationship between the pharmacokinetics of melphalan and myelosuppression and non-hematologic toxicities was recovered. This pharmacokinetic study indicates that on the assumption that there is no more circulating melphalan after seven elimination half-lives, it may be possible to reinfuse autologous PBPC 10-20 hours after melphalan administration.

CD34 progenitor cell subset analyses in normal human bone marrow and marrow harvested after intermediate-dose chemotherapy

Previous attempts to characterize harvested marrow and peripheral blood stem cell (PBSC) in order to predict time to and quality of engraftment post autologous bone marrow transplant (autoBMT) have included use of in vitro colony forming unit (CFU) assays. These assays are hampered by interlaboratory variability and are not uniformly predictive. CD34 quantification by flow cytometric technique has also been used to assess the quality of harvested marrow and PBSC. However, a lack of standardization has hampered direct comparison of published reports. We sought to characterize these early lineage-committed CD34+ progenitor cells from non-ficolled harvested marrow with six progenitor cell (PC) panels containing CD34 antibody plus two additional early lineage markers, using multiparameter flow cytometry. The specific gating technique including simultaneous CD34-PE vs. side scatter and forward vs. side scatter, was verified using morphologic analyses of sorted CD34+ cells. An ungated file was initially acquired to assess total CD34+ content. A second file using a CD34 threshold was then acquired to resolve lineage-committed subsets. The % CD34+ cells as well as cells/microliter of bone marrow was calculated using cell counts at the time of marrow harvest. Bone marrow (mean total cell dose = 3.8 x 10(5)/kg), obtained from 42 normal donors for allogeneic transplantation was first analyzed. CD34+ cells comprised a mean 1.3% of non-ficolled marrow, with 328 CD34+ cells/microliter, and mean CD34+ cells collected was 4.8 x 10(6)/kg. While no significant differences in total cells harvested nor proportion of CD34+ cells was found, a significant decrease in CD34 cells/microliter (= 233, P = .0012) was found in cancer patients. The percentage of CD19+ and CD38+ progenitor cells was significantly increased, while CD5+ and CD71+ cells were decreased. The proportions of all other early lineage-committed CD34 subsets were not different. Measurement of lineage-committed CD34 progenitor cells is a useful technique to characterize harvested marrow and PBSC, and may be applied to predict time and quality of engraftment post ablative conditioning regimens.

Mobilization of tumour cells during biopsy in an infant with Ewing sarcoma

Ewing sarcoma and the closely related peripheral primitive neuroectodermal tumour, recently referred to as Ewing tumour (ET), are characterised by unique gene rearrangements on chromosome 22. The breakpoints have been cloned and shown to fuse the Ewing sarcoma gene to one of two closely related ETS proto-oncogens, FLI-1 or ERG, which reside on chromosomes 11 and 21, respectively. The rearrangement results in the expression of specific hybrid transcripts which can be detected with high sensitivity by the reverse transcriptase polymerase chain reaction technique (RT-PCR) in primary tumours, blood and bone marrow. We report on a 7-month-old boy with a pelvic Ewing sarcoma in whom circulating tumour cells were identified in the peripheral blood during open tumour biopsy by RT-PCR. However, before and 6 days after surgery no tumour cells could be detected in the peripheral blood.

CONCLUSION

The application of RT-PCR to monitor shedding of tumour cells during surgical intervention will help to evaluate if open biopsy potentially contributes to metastatic tumour cell spread.

Intraoperative clotting factor dilution and activated hemostasis in children with Ewing's sarcoma or osteosarcoma: a prospective longitudinal study

BACKGROUND

The study was designed to evaluate prospectively intraoperative changes in coagulation and fibrinolysis in young patients with Ewing's sarcoma (n = 12) or osteosarcoma (n = 12) who underwent major surgery, and to relate them to hematocrit (HCT) readings.

MATERIALS AND METHODS

Blood samples (von Willebrand factor, fibrinogen, antithrombin III, protein C, plasminogen, t-PA ag, PAI 1 activity, F1+2, D-dimer, PAP) were obtained immediately prior to starting anesthesia, two and four hours later, immediately after surgery and on the first postoperative day. Intra- and postoperative hemostatic parameters were adjusted to preoperative HCT readings.

RESULTS

Major surgery induced dilution coagulopathy due to blood product transfusion to support the patient's vascular volume. Postoperatively, VWF (0.01) and fibrinogen (0.007) were found to be significantly enhanced, whereas antithrombin III levels were significantly (0.007) decreased. D-dimer formation showed a clear, significant (0.0019) rise two hours after skin incision and remained elevated through the first postoperative day. F1+2 and PAP showed only minor deviations. T-PA (0.012) and PAI 1 (0.001) rose during the operation and normalized on the first postoperative day. Within 36 hours of the initial operation, six of the 24 patients (25%) returned to surgery to stop severe hemorrhage.

CONCLUSIONS

These findings indicate that hemostatic parameters may be useful when monitoring surgery- and transfusion-induced hemostatic imbalance. Furthermore, the significant differences between the HCT-uncorrected concentration of the various plasma proteins clearly demonstrated the need to use HCT correction factors which may influence the necessity for and/or the frequency of substitution therapy with protein concentrates.

Cytokine levels and systemic toxicity in patients undergoing isolated limb perfusion with high-dose tumor necrosis factor, interferon gamma, and melphalan

PURPOSE

Isolated limb perfusion (ILP) with tumor necrosis factor (TNF), interferon gamma, and melphalan (M) has been reported to result in high response rates for extremity melanoma and sarcoma. We have evaluated the relationship of systemic TNF exposure to induction of several secondary mediators and incidence of systemic toxicity.

PATIENTS AND METHODS

Nineteen patients with extremity melanoma (n = 16) or sarcoma (n = 3), underwent 90-minute ILP with TNF-alpha, interferon gamma (0.2 mg), and M (10 to 13 mg/L of limb volume) (TNF/IFN/M) (n = 12), or M alone (n = 7). Continuous intraoperative monitoring (CIM) for systemic leak from the perfusion circuit was performed using radioactive iodine-131 albumin. Cytokine levels in the perfusate and systemic circulation during and after ILP were measured by enzyme-linked immunosorbent assay.

RESULTS

Systemic leaks > or = 1% from the perfusion circuit occurred in six patients who received TNF/IFN/M and in four who received M alone. Hypotension that required vasopressor support occurred in six of six patients with evidence of a leak (> or = 1%) and zero of six patients without a leak (< 1%). These six patients had significantly higher peak systemic TNF levels during and after perfusion than patients without a leak (2.8 and 8.2 ng/mL v 0.7 and 2.0 ng/mL, respectively; P < .05). All patients who received TNF/IFN/M had significantly greater increases in systemic interleukin-6 (IL-6) levels than in patients with M alone (12,395 +/- 10,374 pg/mL v 79.4 +/- 7.2 pg/mL, respectively; P < .001). Intracellular adhesion molecule (ICAM), IL-8, and TNF-R levels were also increased after ILP with TNF/IFN/M.

CONCLUSION

ILP with TNF/IFN/M can be safely performed, as I131 albumin provides a sensitive measure of systemic leakage from the perfusion circuit. Patients with a measured leak of > or = 1% develop mild and transient postoperative hypotension with significantly higher systemic TNF levels and lower perfusate TNF levels than in patients without leaks.

Selenium concentration and glutathione peroxidase activity in blood of children with cancer

In this work we studied 205 children with cancer, aged 6 months to 7 years, who had been diagnosed as suffering from various types of neoplasm. In blood of these children we determined the selenium concentration and glutathione peroxidase activity by fluorometric and spectrophometric methods, respectively. The control group consisted of 128 healthy children. In all groups of children with cancer we observed a significantly lower selenium concentration and lowered glutathione peroxidase activity. We found statistical differences in selenium concentration between first or second and third, and between first and fourth or fifth stages of the disease, only in 3-7 year-old patients. Glutathione peroxidase activity was statistically depressed in the same age group between the first or second and third stages of the disease. Generally, there were no differences in the concentration of the microelement or in the glutathione peroxidase activity between children before and during treatment with cytostatics.

[Use of recombinant tissue plasminogen activator (rt-PA) in occluding thrombosis of a Hickman catheter after bone marrow transplantation: clinical and coagulation physiologic aspects]

A 12 year-old female patient suffering from multifocal Ewing's Sarcoma underwent bone marrow transplantation in March 1992. The donor was the patient's HLA-identical brother. On day 38 following BMT, an occluding catheter thrombosis of the superior vena cava was diagnosed. Lysis therapy using rt-PA was initiated. During therapy, serious bleeding occurred and administration was temporarily discontinued. Normalisation of previously high fibrinogen levels during an acute phase reaction was seen concomitantly with systemic fibrin and probably also fibrinogen fragments as demonstrated using the Western blot technique. Lysis therapy resulted in regained catheter patency, while thrombosis of the superior vena cava persisted. The reduction in the need for the transfusion of packed thrombocytes following lysis was seen as being a positive result. The use of rt-PA following BMT should be carefully weighed against the risks and requires careful patient observation. Due to the systemic fibrinolytic and fibrinogenolytic effects combined with mucositis and thrombocytopenia as a result of transplantation therapy, a high risk of bleeding complications seems likely.

Serum interleukin-2 receptor levels in Hodgkin disease and other solid tumors of childhood

Serum levels of interleukin-2 receptor (IL2R) were determined in children with newly diagnosed Hodgkin disease (n = 68), Wilms tumor (n = 20), osteosarcoma (n = 18), rhabdomyosarcoma (n = 18), or Ewing sarcoma (n = 15). Measurements of soluble IL2R were positively correlated with disease stage in Hodgkin disease but not in other tumors. Very high levels of soluble IL2R (> or = 5000 U/ml) were significantly associated with a poorer treatment outcome in Hodgkin disease (p = 0.006) and retained significance in a multivariate analysis (p = 0.03). The addition of soluble IL2R measurements to existing prognostic models may improve risk assignment in children with Hodgkin disease.

Serum intercellular adhesion molecule-1 in childhood malignancy

Levels of soluble intercellular adhesion molecule-1 (ICAM-1) were measured in serum samples taken at diagnosis from pediatric patients with Hodgkin's disease (n = 69), acute lymphoblastic leukemia (n = 28), Wilms' tumor (n = 20), osteosarcoma (n = 17), rhabdomyosarcoma (n = 18), or Ewing's sarcoma (n = 15). Median levels of serum ICAM-1 were significantly higher in acute lymphoblastic leukemia and Hodgkin's disease than in controls and other malignancies. Levels were positively correlated with disease stage for patients with Hodgkin's disease, Ewing's sarcoma or Wilms' tumor, and with the frequency of relapse in Hodgkin's disease (P = .016). Serum levels were normal in all of 76 patients tested in remission. It remains to be determined whether increased serum ICAM-1 levels simply reflect a greater tumor burden or whether this molecule contributes directly to the progression of childhood malignancies.

Recovery kinetics after chemotherapy and circulating mononuclear cells expressing the CD34 antigen in pediatric cancer patients

Hematopoietic progenitor cells collected from the peripheral blood are capable of restoring hematopoiesis after myeloablative therapy. The numbers of circulating mononuclear cells expressing the CD34 antigen were calculated and the colony-forming capacity was determined in 26 blood samples, which were drawn during rapid rise of leukocytes after chemotherapy cycles that were followed by aplasia. Culture assay after 14 days revealed a median 507 (210-2029) myeloid progenitors (CFU-GEMM/GM) per 10(5) nucleated cells (NC) in 13 CD34-positive samples, and only a median 76 (9-224) in 13 CD34-negative ones (p less than 0.001). Median 343 (175-2450) erythroid burst-forming units (BFU-E) per 10(5) NC were detected in the CD34-positive samples, whereas only 72 (10-315) per 10(5) NC were found in the negative ones (p less than 0.01). The percentage of CD34-positive cells clearly correlated with the growth of CFU-GEMM/GM and BFU-E (p less than 0.01). The content of CD34-positive cells in circulation was determined within 120 min by FACS analysis and predicted colony-forming capacity of circulating mononuclear cells. These observations will help to select the optimal individual days for leukaphereses.

Modulation of hematopoietic colony formation of stem cells in peripheral blood by anti-TGF-beta in patients with severe immunosuppression

The influence of transforming growth factor-beta (TGF-beta) on hematopoiesis has been evaluated by adding blocking antibodies against TGF-beta to colony forming assays (CFU-c). When optimum concentrations of recombinant growth factors, granulocyte-macrophage colony stimulating factor (GM-CSF), and interleukin-3 (IL-3) were added to stem cells from the peripheral blood of healthy individuals and certain patients with tumors or HIV infection, the anti-TGF-beta capable of blocking 5 ng/ml of active TGF-beta had no significant influence on erythroid or myeloid colony formation. However, in certain immunosuppressed individuals, anti-TGF-beta resulted in a significant decrease of erythroid colony formation and slight suppression of myeloid colony formation. The significant inhibition of hematopoiesis by plasma of HIV patients could be due to the presence of active forms of TGF-beta. The results of the blocking experiments are consistent with the concept that TGF-beta in low concentrations is essential for erythropoiesis and myelopoiesis but that higher levels of TGF-beta primarily inhibit erythropoiesis in vitro. TGF-beta serves as a coordinating factor when efficient recruitment of granulocytes and monocytes is more essential than erythropoiesis and stem cell growth.

[Intra-arterial infusion of cisplatinum in bone and soft tissue tumors]

Cisplatin was administered by intravenous injection, intra-arterial injection, and balloon-occluded arterial infusion. The total Pt, ultrafiltrated Pt, and free Pt levels were measured. Intra-arterial injection, in which ultra-filtrated Pt level on the normal side is the same as in intravenous injection, acts to increase the ultrafiltrated Pt level on the affected side. Thus, intra-arterial injection is as effective as preoperative chemotherapy. In two-route chemotherapy, free Pt level on the affected side is extremely high, so for only local control of tumors, two-route chemotherapy is very effective.

Identification and characterization of a new antithrombin III familial variant (AT Dublin) with possible increased frequency in children with cancer

The antithrombin III (ATIII) isoform pattern of a number of serum and plasma samples was analysed by isoelectric focusing and immuno-blotting. A novel ATIII isoform pattern which was observed in 4/80 children with acute lymphatic leukaemia (ALL) and in 1/4 children with Ewing's sarcoma, has been shown by family studies to be due to a mutant form of ATIII (AT Dublin) in the heterozygous state. The coagulation properties of AT Dublin heterozygotes were normal. In addition the immunological and activity levels of their ATIII were normal. The effects of thrombin and heparin on the mutant ATIII were similar to controls. Neuraminidase treatment reduced the ATIII isoforms to one in controls and two in the mutant. Two-dimensional gel analysis showed the mutant ATIII to have an identical molecular size distribution to the normal form. This mutant is, thus, most likely due to an amino acid substitution giving a more basic molecule that is clinically silent (at the coagulation level). It may be of interest that the frequency of AT Dublin in the ALL group is significantly higher than in the control group (3/430) studied (P less than 0.001).

Decreased stabilization of prostacyclin activity in patients with bone tumors

Tumor metastasis is mediated in part by platelet activation. Since prostacyclin regulates platelet activity, we examined stabilization of bioactivity of exogenous prostacyclin in plasma of patients with malignant bone tumors. Bioactivity of prostacyclin (platelet aggregation inhibition) incubated in patient plasma was found to be significantly less compared to that in normal plasma. In addition, the duration of bioactivity of prostacyclin was considerably less in plasma of patients with bone tumors. These preliminary data indicate decreased prostacyclin activity in plasma of patients with malignant bone tumors, which may be a mechanism of platelet-tumor cell aggregate formation and subsequent evolution of metastasis.