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Biomedical subjects

L E Kun

Publications and source records attributed to L E Kun.

At least 37 records · Page 2Linked to original sources

Cutaneous and subcutaneous Ewing's sarcoma: an indolent disease.

PURPOSE: The occurrence of extraosseous Ewing's sarcoma (ES) in deep soft tissues has been well described, but cases in which this tumor occurs in a primary cutaneous or subcutaneous site have rarely been reported. The superficial variant may be less aggressive than are the more common bony and deep soft tissue counterparts with an apparently favorable outcome. A retrospective review of patients with cutaneous or subcutaneous ES was conducted to analyze outcome and patterns of failure. METHODS AND MATERIALS: Between July 1985 and March 1997, 14 patients with cutaneous or subcutaneous ES were treated at St. Jude Children's Research Hospital. The median age at presentation was 16 years (range 7-21 years). Anatomic locations included trunk and pelvis (7), upper or lower extremity (4), and head and neck (3). The median size of the lesion was 3 cm (range, 1-12 cm). Thirteen had definitive surgical resections, and one had biopsy of the mass at the time of referral. They were enrolled on institutional (12) or cooperative group (2) protocols. All patients received chemotherapy, composed of vincristine, doxorubicin, cyclophosphamide, ifosfamide, etoposide, and dactinomycin. Patients on institutional protocols received radiation (36 Gy) to the operative bed (150-180 cGy/fraction/day). Postoperative radiotherapy was omitted for 2 patients who had complete resection on the cooperative group study. RESULTS: No patients had metastatic disease at presentation. Thirteen patients had wide local excision of the primary tumors prior to enrollment on chemotherapy; surgical margins were negative (10), microscopically positive (2), and indeterminate (1). Eleven patients received radiotherapy to the tumor bed; 2 with clear surgical margins were treated without irradiation. The patient who had biopsy only received induction chemotherapy followed by definitive surgical resection and postoperative radiotherapy. The median follow-up was 77 months (range 17-111 months). None of the patients has developed local recurrence or distant metastasis. Several of the patients developed treatment-related sequelae, including veno-occlusive disease of the lung and hemorrhagic cystitis (1), myelodysplastic syndrome (1), chemotherapy-induced ovarian failure (1), moist desquamation (1), and dermatofibroma within the radiotherapy volumes (1). CONCLUSIONS: Cutaneous and subcutaneous ES are associated with an indolent course and a favorable prognosis when treated with combined modality therapy. Elimination of radiation therapy following complete resection has been tested in the POG 9354 trial. The high rate of local control, low rate of metastatic disease, and excellent overall outcome may suggest a role for less intensive chemotherapy, as well as tailoring to diminish or avoid radiation therapy in completely resected cases, with a goal to minimize toxicity while maintaining a high cure rate.

Adolescent↗

Subtle white matter volume differences in children treated for medulloblastoma with conventional or reduced dose craniospinal irradiation.

Medulloblastoma is the most common malignant brain tumor in children, and approximately seventy percent of average-risk patients will achieve long-term survival. Craniospinal irradiation (CSI), combined with chemotherapy and surgery, is currently the mainstay of treatment but places children who survive at risk for serious neurocognitive sequelae. These sequelae are intensified with a younger age at treatment, greater elapsed time following treatment, and an increased radiation dose. Many newer treatment approaches have attempted to address this problem by reducing the dose of the CSI component of radiation therapy while maintaining the current survival rates. This study evaluates longitudinal MR imaging during therapy to assess the impact of the two CSI doses (conventional [36 Gy] and reduced [23.4 Gy]) on normal appearing white matter volumes (NAWMV) evaluated in a single index slice. Twenty-six children and young adults at least three years of age enrolled on an institutional protocol for newly diagnosed, previously untreated primary medulloblastoma had at least four MR examinations over a minimum nine month period following CSI. These serial volumes were evaluated as a function of time since CSI in three analyses: 1) all subjects, 2) subjects stratified by age at CSI, and 3) subjects stratified by CSI dose. The first analysis demonstrated that medulloblastoma patients treated with CSI have a significant loss of NAWMV in contradistiction to normally expected maturation. Stratifying the patients by age at CSI found no significant differences in the rate of NAWMV loss. The final analysis stratified the patients by CSI dose and revealed that the rate of NAWMV loss was 23% slower in children receiving reduced-dose. Serial quantitative MR measures of NAWMV may provide a neuroanatomical substrate for assessing functional impact of CSI on normal brain function following treatment for medulloblastoma.

Adolescent↗

Long-term results of Total Therapy studies 11, 12 and 13A for childhood acute lymphoblastic leukemia at St Jude Children's Research Hospital.

We present the long-term results of three consecutive clinical trials (Total Therapy studies 11, 12 and 13A) conducted for children with newly diagnosed acute lymphoblastic leukemia (ALL) between 1984 and 1994. In study 11 (1984-1988), the overall event-free survival rates (+/-1 s.e.) were 71.8 +/- 2.4% and 69.3 +/- 2.4%, and the cumulative risks of isolated central nervous system (CNS) relapse 5.6 +/- 1.2% and 5.9 +/- 1.3%, at 5 and 10 years, respectively. In study 12 (1988-1991), event-free survival rates were 67.6 +/- 3.4% and 61.5+/- 9.0%, and isolated CNS relapse rates were 10.4 +/- 2.3% and 10.4 +/- 2.3%, respectively. Early intensive intrathecal therapy in study 13A (1991-1994) has yielded a very low 5-year isolated CNS relapse rate of 1.2 +/- 0.9%, boosting the 5-year event-free survival rate to 76.9 +/- 3.3%. Factors consistently associated with an adverse prognosis included male sex, infant or adolescent age group, leukocyte count >100 x 10(9)/l, nonhyperdiploidy karyotype and poor early response to treatment. Risk classification based on age and leukocyte count had prognostic significance in B-lineage but not T-lineage ALL. Early therapeutic interventions or modifications for patients with specific genetic abnormalities or persistent minimal residual leukemia may further improve long-term results.

Central Nervous System Neoplasms↗

"Large cell/anaplastic" medulloblastomas: a Pediatric Oncology Group Study.

495 medulloblastomas (MBs) from 6 Pediatric Oncology Group (POG) protocols were reviewed to assess the incidence and prognostic significance of "large cell" and "anaplastic" variants. "Large cell" medulloblastomas (LC MBs) were those with focal or diffuse, large, round neoplastic cells with prominent nucleoli. "Anaplastic" MBs (A MBs) were those with nuclei that were also large but markedly atypical with coarse chromatin and irregular shapes. Twenty-one cases were identified in the combined LC/A MB group, comprising about 4% of all MBs. Survival curves and Kaplan-Meier estimates of survival probabilities were examined separately for the LC/A MB and control groups. The logrank test for detecting poorer survival in the 21 cases was significant (p < 0.0001). Fluorescence in situ hybridization for c-myc showed amplification in 4 of 11 cases of the LC/A phenotype and 1 additional case of high level gain at 8q24 was disclosed by comparative genomic hybridization. Comparative genomic hybridization confirmed c-myc amplification and found evidence for isochromosome 17q in 3 of 4 LC/A cases studied successfully. One additional tumor showed high level gain restricted to 2p13 consistent with n-myc amplification. Monosomy 22, common in atypical teratoid/rhabdoid tumors, was not found. These results suggest that LC/A MB phenotype could be, at least in part, a correlate of c-myc, and possibly n-myc, amplification. The study thus confirms original observations about the LC MB in regard to histological features, immunohistochemical findings, c-myc amplification, cytogenetic findings, and poor prognosis.

Anaplasia↗

Carboplatin is effective therapy for young children with progressive optic pathway tumors: a Pediatric Oncology Group phase II study.

The Pediatric Oncology Group conducted a phase II study to evaluate the activity of carboplatin in children 5 years or younger with progressive optic pathway tumors (OPTs). Of the 51 patients accrued to this study, 1 was not eligible because the child was older than 6 years. Fifty patients were eligible and had either neuro-imaging or symptomatic evidence of progressive OPTs. Twenty-one of 50 had evidence of neurofibromatosis type I (NF-1). Therapy consisted of carboplatin 560 mg/m2 at 4-week intervals. Patients with stable disease or better after two courses were continued on therapy for 18 months or until progressive disease. Of the 50 eligible children, 39 had stable disease or better, and 34 completed the 18-month therapy. Our data are sufficient to conclude that the proportion of objective responses (complete, partial, or minor response or stable disease) exceeded 30% (P < 0.00001), and the approximate 95% confidence interval estimate of the objective response rate was 0.665 to 0.895. Twenty-one patients went off protocol because of progressive disease. Fifteen patients progressed during the 18-month therapy, and 6 patients progressed after completing therapy. Six children died with progressive disease. Major toxicities were neutropenia and thrombocytopenia, and 3 children experienced allergic reactions. Carboplatin is active and safe for the treatment of young children with progressive OPTs. The addition of other potentially active drugs may further increase the event-free survival for these children.

Antineoplastic Agents↗

Pediatric low-grade and ependymal spinal cord tumors.

Our institutional experience with pediatric spinal cord tumors includes 25 patients with the diagnosis of ependymoma (EP; n = 4), myxopapillary ependymoma (MPEP; n = 4), juvenile pilocytic astrocytoma (JPA; n = 5), nonpilocytic astrocytoma (WHO grade I or II, n = 6), and other nonastrocytic spinal cord tumors (n = 6) treated during the period 1974-1999. Nineteen patients required radiation therapy (RT). The median progression-free survival following RT was 65 months (range 1-206 months). Seven patients recurred at an average of 22 months. The EP patients recurred at an average of 8.5 months, while the patients with low-grade astrocytoma recurred at an average of 42 months. Including the 6 nonsurviving patients, the median overall survival was 96 months. Two EP patients died with a progression-free survival of 9 months. One patient with MPEP died of other causes at 7 months. The treatment of pediatric spinal cord tumors should be individualized based on the histologic type. Radical surgery is indicated for nonmyxopapillary EP and low-grade astrocytic tumors. The need for adjuvant therapy most often depends on the extent of resection as well as the tumor type. Patients with disseminated EP, MPEP, JPA and nonpilocytic astrocytoma may achieve long-term progression-free survival with craniospinal irradiation.

Adolescent↗

Low-stage medulloblastoma: final analysis of trial comparing standard-dose with reduced-dose neuraxis irradiation.

PURPOSE: To evaluate prospectively the effects on survival, relapse-free survival, and patterns of relapse of reduced-dose (23.4 Gy in 13 fractions) compared with standard-dose (36 Gy in 20 fractions) neuraxis irradiation in patients 3 to 21 years of age with low-stage medulloblastoma, minimal postoperative residual disease, and no evidence of neuraxis disease. PATIENTS AND METHODS: The Pediatric Oncology Group and Children's Cancer Group randomized 126 patients to the study. All patients received posterior fossa irradiation to a total dose of 54 Gy in addition to the neuraxis treatment. Patients were staged postoperatively with contrast-enhanced cranial computed tomography, myelography, and CSF cytology. Of the registered patients, 38 were ineligible. RESULTS: The planned interim analysis that resulted in closure of the protocol showed that patients randomized to the reduced neuraxis treatment had increased frequency of relapse. In the final analysis, eligible patients receiving standard-dose neuraxis irradiation had 67% event-free survival (EFS) at 5 years (SE = 7.4%), whereas eligible patients receiving reduced-dose neuraxis irradiation had 52% event-free survival at 5 years (SE = 7.7%) (P =.080). At 8 years, the respective EFS proportions were also 67% (SE = 8.8%) and 52% (SE = 11%) (P =.141). These data confirm the original one-sided conclusions but suggest that differences are less marked with time. CONCLUSION: Reduced-dose neuraxis irradiation (23.4 Gy) is associated with increased risk of early relapse, early isolated neuraxis relapse, and lower 5-year EFS and overall survival than standard irradiation (36 Gy). The 5-year EFS for patients receiving standard-dose irradiation is suboptimal, and improved techniques and/or therapies are needed to improve ultimate outcome. Chemotherapy may contribute to this improvement.

Adolescent↗

High incidence of secondary brain tumours after radiotherapy and antimetabolites.

BACKGROUND: Brain tumours rarely occur in survivors of childhood acute lymphoblastic leukaemia after cranial radiotherapy. An unusually high frequency of brain tumours seen among children enrolled in one of our leukaemia treatment protocols, Total Therapy Study XII, prompted us to identify the potential causes of this complication. METHODS: We assessed clinical, biological, and pharmacokinetic features in all 52 children who received prophylactic cranial radiotherapy. We compared the cumulative incidence of brain tumours between subgroups, and with that of 421 children who received radiotherapy in previous studies. FINDINGS: The incidence of brain tumours among irradiated children (six of 52, 12.8% [SE 5.0]) was high compared with patients in the same study who did not receive radiotherapy (none of 101; p=0.0008) and with other protocols that included cranial radiotherapy (p<0.0001). Of the six children, four had erythrocyte concentrations of thioguanine nucleotide metabolites higher than the 70th percentile for the entire cohort, and three had a genetic defect in thiopurine catabolism. The 8-year cumulative incidence of brain tumour among children with defective versus wild-type thiopurine methyltransferase phenotype was 42.9% (SE 20.6) versus 8.3% (4.7; p=0.0077). This protocol differed from previous protocols, in that more intensive systemic antimetabolite therapy was given before and during radiotherapy. INTERPRETATION: These data support the elimination of prophylactic radiotherapy for acute lymphoblastic leukaemia except in patients at high risk of central-nervous-system relapse. Underlying genetic characteristics and treatment variables may be associated with an increased risk of radiation-associated brain tumours.

Adolescent↗

Long-term follow-up of patients treated with primary radiotherapy for supradiaphragmatic Hodgkin's disease at St. Jude Children's Research Hospital.

OBJECTIVE: To assess disease control, patterns of relapse, factors predictive of relapse, and late effects of treatment, we reviewed all cases of supradiaphragmatic (SD) Hodgkin's disease (HD) treated with primary radiation therapy (RT) at our institution. METHODS: We retrospectively reviewed the disease characteristics, treatment history, and long-term outcome of the 106 patients with Stage I and II supradiaphragmatic HD who received definitive irradiation at St. Jude Children's Research Hospital between 1970 and 1995. As of the date of analysis, 95 patients are alive, with a median follow-up of 13.3 years (range, 1.9-24.2 years). RESULTS: The median age at diagnosis was 14.7 years (range, 3.7-22.7). Involved-field RT was given to 13 patients (12%), whereas 37 (35%) had mantle RT, 51 patients (48%) had subtotal nodal irradiation, and 5 (5%) had total nodal irradiation. Relapsed disease developed in 26 patients at a median of 1.8 years (range, 0.2-9.3 years). The 5- and 10-year estimated cumulative incidences of relapse were 20.9% +/- 4.0% and 25.1% +/- 4.3%, respectively. With a median dose of 36 Gy (range, 32-40), in-field failure rate was 6.2%, whereas subdiaphragmatic relapse in sites irradiated prophylactically was 1.5%. There was a trend toward an increased incidence of relapse with higher ESR (p = 0.088) and greater number of sites of disease (p = 0.087). Age, stage, histology, nodal disease > or = 6 cm, the presence of bulky mediastinal disease, and the method of staging did not affect the incidence of relapse. The pattern of failure could not be predicted based on the stage of disease, the extent of subdiaphragmatic staging, the extent of radiation therapy, or the sequence of RT fields-"ping pong" vs. sequential. Subset analysis of Stage II patients revealed significantly more relapses in clinically staged patients. Excluding Stage IA patients with high cervical disease or peripheral nodal disease, nodal extension failures were more common for patients undergoing limited-volume RT, whereas extranodal relapses were likely after STNI or TNI. The estimated 10- and 15-year cumulative incidences of second malignancies were 2.9% +/- 1.6% and 7.9% +/- 3.3%, respectively. Our patients are at increased risk of second malignancies (11-fold), and fatal cardiac (68-fold) and infectious (33-fold) complications. Overall survival at 10 years was 90.8% +/- 3.2%; event-free survival was 72.1% +/- 5.0%. CONCLUSIONS: The current analysis confirms the curative potential of RT for HD in children and adolescents. Despite successful salvage therapy, relapsed disease remained the principal cause of death in our cohort. Excess risk of septic death in asplenic patients, fatal heart disease, and second malignancies may further compromise the ultimate cure of HD in long-term survivors.

Adolescent↗

Pediatric choroid plexus neoplasms.

PURPOSE: Choroid plexus tumors (CPT) are rare childhood neoplasms. The relatively small number of reported cases and the controversies surrounding the clinical and pathological classification of these tumors have made it difficult to define a standard of care for these patients. Our intention is to contribute to the body of knowledge of these tumors and further define the role of adjuvant therapy. METHODS AND MATERIALS: We performed a retrospective review of 14 children with choroid plexus neoplasms referred to St. Jude Children's Research Hospital between October 1985 and December 1987. Ten patients had choroid plexus carcinoma (CPC) based on pathologic criteria and evidence of brain invasion at surgery or leptomeningeal disease (M+); 4 patients had choroid plexus papilloma (CPP). Patients with CPP were initially treated with surgery alone whereas patients with CPC were generally treated with postoperative therapy that included chemotherapy (CT) and/or craniospinal irradiation (CSI) with a focal boost to the primary site. For most patients CT consisted of combinations of cyclophosphamide, etoposide, vincristine, and a platinum agent. The median CSI dose was 35.2 Gy (range 24-46.2 Gy). The median primary site dose was 55.2 Gy (range 49.6-64 Gy). RESULTS: Seven of the 10 CPC cases presented with leptomeningeal dissemination; two of these patients have succumbed to disease. Of the 3 patients with M0 status, all are alive with no evidence of disease (NED). The medial time to relapse from the time of surgery was 5.3 mo (range 3-25 mo). Seven CPC patients were treated with gross total resection (GTR). Three of these patients (2 M0, 1 M+) received CT without CSI and are currently NED (27, 69, and 60 mo respectively). One M+ patient progressed on CT and has stable disease after CSI (6 mo), one (M0) received CT and CSI and is NED (120 mo), one (M+) is currently on CT with objective response (3 mo) and one (M+) died of progressive disease (24.5 mo) despite CT and CSI. Three patients with CPC had subtotal resection (STR). One of these patients (M+) received CT and CSI and is NED (23 mo), one (M0) had an elective second resection GTR alone and is currently NED (153 mo), and one (M+) developed progressive disease (13.5 mo) while on CT and died despite CSI. Among the 4 CPP patients, GTR was performed in two; both were NED at 54 and 81 mo. Two patients with CPP (one with focal atypia) were treated with STR initially; both transformed to CPC at 7 and 27 mo, respectively. Both were currently NED following salvage with (1) GTR and CSI alone (98 mo) or (2) STR, CT, and CSI (62 mo). Six of the 12 survivors in this series had significant neuropsychological sequelae. CONCLUSION: The prognosis of CPP is good for patients treated with GTR. Malignant transformation occurred in 2 CPP patients with less than GTR. Patients with localized CPC who undergo GTR have had a favorable outcome with the addition of chemotherapy or irradiation. CSI may not be routinely indicated in M0 children following GTR. There is evidence that salvage with radiation therapy may be successful following progression on chemotherapy. For patients treated with STR, the use of CT and CSI appears to be necessary.

Adolescent↗

There is no role for hyperfractionated radiotherapy in the management of children with newly diagnosed diffuse intrinsic brainstem tumors: results of a Pediatric Oncology Group phase III trial comparing conventional vs. hyperfractionated radiotherapy.

PURPOSE: In June 1992, POG began accrual to a phase III study, POG-9239, designed to compare the time to disease progression, overall survival, and toxicities observed in children with newly diagnosed brainstem tumor treated with 100 mg/m2 of infusional cisplatin and randomized to either conventional vs. hyperfractionated radiotherapy. METHODS AND MATERIALS: Patients eligible for study were those between 3 and 21 years of age with previously untreated tumors arising in the pons. Histologic confirmation of diagnosis was not mandatory, provided that the clinical and MRI scan findings were typical for a diffusely infiltrating pontine lesion. Treatment consisted of a six-week course of local field radiotherapy with either once a day treatment of 180 cGy per fraction to a total dose of 5400 cGy (arm 1) or a twice a day regimen of 117 cGy per fraction to a total dose of 7020 cGy (the second of the three hyperfractionated dose escalation levels of POG-8495) (arm 2). Because of previously reported poor results with conventional radiotherapy alone, cisplatin was included as a potential radiosensitizer in an attempt to improve progression-free and ultimate survival rates. Based on results of the phase I cisplatin dose escalation trial, POG-9139, 100 mg/m2 was chosen for this trial and was delivered by continuous infusion over a 120-hour period, beginning on the first day of radiotherapy and repeated during weeks 3 and 5. One hundred thirty eligible patients were treated on protocol, 66 on arm 1 and 64 on arm 2. RESULTS: The results we report are from time of diagnosis through October 1997. For patients treated on arm 1, the median time to disease progression (defined as time to off study) was 6 months (range 2-15 months) and the median time to death 8.5 months (range 3-24 months); survival at 1 year was 30.9% and at 2 years, 7.1%. For patients treated on arm 2, the corresponding values were 5 months (range 1-12 months) and 8 months (range 1-23 months), with 1- and 2-year survival rates at 27.0% and 6.7%, respectively. Evaluation of response by MRI at 4 or 8 wks post treatment was available in 108 patients and revealed a complete response in 1 patient of each Rx arm, a partial response (> 50% decrease in size) in 18 patients of arm 1 and 15 patients of arm 2, minimal to no response (stable) in 25 patients of arm 1 and 23 patients of arm 2, and progressive disease in 13 patients of arm 1 and 12 patients of arm 2. The pattern of failure was local in all patients. Morbidity of treatment was similar in both Rx arms, with no significant toxicity (including hearing loss) reported. Autopsy was performed in 6 patients, and confirmed the presence of extensive residual tumor in these cases. CONCLUSION: The major conclusion from this trial is that the hyperfractionated method of Rx 2 did not improve event-free survival (p = 0.96) nor did it improve survival (p = 0.65) over that of the conventional fractionation regimen of Rx 1, and that both treatments are associated with a poor disease-free and survival outcome.

Adolescent↗

Neurocognitive deficits in medulloblastoma survivors and white matter loss.

Although previous studies have documented a significant risk of intellectual loss after treatment for childhood medulloblastoma (MED), the pathophysiology underlying this process is poorly understood. The purpose of this study was to test the hypotheses that (1) patients treated for MED in childhood have reduced volumes of normal white matter (NWM) related to their treatment with craniospinal irradiation with or without chemotherapy, and (2) deficits in NWM among patients surviving MED can at least partially explain deficits in their intellectual performance. Eighteen pediatric patients previously treated for MED were matched on the basis of age at the time of evaluation to 18 patients previously treated for low-grade posterior fossa tumors with surgery alone (mean difference, 3.7 months). Evaluations were conducted with age-appropriate neurocognitive testing and quantitative magnetic resonance imaging by using a novel automated segmentation and classification algorithm constructed from a hybrid neural network. Patients treated for MED had significantly less NWM (p < 0.01) and significantly lower Full-Scale IQ values than those treated for low-grade tumors (mean, 82.1 vs 92.9). In addition, NWM had a positive and statistically significant association with Full-Scale IQ among the patients treated for MED. We conclude that irradiation- or chemotherapy-induced destruction of NWM can at least partially explain intellectual and academic achievement deficits among MED survivors.

Adolescent↗

Hypothalamic obesity caused by cranial insult in children: altered glucose and insulin dynamics and reversal by a somatostatin agonist.

OBJECTIVE: Hypothalamic obesity is a rare sequela of cranial insult, for which pathogenesis and treatment remain obscure. In rodents ventromedial hypothalamic damage causes hyperphagia, obesity, hyperinsulinism, and insulin resistance. Reduction of insulin secretion in humans may attenuate weight gain. METHODS: Eight children with intractable obesity after therapy for leukemia or brain tumors underwent oral glucose tolerance testing (OGTT) with simultaneous insulin levels before and after treatment with octreotide for 6 months. RESULTS: In comparison with a 6-month pre-study observation period, patients exhibited weight loss (+6.0 +/- 0.7 kg vs -4.8 +/- 1.8 kg; P =.04) and decrease in body mass index (+2.1 +/- 0.3 kg/m(2) vs -2.0 +/- 0.7 kg/m(2); P =.0001). Recall calorie count decreased during the 6 months of treatment (P =. 015). OGTT demonstrated biochemical glucose intolerance in 5 of 8 patients initially and in 2 of 7 at study end, whereas insulin response was decreased (281 +/- 47 microU/mL vs 114 +/- 35 microU/mL; P =.04). Percent weight change correlated with changes in insulin response (r = 0.72, P =.012) and changes in plasma leptin r = 0.76, P =.0004). CONCLUSIONS: Patients with hypothalamic obesity demonstrate excessive insulin secretion. Octreotide administration promoted weight loss, which correlated with reduction in insulin secretion on OGTT and with reduction in leptin levels. Pre-study biochemical glucose tolerance improved in several patients while they were receiving octreotide. These results suggest that normalization of insulin secretion may be an effective therapeutic strategy in this syndrome.

Adolescent↗

Topotecan for the treatment of recurrent or progressive central nervous system tumors - a pediatric oncology group phase II study.

Topotecan was studied as a 72 h infusion given every 3 weeks. Treatment began at a dose of 1.0 mg/m2/day and was increased to 1.25 mg/m2/day after the first 6 patients tolerated this higher dose without excessive toxicities. Eighty-eight evaluable children were accrued in 6 strata. There were no complete nor partial responses. Twenty subjects had stable disease (astrocytoma 5/11, malignant glioma 5/13, medulloblastoma 0/12, brain stem tumor 4/19, ependymoma 5/17, and miscellaneous histologies 1/16). Two patients (astrocytoma, ependymoma) completed the maximum 18 topotecan courses. The remaining 68 children developed progressive disease within 2 months. Myelosuppression was the main toxicity. Grade 4 leukopenia, neutropenia, anemia, and thrombocytopenia were observed in 18, 32, 5, and 23 participants, respectively. It was concluded that topotecan as given according to this schedule showed insufficient activity to promote it to frontline protocol usage.

Adult↗

Diagnostic markers in paediatric medulloblastoma: a Paediatric Oncology Group Study.

AIMS: We have reviewed immunohistochemically 17 paediatric medulloblastomas in order to determine if correlations exist that might be useful in subclassifying these tumours. METHODS AND RESULTS: The patient group included 11 children who had died (mean survival 13 months) and six still alive (followed for up to 10 years). Ten tumours were diffuse and six were nodular (one biopsy had only perivascular tumour). Of the 10 diffuse tumours, three were desmoplastic: of the six nodular tumours, all six were desmoplastic. All 17 tumours were synaptophysin-reactive: three nodular tumours were glial fibrillary acidic protein (GFAP)-reactive in the nodules (two of three S 100-reactive tumours were also GFAP-reactive). MIB-1 labelling indices (LI) ranged from 5 to 80%. Six tumours exhibited at least 1% LI against Tp53 (Mab D07 and/or Mab 1801). Eight cases were 100% bcl2-reactive with nine cases having an LI <80% ('low labelling'). All nine 'low labelling' bcl2 cases were TP53 non-reactive; all six Tp53-reactive cases were bcl2 100% reactive. Six of 10 patients with diffuse medulloblastomas survived 18 months or less while four of 10 are alive up to 10 years. In contrast, five of six patients with nodular neoplasms died within 48 months of diagnosis with one patient followed up for less than 1 year. CONCLUSIONS: Immunohistochemistry is a useful adjunct in characterizing subsets of paediatric medulloblastomas and confirms that larger co-operative studies may be fruitful in identifying a prognostic utility of a combined histochemical/immunohistochemical analysis on these tumours.

Adolescent↗

High-grade pediatric spinal cord tumors.

Our institutional experience with high-grade pediatric spinal cord tumors includes 11 children treated during the period of 1981-1997. All patients underwent a biopsy or an attempt at resection and received postoperative radiation therapy. Three patients had a gross-total resection of their primary tumor, 6 patients had a subtotal resection and the remaining 2 were biopsied. Histologically, these tumors were characterized as anaplastic astrocytoma (n = 6), glioblastoma multiforme (n = 3) or anaplastic oligodendroglioma (n = 2). Three patients were treated with craniospinal irradiation (38-48 Gy) in addition to a boost to the residual tumor. The median dose to the primary site for all patients was 48.6 Gy (range 38-55 Gy). The median overall survival was 13 months (range 8-149 months). Only 2 patients were alive at 138 and 149 months following radiation therapy. The median progression-free survival following radiation therapy was 10 months (range 2-80 months). There was no difference in progression-free or overall survival for those diagnosed with glioblastoma multiforme when compared to patients diagnosed with anaplastic astrocytoma or anaplastic oligodendroglioma. The pattern of failure was either diffuse or local. For the patients who failed diffusely (n = 6), the median progression-free survival was 2 months compared to 23 months for those whose failure was entirely local (p < 0.01). The median overall survival was significantly shorter for those who failed diffusely compared to those who failed locally (10 vs. 37 months, p < 0.01). High-grade spinal cord tumors in children have a poor prognosis based on this report. It is important to document the extent of disease accurately prior to the initiation of radiation therapy, since a subset of these patients progress rapidly outside of the field of irradiation.

Child↗

Malignant evolution of choroid plexus papilloma.

Choroid plexus tumors are rare CNS neoplasms. The distinction between choroid plexus papilloma (CPP) and choroid plexus carcinoma (CPC) is made on the basis of clinical and histological criteria. Malignant evolution of CPP may occur, and the presence of mitotic figures in CPP may predict the likelihood of recurrence or malignant evolution. Close surveillance is mandated for these patients. We report on two such cases of CPP that transformed to CPC at the time of recurrence.

Cell Transformation, Neoplastic↗