Distinctive clinical course and pattern of relapse in adolescents with medulloblastoma

PURPOSE

To report the clinical course of adolescents with medulloblastoma, with specific emphasis on prognosis and pattern of relapse.

METHODS AND MATERIALS

We retrospectively studied the clinical course and outcomes of children aged 10-20 years with medulloblastoma, treated at centers throughout Canada between 1986 and 2003. To better assess time to relapse, a cohort of patients aged 3-20 years at diagnosis was generated.

RESULTS

A total of 72 adolescents were analyzed. Five-year overall survival and event-free survival rates were 78.3%+/-5.4% and 68.0%+/-6.2%, respectively. Late relapses occurred at a median of 3.0 years (range, 0.3-6.8 years). In univariate analysis, conventional risk stratification and the addition of chemotherapy to craniospinal radiation did not have prognostic significance. Female patients had improved overall survival (p=0.007). Time to relapse increased with age in a linear fashion. After relapse, patients faired poorly regardless of treatment modality. Patients who did not receive chemotherapy initially had improved progression-free survival at relapse (p=0.05).

CONCLUSIONS

Our study suggests that adolescents with medulloblastoma might have a unique prognosis and pattern of relapse, dissimilar to those in younger children. They might benefit from different risk stratifications and prolonged follow-up. These issues should be addressed in future prospective trials.

Weekly vinblastine in pediatric low-grade glioma patients with carboplatin allergic reaction

BACKGROUND

Carboplatin-based regimens have demonstrated activity in unresectable low-grade glioma (LGG) in children. Despite an interesting toxicity profile, the use of these regimens has been limited by the development of carboplatin hypersensitivity reaction (HSR) in up to 30% of patients. Desensitization has been the recommended approach for HSR. However, no guidelines have existed to aid physicians when carboplatin desensitization techniques fail.

METHODS

A pilot study of monotherapy with weekly vinblastine for LGG in 9 children who developed carboplatin HSR on a carboplatin and vincristine regimen was performed.

RESULTS

Vinblastine toxicity was moderate and readily manageable. None of the 9 patients had disease progression on therapy. Magnetic resonance imaging evaluation of tumor size from diagnosis to the end of vinblastine treatment showed 1 complete response (CR), 1 partial response (PR), 5 objective effects (OE), and 2 stable diseases (SD).

CONCLUSIONS

This experience suggested that weekly vinblastine has a good efficacy to toxicity ratio in the treatment of LGG and can be a valuable option for children who develop severe HSR.

Medulloblastoma in the second decade of life: a specific group with respect to toxicity and management: a Canadian Pediatric Brain Tumor Consortium Study

BACKGROUND

Most reported data of chemoradiotherapy protocols for the treatment of medulloblastoma describe children who were treated in the first decade of life. To consider the feasibility of this approach in adolescents, the authors studied their clinical course with specific emphasis on toxicity, tolerability, and prognosis.

METHODS

In this retrospective study, the authors examined the toxicity profiles and outcomes of children age 10-20 years with medulloblastoma who were treated at centers throughout Canada between 1986 and 2003. Detailed toxicity data from 2 chemotherapy protocols were collected for teenagers and were compared with data from a group of control patients age 5-10 years.

RESULTS

In total, 72 teenagers were analyzed. Grade >/= 2 ototoxicity and neurotoxicity occurred in 45% and 71% of chemotherapy-treated patients, respectively. Grade 3-4 hematotoxicty occurred in 95% of patients. Toxicity resulted in delay of treatment for 73% of patients and dose modification in 75% of patients, including protocol discontinuation in 25% of patients. Weight loss > 10% was encountered in 73% of patients and required intervention in 45% of patients. Teenagers had significantly more hematotoxicity and neurotoxicity compared with controls on both chemotherapeutic protocols. Ototoxicity was similar in both age groups. Toxicity resulted in significantly more treatment delays and dose modifications in teenager patients compared with controls. The 5-year overall and event-free survival rates (+/- standard deviation) were 78% +/- 6% and 70% +/- 6%, respectively. The mean time (+/- standard deviation) to disease recurrence was 3.2 +/- 2.2 years.

CONCLUSIONS

The increased toxicity rate and high incidence of treatment modifications in this study suggested that current pediatric protocols may require modifications for teenagers with medulloblastoma. The results highlighted several issues that should be addressed in future prospective trials.

Evolution of a T-B- SCID into an Omenn syndrome phenotype following parainfluenza 3 virus infection

Mutations in both of the recombination activating genes (RAG)1 and RAG2 can lead to either T-B-severe combined immune deficiency (SCID) or Omenn syndrome (OS), two diseases presenting with totally different clinical and laboratory manifestations. The fact that the same mutations can cause either T-B- SCID or OS, even within the same family, lends credibility to the hypothesis that an additional factor (autoantigen or exoantigen) is required in certain circumstances for the development of OS phenotype. We investigated three patients from the same extended family who presented as T-B- SCID due to a homozygous mutation (G1305T) in the RAG2 gene. Our data support the notion that mutated RAG proteins may not always be sufficient to cause OS phenotype, and show evolution from a T-B- SCID into a typical OS phenotype subsequent to parainfluenza 3 virus infection.

Risk of venous thromboembolism in pediatric patients with brain tumors

BACKGROUND

Venous thromboembolism (VTE) is a common event in adults with malignant brain tumors approaching 24% throughout the course of the disease. The high morbidity and mortality of this complication yielded several protocols for prevention of the disease in adults undergoing neurosurgery for brain tumors and possible primary prevention afterwards. We investigated the incidence and complications of VTE in pediatric neuro-oncology patients.

PROCEDURE

We analyzed, retrospectively, the files of all consecutive patients under the age of 18 years who were hospitalized for the treatment of brain tumors between the years 1990 and 2003 in two leading, closely related, Israeli neuro-oncology centers.

RESULTS

A total of 462 children were analyzed. Three hundred eighty-four patients underwent surgery and 78 were treated medically. Only three (0.64%) of the patients developed clinical episodes of VTE that were treated conservatively. Two of these patients developed intracranial bleeding while on secondary prevention for the disease.

CONCLUSIONS

Although this study has considerable limitations in terms of retrospective design, heterogeneous group of patients and diagnoses, the changing awareness for thrombosis over the last 14 years and the inclusion of symptomatic VTE events only, our surprising data suggest that, as opposed to adults, the risk of clinically significant VTE in children with brain tumors may be exceedingly low. These findings set the stage for future forthcoming evaluations in view of the prospective studies that were done in adults and the possible significant implications for the prevention and possible etiologies of the disease.

Multilineage hematopoietic engraftment after allogeneic peripheral blood stem cell transplantation without conditioning in SCID patients

Successful stem cell transplantation for patients with severe combined immunodeficiency (SCID) from matched family donors without conditioning results in engraftment of T lymphocytes. B lymphocytes engraft in only 50% of the cases, while myelopoiesis and erythropoiesis remain of host origin. Full hematopoietic engraftment was reported in one case after bone marrow transplantation without conditioning for a SCID patient. We studied three SCID patients who were transplanted with unmodified mobilized peripheral blood from HLA-identical family sex-mismatched members. They received megadoses of stem cells (18-23 x 10(6)CD34/kg). In contrast to the expected mixed chimerism that usually occurs in the absence of conditioning, we found in our patients 100% donor cell engraftment based on fluorescence in situ hybridization (FISH) and microsatellite techniques. Subset analysis of the engrafted cells using a multiparametric system enabling a combined analysis of morphology, immunophenotyping and FISH showed that both T and B lymphocytes and myeloid cells were of donor origin in two patients, while T lymphocytes and myeloid cells were of donor origin in the third. In the two cases with ABO incompatibility, erythroid engraftment was evidenced by blood group conversion from recipient to donor type. Multilineage donor engraftment is possible in SCID patients even without conditioning.

Detection of RAG mutations and prenatal diagnosis in families presenting with either T-B- severe combined immunodeficiency or Omenn's syndrome

It has been recently shown that mutations in both of the recombination activating genes RAG1 and RAG2 are involved in each of the two different types of severe combined immunodeficiency (SCID) syndromes: T-B- SCID and Omenn's syndrome (OS). The objective of the study was to search for novel mutations in the RAG genes and to offer prenatal diagnosis for families that have been identified as at risk of T-B- SCID or OS. Mutation analyses of polymerase chain reaction products of RAG1/RAG2 genes were performed in 14 cases (T-B- SCID = 6 and OS = 8). Consanguinity was reported in seven (50%) families. Four missense mutations in the RAG2 gene in six of eight OS patients and in four of six T-B- SCID patients were detected. The C1845T transition leading to a Tre215Ile substitution is a novel mutation. All but one of the patients were homozygous for the detected mutations, possibly reflecting the consanguinity in these families and the relative rarity of the disease-causing mutations. In addition, three putative polymorphic sites were found. Prenatal diagnosis was offered to seven families, but three of them declined genetic counseling for religious reasons. In the remaining families, four pregnancies were successfully completed, and in one case, the family chose to have an abortion because of a homozygous mutation. Mutations in RAG1/RAG2 genes were detected in only some of the T-B- SCID or OS patients, and the molecular basis for the remaining cases has yet to be elucidated. Important factors such as religious beliefs need to be considered when offering prenatal diagnosis to certain families.

Repeat computed tomographic scan within 24-48 hours of admission in children with moderate and severe head trauma

OBJECTIVE

To asses the yield and contribution of a routine predetermined repeat head computed tomographic (CT) scan within 24-36 hrs in pediatric patients with moderate to severe head trauma.

DESIGN

Records review.

SETTING

Five pediatric intensive care units.

PATIENTS

We reviewed the charts of 173 consecutive pediatric patients with moderate to severe head trauma (Glasgow Coma Scale score of < or = 11) that survived the first 24 hrs after being admitted to five Israeli trauma centers. Clinical data collected included status at admission, at the time between the first and second CT scans, and after the second scan. Head details of the first, second, and, if performed, third CT scan were collected. Treatment strategy during each period was recorded, including any change in treatment after each CT scan.

MEASUREMENTS AND MAIN RESULTS

A total of 47 (27%) of the second CT scans showed new lesions including six intracranial hemorrhages, 17 cases of worsening brain edema, and 18 newly diagnosed brain contusions. However, none of these findings necessitated surgical intervention or any change in therapy. Of the 67 patients who underwent a third CT scan, two cases required surgical intervention because of new findings in the third CT.

CONCLUSIONS

A second routine prescheduled head CT scan within 24-36 hrs after admission in pediatric patients with moderate to severe head trauma is unlikely to yield any change in therapy. Clinically and intracranial pressure-oriented CT scan may better select and diagnose patients who require changes in therapy, including surgery. Studies aimed to determine the ideal timing for the second are warranted.

L-thyroxine prevents the bone-conserving effect of HRT in postmenopausal women with subclinical hypothyroidism

Hypothyroidism, which is a common disorder among postmenopausal women, may be associated with higher than average bone mineral content. Contrarily, treatment with L-thyroxine may cause a significant bone loss. The aim of our study was to evaluate the effects of hormone-replacement therapy (HRT) on bone density in women with subclinical hypothyroidism treated with L-thyroxine. A total of 73 postmenopausal women with thyroid-stimulating hormone (TSH) levels > 5 mU/l and normal free thyroxine values, who never used HRT or L-thyroxine, were divided into three groups according to the treatment given during a 3-year follow-up period: 34 women received only HRT; 20 women received HRT and L-thyroxine, and the remaining 19 women received neither medications. A euthyroid control group included 41 postmenopausal women with TSH levels between 0.5 and 1.5 mU/l, who were using HRT since the initial visit. Lumbar spine bone density measurements were performed at baseline and study termination. Taken as a whole, the hypothyroid women had a non-significant higher baseline bone mineral density (BMD) as compared to the euthyroid controls (1.068 +/- 0.19 g/cm2 vs. 1.024 +/- 0.15). After 3 years, both the euthyroid and hypothyroid women on HRT only had an increase in BMD (0.032 +/- 0.04 g/cm2 and 0.028 +/- 0.05 g/cm2, respectively; p < 0.001 for both, compared to baseline). Hypothyroid women using no medication had a decrease of 0.034 +/- 0.07 g/cm2 in BMD, and those receiving both HRT and L-thyroxine lost the most: 0.04 +/- 0.08 g/cm2 (p < 0.05 for both, compared to baseline). The addition of L-thyroxine thus prevented the beneficial effect of HRT on BMD. Thyroid hormone replacement is recommended only when overt symptoms of hormone deficiency occur. In such cases, a single bone-conserving treatment with HRT may not suffice.