Phase II study of high-dose chemotherapy before radiation in children with newly diagnosed high-grade astrocytoma: final analysis of Children's Cancer Group Study 9933.

BACKGROUND: High-grade astrocytomas (HGA) carry a dismal prognosis and compose nearly 20% of all childhood brain tumors. The role of high-dose chemotherapy (HDCT) in the treatment of HGA remains unclear. METHODS: In a nationwide study, The Children's Cancer Group (CCG) prospectively evaluated 102 children with HGA and postoperative residual disease for efficacy and toxicity of four courses of HDCT before radiotherapy (RT). Patients were randomly assigned to one of three couplets of drugs: carboplatin/etoposide (Regimen A), ifosfamide/etoposide (Regimen B), or cyclophosphamide/etoposide (Regimen C). After HDCT, all patients were to receive local RT followed by lomustine and vincristine. Twenty-six patients were excluded after central neuroradiographic review (n = 8) or pathology review (n = 18). RESULTS: Of 76 evaluable patients (median age, 11.95 yrs; range, 3-20 yrs), 30 patients relapsed during HDCT, and 11 others did not complete HDCT because of toxicity. Nonhematologic serious toxicities were common (29%), and 21% of patients did not receive RT. Objective response rates were not associated with amount of residual disease and did not statistically differ between regimens: 27% (Regimen A), 8% (Regimen B), and 29% (Regimen C). Overall survival (OS) was 24% +/- 5% at 5 years and did not differ between groups. Median time to an event was longest for Regimen A (283 days compared with 83 and 91 days for Regimens B and C, respectively). The five-year, event-free survival (EFS) rate for all patients was 8% +/- 3% and 14% +/- 7% for Regimen A (P = 0.07). CONCLUSIONS: OS and EFS were not affected by histologic grade. Patients who responded to HDCT had a nominally higher survival rate (P = 0.03 for trend). The authors conclude that these commonly used HDCT regimens provide no additional clinical benefit to conventional treatment in HGA, regardless of the amount of measurable residual tumor.

Cushing's syndrome due to ectopic production of corticotropin-releasing hormone in an infant with ganglioneuroblastoma.

OBJECTIVE: To report the first recognized case of Cushing's syndrome due to a corticotropin-releasing hormone (CRH)-secreting ganglioneuroblastoma, which was found in an 18-month-old boy with hypertensive encephalopathy. METHODS: The clinical, biochemical, and immunohistochemical characteristics of this rare syndrome are described, and the relevant literature is reviewed. RESULTS: An 18-month-old boy with a history of recent weight gain was admitted because of sudden onset of right fixed esotropia and left facial palsy after episodes of emesis. Magnetic resonance imaging showed old left frontal lobe and right hypothalamic infarcts. The patient had generalized obesity, decelerated linear growth, hypertrichosis, hypertension (144/103 mm Hg), hypokalemia, and proteinuria. The 24-hour urinary excretion of free cortisol, catecholamines, and metanephrines was increased. The serum cortisol concentration after a 1-mg overnight dexamethasone suppression test (DST) was 53.7 mg/dL (normal, <5). The serum adrenocorticotropic hormone (ACTH) concentration was 7 pg/mL (normal, 10 to 60), and the CRH level was 439 pg/mL (normal, 24 to 40). An overnight high-dose DST (8 mg) failed to suppress serum cortisol; however, both cortisol and ACTH were responsive to ovine CRH stimulation. Despite discordant dynamic endocrine testing and negative somatostatin receptor scintigraphy, computed tomography showed a right 3.6- by 3.0-cm extra-adrenal retroperitoneal mass with central calcification extending 7 cm cephalocaudally. The patient underwent exploratory laparotomy, followed by chemotherapy. Findings on light microscopic and immunohistochemical examination of the retroperitoneal mass were consistent with a ganglioneuroblastoma that expressed CRH, pro-opiomelanocortin, and ACTH. CONCLUSION: The evaluation of Cushing's syndrome is one of the most complex endocrine challenges. In this case, it was due to ectopic production of CRH by a ganglioneuroblastoma. Because most CRH-producing tumors also secrete ACTH, the ectopic production may represent a paracrine phenomenon in addition to an endocrine phenomenon. The ectopic CRH may also indirectly provoke pituitary ACTH secretion. This dual mechanism may explain the resistance of the tumor to feedback inhibition and a CRH-stimulation response indistinguishable from that observed in pituitary-dependent Cushing's syndrome.