A simulation-based comparison of the traditional method, Rolling-6 design and a frequentist version of the continual reassessment method with special attention to trial duration in pediatric Phase I oncology trials.

The traditional method (TM), also known as the 3+3 up-and-down design, and the continual reassessment method (CRM) are commonly used in Phase I oncology trials to identify the maximum tolerated dose (MTD). The rolling-6 is a relative newcomer which was developed to shorten trial duration by minimizing the period of time during which the trial is closed to accrual for toxicity assessment. In this manuscript we have compared the performance of these three approaches via simulations not only with respect to the usual parameters such as overall toxicity, sample size and percentage of patients treated at doses above the MTD but also in terms of trial duration and the dose chosen as the MTD. Our results indicate that the toxicity rates are comparable across the three designs, but the TM and the rolling-6 tend to treat a higher percentage of patients at doses below the MTD. With respect to trial duration, rolling-6 leads to shorter trials compared to the TM but not compared to the CRM. Additionally, the doses identified as the MTD by the TM and the rolling-6 differ in a large percentage of trials. Our results also indicate that the body surface area-based dosing used in pediatric trials can make a difference in dose escalation/de-escalation patterns in the CRM compared to the cases where such variations are not taken into account in the calculations, even leading to different MTDs in some cases.

Health status in long-term survivors of pediatric craniopharyngiomas.

Craniopharyngiomas are the third most common pediatric brain tumor and most common pediatric suprasellar tumor. Contemporary treatment of craniopharyngiomas uses limited surgery and radiation in an effort to minimize morbidity, but the long-term health status of patients treated in this fashion has not been well described. The purpose of this study was to analyze the health status of long-term survivors of pediatric craniopharyngioma treated primarily with radiation and conservative surgical resection. Medical records of all long-term survivors of craniopharyngioma treated at St. Jude Children's Research Hospital and then transferred to the long-term follow-up clinic were reviewed. The initial cohort comprised 55 patients. Of these, 51 (93%) were alive at the time of this analysis. The median age at diagnosis was 7.1 years (range, 1.2-17.6 years), and 29 (57%) were male. At the time of analysis, the median survival was 7.6 years (range, 5.0-21.3 years). Diagnosis and treatment included surgical biopsy, resection (n = 50), and radiation therapy (n=48). Only 1 patient received chemotherapy. Polyendocrinopathy was the most common morbidity, with hypothyroidism (96%), adrenocorticotropic hormone deficiency (84%), and diabetes insipidus (53%) occurring most frequently. Half of the patients were hypogonadal, and 33 (65%) were overweight or obese. The most common neurologic problems included shunt dependence (37%), seizures (28%), and headaches (39%). Psychological and educational deficits were also identified in a significant number of these individuals. Despite efforts to reduce morbidity in these patients, many survivors remain burdened with significant medical complications. In a small percentage of patients, complications may result in death even during extended remission of craniopharyngioma. Because of the broad spectrum or morbidities experienced, survivors of craniopharyngioma continue to benefit from multidisciplinary care.

Pediatric Hodgkin lymphoma survivors at negligible risk for significant bone mineral density deficits.

BACKGROUND: We hypothesized that pediatric Hodgkin lymphoma (HL) survivors would have bone mineral density (BMD) deficits compared to their peers because of osteotoxic chemotherapy during the time of greatest BMD accretion. METHODS: We retrospectively reviewed records of HL survivors returning for follow-up between 1990 and 2002. Of the 133 eligible survivors, 109 who underwent quantitative computed tomography (QCT) comprised the study group. QCT-determined BMD Z-scores were correlated with patient characteristics and therapeutic exposures by Wilcoxon rank sum or Chi-square tests. Logistic regression models were used to explore risk factors for diminished BMD. RESULTS: The study cohort was half male (50.5%) and 85.3% reported their race as white. Participants were representative of all survivors potentially eligible for study, except that more study participants were female, had hypothyroidism, and had received cyclophosphamide. Median age at diagnosis was 15.1 years (range, 3.1-20.7 years); median time between diagnosis and QCT was 7.5 years (range, 5.0-12.4 years). The proportion of HL survivors with BMD below the mean did not significantly differ from the general population (P = 0.503). However, those with BMD -1.5 SD and BMD -2.0 SD or lower (14.7% and 7.3%, respectively) exceeded that in the general population (6.7% and 2.3%, respectively; P < 0.001 for both degrees of severity). Males, diagnosed at 14 years or older, were at 6.5 times higher risk than females (OR 95% CI: 1.24-34.14; P = 0.027) for BMD deficits. CONCLUSIONS: Overall, pediatric HL survivors had negligible BMD deficits. Male gender was associated with an increased risk of developing BMD deficits.

Endocrine outcomes for children with embryonal brain tumors after risk-adapted craniospinal and conformal primary-site irradiation and high-dose chemotherapy with stem-cell rescue on the SJMB-96 trial.

PURPOSE: To estimate the cumulative incidence of specific hormone deficiencies and the influence of hypothalamic-pituitary (HP) axis radiation dose in a cohort of children with embryonal brain tumors treated with risk-adapted craniospinal irradiation (CSI), conformal primary site irradiation, and high-dose chemotherapy. PATIENTS AND METHODS: Clinical data and HP axis radiation dosimetry data were obtained from 88 eligible children. All patients received regular endocrine follow-up that included screening tests of thyroid function and stimulation testing for growth hormone deficiency (GHD), and adrenocorticotropin hormone deficiency. RESULTS: The cumulative incidence of GHD, thyroid-stimulating hormone (TSH) deficiency, adrenocorticotropic hormone deficiency, and primary hypothyroidism at 4 years from diagnosis was 93% +/- 4%, 23% +/- 8%, 38% +/- 6%, and 65% +/- 7%, respectively. Radiation dosimetry to the HP axis was associated only with the development of TSH deficiency; the 4-year cumulative incidence was 44% +/- 19% and 11% +/- 8% (P = .014) for those receiving more or less than the median dose to the hypothalamus (>or= 42 v < 42 Gy), respectively. The median dose of CSI for the average-risk (AR) patients was 23.4 and 39.6 Gy (36 to 40.5 Gy) for the high-risk patients. The estimated mean decline in height Z-score after radiation therapy was greater in high-risk patients (-0.65 units/yr) when compared with AR patients (-0.54 units/yr; P = .039). CONCLUSION: Pediatric patients with CNS embryonal tumors are at high risk for treatment-related hormone deficiencies. GHD and primary hypothyroidism were diagnosed in a majority of subjects relatively soon after the completion of therapy. Radiation dose to the hypothalamus in excess of 42 Gy was associated with an increase in the risk of developing TSH deficiency.