Genetic disease in the children of Danish survivors of childhood and adolescent cancer.

PURPOSE: Preconception radiation and chemotherapy have the potential to produce germ cell mutations leading to genetic disease in the next generation. Dose-response relationships were evaluated between cancer treatments and untoward pregnancy outcomes. PATIENTS AND METHODS: A case-cohort study was conducted involving 472 Danish survivors of childhood and adolescent cancer and their 1,037 pregnancies. Adverse outcomes included 159 congenital malformations, six chromosomal abnormalities, seven stillbirths, and nine neonatal deaths. Preconception radiation doses to the gonads, uterus, and pituitary gland and administered chemotherapy were quantified based on medical records and related to adverse outcomes using a generalized estimating equation model. RESULTS: No statistically significant associations were found between genetic disease in children and parental treatment with alkylating drugs or preconception radiation doses to the testes in male and ovaries in female cancer survivors. Specifically, the risk of genetic disease was similar among the children of irradiated survivors when compared with nonirradiated survivors (relative risk [RR], 1.02; 95% CI, 0.59 to 1.44; P = .94). A statistically significant association between abdomino-pelvic irradiation and malformations, stillbirths, and neonatal deaths was not seen in the children of female survivors overall (P = .07) or in the children of mothers receiving high uterine doses (mean, 13.5 Gy; max, 100 Gy; RR, 2.3; 95% CI, 0.95 to 5.56). CONCLUSION: Mutagenic chemotherapy and radiotherapy doses to the gonads were not associated with genetic defects in children of cancer survivors. However, larger studies need to be conducted to further explore potential associations between high-dose pelvic irradiation and specific adverse pregnancy outcomes.

Cerebral glucose metabolism in long-term survivors of childhood primary brain tumors treated with surgery and radiotherapy.

Delayed structural cerebral sequelae has been reported following cranial radiation therapy (CRT) to children with primary brain tumors, but little is known about potential functional changes. Twenty-four patients were included, diagnosed and treated at a median age of 11 years, and examined after a median recurrence free survival of 16 years by MRI and Positron Emission Tomography using the glucose analog 2-18F-fluoro-2-deoxy-D-glucose (18FDG). Three patients were not analyzed further due to diffuse cerebral atrophy, which might be related to previous hydrocephalus. Twenty-one patients were evaluable and regional cerebral metabolic rate for glucose (rCMRglc) was estimated in nontumoral brain regions in 12 patients treated with surgery alone and 9 patients treated with both surgery and CRT. Furthermore 10 normal controls matched for age at examination were included. Patients treated with both surgery and CRT had a general decreased rCMRglc compared to normal controls and patients treated with surgery alone, significantly (p < 0.05) in 5 of 11 regions of interest. No difference was found in rCMRglc between normal controls and patients treated with surgery alone. We conclude that there is a general reduction in rCMRglc in long-term recurrence free survivors of childhood primary brain tumors treated with CRT in high doses (44-56 Gy).

Long-term neurological outcome of childhood brain tumors treated by surgery only.

PURPOSE: To evaluate the pattern of neurological late effects in patients who have received surgery only for a brain tumor in childhood and to identify possible risk factors for neurological sequelae. PATIENTS AND METHODS: The medical, histologic, and operative records were reviewed for 65 consecutive patients operated for a benign brain tumor from 1970 to 1997, and all patients were re-examined after a median length of follow-up of 10.7 years. Thirty-four patients had posterior fossa tumors, 22 patients had cerebral hemisphere tumors, and nine patients had midline tumors. RESULTS: At the time of follow-up, 20 patients (31%) had no neurological deficits, 22 patients (34%) had minor deficits that did not interfere with their daily life activities, and 23 patients (35%) had moderate or severe deficits such as severe ataxia, spastic paresis, seriously reduced vision, or epilepsy with more than two seizures per year. Fourteen of the 31 patients (45%) registered with ataxia preoperatively had recovered fully. Six of seven patients had persistence of a pre- or postoperatively developed hemiparesis. Thirteen of 23 patients had persistence of cranial nerve deficits that developed second to surgery. Fifty-five percent of the 18 patients with seizures at diagnosis were seizure-free at follow-up. At follow-up both ataxia and hemiparesis were significantly more frequent among females (P =.02 and P =.03, respectively). CONCLUSION: In patients who received operation as the only treatment for their brain tumor, there was a good chance of total or partial recovery of preoperative and postoperative neurological deficits, although only one third of the patients will have no long-term neurological deficits.

Cognitive deficits in long-term survivors of childhood brain tumors: Identification of predictive factors.

BACKGROUND: To describe cognitive function and to evaluate the association between potentially predictive factors and cognitive outcome in an unselected population of survivors of childhood brain tumors. PROCEDURE: We studied a consecutive sample of 133 patients (76 had received radiotherapy (RT)) who had a brain tumor diagnosed before the age of 15 years and were treated during the period January 1970 through February 1997 in the Eastern part of Denmark. Biologic effective dose of irradiation (BED) was assessed in 71 patients. One hundred twenty-seven patients were able to cooperate to WISC-R and WAIS-R. Multiple regression models were constructed to evaluate relationships between possible risk factors and cognitive outcome. RESULTS AND CONCLUSIONS: The mean intelligence (IQ) scores were substantially lower than the expected means of the general population. Younger age at diagnosis, tumor site in cerebral hemisphere, hydrocephalus treated with shunt, and treatment with RT were found to be significant predictors of lower cognitive functions. RT was the most important risk factor for impaired intellectual outcome. The mean observed full scale IQ was 97.1 (SD = 14.3) for the non-irradiated patients and 78.8 (SD = 14.3) for the irradiated patients (adjusted P < 0.001). Verbal IQ, but not performance and full scale IQ, had a significant negative correlation to BED to the tumor site (P < 0.05). These results can be used to identify subgroups of children who are at increased risk for cognitive deficits allowing early and goal-directed intervention.

An audit of the insulin-tolerance test in 255 patients with pituitary disease.

OBJECTIVE: The insulin-tolerance test (ITT) is currently considered to be the gold standard for evaluating adults suspected of GH deficiency (GHD). The aim of this study was to determine factors that may influence nadir blood glucose (BG) when using a mean insulin dose of 0.1 IU/kg body weight. Furthermore, we wanted to evaluate the safety and GH-related aspects of the ITT. DESIGN: ITT was performed in 277 patients, of whom 255 (129 females) were eligible for evaluation. RESULTS: Multiple regression analysis, including the whole population, showed that the major determining factors for nadir BG were basal BG and body mass index (BMI) (P<0.02). No serious adverse event was recorded. Sixty-three percent of all patients tested had severe GHD with peak GH response to hypoglycaemia below 7.8 mIU/l. The positive predictive value for IGF-I was 0.82 and the negative predictive value was 0.47, using a cut-off value corresponding to -2 s.d. GH peak response to hypoglycaemia decreased with increasing numbers of other pituitary hormone deficiencies. CONCLUSIONS: When determining the dose of insulin based on weight, factors like pre-test BG and BMI should also be considered. We propose an algorithm stating that the dose of insulin should be 0.1 IU insulin/kg body weight minus 2 IU if pre-test BG is <4.0 mmol/l and minus 2 IU if BMI is <20 kg/m(2) in order to take these factors into account. Our findings furthermore support the concept that the low-dose ITT is a safe test in adults, when performed in experienced hands. It was confirmed that IGF-I is not sufficient when diagnosing GHD in adults, and reliable stimulation tests like ITT are required in the diagnosis.