New primary neoplasms of the central nervous system in survivors of childhood cancer: a report from the Childhood Cancer Survivor Study.

BACKGROUND: Subsequent primary neoplasms of the central nervous system (CNS) have frequently been described as late events following childhood leukemia and brain tumors. However, the details of the dose-response relationships, the expression of excess risk over time, and the modifying effects of other host and treatment factors have not been well defined. METHODS: Subsequent primary neoplasms of the CNS occurring within a cohort of 14,361 5-year survivors of childhood cancers were ascertained. Each patient was matched with four control subjects by age, sex, and time since original cancer diagnosis. Tumor site-specific radiation dosimetry was performed, and chemotherapy information was abstracted from medical records. Conditional logistic regression was used to estimate odds ratios (ORs), to calculate 95% confidence intervals (CIs), and to model the excess relative risk (ERR) as a function of radiation dose and host factors. For subsequent gliomas, standardized incidence ratios (SIRs) and excess absolute risks (EARs) were calculated based on Surveillance, Epidemiology, and End Results data. RESULTS: Subsequent CNS primary neoplasms were identified in 116 individuals. Gliomas (n = 40) occurred a median of 9 years from original diagnosis; for meningiomas (n = 66), it was 17 years. Radiation exposure was associated with increased risk of subsequent glioma (OR = 6.78, 95% CI = 1.54 to 29.7) and meningioma (OR = 9.94, 95% CI = 2.17 to 45.6). The dose response for the excess relative risk was linear (for glioma, slope = 0.33 [95% CI = 0.07 to 1.71] per Gy, and for meningioma, slope = 1.06 [95% CI = 0.21 to 8.15] per Gy). For glioma, the ERR/Gy was highest among children exposed at less than 5 years of age. After adjustment for radiation dose, neither original cancer diagnosis nor chemotherapy was associated with risk. The overall SIR for glioma was 8.7, and the EAR was 19.3 per 10,000 person-years. CONCLUSIONS: Exposure to radiation therapy is the most important risk factor for the development of a new CNS tumor in survivors of childhood cancers. The higher risk of subsequent glioma in children irradiated at a very young age may reflect greater susceptibility of the developing brain to radiation.

Female survivors of childhood cancer: preterm birth and low birth weight among their children.

BACKGROUND: Improved survival after childhood cancer raises concerns over the possible long-term reproductive health effects of cancer therapies. We investigated whether children of female childhood cancer survivors are at elevated risk of being born preterm or exhibiting restricted fetal growth and evaluated the associations of different cancer treatments on these outcomes. METHODS: Using data from the Childhood Cancer Survivor Study, a large multicenter cohort of childhood cancer survivors, we studied the singleton live births of female cohort members from 1968 to 2002. Included were 2201 children of 1264 survivors and 1175 children of a comparison group of 601 female siblings. Data from medical records were used to determine cumulative prepregnancy exposures to chemotherapy and radiotherapy. Logistic regression was used to estimate odds ratios (ORs) for the association between quantitative therapy exposures and preterm (<37 weeks) birth, low birth weight (<2.5 kg), and small-for-gestational-age (SGA) (lowest 10th percentile) births. All statistical tests were two-sided. RESULTS: Survivors' children were more likely to be born preterm than the siblings' children (21.1% versus 12.6%; OR = 1.9, 95% confidence interval [CI] = 1.4 to 2.4; P<.001). Compared with the children of survivors who did not receive any radiotherapy, the children of survivors treated with high-dose radiotherapy to the uterus (>500 cGy) had increased risks of being born preterm (50.0% versus 19.6%; OR = 3.5, 95% CI = 1.5 to 8.0; P = .003), low birth weight (36.2% versus 7.6%; OR = 6.8, 95% CI = 2.1 to 22.2; P = .001), and SGA (18.2% versus 7.8%; OR = 4.0, 95% CI = 1.6 to 9.8; P = .003). Increased risks were also apparent at lower uterine radiotherapy doses (starting at 50 cGy for preterm birth and at 250 cGy for low birth weight). CONCLUSIONS: Late effects of treatment for female childhood cancer patients may include restricted fetal growth and early births among their offspring, with risks concentrated among women who receive pelvic irradiation.

Stroke as a late treatment effect of Hodgkin's Disease: a report from the Childhood Cancer Survivor Study.

PURPOSE: The objectives of this report are to examine the incidence of and risk factors for stroke among childhood Hodgkin's disease (HD) survivors. PATIENTS AND METHODS: The Childhood Cancer Survivor Study is a multi-institutional cohort study of more than 5-year cancer survivors diagnosed between 1970 and 1986 and a sibling comparison group. Incidence rates of stroke among HD survivors (n = 1,926) and siblings (n = 3,846) were calculated and compared. Cox proportional hazards models were used to estimate the hazard ratios, reported as relative risks (RR), of developing stroke between HD survivors and siblings. RESULTS: Nine siblings reported a stroke, for an incidence of 8.00 per 100,000 person-years (95% CI, 3.85 to 14.43 per 100,000 person-years). Twenty-four HD survivors reported a stroke. The incidence of late-occurring stroke among HD survivors was 83.6 per 100,000 person-years (95% CI, 54.5 to 121.7 per 100,000 person-years). The RR of stroke among HD survivors was 4.32 (95% CI, 2.01 to 9.29; P = .0002). All 24 survivors received mantle radiation exposure (median dose, 40 Gy). The incidence of late-occurring stroke among HD survivors treated with mantle radiation was 109.8 per 100,000 person-years (95% CI, 70.8 to 161.1 per 100,000 person-years). The RR of late-occurring stroke among HD survivors treated with mantle radiation was 5.62 (95% CI, 2.59 to 12.25; P < .0001). CONCLUSION: Survivors of childhood HD are at increased risk of stroke. Mantle radiation exposure is strongly associated with subsequent stroke. Potential mechanisms may include carotid artery disease or cardiac valvular disease.