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Purpose: Therapeutic radiation in childhood cancer has decreased over time with a concomitant increase in chemotherapy. Limited data exist on chemotherapy-associated subsequent malignant neoplasm (SMN) risk., Patients and Methods: SMNs occurring > 5 years from diagnosis, excluding nonmelanoma skin cancers, were evaluated in survivors diagnosed when they were < 21 years old, from 1970 to 1999 in the Childhood Cancer Survivor Study (median age at diagnosis, 7.0 years; median age at last follow-up, 31.8 years). Thirty-year SMN cumulative incidence and standardized incidence ratios (SIRs) were estimated by treatment: chemotherapy-only (n = 7,448), chemotherapy plus radiation (n = 10,485), radiation only (n = 2,063), or neither (n = 2,158). Multivariable models were used to assess chemotherapy-associated SMN risk, including dose-response relationships., Results: Of 1,498 SMNs among 1,344 survivors, 229 occurred among 206 survivors treated with chemotherapy only. Thirty-year SMN cumulative incidence was 3.9%, 9.0%, 10.8%, and 3.4% for the chemotherapy-only, chemotherapy plus radiation, radiation-only, or neither-treatment groups, respectively. Chemotherapy-only survivors had a 2.8-fold increased SMN risk compared with the general population (95% CI, 2.5 to 3.2), with SIRs increased for subsequent leukemia/lymphoma (1.9; 95% CI, 1.3 to 2.7), breast cancer (4.6; 95% CI, 3.5 to 6.0), soft-tissue sarcoma (3.4; 95% CI, 1.9 to 5.7), thyroid cancer (3.8; 95% CI, 2.7 to 5.1), and melanoma (2.3; 95% CI, 1.5 to 3.5). SMN rate was associated with > 750 mg/m 2 platinum (relative rate [RR] 2.7; 95% CI, 1.1 to 6.5), and a dose response was observed between alkylating agents and SMN rate (RR, 1.2/5,000 mg/m 2 ; 95% CI, 1.1 to 1.3). A linear dose response was also demonstrated between anthracyclines and breast cancer rate (RR, 1.3/100 mg/m 2 ; 95% CI, 1.2 to 1.6)., Conclusion: Childhood cancer survivors treated with chemotherapy only, particularly higher cumulative doses of platinum and alkylating agents, face increased SMN risk. Linear dose responses were seen between alkylating agents and SMN rates and between anthracyclines and breast cancer rates. Limiting cumulative doses and consideration of alternate chemotherapies may reduce SMN risk.

Purpose We aimed to predict individual risk of ischemic heart disease and stroke in 5-year survivors of childhood cancer. Patients and Methods Participants in the Childhood Cancer Survivor Study (CCSS; n = 13,060) were observed through age 50 years for the development of ischemic heart disease and stroke. Siblings (n = 4,023) established the baseline population risk. Piecewise exponential models with backward selection estimated the relationships between potential predictors and each outcome. The St Jude Lifetime Cohort Study (n = 1,842) and the Emma Children's Hospital cohort (n = 1,362) were used to validate the CCSS models. Results Ischemic heart disease and stroke occurred in 265 and 295 CCSS participants, respectively. Risk scores based on a standard prediction model that included sex, chemotherapy, and radiotherapy (cranial, neck, and chest) exposures achieved an area under the curve and concordance statistic of 0.70 and 0.70 for ischemic heart disease and 0.63 and 0.66 for stroke, respectively. Validation cohort area under the curve and concordance statistics ranged from 0.66 to 0.67 for ischemic heart disease and 0.68 to 0.72 for stroke. Risk scores were collapsed to form statistically distinct low-, moderate-, and high-risk groups. The cumulative incidences at age 50 years among CCSS low-risk groups were < 5%, compared with approximately 20% for high-risk groups ( P < .001); cumulative incidence was only 1% for siblings ( P < .001 v low-risk survivors). Conclusion Information available to clinicians soon after completion of childhood cancer therapy can predict individual risk for subsequent ischemic heart disease and stroke with reasonable accuracy and discrimination through age 50 years. These models provide a framework on which to base future screening strategies and interventions.

Purpose: To create clinically useful models that incorporate readily available demographic and cancer treatment characteristics to predict individual risk of heart failure among 5-year survivors of childhood cancer., Patients and Methods: Survivors in the Childhood Cancer Survivor Study (CCSS) free of significant cardiovascular disease 5 years after cancer diagnosis (n = 13,060) were observed through age 40 years for the development of heart failure (ie, requiring medications or heart transplantation or leading to death). Siblings (n = 4,023) established the baseline population risk. An additional 3,421 survivors from Emma Children's Hospital (Amsterdam, the Netherlands), the National Wilms Tumor Study, and the St Jude Lifetime Cohort Study were used to validate the CCSS prediction models., Results: Heart failure occurred in 285 CCSS participants. Risk scores based on selected exposures (sex, age at cancer diagnosis, and anthracycline and chest radiotherapy doses) achieved an area under the curve of 0.74 and concordance statistic of 0.76 at or through age 40 years. Validation cohort estimates ranged from 0.68 to 0.82. Risk scores were collapsed to form statistically distinct low-, moderate-, and high-risk groups, corresponding to cumulative incidences of heart failure at age 40 years of 0.5% (95% CI, 0.2% to 0.8%), 2.4% (95% CI, 1.8% to 3.0%), and 11.7% (95% CI, 8.8% to 14.5%), respectively. In comparison, siblings had a cumulative incidence of 0.3% (95% CI, 0.1% to 0.5%)., Conclusion: Using information available to clinicians soon after completion of childhood cancer therapy, individual risk for subsequent heart failure can be predicted with reasonable accuracy and discrimination. These validated models provide a framework on which to base future screening strategies and interventions., (© 2014 by American Society of Clinical Oncology.)