Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA.
Citations 4
Cardiac Substructure Radiation Dose and Risk of Late Cardiac Disease in Survivors of Childhood Cancer: A Report From the Childhood Cancer Survivor Study
PURPOSE Radiation-associated cardiac disease is a major cause of morbidity/mortality among childhood cancer survivors. Radiation dose-response relationships for cardiac substructures and cardiac diseases remain unestablished. METHODS Using the 25,481 5-year survivors of childhood cancer treated from 1970 to 1999 in the Childhood Cancer Survivor Study, we evaluated coronary artery disease (CAD), heart failure (HF), valvular disease (VD), and arrhythmia. We reconstructed radiation doses for each survivor to the coronary arteries, chambers, valves, and whole heart. Excess relative rate (ERR) models and piecewise exponential models evaluated dose-response relationships. RESULTS The cumulative incidence 35 years from diagnosis was 3.9% (95% CI, 3.4 to 4.3) for CAD, 3.8% (95% CI, 3.4 to 4.2) for HF, 1.2% (95% CI, 1.0 to 1.5) for VD, and 1.4% (95% CI, 1.1 to 1.6) for arrhythmia. A total of 12,288 survivors (48.2%) were exposed to radiotherapy. Quadratic ERR models improved fit compared with linear ERR models for the dose-response relationship between mean whole heart and CAD, HF, and arrhythmia, suggesting a potential threshold dose; however, such departure from linearity was not observed for most cardiac substructure end point dose-response relationships. Mean doses of 5-9.9 Gy to the whole heart did not increase the risk of any cardiac diseases. Mean doses of 5-9.9 Gy to the right coronary artery (rate ratio [RR], 2.6 [95% CI, 1.6 to 4.1]) and left ventricle (RR, 2.2 [95% CI, 1.3 to 3.7]) increased risk of CAD, and to the tricuspid valve (RR, 5.5 [95% CI, 2.0 to 15.1]) and right ventricle (RR, 8.4 [95% CI, 3.7 to 19.0]) increased risk of VD. CONCLUSION Among children with cancer, there may be no threshold dose below which radiation to the cardiac substructures does not increase the risk of cardiac diseases. This emphasizes their importance in modern treatment planning.
Morbidity and Mortality Differences Between Hematopoietic Cell Transplantation Survivors and Other Cancer Survivors
Purpose To compare the risks of serious health outcomes among hematopoietic cell transplantation (HCT) survivors versus a matched population of patients with cancer who did not undergo HCT, where the primary difference may be exposure to HCT. Methods Two-year HCT survivors treated at a comprehensive cancer center from 1992 through 2009 who were Washington State residents (n = 1,792; 52% allogeneic and 90% hematologic malignancies) were frequency matched by demographic characteristics and underlying cancer diagnosis (as applicable) to non-HCT 2-year cancer survivors, using the state cancer registry (n = 5,455) and the general population (n = 16,340) using driver’s license files. Late outcomes for all three cohorts were ascertained from the state hospital discharge and death registries; subsequent cancers were ascertained from the state cancer registry. Results After median follow-up of 7.1 years, HCT survivors experienced significantly greater rates of hospitalization compared with matched non-HCT cancer survivors (280 v 173 episodes per 1,000 person-years, P < .001) and greater all-cause mortality (hazard ratio [HR], 1.1; 95% CI, 1.01 to 1.3). HCT survivors had more hospitalizations or death with infections (10-year cumulative incidence, 31% v 22%; HR, 1.4; 95% CI, 1.3 to 1.6) and respiratory complications (cumulative incidence, 27% v 20%; HR, 1.4; 95% CI, 1.2 to 1.5). Risks of digestive, skin, and musculoskeletal complications also were greater among HCT versus non-HCT cancer survivors. The two groups had similar risks of circulatory complications and second cancers. Both HCT and non-HCT cancer survivors had significantly greater 10-year cumulative incidences of all major organ-system outcomes versus the general population. Conclusion History of HCT was associated with late morbidity and mortality among cancer survivors. In particular, clinicians who care for HCT survivors should be aware of their high rates of late respiratory and infectious complications.
Patterns and predictors of clustered risky health behaviors among adult survivors of childhood cancer: A report from the Childhood Cancer Survivor Study
Purpose To determine the influence of modifiable lifestyle factors on the risk of cardiovascular disease after hematopoietic cell transplantation (HCT). Patients and Methods HCT survivors of ≥ 1 year treated from 1970 to 2010 (n = 3,833) were surveyed from 2010 to 2011 on current cardiovascular health and related lifestyle factors (smoking, diet, recreational physical activity). Responses (n = 2,362) were compared with those from a matched general population sample (National Health and Nutrition Examination Survey [NHANES]; n = 1,192). Results Compared with NHANES participants, HCT survivors (median age, 55.9 years; median 10.8 years since HCT; 71.3% allogeneic) had higher rates of cardiomyopathy (4.0% v 2.6%), stroke (4.8% v 3.3%), dyslipidemia (33.9% v 22.3%), and diabetes (14.3% v 11.7%; P < .05 for all comparisons). Prevalence of hypertension was similar (27.9% v 30.0%), and survivors were less likely to have ischemic heart disease (6.1% v 8.9%; P < .01). Among HCT survivors, hypertension, dyslipidemia, and diabetes were independent risk factors for ischemic heart disease and cardiomyopathy, and smoking was associated with ischemic heart disease and diabetes (odds ratios [ORs], 1.8 to 2.1; P = .02). Obesity was a risk factor for post-transplantation hypertension, dyslipidemia, and diabetes (ORs ≥ 2.0; P < .001). In contrast, lower fruit/vegetable intake was associated with greater risk of dyslipidemia and diabetes (ORs, 1.4 to 1.8; P ≤ .01), and lower physical activity level was associated with greater risk of hypertension and diabetes (ORs, 1.4 to 1.5; P < .05). Healthier lifestyle characteristics among HCT survivors attenuated risk of all cardiovascular conditions assessed. Conclusion Attention of clinicians to conventional cardiovascular risk factors and modifiable lifestyle characteristics offers hope of reducing serious cardiovascular morbidity after HCT.