Table of Contents
ISRN Oncology
Volume 2012, Article ID 439070, 9 pages
http://dx.doi.org/10.5402/2012/439070
Clinical Study

Sex Variability in Pediatric Leukemia Survival: Large Cohort Evidence

1American Health Research Institute, Heights Medical Tower, Houston, TX 77008, USA
2Nemours Center for Childhood Cancer Research, Wilmington, DE 19803, USA
3Orthopedic Department, Epidemiology & Biostatistics Section, A.I.duPont Hospital for Children, Wilmington, DE 19803, USA
4University of Delaware, Newark, DE 19716, USA
5Biomedical Research Department, A.I.duPont Hospital for Children, Wilmington, DE 19803, USA
6Texas A & M University, Houston, TX 77030, USA

Received 5 December 2011; Accepted 15 January 2012

Academic Editors: H. U. Gali-Muhtasib and H. M. Warenius

Copyright © 2012 L. Holmes Jr. et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Purpose. Sex disparities in pediatric leukemia have been previously reported, and male children continue to present with poorer survival. However, the observed disparities are not fully understood. This current study sought to examine disparities in survival by the sex, and to determine if tumor prognostic factors impact on these disparities. Patients and Methods. We used the Surveillance Epidemiology and End Results dataset of pediatric leukemia patients (ages 0–19 years) diagnosed in the United States from 1973 to 2006. There were 15,215 patients of whom 8,622 (65.7%) were boys and 6,593 (43.3%) were girls. The Kaplan-Meier survival estimates, log rank test, and Cox proportional hazard methods were used to assess the data. Results. The overall (both sexes) five-year survival rate was 67.9%. Girls had a survival rate of 70.1%, while the rate was 66.3% in boys. Girls had a significant 14% decreased risk of dying relative to boys, hazard ratio (HR) = 0.86, 99% CI = 0.80–0.93. There were significant differences between boys and girls with respect to tumor cell type, race, age at diagnosis, year of diagnosis, and number of primaries, 𝑃 < 0 . 0 0 1 . After controlling for these factors, the sex differences in survival persisted, with girls still less likely to die from leukemia compared to boys, adjusted HR (AHR) = 0.85, 99% CI = 0.72–1.00, 𝑃 < 0 . 0 1 . Conclusion. In a large population-based pediatric leukemia study, boys continued to show poorer survival. These disparities were not completely explained by treatment received, tumor prognostic or socio-demographic factors.