Abstract

Sex is a significant prognostic factor in the survival of pediatric acute lymphoblastic leukemia (ALL) with girls having superior outcome. This phenomenon could be partly due to the intrinsic relationship between sex and other prognostic factors. The present study aimed to assess the effect of sex on ALL survival after accounting for interactions of sex with age at diagnosis and radiation, in addition to known prognostic factors. We utilized 1973 to 2009 surveillance epidemiology and end results data. In a multivariable Cox proportional hazard model, stratified by the year of diagnosis, the prognostic value of sex diminished (adjusted hazard ratio (AHR) = 1.21, 95% confidence interval (CI): 0.93, 1.57). The difference in mortality between girls and boys was the lowest in the irradiated children diagnosed between ages 10 and 19 years. In this subgroup, boys’ risk of mortality was not substantially different from that of girls (AHR = 0.96, 95% CI: 0.70, 1.33). In the large population based study, after accounting for the aforementioned interaction effects, the prognostic value of sex in ALL survival diminished, and it is eliminated in the irradiated children diagnosed between ages 10 to 19 years.

Key words: Sex, lymphoblastic leukemia, prognostic factors.