Differential effects of radiotherapy on growth and endocrine function among acute leukemia survivors: a childhood cancer survivor study report.

BACKGROUND

The differential effects of cranial radiotherapy (CRT), spinal radiotherapy (SRT), and total body irradiation (TBI) on growth and endocrine outcomes have rarely been examined in combination among childhood acute leukemia survivors.

PROCEDURE

Self-reported height/weight, hypothyroidism, and pregnancy/live birth were determined among acute lymphoblastic and myeloid leukemia survivors (n = 3,467) participating in the Childhood Cancer Survivor Study, an ongoing cohort study of 5-year survivors of pediatric cancers diagnosed from 1970 to 1986.

RESULTS

Compared with no radiotherapy, risk estimates were consistent across outcomes (adult short stature, hypothyroidism, absence of pregnancy/live birth) with CRT treatment associated with 2-3-fold increased risks, TBI associated with 5-10 fold increased risks, and CRT + TBI associated with >10 fold increased risks. Exposure to any SRT further increased risk of these outcomes 2-3-fold. Changes in body composition were more nuanced as CRT only was associated with an increased risk of being overweight/obese (OR 1.6, 95% CI 1.3-1.9) whereas TBI only was associated with an increased risk of being underweight (OR 6.0, 95% CI 2.4-14.9).

CONCLUSIONS

Although patients treated with CRT + TBI were at greatest risk for short stature, hypothyroidism, and a reduced likelihood of pregnancy/live birth, those treated with either modality alone had significantly increased risks as well, including altered body composition. Any SRT exposure further increased risk in an independent fashion.