Adult height lower in childhood leukemia survivors

Survivors of childhood acute lymphoblastic leukemia (ALL) have an increased risk of attaining a short stature as adults, regardless of the type of treatment they received for the cancer.

High doses of radiotherapy to the skull have been associated with growth deficits, the authors explain, but other therapies for ALL have not been consistently linked with growth suppression.

To further investigate, Dr. Eric J. Chow from the University of Washington, Seattle, and colleagues compared the adult height of 2,434 survivors of pediatric ALL, diagnosed between 1970 and 1986, with that of 3,009 of their siblings to determine the risk factors associated with short stature.

All survivor treatment groups, including those treated with chemotherapy alone, had a decreased adult height and height standard deviation scores compared with their siblings, the authors report.

Among children diagnosed with ALL before puberty, the height standard deviation scores were lower on average among those exposed to any dose of craniospinal radiotherapy than those treated with cranial radiotherapy alone.

The effect of radiotherapy on adult height was not as great for children who were diagnosed after puberty, the researchers report in the Journal of Pediatrics, and the effect was not statistically different than that of chemotherapy alone.

Survivors of ALL were more than 12 times as likely as their siblings to be short, the report indicates, and the risk of adult short stature was greater for those diagnosed before puberty than for those diagnosed later.

Female survivors were more likely than male survivors to have a short stature in adulthood, even after the investigators factored in the effects of age, puberty status at diagnosis, ethnicity and radiotherapy exposures.

"As most patients with ALL are currently treated exclusively with chemotherapy," the authors conclude, "future analyses should focus on understanding better the relationships between adult height and chemotherapy dose, duration and type."

SOURCE: Journal of Pediatrics, April, 2007.