Survivors of childhood cancer are more likely to suffer low bone density during their adulthood, according to researchers from the University of Michigan Comprehensive Cancer Center.
Led by James G. Gurney, Ph.D., of the university, the study found that 24 percent of the 74 survivors studied had abnormally low bone mineral density, a measure of the strength of bones.
The average age of the survivors was 30, and they had been treated an average of 24 years ago for the most common type of childhood cancer, acute lymphoblastic leukemia.
According to the World Health Organization, 11 percent of 30-year-old men and 19 percent of 30-year-old women on average have low bone mineral density, a condition known as osteopenia.
In this study, 36 percent of men and 16 percent of women had low bone mineral density.
Low bone mineral density can progress to osteoporosis, a bone disorder common in older adults that can lead to fractures.
The researchers found that male survivors were more likely than female survivors to have lower bone mineral density, and shorter men and women were also more likely to have weaker bones.
The researchers also looked at levels of growth hormones, which are known to be affected by leukemia treatment.
Low growth hormone levels and low levels of another hormone called IGF-1 can contribute to poor bone health, but that they are not the only factors involved.
The researchers believe the disease itself or the treatments such as radiation - particularly radiation to the brain - and chemotherapy may affect bone growth.
"Survivors with known growth hormone deficiency or insufficiency should definitely be screened, but we would argue that all adult survivors should be screened as well. The disease, chemotherapy and cranial radiation - even if they do not lead to growth hormone deficiency - may play a role in the development of osteopenia or osteoporosis," Thomas said.
The study is published in the journal Cancer.