Radiotherapy for childhood tumors tied to adverse body-composition changes in adulthood

Last Updated: 2020-08-19

By Will Boggs MD

NEW YORK (Reuters Health) - Abdominal and pelvic radiotherapy for childhood tumors is associated with body-composition changes in adulthood that can increase cardiovascular-disease risk, researchers report.

"Low lean muscle mass should be considered as a potential problem in childhood cancer survivors and can be addressed with resistance training and adequate protein intake," said Dr. Kirsten K. Ness of St. Jude Children's Research Hospital, in Memphis, Tennessee.

"Interventions to address body-composition abnormalities are likely to impact metabolic health and fitness and may be one strategy to help mitigate early development of serious cardiovascular complications in this vulnerable population," she told Reuters Health by email.

Body-composition abnormalities and cardiometabolic impairments have been described among survivors of pediatric leukemia, brain tumors and hematopoietic-stem-cell transplant. But little information is available regarding survivors of childhood abdominal and pelvic tumors.

Dr. Ness and colleagues characterized body composition, metabolic impairments and physical performance in 431 survivors of abdominal or pelvic tumors during childhood (diagnosed at a median age of 3.6 years) who had reached a median age of 29.9 years (range, 18.7-55.1 years).

Compared with normative data, survivors had significantly reduced mean relative lean mass and significantly reduced mean relative fat mass, the researchers report in Cancer Epidemiology, Biomarkers and Prevention.

Increasing abdominal and pelvic radiation doses were associated with decreasing lean mass among both male and female survivors.

The prevalence of BMI values in the obesity range was significantly lower among survivors (27.2% vs. 34.5%), whereas the prevalence of underweight BMI was significantly higher (6.0% vs. 1.5%, respectively).

Survivors had a significantly higher prevalence of insulin resistance (40.2%) than expected based on National Health and Nutrition Examination Survey data (33.8%). The risk of insulin resistance was increased among survivors with high to normal muscle mass and high adiposity and decreased among those with low muscle mass and low adiposity, compared with survivors with high to normal muscle mass and low adiposity.

The prevalence of low HDL was higher among survivors (33.5% vs. 28.9% in the general population), as was the prevalence of high triglycerides (18.4% vs. 10.02%).

"The finding that relatively higher fat mass - even in normal weight individuals - was associated with insulin resistance and low HDL was somewhat surprising," Dr. Ness said.

Compared with survivors with high to normal lean mass and low adiposity, both male and female survivors with high to normal lean mass and high adiposity performed more poorly on measures of quadriceps strength and had reduced performance on the sit and reach test and the distance covered in the 6-minute walk.

Handgrip strength was significantly reduced among male and female survivors with low lean mass and low adiposity, compared with survivors with high to normal lean mass and low adiposity.

"While we did not observe a difference in adiposity among survivors relative to normative data, survivors with high relative fat mass had an increased risk of developing poor cardiometabolic profiles and were also at risk of demonstrating reduced strength and physical performance," the researchers note.

"Moving forward, while it may not be possible to avoid radiotherapy as a key treatment for many solid tumors, further research is required to assess whether interventions in both child- and adulthood could remediate abnormalities in body composition and cardiometabolic impairments," the authors conclude.

SOURCE: https://bit.ly/314B9BT Cancer Epidemiology, Biomarkers and Prevention, online August 13, 2020.