Radiation May Cause Body Composition Abnormalities in Adult Survivors of Pediatric Cancer

Adult survivors of childhood abdominal and pelvic cancers who underwent radiation therapy experienced body composition abnormalities and had worse cardiometabolic health when compared to the general public, according to data published in Cancer Epidemiology, Biomarkers & Prevention.

“Body composition abnormalities and cardiometabolic impairments are of concern among survivors given that in the general population, these conditions increase the risk of developing life-threatening diseases including cardiovascular disease and type 2 diabetes,” corresponding author of the study, Carmen Wilson, PhD, said in a press release.

Carmen explained that, while the impacts of radiation therapy on metabolic health have been reported previously for survivors of pediatric leukemia, brain tumors, and hematopoietic stem cell transplants, the impacts of radiation for pediatric abdominal and pelvic tumors remained unclear.

Compared to data from the National Health and Nutrition Examination Survey (NHANES), the study data found that the survivors examined were significantly more likely to have insulin resistance (33.8% vs. 40.6%), high triglycerides (10.02% vs. 18.4%), and low levels of high-density lipoproteins (28.9% vs. 33.5%).

More, the results found that survivors of abdominal and pelvic solid tumors saw lower relative lean body mass compared to the general population. The lower relative lean body mass was found to be associated with the dose of prior abdominal or pelvic radiation.

The researchers found no significant difference when looking at relative fat body mass between survivors and the general population, but survivors with high relative fat mass saw reduced quadricep strength and poor physical performance compared to survivors with low relative fat mass.

“It is possible that abdominal and pelvic-directed radiation therapy damages postural muscles or subtly impairs sex hormone production, ultimately affecting muscle mass,” said Wilson in a press release.

The study included 431 adult survivors of pediatric abdominal or pelvic solid tumors who were previously treated at St. Jude Children’s Research Hospital. The median age for the participants was 29.9 years.

The most frequent childhood diagnoses were neuroblastoma, Wilms tumor, and germ cell tumor, with a median age at diagnosis of 3.6 years. As a part of treatment, approximately 37% and 36% of participants received abdominal and pelvic radiation therapy, respectively.

The main limitation of the research was that cardiometabolic outcomes were potentially measured differently in the study cohort compared to data measured for those surveyed by NHANES.

Future research should examine the impact of radiation therapy and other cancer treatments on the distribution of fat across the body. When compared to overall obesity, increased abdominal obesity has been shown to be a better predictor of adverse health effects and warrants further examination, according to the researchers.

“While it may not be possible to avoid radiation therapy as a key treatment for many solid tumors, early research suggests that resistance training interventions in survivors increase lean mass,” said Wilson. “Further work is needed to see if training would also impact cardiometabolic impairments in this population.”

Reference:

Radiation Therapy for the Treatment of Pediatric Cancers May Have Long-term Impacts on Cardiovascular and Metabolic Health [news release]. Philadelphia, Pennsylvania. Published August 13, 2020. https://www.aacr.org/about-the-aacr/newsroom/news-releases/radiation-therapy-for-the-treatment-of-pediatric-cancers-may-have-long-term-impacts-on-cardiovascular-and-metabolic-health/. Accessed September 22, 2020.