Childhood cancer treatment and age influence obesity risk for childhood cancer survivors

Childhood cancer survivors - especially those whose treatment included brain irradiation or chemotherapy with glucocorticoids - are 14 percent more likely to be obese than their healthy peers. The St. Jude Children's Research Hospital study appears today in the journal Cancer.

Of the 1,996 childhood cancer survivors in this study, 36.2 percent had a body mass index (BMI) of 30 kilograms per meters squared or more, which qualifies as obese. That was 14 percent greater than the expected prevalence based on federal health survey data of a comparison group of U.S. residents.

Among the strongest predictor of obesity in survivors was childhood obesity, which is also a strong predictor of adult obesity in the general public. Survivors who were obese when their pediatric cancer was discovered were almost five times more likely than other survivors to be obese when their BMI was calculated for this study.

Other obesity risk factors were age and childhood cancer treatment. Survivors who were ages 30 and older when their BMI was calculated were more likely than younger survivors to be obese. Also, 47 percent of survivors who received brain irradiation as part of their treatment were obese, compared to 29.4 percent of survivors who received other therapies. The risk increased for survivors whose cancer was diagnosed when they were younger than age 4 and whose treatment included glucocorticoids.

In comparison, survivors treated with chest, abdominal or pelvic irradiation were about half as likely as other survivors to be obese.

"The high prevalence of obesity in cancer survivors is of great concern and underscores the need to develop more effective counseling and weight-loss interventions for this growing population," said first author Carmen Wilson, Ph.D., a research associate in the St. Jude Department of Epidemiology and Cancer Control.

Key Messages:

- Being overweight or obese is a risk factor for several types of cancer. Although a higher weight may not necessarily cause cancer, maintaining a healthy weight is thought to be associated with a lower risk of many chronic diseases.

- Many resources are available to help you maintain a healthy weight, including doctors and dietitians.

- Talk with your doctor about developing an appropriate weight control plan for you.

More than two-thirds of American adults are overweight or obese (substantially or extremely overweight). When a person is overweight or obese, it means that they have too much body fat in relation to lean body tissue, such as muscle. Many factors cause people to become overweight or obese, including genetic, hormonal, environmental, emotional, and cultural factors. People who are overweight or obese have a higher risk of many serious health conditions, including type II diabetes, high blood pressure, and heart disease. Being overweight or obese is also associated with an increased risk of cancer.