New research on children diagnosed with acute lymphoblastic leukaemia (ALL) shows that the longer a patient’s body mass index (BMI) falls within the overweight/obese category during treatment, the greater the risk of relapse and the lower the chance of survival. The study, led by a collaborative team of investigators at Roswell Park Comprehensive Cancer Centre and Columbia University Irving Medical Centre, was published today by JAMA Network Open.

“Many previous studies focused primarily on long-term side effects of overweight and obesity following treatment for acute lymphoblastic leukemia, such as late cardiovascular complications or metabolic syndrome, whereas the effects of being overweight or obese on survival and relapse of leukemia have been inconsistently studied,” says Kara Kelly, MD, Chair of the Roswell Park Oishei Children’s Cancer and Blood Disorders Program and the Waldemar J. Kaminski Endowed Chair of Pediatrics at Roswell Park. “We observed that the duration of exposure to overweight and obesity during treatment may be a better indicator of the risk of death or relapse of leukaemia.”

Dr. Kelly and Song Yao, MD, PhD, Professor of Oncology, Department of Cancer Prevention and Control at Roswell Park, are co-senior authors of “Overweight or Obesity and Outcomes in Children with Acute Lymphoblastic Leukaemia.” Elena Ladas, PhD, RD, Professor of Global Integrative Medicine in the Department of Paediatrics at Columbia University Vagelos College of Physicians and Surgeons, is the first author.

“Treatment for obesity is evolving, and our study highlights the importance of working closely with children and their families to provide comprehensive care, whether by treating obesity during therapy or preventing it altogether,” says Dr. Ladas. “Our findings support a new clinical approach that includes proactive nutrition therapy for children undergoing treatment for acute lymphoblastic leukaemia.”

The prospective cohort study aimed to find out whether overweight and obesity affect the risk of disease relapse or the length of overall survival, among other outcomes. The research team examined data for 794 children who enrolled in a Dana-Farber Cancer Institute ALL Consortium clinical study between May 2005 and December 2011.

Height and weight data obtained from their medical records were used to track fluctuations in the children’s BMI throughout treatment. At the time of diagnosis, 234 patients (29.5%) were overweight or obese, and that proportion increased to 346 patients (48.4%) by the end of treatment. Children who fell into the overweight/obese categories on at least two time points during treatment experienced poorer overall survival, greater risk of relapse and lower event-free survival (periods without complications) compared with those categorised as overweight or obese at only one time point, or not at all.

“Because overweight and obesity are modifiable risk factors, these are significant findings that present important opportunities to improve outcomes,” says Dr. Kelly. “Our results underscore the need for interventions aimed at avoiding new-onset overweight or obesity as well as treatment-based interventions for children who are overweight or obese at diagnosis and throughout treatment. This has the potential to reduce the risk of leukaemia relapse and improve overall survival.”

The research was enabled by grants from the American Cancer Society and the Roswell Park Alliance Foundation.