Modest dietary changes and increased physical activity may improve the success of chemotherapy in children and adolescents with B-cell acute lymphoblastic leukemia (B-ALL), the most common childhood cancer. In a pilot study, researchers found that patients with newly diagnosed B-ALL who reduced their calorie intake and engaged in regular moderate exercise were less likely to have lingering leukemia cells after a month of chemotherapy than a historical control group. "We tested a very mild diet because this was our first time trying it, and the first month of treatment is already so difficult for patients and families. But even with these mild changes in diet and exercise, the intervention was extremely effective in reducing the chance of having detectable leukemia in the bone marrow," senior author Dr. Steven Mittelman of UCLA Mattel Children's Hospital and UCLA Jonsson Comprehensive Cancer Center, said in a news release. Being overweight or obese during induction therapy for B-ALL is associated with chemoresistance as quantified by minimal residual disease (MRD). The researchers hypothesized that a low-calorie diet and exercise could lessen gains in fat mass and reduce post-induction MRD. The Improving Diet and Exercise in ALL (IDEAL) trial enrolled 40 patients aged 10 to 21 years undergoing chemotherapy for newly diagnosed high-risk B-ALL. A dietician and physical therapist worked with the patients and their families to adopt a low-carbohydrate, low-fat, low-sugar diet plan and increase moderate daily exercise. The dual intervention was designed to induce a 20% or greater caloric deficit, divided equally between reduced intake and increased calories burned. Adherence to the diet portion of the program was high, with 82% of patients achieving a caloric deficit throughout their time on chemotherapy. Adherence to the exercise program was lower, with 31% reaching the target level of 200 minutes per week of moderate exercise. At the end of chemotherapy, compared to 80 patients in a historical control group, patients on the study's diet and exercise program were 70% less likely to have MRD, regardless of their starting body weight or composition. While fat mass decreased only in patients who started out as overweight or obese, patients in all weight categories showed a beneficial effect on MRD. "To our knowledge, this is the first study in any hematologic malignancy to demonstrate potential benefit from caloric restriction via diet and exercise to augment chemotherapy efficacy and improve disease response," the researchers write in Blood Advances. The researchers hope to validate their findings in a prospective, randomized trial funded by the National Institutes of Health, which is slated to begin accruing patients this summer. The study was supported by the Gabrielle Angel Foundation for Cancer Research, the National Institutes of Health and the National Cancer Institute. —Reuters Staff Source
