Childhood body mass index at diagnosis and its association with non-Hodgkin lymphoma in the United States: a children's oncology group data analysis project.

Childhood obesity has historically increased with time. Associations are noted between obesity and cancer in adults; but little investigation has been done in children. We conducted a matched case control study to assess the association between body mass index (BMI) and Non-Hodgkin Lymphoma (NHL) in children. Case information is from Children's Oncology Group and controls from National Health and Nutrition Examination Survey. There was no association between obesity and NHL overall, but patients less than 10 years, showed a positive association if outside of the normal BMI range, both obesity and underweight. Additionally, there was an association between NHL and underweight overall, in males, and in non-Hispanic/Latino children. Obesity showed an inverse association with NHL in females and children older than 10. We were not able to assess causality. Disease causing weight loss prior to diagnosis likely skewed baseline weights lower. Additional studies with BMI prior to diagnosis are needed.