Overweight in childhood cancer patients at diagnosis and throughout therapy: A multicentre cohort study

Childhood cancer patients (CCP) have been reported to be at increased risk of becoming overweight during treatment. We assessed prevalence of overweight in CCP at diagnosis and at the end of treatment, determined risk factors, and identified weight change during treatment by type of cancer. In a multicentre cohort study, we collected height and weight measurements of CCP at diagnosis and repeatedly during treatment. We calculated age- and sex-adjusted BMI Z-scores using references of the International Obesity Taskforce for children. Risk factors were described by multivariable linear regression, and weight change during treatment by multilevel segmented linear regression. The study included 327 CCP with a median age of 7 years (IQR 3–12) at diagnosis (55% boys), who had been diagnosed with acute lymphoblastic leukaemia (ALL, 29%), lymphoma (16%), central nervous system (CNS) tumours (13%), sarcoma (18%), and other types of cancer (24%). At diagnosis, 27 CCP (8%) were overweight. This increased to 43 (13%) at end of treatment, on average 0.7 years after diagnosis. Being a boy (p = 0.005) and having been diagnosed with ALL or lymphoma (p < 0.001) were risk factors for weight gain during treatment. During the first half of treatment, BMI Z-scores increased in ALL (regression slope β = 0.4, 95% CI 0.1–0.7) and lymphoma (β = 1.5, 95% CI 0.2–2.9) patients, whereas for patients with CNS tumours (β = -1.4, 95% CI −2.7 to −0.2), sarcoma (β = -1.4, 95% CI −2.0 to −0.7), or other types of cancer (β = -0.3, 95% CI −1.5–0.9) BMI Z-scores tended to drop initially. During the second half of treatment BMI Z-scores of all patients tended to increase. Exploratory analyses showed that BMI Z-scores of younger ALL patients (<7 years at diagnosis) increased during induction (β = 3.8, 95% CI 0.5–7.0). The inverse was seen for older ALL patients (≥7 years at diagnosis), in whom BMI Z-scores tended to decrease during induction (β = -1.5, −5.1–2.2), both groups tended to increase afterwards. CCP diagnosed with ALL or lymphoma are at increased risk of weight gain during treatment, and might particularly benefit from early lifestyle interventions.