Weekly physical activity trajectories in short- and long-term survivors of childhood cancer: the PACCS and SURfit studies

PURPOSE: Identify and describe weekly physical activity (PA) trajectories in adolescent and adult childhood cancer survivors (survivors), describe characteristics of survivors following different PA trajectories, and compare PA trajectories to controls. METHODS: This study includes adolescent (9-18 years) survivors and controls from the Physical Activity in Childhood Cancer Survivors (PACCS) study and adult (18-49 years) survivors from the survivor fitness (SURfit) study and controls from the Norwegian National Physical Activity Survey 2. Weekly trajectories of accelerometer-measured PA were identified by multivariate latent class mixed models using daily minutes of moderate-to-vigorous and light PA (MVPA, LPA). Survivors' characteristics related to different PA trajectories were assessed using a descriptive approach, and PA trajectories between survivors and controls were visually compared. RESULTS: We identified four PA trajectories among adolescents (Low regular; Medium, drop weekend; Medium, peak Friday; and Medium regular) and four among adult survivors (Medium regular; Medium, drop weekend; Medium regular MVPA, high regular LPA; and High, drop weekend). The main factors related to the different PA trajectories were sex, age at assessment, sleep, and (parental) education, whereas diagnosis seemed important in adolescent survivors only. In adolescents, trajectories were comparable between survivors and controls, while in adults, only three trajectories were comparable. The allocation to the different trajectories was more favorable in adolescent survivors (fewer in the Low trajectory) and adult survivors (no Low regular MVPA trajectory was identified in survivors) compared to controls. IMPLICATIONS FOR CANCER SURVIVORS: Our findings show many different behavioral approaches to accumulate PA over a week. They highlight the need for targeted PA interventions in a subset of survivors (i.e., adolescent, female survivors of CNS tumors). Developing interventions to prevent PA drops on the weekend holds high potential.