Functional trajectories and associated factors in older adults with cancer after radiotherapy.

INTRODUCTION: Functional ability is vital for independent living. In this study, we explored functional trajectories of instrumental activities of daily living (IADL) and participation in working- or leisure activities (role function) in older adults undergoing radiotherapy (RT) and aimed to identify individuals at risk of functional decline. MATERIALS AND METHODS: Patients were ≥ 65 years and received RT with curative or palliative intent. IADL was assessed by Nottingham Extended Activities of Daily Living (NEADL) scale at start and end of RT, and at 2, 8, and 16 weeks after treatment. Simultaneously, patients reported role function and symptoms using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-C30 (QLQ-C30). Data were analysed by growth mixture modelling and linear mixed models. RESULTS: We included 258 patients, mean age 73.5 years, 129 (50%) were female, and 232 (89.9%) had an Eastern Cooperative Oncology Group performances status scale (PS) of 0-1. For both NEADL and the role function scale of the QLQ-C30, four groups with distinct trajectories were identified. The group with the poorest baseline scores showed a clinically significant decline. Patients in this group were older, had more geriatric impairments, poorer PS and received palliative RT. Fatigue, pain and loss of appetite were associated with poorer NEADL and role function scores during and after RT. DISCUSSION: Although most patients preserved their IADL and role function during RT treatment, patients with poor IADL and role function at the start of RT were at risk of further functional decline. This knowledge should be incorporated into treatment decision-makings. Geriatric impairments and symptom burden are important targets for supportive measures and should be identified and assessed both before and during treatment.