BackgroundCancer navigation programs aim to support, educate, and empower patients and families, addressing barriers to diagnostics, treatment, and care. Navigators engage with people to ensure timely access to services and resources. While promising for older people with cancer, these programs are scarce in Europe, and research on their effectiveness and implementation is limited. We describe the protocol of the EU NAVIGATE randomized controlled trial, aimed to evaluate (1) effectiveness and cost-effectiveness of NavCare-EU, an intervention that aims to support older people with cancer throughout their illness trajectory, spanning the continuum of supportive, palliative, and end-of-life care, and (2) the intervention's implementation processes and feasibility of its integration into different health care systems in Europe, contextual barriers and facilitators for effective and sustainable implementation, and mechanisms involved in reaching the outcomes.MethodsWe will conduct a multisite pragmatic fast-track randomized controlled trial with embedded convergent mixed-method process evaluation in Belgium, Ireland, Italy, Netherlands, Poland, and Portugal. The study targets people with cancer and declining health, 70 years or older, and their close family caregivers. The trial compares the NavCare-EU intervention plus standard care with standard care alone. We will perform a baseline measurement prior to randomization and follow-up measurements at 12 weeks, 24 weeks, and 48 weeks in intervention and control group, and an additional measurement at 72 weeks in the control group. Primary outcomes, measured at 24 weeks are (1) the older person's global health status/quality of life, a 2-item subscale from EORTC-QLQ-C30 (revised) measuring health-related quality of life, (2) level of social support measured with Medical Outcomes Study Social Support Survey (MOS-SSS scale). The study will include at least 246 older persons with completed global health status/quality of life at 24 weeks.DiscussionThe EU NAVIGATE trial will cross-nationally test the effectiveness and cost-effectiveness of a navigation intervention for older people with cancer and their family caregivers, and its implementation in different health care systems in Europe. As continuity and access to health, social, and community care is a priority for patients and caregivers, the trial is timely and critically needed.Trial registrationClinicaltrials.gov: identifier NCT06110312 (2023/10/31).