Cancer recurrence: Detection and diagnostic intervals in Danish primary care

e13110 Background: Danish cancer survivors receive hospital-based, specialized follow-up care with one central aim to detect cancer recurrence (CR) at an early stage. Nevertheless, CR is frequently detected outside of scheduled follow-up visits as 40-60% of CR patients encounter and present symptoms. The family physician (FP) is presumed to facilitate most of these diagnostic pathways. However, little is known about CR detection in primary care. We aim to examine diagnostic intervals, actions taken by the FP and sub-optimal events for patients presenting symptoms of CR in primary care. Methods: We are conducting a retrospective, national cohort study based on questionnaire data linked to register data at the individual level. Patients diagnosed with CR of melanoma, lung, breast, colorectal, bladder, ovarian and endometrial cancer between Jan 2022 and May 2024 are included. Patients are identified consecutively using validated, register-based algorithms. All Danish citizens have access to free healthcare and 99% are listed with a specific FP. The affiliated FP is invited to complete a questionnaire on the diagnostic pathway utilizing the patient medical record. Danish health registers provide information on the primary cancer, CR diagnosis date, comorbidity, education, sex, and age. Results: We aim to include 3,000 CR patients and expect to receive information on 1,000 CR diagnostic pathways initiated in primary care. We will present preliminary results from the first 500 responders. The proportion of diagnostic pathways initiated in primary care was 33%, hospital-based follow-up was 44%, and another route was 23%. The FPs initiated the diagnostic pathway by referral to cancer specific urgent pathway for 31% of patients, by referral to specialized private or hospital-based physician including diagnostic imaging for 30% of patients. For 31% of diagnostic pathways, the FPs reported sub-optimal or delaying events. The most frequently reported sub-optimal event was regarding clinical decisions by the FP (12%). For patients with CR of breast cancer (n=53), the mean diagnostic interval (time from first contact to CR diagnosis) was 86 days [95% CI = 61 to 112days]. Conclusions: One third of diagnostic pathways for CR was initiated in primary care. This project will provide novel, comprehensive evidence on these diagnostic pathways to inform the efforts for early detection of CR and survivorship in primary care.