General practitioners’ involvement in oncological aftercare (ACTION): a study protocol for a mixed-methods study

Background The growing number of cancer survivors in Germany necessitates sustainable, interdisciplinary aftercare. General practitioners (GPs) are well-positioned to provide long-term, trust-based support, including early detection of recurrences and late effects. However, evidence on the level of GP involvement in oncological aftercare, on interdisciplinary aftercare models involving GPs and specialists, and on associated barriers and facilitators remains limited. Methods The project “general practitioners’ involvement in oncological aftercare” (ACTION; funded by the German Cancer Aid; grant number 70116960) will employ a mixed-methods approach across two phases. In phase 1, experiences with GPs involvement in oncological aftercare will be examined. Therefore, routine data from the AOK Lower Saxony and the Lower Saxony Cancer Registry will be analysed retrospectively (WP1a), supplemented by surveys of GPs (WP1b) and oncologists (WP1c), and qualitative interviews with patients (WP1d). Phase 2 will then build on the results from phase 1 to develop and agree on recommendations for GP involvement in oncological aftercare. An expert workshop will aim to develop structured recommendations for enhanced GP involvement (WP2a), which are refined via a Delphi consensus process (WP2b). Discussion The ACTION project will generate new insights into the involvement of GPs in oncological aftercare and contribute to adequately addressing future challenges in patient care. It will stimulate the empirically supported development and implementation of interdisciplinary aftercare models in clinical practice and has thus the chance to improve the long-term care of cancer survivors in Germany. Trial registration The study was registered with the German Clinical Trials Register (Deutsches Register Klinischer Studien; DRKS00040034; date of registration: 11 May 2026).