Ethics approval and consent to participate
The independent medical ethics committees approved the KOKON-KTO study (Ethics Committee of Charité–Universitätsmedizin Berlin (EA1/127/17), Medical Association Hamburg (MC-368/17), Medical Association Baden-Wuerttemberg (B-F-2017–10), Medical Association Nord Rhine (2417337), Ethics Committee of the Medical Association of Westphalia-Lippe (2017–624-b-S), Ethics Committee at the Medical Faculty of Würzburg (274/17_z-me), Ethics Committee of the Medical Faculty of Heidelberg (S-550/2017), Ethics Commission of the Albert-Ludwigs-University of Freiburg (531/17)). The study was conducted in accordance with the Declaration of Helsinki and ethical guidelines for clinical studies. Informed consent was obtained from all participants (oncology physicians and patients).