Received: 2 July 2018
Accepted: 22 November 2018
First Online: 3 December 2018
Ethics approval and consent to participate
: This study was designed as a quality development study, utilizing only residual material that otherwise would have been discarded. All patient samples were surplus samples and completely anonymized prior to use in the study. The study was performed following the guideline of the Declaration of Helsinki. According to German law an ethical approval is not required if using completely anonymized surplus samples in such a retrospective study setting.
: Not applicable.
: MS, AH, KE and DS are shareholders and/or employees of oncgnostics GmbH, a company that aims to commercialize DNA methylation markers.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.