Received: 29 May 2019
Accepted: 5 September 2019
First Online: 24 October 2019
Ethics approval and consent to participate
: All procedures performed in studies involving human participants were in accordance with the Institutional Review Board of the Netherlands Cancer Institute, Amsterdam, The Netherlands (IRB File No. IRBd18058), and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. The need for informed consent was waived because of the retrospective nature of this study.
: Not applicable
: The authors declare that they have no competing interests.