Text and Data Mining valid from 2019-10-24
Received: 8 March 2019
Accepted: 25 September 2019
First Online: 24 October 2019
Ethics approval and consent to participate
: Ethical approval was taken from Institutional review board (IRB, Chiba Cancer Center (H29–262)). Informed written consent was obtained from the patients themselves (or their guardians) in all cases and also stated that their data would be available for further research.
: Not applicable.
: None of the authors has any conflict of interest to disclose. We confirm that we have read the Journal’s position on issues involved in ethical publication and affirm that this report is consistent with those guidelines.