Funding for this research was provided by:
Ministry of Health, Labour and Welfare (H26-016)
Text and Data Mining valid from 2016-11-26
Received: 21 July 2016
Accepted: 11 November 2016
First Online: 26 November 2016
Compliance with ethical standards
: The authors declare that they have no conflict of interest.
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
: The need for informed consent was waived by the Institutional Review Board and Ethics Committee of the National Cancer Center of Japan, but we explained to them the research purpose, procedure, privacy protection, and right to voluntary participation.Informed consent was obtained from all individual participants included in the study.