Funding for this research was provided by:
A grant-in-aid from the Ministry of Health, Labour and Welfare, Japan. (H26-GANSEISAKU-IPPAN-003)
Received: 5 September 2017
Accepted: 14 August 2018
First Online: 24 August 2018
Ethics approval and consent to participate
: The study design was approved by the Institutional Review Boards of the National Cancer Center of Japan (No. 2014–353) and Aomori Prefectural Central Hospital (No. H260405). Prior to the research, all participants were duly informed and provided oral consent to participate as per the requirements of the ethical guidelines on epidemiological research in Japan for non-invasive studies. Additionally, information on the research was posted on hospital bulletin boards, the official website, and in public relations magazines so that the participants can withdraw their consent and request us to stop using their information at any time.
: Not applicable.
: The authors declare that they have no competing interests.
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