Funding for this research was provided by:
Grants-in-Aid for Scientific Research from the Japanese Society for the Promotion of Science (18k08145)
Received: 22 February 2020
Accepted: 18 August 2020
First Online: 14 September 2020
Ethics approval and consent to participate
: The study protocol was approved by the Institutional Review Board at Nagasaki University Hospital (approval number 17112009), and the study was conducted in accordance with the Declaration of Helsinki. Informed consent was not required in view of the retrospective study design and the anonymity of the patient records reviewed, pursuant to the ethical guidelines of the Japanese Ministry of Health, Labor, and Welfare.
: Not applicable.
: This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.