Funding for this research was provided by:
Painter Research Fund
Received: 27 February 2019
Accepted: 12 September 2019
First Online: 17 October 2019
Ethics approval and consent to participate
: This study was approved by the ethics committee at MD Anderson Cancer Center. A waiver for informed consent was granted since this retrospective analysis involved no more than minimal risk to the subjects.
: Not applicable.
: The authors have declared no competing interests.