Received: 8 August 2018
Accepted: 26 June 2019
First Online: 4 July 2019
Ethics approval and consent to participate
: This study involved a secondary analysis of data collected during two multi-site trials, which were approved by the Fred Hutchinson Cancer Research Center/University of Washington Cancer Consortium Review Board and the Dana-Farber/Harvard Cancer Center Institutional Review Board, respectively.
: Not applicable.
: The authors declare that they have no competing interests.