Text and Data Mining valid from 2018-10-01
Received: 14 January 2018
Revised: 6 July 2018
Accepted: 10 July 2018
First Online: 7 November 2018
<!--Emphasis Type='Bold' removed-->Ethics approval and consent to participate
: The study was approved by The Regional Committee for Medical and Health Research Ethics South East (REK 2011/500), and all patients gave informed written consent to participate. The study was performed in accordance with the Declaration of Helsinki.
: This work was supported by grants from the South–East Norwegian Health Authority (Grant 2012064), Norwegian Research Council (Grant 213997), Active Against Cancer-Gjensidige Siftelsen (Grant 2012) and the Norwegian Cancer Society (Grant 163243).
: The metabolomics data can be made available from the authors upon request.
: The authors declare no competing interests.
: This work is published under the standard license to publish agreement. After 12 months the work will become freely available and the license terms will switch to a Creative Commons Attribution 4.0 International (CC BY 4.0).