Funding for this research was provided by:
Received: 10 October 2019
Accepted: 2 January 2020
First Online: 11 January 2020
Compliance with ethical standards
: RHAV reports grants from BMS and Roche, outside the submitted work. NHM has served as a consultant for BMS, Lilly and MSD. JdV has received non-financial support from BTG, and Servier, and has served as a consultant for Shire and has received institutional research funding from Servier. MGHvO reports grants from Roche, during the conduct of the study, has received unrestricted research grants from BMS, Merck Serono, Nordic, Roche and Servier. HMWvL reports grants from Roche, during the conduct of the study, has served as a consultant for BMS, Celgene, Lilly, and Nordic and has received unrestricted research funding from Bayer, BMS, Celgene, Lilly, Merck Serono, MSD, Nordic, Philips, and Roche. The other authors have nothing to disclose.
: According to the Central Committee on Research involving Human Subjects, this type of study does not require approval from an ethics committee in the Netherlands. The study was approved by the Privacy Review Board of the NCR and the scientific committee of the Dutch Upper GI Cancer Group.
: Consent to participate was not considered necessarily.