Ethics approval and consent to participate
All ethical considerations in this post-hoc study were within the intended use of the HOVON-43 randomized controlled trial and in accordance to the ethical principles as posed in the declaration of Helsinki as well as current national legislation. The HOVON-43 study was approved by the ethics committee of the Erasmus University Rotterdam/Academic Hospital Rotterdam (METC EUR/AZR, 30 August 2000) and the ethics committee of each participating institution (