1 European Organisation for Research and Treatment of Cancer (EORTC) Headquarters, 1200 Brussels, Belgium. Electronic address: emanuel.buhrer@bluewin.ch.
2 European Organisation for Research and Treatment of Cancer (EORTC) Headquarters, 1200 Brussels, Belgium.
3 Comprehensive Cancer Center Munich of the Technical University Munich and the Ludwig Maximiliaan University, Munich, Germany; Princess Máxima Center and University Medical Center Utrecht, Utrecht, Netherlands.