1 Department of Medical Oncology, West German Cancer Centre, Ruhrlandklinik, University Hospital Essen, University Duisburg-Essen, Essen, Germany. Electronic address: wilfried.eberhardt@uni-duisburg-essen.de.
2 Cancer Research and Biostatistics, Seattle, Washington.
3 Department of Thoracic Surgery, Hospital Universitari Mutua Terrassa, CIBERES Lung Cancer Group, Terrassa, Barcelona, Spain.