Nijmegen, The Netherlands The Dutch study population was previously described.22 The 634 patients with LC were identified through the population-based cancer registry of the Comprehensive Cancer Center IKO, Nijmegen, the Netherlands, and recruited through several independent studies.22 The 4670 cancer-free controls were selected from participants of the ‘Nijmegen Biomedical Study'.23 All controls are of self-reported European descent. The study protocols of the Nijmegen Biomedical Study were approved by the Institutional Review Board of the Radboud University Nijmegen Medical Centre.
