- (1) Spanish National Cancer Research Centre, grid.7719.8
- (2) Hannover Medical School, grid.10423.34
- (3) Helsinki University Central Hospital, grid.15485.3d
- (4) German Cancer Research Center, grid.7497.d
- (5) University Medical Center Hamburg-Eppendorf, grid.13648.38
- (6) Erasmus University Medical Center, grid.5645.2
- (7) International Agency For Research On Cancer, grid.17703.32
*Analyses excluded data from three studies (GESBC, MCBCS and SEARCH) without information on node involvement.**Per-allele OR adjusted for study.***P value for heterogeneity of ORs from case-only analyses adjusted by study.****Permutation adjusted P for heterogeneity.