About the Authors

Sonja Eaker, Lars Holmberg
Department of Surgery, University Hospital of Uppsala and Regional Oncologic Centre, Uppsala, Sweden

Paul W Dickman
Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden

Leif Bergkvist
Department of Surgery, Centre for Clinical Research, Central Hospital of Västerås, Västerås, Sweden

Corresponding Author

sonja.eaker@roc.se

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

SE performed all of the analyses, contributed to the interpretation of the data, and drafted the article. PWD contributed with the analysis and interpretation of the data. LB contributed with the acquisition of the data, with detailed knowledge about the register, and with revising the article for intellectual content. LH contributed with the conception and the design of the study, interpretation of the data, and revising the article for intellectual content.