1. Department of Upper Gastrointestinal Diseases, Karolinska University Hospital and Karolinska Institute, Stockholm, Sweden
2. Clinical Epidemiology Unit, Department of Medicine, Solna, Karolinska Institutet, Stockholm, Sweden
3. Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
4. Institute of Pathology, Klinikum Bayreuth, Bayreuth, Germany
5. Department of Pathology, Karolinska University Hospital and Karolinska Institute, Stockholm, Sweden