Cohort Profile: The Janus Serum Bank Cohort in Norway

The Janus Serum Bank Cohort in Norway is a population-based prospective cancer biobank formally established in 1973.The biobank consists of residual blood serum samples from a large number of men and women, who participated in different population-based cardiovascular disease health surveys in Norway during the period 1972–2004. The biobank was established on the initiative of Professor of Pathology, Olav Torgersen (1907–78).The collection was organized as a collaboration between former national X-ray examinations, the national health screening services, Ullevål University hospital in Oslo and the Cancer Registry of Norway (CRN). The purpose of the biobank was to build up a resource for studies of cancer aetiology and early detection of cancer, by measuring biochemical and immunological changes several years before the patient’s diagnosis. The Janus cohort, with comprehensive registry-based follow-up, enables longitudinal assessment of the preclinical stage in cancer patients or the latent period before the tumour has been established, and is ideal for the search of novel biomarkers of cancer.1 An additional aim was to collect diagnostic samples from a sub-group of the cohort members who developed cancer at a later stage in life, to investigate biochemical changes after diagnosis. The cohort was named after the Roman god, Janus. The dual-faced image symbolizes the multipurpose nature of the cohort and how stored specimens with registry-based follow-up can be used for longitudinal studies of cancer, looking both backwards and forwards at the same time. The CRN took over the cohort in 2004.