THE JANUS-SERUM-BANK

The on-going JANUS project was initiated by the Norwegian Cancer Socie ty in 1973. The serum bank comprises close to 0.5 million serum sample s collected from 170 000 donors. From 2-16 consecutive samples are ava ilable from each donor. The sera are stored at -25-degrees-C. At regul ar intervals the JANUS-collection is matched against the files of the Norwegian Cancer Registry. From 1973 to 1991 almost 5000 of the donors have developed some form of cancer. Frozen serum samples collected fr om a few months to 18 years prior to clinical recognition of their dis ease are consequently available for research purposes. The aim of the JANUS-project is to search in these premorbid sera for chemical, bioch emical, immunological or other changes that might be indicative of can cer development at early stages. Gas chromatography-mass spectrometry and two-dimensional protein electrophoresis have been used to evaluate the stability of the frozen sera. Some recent findings are: CA125 is elevated several months prior to diagnosis of ovarian cancer; serum th yroglobulin may be a preclinical tumour marker in subgroups of thyroid cancer; low level of selenium in serum reflects increased risk of thy roid cancer; and raised antibodies in serum against Epstein-Barr virus is a risk factor for development of Hodgkin's disease. On-going resea rch includes trace elements and cancer, and studies on lipid-profiles, diet and cancer. The serum bank may in principle be used for other pu rposes, e.g. in environmental studies. Analysis of sequential sera may determine chemical substances in the sera that might reflect differen ces in exposure to environmental pollutants in the period 1973-1991.