Employess and students were identified by their personal identification number and linked to the Cancer Registry of Norway, in order to obtain a complete coverage of such cancers in the cohort. Indicators of historical exposures were established (exposure in different courses and tasks) and a SIR of lymphohaematological cancers of 1,8 (95 % confidence 0.6-4.2) of the total group was identified, as well as increased risks linked to certain courses where carcinogenic substances had been in use. The Ministry of Education and Health appointed an advisory group to evaluate the report of this linkage, and a new linkage updating cancer incidence in the cohort after an additional period of 5 years was suggested.
The Ministry in 2014 commisioned STAMI and the Cancer Registry to perform this new update including 5 years of extended follow-up time. STAMI leads this work.