Objectives Established risk factors for leukaemia do not explain the majority of leukaemia. Previous studies have suggested the importance of occupation in leukaemogenesis.

To evaluate associations between job title and leukaemia in the population the MCC-Spain

We studied occupational variation of the risk of chronic lymphocytic leukaemia

Method We have 30 744 occupational interviews recruited during 2007 to 2012 all was codified on 67 group homogeneous units, according to a defined criteria, in the same category defined by a set of tasks of the same characteristics. We analysed 196 cases of leukaemia (aged 20–75 years) and yours controls randomly selected from 9 regions in a population based case-control study in Spain (MCC-Spain study) whit demographic details, information on potential confounders and a comprehensive employment history. Each case of leukaemia may have one or more occupations. All occupation were codified by Occupational National Code (CNO 94) and The International Standard Classification of Occupations (ISCO-88) Associations between occupation and leukaemia were analysed using logistic regression adjusting for gender, age, and smoking.

Results We analysed the 27,4% of leukaemias.6% never had occupation with risk of leukaemia and 41% were worked at least one occupation with probably exposition to carcinogens for leukaemia. Analysis is ongoing and results will be presented at the conference.

Conclusions In summary, our study showed some evidence supporting the role of some kind occupation in the development of leukaemia. However, given the relative low numbers the results have to be interpreted with some caution. On have analyse the exposition on these occupations.