Introduction Many studies and meta-analyses concluded that farmers have an excess risk of Non-Hodgkin’s Lymphoma (NHL) overall but results remain scarce for rare subtypes, like Lymphoplasmocytic Lymphoma/Waldenström macroglobulinemia (LPL/WM). In the AGRICAN cohort, the incidence of LPL/MW was found significantly higher among farmers than in the general population.

Objective Our aim was to study the association of LPL/WM with some agricultural exposures, like specific crops and livestock, or related tasks.

Methods Our analysis included 155,192 individuals from the 181,842 affiliated to the social agricultural scheme enrolled in 2005–2007 in 11 French areas. Exposure was determined from the report of work on 13 different crops and 5 livestock, for which 2 to 5 specifics tasks (including duration and size information) were collected. Incident cases were identified by cross-linkage with population-based cancer registries. Associations with crops, animals and specific tasks were analyzed using Cox models with age as time scale and farmers who were not exposed to the crop/livestock of interest as the referent group.

Results From enrollment to 2015, 1,349 incident NHL cases were identified including 122 LPL/WM cases. Elevated LPL/WM risks were observed in (i) users of pesticides on crops (HR=1.56, 95%CI=1.03–2.38), especially on grasslands (HR=1.85, 95%CI=1.01–3.38), wheat/barley (HR=1.98, 95%CI=1.24–3.16), and corn (HR=2.21, 95%CI=1.41–3.47); (ii) hay-makers (HR=1.66, 95%CI=1.02–2.71); (iii) sowers (HR=1.28, 95%IC=0.75–2.20), especially on wheat/barley: (HR=1.70, 95%CI=1.09–2.65), corn (HR=1.59, 95%CI=0.997–2.551) and root (HR=1.52, 95%IC=0.93–2.50) ; (iv) cattle breeders (HR=1.92, 95%CI=1.00–3.70), particularly with care (HR=1.97, 95%CI=1.02–3.81). Inverse associations were observed in poultry breeders (HR=0.44, 95%CI=0.28–0.70), particularly with care (HR=0.52, 95%CI=0.32–0.85), and disinfection of livestock premises (HR=0.28, 95%CI=0.11–0.68).

Conclusion Elevated LPL/WM risks were linked with use of pesticide, haymaking and sowing tasks on several crops. Furthermore, specific associations were observed with some livestock in both directions (positive with cattle breeding and inverse with poultry), although based on small numbers for some activities.