[Rheumatoid arthritis and malignancy].

Rheumatoid arthritis (RA) is associated with excess mortality. Especially, malignancy is a major cause of mortality. According to previous reports, the overall incidence of malignancies in RA patients has been reported to be comparable or slightly higher than that in general population. The increased incidence of malignant lymphoma and lung cancer has been reported to be consistent in most studies. The use of some csDMARD was also reported as risk factors for malignancy. Recently, MTX associated lymphoproliferative disorder(MTX-LPD) is one of the important complications in RA treatment. We revealed the mean MTX dose was demonstrated to be an independent risk factor regarding MTX-LPD onset in RA patients. This data suggest that the treatment with higher MTX dose promotes LPD onset in Japanese RA patients.