TNF and rheumatoid arthritis: Similarly, two Swedish-population-based studies that were linked with the Swedish Nationwide Cancer and Census Registers, and differentiated between solid cancers [125] and hematopoietic malignancies [126] in three RA cohorts (one with prevalent pathology, admitted to hospital between 1990–2003 (n = 53,067); one incident cohort, with a cancer diagnosis between 1995–2003 (n = 3703); and one RA cohort treated with TNF antagonists between 1999–2003 (n = 4160)), was followed up for cancer occurrence through 2003.