Arthritis and the Risk of Cancer: Determining Occurence, Morality, and Subgroups at Risk Using a Population and Case Control Study

Malignancies are important outcomes in patients with rheumatoid arthritis (RA). This study proposes the exact definition of the risk for cancer in these patients, the determination of predictors of cancer development, and the mortality of RA patients with malignancies. In patients with rheumatoid arthritis (RA) the development of malignancies may lead to an increased morbidity and mortality. This project will utilize data from the Surveillance Epidemiology End Result (SEER) Program, in which all newly diagnosed cancer cases of approximately 26% of the U.S. population are recorded. A data-link to Medicare, the primary health insurer for 97% of the US population 65 years and older, will provide diagnosis and procedures for these patients, and enable identification of cancer patients with rheumatoid arthritis. This study proposes a series of analyses: (1) To define the rate of occurrence for cancer located in 43 different sites and 16 organ systems (oral cavity, digestive system, respiratory system, bones and joints, soft tissue, skin, breast, genital organs, urinary system, eye and orbit, brain and other nervous system, endocrine system, lymphoma, myeloma, leukemia, all other sites) among patients with RA compared to the general population; (2) to compare mortality of RA patients and non-RA patients who have the same type of cancer; (3) to evaluate the contribution of the frequency of control examinations, type of health care supply (hospital or physician`s office), the number of previous hospital admissions, and screening procedures in the follow-up of RA on the development of malignancies. Analyses (1) - (3) will then be performed also for patients with psoriatic arthritis (PsoA). In addition, RA and PsoA will be compared with respect to cancer development and mortality. Knowledge of this reciprocal relationship between chronic arthritis and cancer will provide a more complete understanding of the health consequences of RA (and PsoA), identify individual risk factors for cancer, and suggest strategies for prevention and intervention.