Large‐scale real‐world data analyses of cancer risks among patients with rheumatoid arthritis

• Published in: International journal of cancer Vol. 153; no. 6; pp. 1139 - 1150
• Main Authors: Wang, Feicheng, Palmer, Nathan, Fox, Kathe, Liao, Katherine P., Yu, Kun‐Hsing, Kou, Samuel C.
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 15.09.2023; Wiley Subscription Services, Inc
• Subjects: Arthritis, Rheumatoid - complications; Arthritis, Rheumatoid - drug therapy; Arthritis, Rheumatoid - epidemiology; bDMARDs; Cancer; cancers; Comorbidity; Data Analysis; Humans; Lung cancer; Lung Neoplasms - complications; Lung Neoplasms - etiology; Lymphoma; matching method; Medical research; Pathophysiology; Rheumatoid arthritis; TNF inhibitors; cancers; TNF inhibitors; matching method; bDMARDs; rheumatoid arthritis
• ISSN: 0020-7136; 1097-0215; 1097-0215
• DOI: 10.1002/ijc.34606

Rheumatoid arthritis (RA) affects 24.5 million people worldwide and has been associated with increased cancer risks. However, the extent to which the observed risks are related to the pathophysiology of rheumatoid arthritis or its treatments is unknown. Leveraging nationwide health insurance claims data with 85.97 million enrollees across 8 years, we identified 92 864 patients without cancers at the time of rheumatoid arthritis diagnoses. We matched 68 415 of these patients with participants without rheumatoid arthritis by sex, race, age and inferred health and economic status and compared their risks of developing all cancer types. By 12 months after the diagnosis of rheumatoid arthritis, rheumatoid arthritis patients were 1.21 (95% confidence interval [CI] [1.14, 1.29]) times more likely to develop any cancer compared with matched enrollees without rheumatoid arthritis. In particular, the risk of developing lymphoma is 2.08 (95% CI [1.67, 2.58]) times higher in the rheumatoid arthritis group, and the risk of developing lung cancer is 1.69 (95% CI [1.32, 2.13]) times higher. We further identified the five most commonly used drugs in treating rheumatoid arthritis, and the log‐rank test showed none of them is implicated with a significantly increased cancer risk compared with rheumatoid arthritis patients without that specific drug. Our study suggested that the pathophysiology of rheumatoid arthritis, rather than its treatments, is implicated in the development of subsequent cancers. Our method is extensible to investigating the connections among drugs, diseases and comorbidities at scale. What's new? Cancer risk is increased by chronic inflammation, a significant feature of rheumatoid arthritis (RA). While RA patients are at increased risk of cancer, however, the degree to which cancer risk can be attributed to RA pathophysiology or treatment remains uncertain. Here, the authors examined relationships between RA, RA treatments and risk of different cancer types. RA patients were 1.69 to 2.08 times more likely than those without RA to develop lymphoma or lung cancer within 1 year of RA diagnosis. No significant difference in risk was detected for other cancer types. Commonly used RA treatments were also unlikely to increase cancer risk.