Exploring the Link between Head and Neck Cancer and Elevated Risk of Rheumatoid Arthritis: A National Population-Based Cohort Study.

An increased risk of cancer among patients with rheumatoid arthritis (RA) has been reported. However, the risk of RA events among patients with head and neck cancer (HNC) is unknown. Therefore, we investigated the incidence and risk of RA among patients with HNC. This study was based on a cohort dataset. Overall, 2824 individuals without HNC and 706 patients with HNC were selected using propensity score matching. The overall RA event rate was 12.19 for patients with HNC and 7.60 for those without HNC. A significantly increased risk of developing RA was also observed among patients with HNC. The risk of developing RA over time was relatively high within the first year after HNC diagnosis; further, it increased significantly during the follow-up period. Moreover, middle-aged male patients with HNC exhibited an increased risk of developing RA compared with the controls; however, no significant difference was noted among female patients or other age groups. Notably, subgroup analysis according to cancer subtype revealed that only oral cancer survivors had an increased risk of developing RA. These results underscore the importance of vigilant monitoring by clinicians to promptly identify the onset of RA in patients with HNC.