Association between autoimmune rheumatic diseases and head and neck cancer: Systematic review and meta‐analysis

Background Personal history of autoimmune rheumatic diseases has been implicated in the development of malignant neoplasms. Our aim was to assess the risk of head and neck (H&N) cancers in patients with autoimmune rheumatic diseases. Methods The articles search included PubMed, EMBASE, LILACS, The Cochrane Library, CINAHL, Scopus, Web of Science, and Google Scholar with no language restrictions for studies published from inception of the databases to August 20, 2022, assessing the risk of H&N cancer in patients with autoimmune rheumatic diseases. Studies were included if they reported the standardized incidence ratio (SIR) with corresponding 95% confidence intervals (CIs). The primary outcome was risk of H&N cancers in patients with autoimmune rheumatic diseases compared with the general population. Pooled summary estimates were calculated using a random‐effects model, and subgroup analyses were done to establish whether risk of H&N cancers varied according to study site. Results Our search identified 5378 records, of which 32 cohort studies were eligible for systematic review and 24 for meta‐analysis (including 273 613 patients). A significant association was found between H&N cancer and autoimmune rheumatic diseases (SIR = 2.35; 95% CI: 1.57–3.50; p