The troubling liaison between cancer and metabolic syndrome in chronic inflammatory rheumatic diseases

BACKGROUND: Several studies on community populations found that metabolic syndrome (MetS) is associated with higher risk for total incident cancer with a predisposition for specific types of cancer. These findings have never been analyzed in patients with chronic inflammatory rheumatic and musculoskeletal diseases (RMD). We assessed prevalence/incidence and factors related to the development of cancer in a large cohort of these patients and evaluate whether MetS and its components were associated with cancer independent of traditional markers of inflammation. METHODS: Between March 2014 and April 2016, 474 patients with RMD involved in a cardiovascular primary prevention program were consecutively recruited into this ambispective (combination of retrospective/prospective) study. They underwent clinical, laboratory, and echocardiographic evaluations. MetS was diagnosed according to the ATPIII criteria. RESULTS: Duration of follow-up was 42 [18–60] months. Patients with a diagnosis of cancer (made before recruitment or during follow-up) were 46 (9.7%). Cancer was diagnosed in 22/76 patients (29%) with MetS and in 24/398 patients (6%, p < 0.001) without MetS; nearly two thirds of malignancies belonged to those traditionally related to MetS. MetS was the strongest cancer risk factor. Cancer was positively associated with the number of MetS components identified in each patient. Beyond MetS, cancer was associated to older age and increased inflammatory disease activity; this information allowed to build a simple performance indicator highly sensitive for cancer development. CONCLUSION: In light of our results, an increasingly accurate assessment of MetS would be required in patients with RMD as potential measure of clinical outcomes including the risk of cancer.