Malignancy in Idiopathic Inflammatory Myopathies: Recent Insights

Idiopathic inflammatory myopathies (IIMs) are a group of rare autoimmune diseases in which several subtypes, primarily dermatomyositis (DM), are associated with a high risk of malignancy. Although the relationship between the pathogenesis of IIMs and co-occurring malignancy is poorly understood, there is a growing evidence base for specific risk factors which are associated with cancer-associated myositis (CAM), including myositis-specific or myositis-associated autoantibodies (MSAs/MAAs). In addition, given that patients with different subtypes of IIMs, as classified according to clinical manifestations or serum autoantibody measurement, exhibit heterogeneity in tumorigenesis, further research is urgently needed to explore the pathogenesis of CAM, in order to develop novel biomarkers and therapeutic alternatives for patients. This review discusses the risk and protective factors for CAM using the available evidence, thereby offering fresh insights into its pathogenesis, screening, and management strategies and highlighting possible future breakthroughs and obstacles in this field.