Defining cancer risk in dermatomyositis. Part II. Assessing diagnostic usefulness of myositis serology.

In part 1 of this review, we examined the evidence behind the association between idiopathic inflammatory myopathies (IIM) and cancers. In view of the well-recognized association between cancer and myositis (hence the term cancer-associated myositis, or CAM), clinicians responsible for the management of patients with myositis must make important decisions regarding how intensively they undertake searches for malignancy. Clinicians must also decide how often such searches are repeated, and again how intensively, to optimize both cancer detection and treatment, and thus patient survival. As the risks of CAM are greatest in dermatomyositis, this is an issue of obvious importance to dermatologists. In this second of two reviews, we examine the role of autoantibodies as potential predictors of cancer risk in patients with IIM.