Dermatomyositis and malignancy: should all patients with dermatomyositis undergo malignancy screening?

Dermatomyositis is an autoimmune disease that occurs in association with underlying malignancy in a subset of patients. Given this association, diagnosis of dermatomyositis typically triggers malignancy screening. Although various malignancy screening protocols have been proposed, none have been extensively studied or taken into account prevalence of dermatomyositis-associated malignancies. We utilized peer-reviewed manuscripts identified by a Medline search from May 2000 to April 2020 to present a focused review concerning the association between dermatomyositis and malignancy, and controversies related to screening for malignancies most commonly occurring in dermatomyositis patients. This information was then synthesized to propose a rational strategy for approaching malignancy screening in dermatomyositis patients. Our review supports that risk of malignancy in dermatomyositis patients is well-established. However, the subset of dermatomyositis patients in whom the benefits of malignancy screening outweigh the risks of harm is unknown. Additionally, an evidence-based malignancy screening protocol for dermatomyositis patients that optimizes the risk:benefit ratio does not exist. Given the clear harms that can result, we propose that shared decision-making strategies be implemented to determine whether pursuit of malignancy screening conforms with dermatomyositis patients' desires and values. Physicians should be clear about potential risks and benefits of malignancy screening, and discuss clinical and serologic features present that may suggest/refute underlying malignancy during conversations aimed at shared decision-making. Research is greatly needed to determine which dermatomyositis patients warrant malignancy screening, which tests should be performed, and the intensity with which they should be ordered. Only after such work is done can malignancy screening in dermatomyositis patients be considered to have high value.