Diagnostic Approaches to Malignancy-Associated Dermatomyositis

by Anthony P. Fernandez, MD, PhD, and Carmen Gota, MD

Patients with dermatomyositis (DM), an idiopathic inflammatory myositis affecting the skin, are at a significantly increased risk of developing several types of cancer. One meta-analysis found a pooled risk ratio of 5.50 (95% CI, 4.31-6.70) for overall malignancy in this patient population.

At Cleveland Clinic, patients with DM are frequently seen in the departments of dermatology, rheumatology and neurology. Although individual patients may be cared for entirely by a clinician or clinicians in one of these departments based on their particular disease manifestations, we most often collaborate in an interdisciplinary way to provide optimal care for these patients.

As part of our efforts to improve treatment and treatment protocols, we studied diagnostic approaches to suspected malignancy in patients with DM. Currently there are no evidence-based guidelines for malignancy screening, and work-up protocols are not consistent across institutions, departments or even clinicians within the same department.

Our research looked at 50 patients from Cleveland Clinic with malignancies within three years of DM diagnosis. This cohort was then compared with age- and sex-matched control DM patients without malignancy and with five or more years follow-up from diagnosis.

The research confirmed patients with malignancies unfortunately often present without symptoms.

When malignancy screening is most beneficial

The data we analyzed suggest malignancy screening is most beneficial in DM patients within 12 months of diagnosis who have classic DM, are over 50 years old and present with dysphagia (if in the setting of classic DM as opposed to amyopathic DM). Further, our study identified common malignancies on which screening should focus — lung, colon, breast, hematologic, oropharyngeal, ovarian, renal, thyroid, esophageal and prostate. These were consistent with two meta-analyses that investigated which malignancies occur with greater incidence in patients with malignancy-associated DM.

Currently, we discuss possible association with underlying malignancy with patients who are diagnosed with DM, as well as potential risks of malignancy screening. Then, we make shared decisions about whether to pursue malignancy screening and the extent of screening.

We expect this study, combined with other research and sorely needed prospective studies, will help develop more consistent and evidence-based malignancy screening protocols for patients diagnosed with DM that optimize balancing risks, benefits and costs. Results of our study were published in the Journal of the American Academy of Dermatology in January 2018.

Dr. Fernandez is Director of Medical Dermatology. Dr. Gota is staff in the Department of Rheumatologic and Immunologic Diseases.