Can Serologic Testing Aid in the Identification of Dermatomyositis-Associated Cancer?

Jeffrey P. Callen, MD

Many patients with this association have certain antibodies, but blood testing may not yet be practical.

Adult patients with dermatomyositis have an increased risk for malignancy, and some form of search is initiated in almost all patients upon diagnosis. The risk for malignancy increases with patient age, and evaluation might differ depending on age, ethnicity, and sex. The cost of testing and retesting patients over years might not be justifiable, and a marker that could reliably identify patients at risk would save money and prevent morbidity resulting from unnecessary testing.

These authors tested 213 patients with dermatomyositis seen at two referral centers for the presence of two antibodies: anti-nuclear matrix protein (NXP) antibodies and anti–transcription intermediary factor 1γ (anti–TIF-1γ) antibodies. Anti-NXP antibodies were found in 37 patients (17.4%) and anti–TIF-1γ in 82 patients (38.4%).Two patients had both. Cancer was found in 29 patients (13.6%). The antibodies, alone or in combination, were identified as risk factors for malignancy (odds ratio, 4.7 [95% CI 1.7–12.8], P = 0.003). A stronger association of cancer with antibodies was seen in older and male patients.

Citation(s):

Fiorentino DF et al. Most patients with cancer-associated dermatomyositis have antibodies to nuclear matrix protein NXP-2 or transcription intermediary factor 1γ. Arthritis Rheum 2013 Nov; 65:2954.