A Case of Dermatomyositis Along with Esophageal Cancer and Screening of Serum Transcriptional Intermediary Factor 1 Gamma Antibodies in Various Cancer Patients.

Objective: Unknown ethiology Background: Dermatomyositis (DM) is occasionally associated with malignancy, which is so-called cancer-associated myositis. The cancer screening in patients with dermatomyositis is an important clinical issue. That is because malignant disease underlying dermatomyositis is potentially life-threatening. Transcriptional intermediary factor 1 gamma (TIF1 gamma) antibodies (anti-TIF1 gamma Abs) are one of the myositis-specific autoantibodies, which are investigated as potential predictors of malignancy in patients with dermatomyositis. However, the etiology of anti-TIF1 gamma Abs generations in various cancer patients is not known. Case Report: A 70-year-old male patient was admitted for muscle pain and weakness in both legs. Erythematous on the face, eruption, and a V sign were also observed. Laboratory tests showed the elevation of creatine kinase, myoglobin, and aldolase. He was diagnosed as dermatomyositis. Cancer screening was performed, and esophageal cancer was detected in the lower esophagus. Despite the symptoms of dermatomyositis were improved with steroid, methotrexate, and radical esophagectomy, he died with esophageal cancer 3 years after the onset of dermatomyositis. TIF1g is frequently overexpressed in cancer tissues. Therefore, some cancer patients without dermatomyositis could be positive for anti-TIF1 gamma Abs. We retrospectively analyzed anti-TIF1 gamma Abs in cancer patients (n=131). However, the screening of anti-TIF1 gamma Abs in cancer patients without dermatomyositis (n=130) showed there were no seropositive patients. Only this cancer-associated myositis patient was positive for anti-TIF1 gamma Abs. Conclusions: Our result suggested the generation of anti-TIF1g Abs is specific for cancer associated myositis, not for tumorigenesis.