Abstract:

Objective To investigate the incidence of malignant tumor and evaluate the potential risk factors in DM patients. Methods A retrospective case analysis was conducted on patients with dermatomyositis from 2006 to 2015 in Guangzhou First People′s Hospital，including general information，clinical symptoms，labo⁃ ratory examination results，and drug records. The end point of the study was defined as the occurrence or death of a malignant tumor. Results In this study，59 of the 238 patients with dermatomyositis had a 24.8% overall incidence of malignant tumors.Nasopharyngeal cancerand lung cancerare the most common malignant diseases. Among the 59 patients with malignant tumor，35（59.3%）developed dermatomyositis within 1 year after diagnosis. In subsequent years，and only 1 patient had tumor after the third year.multivariate Logistic regression analysis showed that the male gender，dyspneaand high level of CRP for the risk factors，Interstitial Lung Disease（ILD）was a protective factor for malignant tumor. Conclusion Due to the high incidence of Chinese patients with dermatomyositis malig⁃ nant tumor，We should be on high alert for the presence of malignant tumors in these patients. Nasopharyngeal car⁃ cinoma and lung cancer is the most common malignant disease. The risk of malignant tumor in dermatomyositis is the highest rates in the first year after diagnosis. After systemic malignant tumor screening work shall be carried out in the first year. Male gender，dyspnea，high level of CRP is risk factosr for malignant tumors occur. The presence of pulmonary interstitial disease reduces the risk of malignant tumors of coexist.

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