Dermatomyositis And Polymyositis Associated With Malignancy: A Retrospective Analysis Of 21 Cases

Objective To investigate the clinical features of dermatomyositis and polymyositis associated with malignancy, and study the relationship between DM/PM and malignancy.Methods A retrospective study was performed of 21 patients who diagnosised DM/PM associated with malignancy admitted to the First Affiliated Hospital of Chongqing Medical University over a period of 6 years. Compared with 31 patients who diagnosised DM/PM, the clinical characteristics and risk factors of cases associated with malignancy were analyzed.Results The incidence of malignancy among DM/PM was 11.54%, a lot of patient were older than 40 years. The most common malignancies were lung cancer, liver cancer and nasopharyngeal carcinoma. Statistical analyses revealed that the high risk factors of concomitant malignancy included an onset in age >40 years (P=0.02), malignant erythema (P=0.04), dysphagia (P=0.03), CK≤reference (P=0.04), ESR>35mm/h ( P=0.03, severe itching(P=0.05) and invalid treated with prednisone(45mg/d, persist 30d)(P<0.01). The survival rate in first year of the patients who diagnosis DM/PM associated with malignancy was 42.11%, the common cause of death was malignancy and complication.Conclusions The morbility of malignancy in the patients with DM/PM was more higher than basical morbility of maliganancy in the locality;The types of malignancy were similar to prevail types in the locality,and the particularly carcinoma was different in defferent area;The high risk factors of concomitant malignancy included an onset in age >40 years, malignant erythema, dysphagia, CK≤reference, ESR>35mm/h, severe itching and invalid treated by prednisone(45mg/d, persist 30d);When the malignancy was controlled, the dermatitis and myositis would relieve. The survival rate in first year of the patients who diagnosised DM/PM associated with malignancy was 42.11%, the common cause of death was malignancy and complication.