Clinical characteristics and prognostic analysis of Chinese dermatomyositis patients with malignancies

Although a strong association between idiopathic inflammatory myositis (IIM) and malignancy has been widely reported, few studies have solely focused on the concurrence of dermatomyositis (DM) and malignancies (DM-malignancy).We conducted a retrospective analysis of 37 DM-malignancy cases among 363 DM patients admitted to our hospital between January 2012 and December 2017.(1) The mean age at DM diagnosis was higher for DM-malignancy patients than for DM-non-malignancy patients [(54.76 ± 9.77) years vs (48.57 ± 12.82) years, t = 2.84, P = .005]. (2) Gynecological malignancies (35.90%/14 cases) were the most common malignancies. Malignancies were diagnosed before DM for 7 DM-malignancy patients. The interval between the DM and malignancy diagnoses for the remaining 32 DM-malignancy patients was less than 6 months for 18 patients (46.15%), less than 1 years for 23 patients (58.9%), and less than 2 years for 29 patients (74.26%). (3) There was no significant difference either in antinuclear antibody or anti-Ro-52 positivity between the 2 groups (P > .05). (4) Multivariate analysis demonstrated that DM onset age ≥50 years and concurrence with ILD increased the risk of death for DM patients [hazard ratio (HR): 1.62 and 2.72; 95% confidence interval (CI): (1.08-2.43) and (1.47-5.02); P = .02 and 0.001, respectively], and male gender decreased the risk of death [HR 0.66, 95% CI (0.44-0.98), P = .04]. DM-malignancy patients were older than DM-non-malignancy patients. Gynecological malignancies were the most common malignancies among these patients. A DM onset age ≥50 years, female sex and the presence of ILD were independent risk factors for death.