Dermatomyositis and malignancy. A multicenter cooperative study.

A retrospective analysis of 118 cases of dermatomyositis (DM) collected in 22 departments of dermatology over a 5-year period is presented. 34 cases (28%) were associated with a cancer that was diagnosed more than 1 year prior to (7 cases), concomitantly (22 cases) or more than 1 year after (5 cases) the occurrence of DM. There was a clear correlation between the evolution of DM and a cancer paraneoplastic evolution in 8 cases only (22%). In most of the cases, no extensive diagnostic procedures were necessary for identifying the tumors. 58% of the patients with cancer-associated DM died 20 (8-29) months after the diagnosis of DM. This multicenter study based on a short period of time confirms and extends previous observations based on retrospective single-center analyses.