Malignancy associated with dermatomyositis - a retrospective single-center study with 33 patients

Dermatomyositis is a multisystemic inflammatory disease that has been associated with neoplastic disease.

To assess the clinical/ laboratory data in a series of patients with dermatomyositis (DM) and identify associations with malignancy.

Retrospective study of DM inpatient files between 1965 and 2011. The patients were included if fulfilled at least four of the five Bohan and Peter diagnostic criteria. DM was considered associated with malignancy only if its diagnosis had preceded or followed the DM diagnosis by up to three years. Data was analyzed with a significance level of 5%.

Our results have a retrospective nature and represent only a single-center experience. Between 1965 and 2011, 33 patients fulfilled the inclusion criteria, with a median age of 56 years old (s= 14.329) and female to male ratio of 1.36:1. Neoplastic disease was associated to DM in 30% of the patients and men had significantly more cases of associated neoplasia than women (p=0.042 in Fisher´s exact test). In 70% of these patients, malignancy was diagnosed simultaneously or in the first year after DM diagnosis.

In our series, DM was more frequent in women but, when associated with malignancy, it was more frequent in men, in contrast to the female predominance reported in Western series. Malignancy was found in about one third of DM patients and, in terms of target organs, did not differ from the general population. Therefore, as the majority of malignancies were detected at the time of or in the year following DM diagnosis, screening should be performed for the most frequent neoplasms at the time of diagnosis and repeated one year later.