Dermatomyositis and breast cancer: a multicenter Tunisian retrospective study of 13 cases.

Aim: To evaluate the epidemiological, clinical, biological features and prognostic factors in patients presenting an association of dermatomyositis (DM) and breast cancer (BC).

Methods: Medical records of 13 patients with DM and BC among 210 DM collected from January 1982 to march 2009 were retrospectively reviewed.

Results: Mean age was 47 ± 18 years. DM preceded BC in 3 patients, was concurrent with BC in 2 cases and followed it in 8 cases. Clinically, ulcerative and bullous lesions predominating on limbs were observed in 2 patients. A severe proximal muscular weakness was observed in 4 cases and one patient has presented an amyopathic dermatomyositis. BC was staged IV in 3 pts, IIIA in 2 cases while 3 had stage IIB, 3 stage IIA and 2 stage I according to TNM classification. Nine out of 13 patients had parallel improvement of DM symptoms after treatment of BC. Five patients died of recurrence or distant metastasis (mortality 41.66%). Median survival was 35 months (3-177) after DM diagnostic.

Conclusion: In Tunisia, DM is associated with an increased incidence of BC. A paraneoplastic course of DM is noted in 70% of patients. In view of the increased risk of BC in our country, in addition to routine examination and laboratory screening, mammography, chest ultrasound, and gynaecological examination, are indicated in women with DM older than 40 years, particularly in case of previous personal or familial history of breast neoplasm.