[Prognostic factors and predictive signs of malignancy in adult dermatomyositis]. / Facteurs pronostiques et signes prédictifs de cancer au cours de la dermatomyosite de l'adulte.

ABSTRACT

INTRODUCTION: Prognosis in dermatomyositis is severe, partly due to the development of cancer. The aim of this study was to identify factors predicting cancer development and assess factors predicting reduced survival rate. PATIENTS AND METHODS: A retrospective analysis of 32 cases of dermatomyositis diagnosed on the basis of the Bohan and Peter criteria was performed. Diagnosis was certain in 7 cases, probable in 13 and possible in 5. There were thus 7 cases of pure cutaneous dermatomyositis. Clinical and laboratory data were compared between patients with and without cancer and between deceased and surviving patients. RESULTS: Overall mortality was 37.5% at 4 years, confirming the gravity of dermatomyositis. Malignancy developed in 9 patients (28.1%) leading to death in all cases, within 18 months in 8. Amyopathic dermatomyositis was observed in 2 of these patients. Necrotic skin ulcerations (p < 0.01) and pruritus (p < 0.05) were significant predictive factors for the development of cancer. Poor prognosis factors were malignancy (p < 0.001), necrotic skin ulcerations (p < 0.01), and pruritus (p < 0.05). CONCLUSION: Prognosis is poor in certain sub-groups of patients with dermatomyositis. Such patients can be identified on the basis of skin lesions, notable necrotic ulcerations.