Oldroyd et al reported criteria for when to screen a patient with idiopathic inflammatory myopathy for underlying cancer. The authors are from multiple institutions in the United States and Europe.
Patient selection: idiopathic inflammatory myopathy
High risk factors:
(1) dermatomyositis
(2) anti-TIF1
(3) anti-NXP2
(4) age > 40 years at myositis onset
(5) persistent high disease activity despite immunosuppressive therapy
(6) moderate to severe dysphagia
(7) cutaneous necrosis
Intermediate risk factors:
(1) clinically amyopathic dermatomyositis
(2) polymyositis
(3) immune-mediated necrotising myopathy IMNM
(4) anti-SAE1
(5) anti-HMGCR
(6) anti-Mi2
(7) anti-MDA5
(8) male sex
Low risk factors:
(1) antisynthetase syndrome
(2) overlap of idiopathic inflammatory myositis and connective tissue disease-associated myositis
(3) anti-SRP
(4) anti-Jo1
(5) non-Jo1 ASS (argininosuccinate synthetase) antibody positivity
(6) myositis-associated antibody positivity (PM-Sci, Ku, RNP, Ro/La)
(7) Raynaud's
(8) inflammatory arthropathy
(9) interstitial lung disease
If the patient has >= 2 high risk factors, then high risk.
If the patient has 1 high risk factor OR >= 2 intermediate risk factors, then intermediate risk.
If neither rule applies, then low risk.
