Tumor antigen markers for the detection of solid cancers in inflammatory myopathies

Dermatomyositis and polymyositis patients have an increased risk of developing cancers. We have assessed the diagnostic values of serum tumor markers for the detection of solid cancer in dermatomyositis/polymyositis patients. Serum carcinoembryonic antigen, CA15-3, CA19-9, and CA125 were assayed by immunoradiometric methods in 102 dermatomyositis/polymyositis patients. All the patients had complete physical examination, chest X-ray, echocardiogram, gastrointestinal tract endoscopic explorations, thoracoabdomino-pelvic computed tomography scan, and all women had gynecologic examination and mammogram. Exclusion criteria for study were childhood dermatomyositis, inclusion body myositis, myositis associated with a connective tissue disease, prior history of cancer, and the presence of benign conditions known to elevate serum tumor markers. After a median follow-up of 59 months, 10 (9.8%) patients had a solid cancer. Initial elevation of CA125 was associated with an increased risk of developing solid cancer [P = 0.0001 by Fisher's exact test; odds ratio (OR), 29.7; 95% confidence interval (95% CI), 8.2-106.6]. For CA19-9, there was a trend towards a significant association (P = 00.7; OR, 4.5; 95% CI, 1-18.7, respectively). Diagnostic values of elevated CA125 and CA19-9 at screening increased when the study analysis was restricted to patients who developed a cancer within 1 year (P < 0.0001 and P = 0.018, respectively) or to patients without interstitial lung disease (P = 0.00001; OR, 133; 95% CI, 6.5-2733 and P = 0.027; OR, 9; 95% CI, 1.5-53, respectively). Individual comparisons of the baseline and the second CA125 value showed that three of the eight patients with cancers versus 3 of the 76 patients without, displayed an increase of their CA125 level (P = 0.01 by Fisher's exact test). We conclude that CA125 and CA19-9 assessment could be useful markers of the risk of developing tumors for patients with dermatomyositis and polymyositis and should therefore be included in the search for cancer in dermatomyositis/polymyositis patients, especially for patients without interstitial lung disease.