Tumour-associated antigens in systemic sclerosis patients with interstitial lung disease: association with lung involvement and cancer risk

Objective: To evaluate the serum levels of tumour-associated antigens (TAAs) in patients with SSc and interstitial lung disease (ILD) and to define whether their levels mirror the severity and the progression of lung damage.

Methods: Data from 80 SSc patients with ILD were collected at baseline and after 2 years as well as from 40 SSc controls without ILD. The occurrence of any malignancy was recorded.

Results: At baseline, an increase of at least one TAA was present in 35 SSc patients with ILD compared with 6 SSc patients without ILD (P < 0.0001); this was associated with lower forced vital capacity (FVC) and higher interstitial and alveolar scores. Levels of carbohydrate antigen 15-3 and carcinoembryonic antigen inversely correlated with FVC and directly correlated with alveolar and interstitial scores and their levels were higher in patients who presented a progression of lung damage after 2 years. During 4 years of follow-up, a malignancy was detected in seven patients who already had an increase of at least one TAA. Values of TAAs increased over time in patients who developed cancer, while their trend remained stable in the others. At multivariate analysis, to have three or more TAAs emerged as a strong independent predictor of the development of malignancies [relative risk 24.1 (95% CI 1.8, 315.0), P = 0.02].

Conclusion: TAAs can be elevated in the sera of SSc patients and correlate with the degree of lung damage, suggesting a role as severity biomarkers. Close follow-up is necessary in SSc patients because of the increased cancer risk overall in patients with increased TAAs.