Baseline and postoperative C-reactive protein levels predict mortality in operable lung cancer

Higher blood levels of C-reactive protein (CRP) have been associated with shorter survival in patients with cardiovascular, chronic obstructive pulmonary disease and cancer. We investigated the impact of baseline and postoperative CRP levels on survival of patients with operable lung cancer (LC).

CRP values at baseline (CRP₀) and 3 days after surgery (CRP₃) were measured in a consecutive series of 1750 LC patients who underwent complete resection between 2003 and 2015. Patients were classified as having 0 (N = 593), 1 (N = 658) or 2 (N = 553) risk factors: CRP₀ and/or CRP₃ values above the respective median value. The effect of higher CRP was evaluated by Kaplan-Meier mortality curves and adjusted hazard ratio (HR) with 95% confidence interval (CI), by fitting Cox proportional hazards models.

Cumulative proportions of 5-year survival were 67% for 0 risk factors, 58% for 1 risk factor and 41% for 2 risk factors (P < 0.0001). The overall 5-year mortality risk was significantly higher in patients with 1 risk factor (adjusted hazard ratio [aHR] 1.43 [95% CI 1.14-1.79]), or 2 risk factors (aHR 2.49 [95% CI 1.99-3.11]). A significant impact on survival was observed in each tumour-node-metastasis stage group, and in the subset of non-smokers. Postoperative 30-day mortality was significantly higher in patients with 2 risk factors only (aHR 2.2% versus 0.6%, p < 0.0475).

Baseline and postoperative CRP levels predict immediate and long-term mortality in all stages of operable lung cancer. Patients with higher CRP levels could be candidate to randomised adjuvant trials with anti-inflammatory agents.