Preoperative C-reactive protein levels are associated with tumor size and lymphovascular invasion in resected non-small cell lung cancer

Background: This study focused on the association between preoperative serum C-reactive protein (CRP) levels and pathologic parameters in patients with resected non-small cell lung cancer (NSCLC). Our primary objective was to find pathologic factors that may explain poor prognosis in patients with preoperative serum CRP elevation. Methods: The records of 102 patients who had undergone pulmonary resection of NSCLC were reviewed. The association between preoperative serum CRP levels and variables that had p-values of less than 0.05 in t-test or one-way ANOVA was examined using multiple linear regression analysis. Results: Mean serum CRP level prior to surgery was 3.8 ± 4.9 (range, 0.1-19.8) mg/dL. The Pearson correlation coefficient indicated that serum CRP level and pathologic tumor diameter are positively correlated (r = 0.487, p < 0.001). Serum CRP levels were associated with sex (male vs. female, p = 0.003), smoking status (smoker vs. never smoker, p = 0.007), histology (squamous vs. non-squamous, p = 0.001), tumor size (size > 3 cm vs. size ≤ 3, p < 0.001), tumor necrosis (yes vs. no, p < 0.001), lymphovascular invasion (yes vs. no, p < 0.001), and pleural invasion (P0 vs. P1 vs. P2 vs. P3, p = 0.013), but not with age (age > 64.5 vs. age ≤ 64.5, p = 0.508), atelectasis or obstructive pneumonia (yes vs. no, p = 0.119), location of tumor (peripheral vs. central, p = 0.474), and lymph node involvement (N0 vs. N1 vs. N2 vs. N3, p = 0.558). Multiple linear regression analysis indicated that pathologic tumor size (β = 0.583, p = 0.005) and lymphovascular invasion (β = 3.002, p = 0.009) were associated with preoperative serum CRP level. Conclusion: Our results indicate that lymphovascular invasion and pathologic tumor size are associated with preoperative serum CRP level, which may be considered a prognostic factor in patients with NSCLC. This additional information might serve as a basis to explain poor prognosis in patients with preoperative serum CRP elevation.