Elevated serum C-reactive protein, carcinoembryonic antigen and N2 disease are poor prognostic indicators in non-small cell lung cancer.

AIM: To assess the prognostic value of mediastinal lymph node metastases (N2 disease), carcinoembryonic antigen (CEA) levels and C-reactive protein (CRP) in non-small cell lung cancer (NSCLC), according to the 7th edition of the TNM classification.

METHODS: Newly diagnosed stage III-IV NSCLC were enrolled, including 75 patients with malignant pleural effusion. The relationship between serum CRP levels and other relevant variables such as sex, Eastern Cooperative Oncology Group status, smoking status, initial staging, N2 disease, serum albumin, white blood cell count, platelet count, CEA, comorbidity and pathology were analyzed. Univariate and multivariate analyses were performed to find prognostic markers using Cox's proportional hazards model.

RESULTS: Of the 127 patients enrolled, 55 (43%) had elevated CRP levels. There was a significant correlation between serum CRP level and platelet count (P = 0.011). Median overall survival (OS) in the normal CRP group was significantly longer than in the high CRP group (15.7 months vs 9.1 months, P = 0.013). Hypoalbuminemia (P = 0.047), higher CEA (P = 0.043) and N2 disease (P = 0.040) were additional prognostic factors on univariate analysis. On multivariate analysis an elevated CRP serum level (HR = 1.796; P = 0.005), higher CEA (HR = 1.563; P = 0.031) and N2 disease (HR = 1.723; P = 0.012) were independent prognostic factors for poor survival.

CONCLUSION: High levels of serum CRP and CEA, and N2 disease are independent prognostic indicators for the survival of patients with stage III-IV NSCLC.