Predictive value of CRP combined with peripheral blood cell ratio for the prognosis of advanced NSCLC

Lung cancer remains the leading cause of cancer-related deaths worldwide, with non-small cell lung cancer (NSCLC) accounting for the vast majority. In recent years, the interaction between inflammation and tumorigenesis has become the focus of attention, which has also confirmed the importance of inflammatory markers such as C-reactive protein (CRP) in prognosis. In this study, we explored the effects of CRP, systemic inflammatory immune index (SII), and monocyte/lymphocyte ratio (MLR) on the prognosis of patients with advanced NSCLC. We conducted a retrospective study of 274 patients suffering from stage III/IV NSCLC. Among them, 224 patients served as the training set and 50 patients served as the validation set. The independent factors affecting PFS (Progression-Free Survival) and OS (Overall Survival) in the patients were analyzed by Cox regression. Our results showed that CPR (HR=1.691, P=0.004), SlI (HR=1.960, P<0.001), MLR (HR=1.578, P=0.003), CEA (HR=1.845, P=0.006), NSE (HR=2.138, P=0.003) and adrenal metastasis (HR=2.896, P<0.003) were independent factors affecting the PFS of NSCLC patients. SII (HR=1.645, P=0.004), CEA (HR=2.021, P=0.002) and brain metastasis (HR=2.899, P<0.001) were independent factors affecting the OS of NLSCL patients. The DCA curve demonstrated that the prediction model provided better clinical net benefit in predicting patients' 6-month PFS and 12-month OS under different threshold probabilities. DeLong test showed no significant difference between AUCs of SII and risk score (P>0.05). Compared with CEA, SII and risk score had higher predictive value for patients' 6-month PFS and 12-month OS (P<0.05). In conclusion, the results of this study indicate that serum inflammatory factor SII can be used as an independent indicator to evaluate 6-month PFS and 12-month OS in patients with advanced NSCLC, and its predictive value is similar to that of the nomogram model.