Lymphocyte-to-C-reactive protein ratio predicts prognosis in unresectable locally advanced non-small cell lung cancer patients

The lymphocyte-to-C-reactive protein ratio (LCR) is a promising inflammation-based tool for assessing the status of patients with malignant tumours. This study evaluated the ability of LCR to predict the prognosis of patients with unresectable locally advanced non-small cell lung cancer (LA-NSCLC) after chemoradiotherapy. We retrospectively investigated 206 consecutive patients with unresectable LA-NSCLC who underwent chemoradiotherapy between January 2016 and November 2019. The LCR was calculated from the differential count by dividing the absolute lymphocyte count by the C-reactive protein level. The optimal cut-off value of LCR was determined using the receiver operating characteristic (ROC) curve, and the enrolled patients were divided into two groups for further analysis according to LCR. Overall survival (OS) and disease-free survival (DFS) were assessed using univariate and multivariate Cox regression analyses. In patients with unresectable LA-NSCLC, the level of LCR was significantly associated with pathology (<i>p</i> = 0.042) and TNM stage (<i>p</i> = 0.002). High LCR and low LCR patients had different distinct outcomes (median OS: 36 vs. 34 months, <i>p</i> &lt; 0.0001) and recurrence risk (median DFS: 31 vs. 23 months, <i>p</i> &lt; 0.001). Univariate analysis indicated that Eastern Cooperative Oncology Group (ECOG) performance status, TNM stage, CEA level, response, neutrophil-to-lymphocyte ratio (NLR), lymphocyte-to-monocyte ratio (LMR), systemic immune inflammation index (SII), and LCR were predictors of OS and DFS. Multivariate analysis showed that a high LCR was an independent prognostic factor for OS (hazard ratio [HR], 0.526; 95% CI, 0.364-0.762; <i>p</i> = 0.001) and DFS (HR, 0.390; 95% CI, 0.275-0.554; <i>p</i> &lt; 0.001) LCR is a promising prognostic index in patients with LA-NSCLC undergoing chemoradiotherapy, and an increase in the LCR level contributes to better outcomes.