High C-reactive protein/albumin ratio predicts unfavorable distant metastasis-free survival in nasopharyngeal carcinoma: a propensity score-matched analysis

BACKGROUND: Recent studies have indicated that the C-reactive protein/albumin (CRP/ALB) ratio (CAR) may represent a simple inflammation-based index for assessing the host inflammatory response. In this study, the prognostic value of the CAR for distant metastasis-free survival (DMFS) in nasopharyngeal carcinoma (NPC) was assessed. METHODS: A total of 1,168 non-metastatic NPC patients from Sun Yat-sen University Cancer Center were retrospectively included. The optimal cutoff value for CAR was defined by the Cutoff Finder online tool. Propensity case-matched analysis was performed to adjust for potential differences in baseline characteristics. Subsequently, the prognostic value of the CAR for DMFS was validated in a 756 validation cohort with NPC. RESULTS: The optimal CAR cutoff value was 0.081. Patients with high CAR values had significantly poorer DMFS than those with low CAR in univariate and multivariate analyses before propensity score matching. The CAR could also significantly stratify patients into different risks of developing distant metastasis in subgroup analysis. Propensity score analyses showed that CAR remained a prognostic factor for DMFS, thus excluding other interpretations and selection bias. Moreover, the prognostic value of the CAR was robustly confirmed in the external validation cohort. CONCLUSION: CAR is an inexpensive and easy-to-measure inflammatory index that may aid clinicians in the development of individualized treatment and follow-up strategies for patients with non-metastatic NPC.