Serum Calcium Levels Before Antitumour Therapy Predict Clinical Outcomes in Patients with Nasopharyngeal Carcinoma

PURPOSE: The prognostic value of serum calcium levels in nasopharyngeal carcinoma (NPC) remains unknown. This study aimed to evaluate the prognostic value of serum calcium levels in patients with NPC. PATIENTS AND METHODS: A total of 2094 patients diagnosed with NPC between April 2009 and September 2012 were enrolled in this retrospective analysis. The median follow-up time was 96.3 months (range: 4.1–120.0 months). Univariate and multivariable Cox proportional hazards models were used to identify significant and independent prognostic predictors of overall survival (OS), disease-free survival (DFS), distant metastasis-free survival (DMFS), and relapse-free survival (RFS). RESULTS: Overall, low serum calcium levels were detected in 1109/2094 (53.00%) patients and tended to be more frequently detected in older (P<0.001) and female (P=0.001) patients. Patients with low serum calcium levels had poorer OS (P=0.011), DFS (P=0.012) and DMFS (P=0.004) than those with high serum calcium levels, but serum calcium levels had no significant effect on RFS (P=0.376). In univariate and multivariable analyses, low serum calcium levels were a statistically significant and independent prognostic factor for OS, DFS, and DMFS but had no prognostic value for RFS. CONCLUSION: Serum calcium levels can serve as a prognostic predictor and guide more individualized treatment for NPC patients.