Abnormal Sodium and Chlorine Level Is Associated With Prognosis of Lung Cancer Patients

Objective: The imbalance of sodium and chloride ions occurs frequently in patients with lung cancer. However, the correlation between ion concentration change and patients prognosis have not been studied thoroughly. Our research will fill the gap, especially for high ion concentration. Methods: We retrospectively studied inpatients diagnosed with primary NSCLC and treated between May 2015 and July 2017. The basic clinical information and blood test data before and after treatment were collected. According to the clinical reference range of normal ion concentration, the patients were divided into three groups: low, normal and high level. Kaplan-Meier curve was used to analyze the difference of overall survival (OS) prognosis among each group. The correlation between ion concentration and other clinical parameters was further analyzed. Finally, a prognostic nomogram model was established by LASSO-COX method. Results: In the 1237 patients cohort, the median follow-up period was 861 days (range 3-2128 days). Firstly, 6 serum ions were included in the study, and only sodium (Na) and chloride (cl) ions were significantly associated with OS. Low level patients were found nearly just in III-IV stage patients, in contrast, high level patients distribute evenly in all stages. Then, correlation analysis showed that increased Na and cl concentrations were associated with decreased neutrophil number and elevated lymphocyte proportion. Finally, prognostic model analysis showed that cl is a crucial parameter. Conclusion: Serum Na and cl ion concentrations are closely related to the OS of lung cancer patients, and should be considered as clinical prognostic factors.