Abstract:Objective To investigate the correlations among preoperative electrolytes K+, Na+, Cl-, Mg2+, P2+, their relationships with clinical data, and their effects on survival prognosis in patients with gastric cancer (GC). Methods The complete clinical and follow-up (up to 127 months) information of 320 GC patients were collected from our Department of Pathology registered from January 2004 to June 2013. Blood electrolytes were tested before surgery and statistically analyzed. Results There were correlations between electrolytes and clinical data in the GC patients. The level of K+ was correlated with cell differentiation (P = 0.022). The level of Cl- in the GC patients was correlated with age (P = 0.042). There were correlations between Cl- and Na+ (r = 0.610, P = 0.000), Cl- and K+ (r = 0.206, P = 0.000), Cl- and Mg2+ (r = 0.115, P = 0.047). Patients' survival prognosis was impacted by K+ based on reference range grouping and the patients with 3.5-5.3 mmol/L K+ had the best prognosis (P = 0.005). The patients with P2+ ≥1.04 mmol/L had better prognosis than those with P2+ ≤1.04 mmol/L (P = 0.008) based on median grouping. Conclusions Blood level of K+ is correlated with cell differentiation and can influence the survival prognosis of GC patients. The level of P2+ also has an impact on the survival prognosis of GC patients. We propose that, combined with clinical and imaging diagnoses, utilizing electrolyte levels to preoperatively assess survival prognosis may help to select the best personalized strategies for surgery, chemotherapy, radiotherapy and follow-up intervals. These personalized strategies may help to achieve quality treatments, therefore improve quality of life and prolong survival of GC patients.