Abstract
BACKGROUND: The prognostic values of serum cytokines in cancer have not yet been fully determined. The objective of this study was to identify potential biomarkers associated with clinical outcomes in critical gastrointestinal (GI) cancer patients. METHODS: A retrospective analysis was performed to quantify serum interleukin (IL)-2, IL-8, tumor necrosis factor-α (TNF-α), procalcitonin (PCT), and C-reactive protein (CRP) for correlation with clinical outcomes in GI cancer patients. The patients were divided into tertiles or quartiles based on the cytokine levels: Q1, Q2, and Q3, or Q1, Q2, Q3, and Q4. Receiver operating characteristic (ROC) curves were drawn to determine the optimal cutoff values of the cytokines. RESULTS: Trend analysis showed that IL-2, IL-8, TNF-α, PCT, and CRP levels had significant positive correlations with mortality in GI cancer patients (all P-values were lower than 0.05). The significance was observed in Q3 vs. Q1 in IL-2 (P=0.026), Q3 vs. Q1 in IL-8 (P=0.003), Q2 and Q3 vs. Q1 in TNF-α (P=0.012 and P=0.002, respectively), Q4 vs. Q1 in PCT (P=0.031), Q3 and Q4 vs. Q1 in CRP (P=0.011 and P=0.001, respectively). The area under curve (AUC) of IL-2, IL-8, TNF-α, PCT, and CRP were 0.706, 0.729, 0.743, 0.769, and 0.736, and the optimal cutoff points were determined at 838 U/mL, 46.15 pg/mL, 11.95 pg/mL, 0.77 pg/mL, and 109.38 mg/L, respectively. Under these critical values, the sensitivity was 73.3%, 66.7%, 80.0%, 93.3%, and 86.7%, and the specificity was 64.9%, 72.0%, 60.4%, 61.8%, and 68.9%, respectively. CONCLUSIONS: In GI cancer patients, serum IL-2, IL-8, TNF-α, PCT, and CRP levels can provide potential prognostic values for predicting clinical outcomes. The results may facilitate the exploration of cancer-related cytokine networks and development of novel therapy for GI cancer patients.