ResultsSignificant differences were identified in peripheral blood parameters between the groups with different clinicopathological features. Hemoglobin (Hb, p = 0.014), eosinophil counts (p = 0.028), CD4+CD28+T/CD4+T percentage (p = 0.049), CD8+CD38+T/CD8+T percentage (p = 0.044), memory CD4+T (p = 0.007), and CD4+CD28+T (p = 0.007) were determined as predictors for achieving non-PD (progression disease) in the ESCC cohort. High levels of eosinophils (p = 0.030) and memory CD4+T cells (p = 0.026) and high eosinophil-to-lymphocyte ratio (ELR, p = 0.013) were predictors of non-PD in patients with GAC. The combined detection models exhibited good ability to distinguish between partial response (PR)/non-PR and PD/non-PD in patients with ESCC and GAC, respectively. Using the multivariate Cox model, the Eastern Cooperative Oncology Group (ECOG) score status (hazard ratio [HR]: 4.818, 95% confidence intervals [CI]: 2.076–11.184, p < 0.001) and eosinophil count (HR: 0.276, 95% CI: 0.120–0.636, p = 0.003) were independent prognostic factors of progression-free survival (PFS) in patients with ESCC. Metastatic sites (HR: 2.092, 95% CI: 1.307–3.351, p = 0.002) and eosinophil-to-lymphocyte ratio (ELR; HR: 0.379, 95% CI: 0.161–0.893, p = 0.027) were independent prognostic factors for overall survival (OS) in patients with ESCC. Differentiation (HR: 0.041, 95% CI: 0.200–0.803, p = 0.010), memory CD4+T (HR: 0.304, 95% CI: 0.137–0.675, p = 0.003), NK cells (HR: 2.302, 95% CI: 1.044–3.953, p = 0.037), and C-reactive protein-to-lymphocyte ratio (CLR; HR: 2.070, 95% CI: 1.024–4.186, p = 0.043) were independent prognostic factors for PFS in patients with GAC. Total lymphocyte counts (HR: 0.260, 95% CI: 0.086–0.783, p = 0.017), CD8+T (HR: 0.405, 95% CI: 0.165–0.997, p = 0.049), NK cells (HR: 3.395, 95% CI: 1.592–7.238, p = 0.002), and monocyte-to-lymphocyte ratio (MLR; HR: 3.076, 95% CI: 1.488–6.360, p = 0.002) were identified as independent prognostic factors associated with OS of GAC.