Inflammatory markers correlate with lymphocytes infiltrating and predict immunotherapy prognosis for esophageal cancer.

To investigate the prognostic value of inflammatory markers in esophageal squamous cell carcinoma (ESCC) patients treated with immune checkpoint inhibitors (ICIs). The infiltration of CD3 and CD8 T cells in tissue microarrays from 180 patients who underwent radical esophagectomy was detected using immunohistochemistry. A separate cohort of 351 patients with metastatic/recurrent or unresectable ESCC treated with ICIs was enrolled for further investigation. The overall survival difference among groups was assessed using Kaplan-Meier analysis. Cox proportional hazards models were employed to investigate the prognostic impact of the inflammatory markers, along with other factors. Decreased inflammation was found to be associated with increased CD3 and CD8 T-cell infiltration and a better prognosis. Then, the value of inflammatory markers in predicting survival in 351 ESCC patients receiving immunotherapy was validated. Ultimately, the systemic immune-inflammation index was identified as an independent prognostic factor for overall survival. Additionally, the patients with no distant organ metastasis, or treated by first-line immunotherapy combined with concurrent chemoradiotherapy can considerably prolong survival. Inflammation is associated with the level of tumor infiltrating lymphocytes and that the systemic immune-inflammation index is an effective prognostic predictor for ESCC patients treated with ICIs.