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

Aim: To investigate the prognostic value of inflammatory markers in esophageal squamous cell carcinoma (ESCC) patients treated with immune checkpoint inhibitors (ICIs).Materials & methods: 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.Results: 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.Conclusion: 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.