Preoperative immune prognostic index predicts the prognosis and postoperative adjuvant chemotherapy benefits of esophageal squamous cell carcinoma after minimally invasive esophagectomy.

Background: The utility of the immune prognostic index (IPI) for esophageal squamous cell carcinoma (ESCC) has yet to be established after minimally invasive esophagectomy (MIE). The purpose of this study was to investigate the value of IPI in predicting the prognosis and postoperative adjuvant chemotherapy (AC) benefits of ESCC patients.

Methods: Between January 2011 and December 2018, 613 ESCC patients underwent MIE at our center and were divided into two groups: low IPI and high IPI.Log-rank tests were used to compare the overall survival (OS) and disease-free survival (DFS) of patients in different groups based on Kaplan-Meier survival analysis. Differences in clinical characteristics between groups were eliminated by propensity score matching (PSM) analysis. To identify independent risk factors influencing OS and DFS, the Cox proportional risk model was used.

Results: In comparison to the high IPI group, the low IPI group had a better 5-year OS and DFS in both the entire and matched cohorts (P < 0.05). IPI was found to be an independent prognostic factor for OS and DFS in a multivariate analysis of the entire cohort and the matched cohort (P < 0.05). In subgroup analyses of most clinicopathological factors, high IPI was associated with a higher risk of death or recurrence in the matched cohorts. When combined with 8th TNM staging, the 5-year OS and DFS of stage II or III patients with low IPI in the AC group were not different from those in the non-AC group (P > 0.05), and AC of stage III patients with high IPI significantly prolonged 5-year OS and DFS (OS: 37.4% vs 26.2%, P = 0.018; DFS: 33.6% vs 19.8%, P = 0.042).

Conclusion: Preoperative IPI is a promising predictor of ESCC after MIE. For stage III ESCC patients with high IPI, AC can significantly reduce the risk of death or recurrence.