Comparison of the prognostic value of LODDS and pN stage for esophageal squamous cell carcinoma patients treated with neoadjuvant immunochemotherapy: a multicenter retrospective study

Background As a novel prognostic factor, log odds of positive lymph nodes (LODDS) has been shown to be associated with the prognosis of many cancers. This study mainly explored whether LODDS is a better lymph node-based prognostic factor compared with traditional pN stage for patients with esophageal squamous cell carcinoma who underwent surgical treatment after neoadjuvant immunochemotherapy. Methods A multicenter retrospective cohort of 305 clinical stage II–III esophageal squamous cell carcinoma (ESCC) patients treated with neoadjuvant immunochemotherapy followed by curative surgery at four tertiary centers in China (2019–2024) was analyzed. LODDS was calculated as ln[(pLNs+0.5)/(nLNs+0.5)] (pLNs, positive lymph nodes; nLNs, negative lymph nodes). Patients were stratified into three LODDS risk groups using X-tile. Overall survival (OS) and recurrence-free survival (RFS) were assessed by Kaplan–Meier analysis and log-rank tests. For each endpoint, multivariable Cox models including either pN stage or LODDS (with identical covariates) were compared using Harrell’s C-index, AIC/BIC, 3-year Brier score, decision curve analysis, and time-dependent IDI and category-free NRI. Results The 3-year overall survival (OS) and recurrence-free survival (RFS) rates were 71.8% and 63.2%, respectively. Kaplan–Meier analyses showed progressively worse OS and RFS with increasing pN stage and LODDS categories, with clearer separation across LODDS risk groups. After adjustment for clinicopathological covariates, LODDS remained an independent adverse prognostic factor for both endpoints, whereas the prognostic effect of pN stage was weaker and less consistent. Compared with pN stage–based models, LODDS-based models showed slightly higher C-index (OS: 0.743 vs 0.737; RFS: 0.735 vs 0.723), lower AIC/BIC (OS AIC: 749.7 vs 753.4; OS BIC: 765.9 vs 771.9; RFS AIC: 978.1 vs 985.8; RFS BIC: 1001.2 vs 1011.1), and lower 3-year Brier scores (OS: 0.151 vs 0.159; RFS: 0.141 vs 0.155). Decision curve analysis suggested higher net benefit for LODDS-based models across commonly used threshold probabilities. Although IDI and NRI at 18 and 36 months did not reach conventional statistical significance, most estimates favored LODDS and were consistent with other performance metrics. Conclusions For the ESCC patients treated with surgery following neoadjuvant immunochemotherapy, LODDS is a superior prognostic factor to pN stage.