Predictive value of number of metastatic lymph nodes and lymph node ratio for prognosis of patients with FIGO 2018 stage IIICp cervical cancer: a multi-center retrospective study

Background To identify the cut-off values for the number of metastatic lymph nodes (nMLN) and lymph node ratio (LNR) that can predict outcomes in patients with FIGO 2018 IIICp cervical cancer (CC). Methods Patients with CC who underwent radical hysterectomy with pelvic lymphadenectomy were identified for a propensity score-matched (PSM) cohort study. A receiver operating characteristic (ROC) curve analysis was performed to determine the critical nMLN and LNR values. Five-year overall survival (OS) and disease-free survival (DFS) rates were compared using Kaplan-Meier and Cox proportional hazard regression analyses. Results This study included 3,135 CC patients with stage FIGO 2018 IIICp from 47 Chinese hospitals between 2004 and 2018. Based on ROC curve analysis, the cut-off values for nMLN and LNR were 3.5 and 0.11, respectively. The final cohort consisted of nMLN <= 3 (n = 2,378) and nMLN > 3 (n = 757) groups and LNR <= 0.11 (n = 1,748) and LNR > 0.11 (n = 1,387) groups. Significant differences were found in survival between the nMLN <= 3 vs the nMLN > 3 (post-PSM, OS: 76.8% vs 67.9%, P = 0.003; hazard ratio [HR]: 1.411, 95% confidence interval [CI]: 1.108-1.798, P = 0.005; DFS: 65.5% vs 55.3%, P < 0.001; HR: 1.428, 95% CI: 1.175-1.735, P < 0.001), and the LNR <= 0.11 and LNR > 0.11 (post-PSM, OS: 82.5% vs 76.9%, P = 0.010; HR: 1.407, 95% CI: 1.103-1.794, P = 0.006; DFS: 72.8% vs 65.1%, P = 0.002; HR: 1.347, 95% CI: 1.110-1.633, P = 0.002) groups. Conclusions This study found that nMLN > 3 and LNR > 0.11 were associated with poor prognosis in CC patients.