Prognostic significance of metastatic lymph node ratio in squamous cell carcinoma of the cervix

PURPOSE: Metastatic lymph node ratio (MLNR) was reported to be an important prognostic factor in several tumors. However, depth of primary tumor invasion is also important in cervical cancer prognostic analysis. In this study, the objective was to determine if MLNR can be used to define a high-risk category of patients with squamous cell carcinoma of the cervix (SCC). And we combined MLNR and depth of invasion to investigate whether prognosis of SCC can be predicted better. PATIENTS AND METHODS: We performed a retrospective review of patients with SCC who underwent radical hysterectomy and pelvic lymphadenectomy at QiLu Hospital of Shandong University from January 2007 to December 2009. Prognostic factors for disease-free survival (DFS) and overall survival (OS) were identified by univariate and multivariate analyses. RESULTS: One hundred and ninety-eight patients met the inclusion criteria and were included in the analysis. By cut-point survival analysis, MLNR cutoff was designed as 0.2. On multivariate analysis, an MLNR >0.2 was associated with a worse OS (hazard ratio [HR] =2.560, 95% CI 1.275–5.143, P=0.008) and DFS (HR =2.404, 95% CI 1.202–4.809, P=0.013). Depth of invasion cutoff was designed as invasion >1/2 cervix wall and was associated with a worse OS (HR =1.806, 95% CI 1.063–3.070, P=0.029) and DFS (HR =1.900, 95% CI 1.101–3.279, P=0.021). In addition, subgroup analysis revealed significant difference in OS and DFS rates between different MLNR categories within the same depth of invasion category (P<0.05), however, not between different depth of invasion categories within the same MLNR category (P>0.05). CONCLUSION: MLNR may be used as the independent prognostic parameter in patients with SCC. Combined MLNR and depth of invasion can predict both OS and DFS better in SCC than one factor. Besides, MLNR appears to be a better prognostic value than depth of invasion for SCC.