Purpose: Lymph node metastasis (LNM) is the most significant prognostic factor in cervical cancer that was recently incorporated into the International Federation of Gynecology and Obstetrics (FIGO) staging system. This study was performed to evaluate whether the prognostic significance of LNM differs according to disease status.
Materials and methods: Patients with FIGO stage IB or higher cervical cancer who had pretreatment computed tomography and/or magnetic resonance imaging studies as well as long-term follow-up were enrolled in this retrospective study. The hazard ratio (HR) of Cox regression was used to determine the prognostic significance of LNM. The HRs were compared between the different tumor groups (based on stage, histology, tumor size, primary treatment, age, parametrium involvement, and lymphovascular space invasion).
Results: A total of 970 patients treated between January 1999 and December 2007 were included. The pretreatment LNM had prognostic significance in patients with stage IB1/IIA (HR for progression-free survival 2.10, p=0.001; HR for overall survival 1.99, p=0.005). However, the significance gradually decreased or disappeared with advancing stages. Similarly, the prognostic significance of the pretreatment LNM decreased with advancing disease status, including old age, parametrial involvement or lymphovascular space involvement. In contrast, the tumor size was associated with the prognostic significance of LNM with advancing status. The significance of the clinical LNM did not reflect the significance of the clinical stage. In contrast, the tumor size, parametrial involvement, and significance of the pathologic LNM reflected the clinical stage.
Conclusion: In patients with cervical cancer, pretreatment LNM on imaging has different clinical significance depending on the tumor status.
Keywords: Diagnostic imaging; Lymph nodes; Neoplasm metastasis; Neoplasm staging; Prognosis; Uterine cervical neoplasms.