Significance of tumor size and number of positive nodes in patients with FIGO 2018 stage IIIC1 cervical cancer

OBJECTIVE: This study aimed to investigate the prognostic significance of tumor size and number of positive pelvic lymph nodes (PLN) in International Federation of Gynecology and Obstetrics (FIGO) 2018 stage IIIC1 cervical cancer patients. METHODS: Clinical data from 626 women with cervical cancer treated at Osaka International Cancer Center in 2010-2020 were retrospectively reviewed. Using the cutoff value obtained on the receiver operating characteristic analysis, the prognostic significance of tumor size and number of positive PLN in stage IIIC1 patients was first evaluated via uni- and multivariate analyses. Then, the impact of incorporating tumor size and number of positive PLN into the FIGO staging system was investigated using the Kaplan-Meier method. RESULTS: Among 196 women with Stage IIIC1 disease, larger tumors (>4 cm) and multiple PLN metastases (≥4) were independent predictors of progression-free survival (PFS) in patients with stage IIIC1 cervical cancer. The PFS of patients with stage IIIC1 disease was inversely associated with the number of risk factors. Although patients with stage IIIC1 disease had significantly increased survival rates compared to those with stage IIIA or IIIB disease in the original FIGO 2018 staging system, this reversal phenomenon was resolved by incorporating larger tumors (>4 cm) and multiple PLN metastases (≥4) into the revised staging system. CONCLUSIONS: Incorporating tumor size and number of metastatic lymph nodes into the FIGO staging system allows additional risk stratification for women with stage IIIC1 cervical cancer and improves survival prediction performance.