Prognostic value and adjuvant treatment outcomes for the use of the JGOG prognostic model in early-stage intermediate-risk cervical cancer: a Korean Gynecologic Oncology Group study (KGOG 1028)

OBJECTIVE: The aim of this study was to validate a new Japanese risk grouping in the Korean population and to identify the group benefit from adjuvant treatment. METHODS: A total of 561 patients with stage IB cervical cancer who underwent radical hysterectomy with lymphadenectomy from 2000 to 2008 across 9 Korean Gynecologic Oncology Group-affiliated institutions were included in this study. Patients had at least one intermediate-risk factor: lymphovascular space invasion, outer one-third of the deep cervical stromal invasion, or a tumor 4 cm or larger. Disease-free survival (DFS) was analyzed based on adjuvant therapies: no treatment, radiation therapy, concurrent chemoradiation therapy or systemic chemotherapy. RESULTS: Patients were classified into 3 groups based on their histologically-incorporated intermediate risk factors. Group 1 included patients with limited risk factors (n=385, 68.6%), group 2 (n=106, 18.9%), and group 3 (n=70, 12.5%) had increasing risk. DFS differed across groups (group 1 vs. group 2, p=0.048; group 2 vs. group 3, p=0.030). Group 1 showed no DFS benefit from adjuvant treatment, while in groups 2 and 3, receiving radiation therapy improved DFS (group 2: adjusted hazard ratio [aHR]=0.09; 95% confidence interval [CI]=0.01-0.80; p=0.031 and group 3: aHR=0.21; 95% CI=0.04-1.08; p=0.047). In group 3, receiving concurrent chemotherapy treatment did not significantly affect DFS compared to radiation alone (aHR=0.84; 95% CI=0.11-6.30; p=0.861). CONCLUSION: This study revealed the prognostic value of histology-incorporated intermediate-risk stratification for early-stage cervical cancer in the Korean population. Unlike the results seen in Japanese populations, adjuvant treatment benefited higher-risk patients in terms of DFS.