Objective Patients who undergo radical hysterectomy may require postoperative adjuvant radiotherapy, and all efforts should be made to reduce dual therapy in such patients. The aim of this study was to determine the optimal upper limit of tumor size in patients with International Federation of Gynecology and Obstetrics (FIGO) stage IB2 cervical cancer who undergo radical hysterectomy.

Methods We retrospectively reviewed the records of 114 patients with FIGO 2018 stage IB2 cervical cancer who underwent primary surgery either with (n=55) or without (n=59) adjuvant radiotherapy from June 2004 to December 2018. The inclusion criteria were as follows: women diagnosed with stage IB2 cervical cancer; primary radical surgery with pelvic lymph node dissection with or without para-aortic lymph node dissection; and patients treated with or without postoperative adjuvant radiation therapy, concurrent chemoradiation therapy, or chemotherapy. A receiver operating characteristic (ROC) curve analysis was used to determine the optimal tumor size cut-off value. The optimal tumor size cut-off value was determined by the maximum sum of sensitivity and specificity.

Results There were 55 and 59 patients treated with or without adjuvant therapy, respectively, after radical hysterectomy. Age, histologic type, and pelvic and para-aortic lymph node sampling/dissection status were similar between each group. The number of patients with a tumor size <2.7 cm and ≥2.7 cm was 39 and 75, respectively. The decision for adjuvant treatment after radical hysterectomy in patients with stage IB2 cervical cancer was influenced by intermediate risk factors (lymphovascular space invasion, 23.7% vs 76.4%, p<0.001; deep 1/3 of invasion, 16.9% vs 61.8%, p<0.001) and high risk factors (lymph node metastasis, 0% vs 40.0%, p<0.001; involvement of parametrium, 1.7% vs 16.4%, p=0.007). According to the ROC curve results considering the best sensitivity and specificity, the optimal cut-off value of tumor size for predicting adjuvant treatment was 2.7 cm (sensitivity 0.85, specificity 0.52). The number of patients with a tumor size <2.7 cm and ≥2.7 cm was 39 (34.2%) and 75 (65.8%), respectively. No significant differences were observed in the progression-free survival (p=0.22) and overall survival (p=0.28) rates between tumor size smaller than 2.7 cm and larger than 2.7 cm.

Conclusions A cervical tumor larger than 2.7 cm before radical surgery in stage IB2 may predispose to potential complications from combining radical hysterectomy and concurrent chemoradiation,. We consider that concurrent chemoradiation therapy is a more appropriate choice for tumor size over 2.7 cm per the revised FIGO 2018 criteria for stage IB2 cervical cancer.