TP004/#1496 Sentinel lymph node biopsy versus pelvic lymphadenectomy in early- stage cervical cancer: a multi-center randomized trial

Introduction

Sentinel lymph node (SLN) biopsy has long been considered as an alternative for pelvic lymphadenectomy in cervical cancer. However, the optimal strategy for applying SLN biopsy in cervical cancer remains lacking.

Methods

We are performing a multicenter, randomized controlled trial to compare the two approaches for lymph node dissection in cervix cancer (PHENIX trial, ClinicalTrials.gov number, NCT02642471). We enroll patients with FIGO 2018 stage IA1 (lymphovascular space involvement), IA2, IB1, IB2 and IIA1 cervical squamous carcinoma, adenocarcinoma, or adenosquamous carcinoma. SLN biopsy were performed at the start of surgery. The SLNs were submitted for frozen section examination and patients were triaged into the PHENIX-I (SLN-negative) or PHENIX-II (SLN-positive) cohort. In each cohort, patients were randomized in a 1:1 ratio into the experimental (SLN biopsy alone) or reference (pelvic lymphadenectomy) arm. This trial was designed with non-inferiority hypothesis and the primary endpoint is disease-free survival. Estimated sample sizes of 830 and 250 are required to fulfill the study objectives of PHENIX-I and II, respectively.

Current Trial Status

Up to June 2023, 826 and 67 patients enrolled PHENIX-I and PHENIX-II cohort, respectively. Twenty-five patients were excluded due to inappropriate postoperative pathology. Among the current data, the bilateral detecting rate of SLN was 82.4%. The frozen section examination was found false-negative in 7 patients and false-positive in 3. Adjuvant therapies were administered in 47.9% patients with pathological risks. The median follow-up time reached 30 months. Neither of the cohorts showed difference in disease-free survival between the arms. The final presentation of results is expected in 2026.