Trial study protocol.

<div><p>Lower limb lymphedema (LLL) is a common postoperative complication following lymphadenectomy in cervical and endometrial cancers. Removal of the circumflex iliac nodes distal to the external iliac node (CINDEIN) is associated with LLL. Here, we sought to evaluate whether preserving the CINDEIN is helpful in reducing the incidence of LLL in women with cervical and endometrial cancers and to evaluate the safety of preserving CINDEIN. In this prospective randomized controlled trial, patients with clinical stage I A2 to II A cervical cancer and stage I to III endometrial carcinoma undergoing surgery were randomly assigned (1:1) to undergo pelvic lymphadenectomy with CINDEIN removal or preservation. The primary endpoint was the incidence of LLL at 24 months post-surgery. Eligible patients underwent sentinel lymph node (SLN) mapping with carbon nanoparticles (CNP). The study was registered with ClinicalTrials.gov, number ChiCTR2300071911. Between Jun 1, 2017, and Dec 31, 2018, 328 participants were randomly assigned to the two groups. Thirteen patients were excluded from the lymphedema analysis. A total of 158 patients in the CINDEIN preservation group and 157 in the CINDEIN removal group completed the follow-up examination. At baseline, no significant differences were observed between the two groups. The 3-year overall survival rate was 96.9% in the preservation group and 95.7% in the resection group. For cervical cancer and endometrial carcinoma, the incidence of LLL were significantly lower in the preservation group than in the removal group both at 24 months. No differences in the occurrence time of LLL were observed between the two groups. The LLL stages also showed no significant difference between the two groups. In the removal group, no CINDEIN metastases were identified in any patient. A total of 125 evaluable patients received the injection of CNP. None of the patients had CINDEIN detected as SLNs. CINDEIN removal is an important risk factor for LLL following lymphadenectomy in cervical and endometrial cancers. The metastasis rate of CINDEIN in cervical cancer and early endometrial cancer is relatively low, and preserving CINDEIN might be safe and helpful in reducing the occurrence of LLL.</p></div>