Endometrial cancer is a common cancer in women, and surgery is usually the first step in treatment. During surgery, doctors often check nearby lymph nodes to see if the cancer has spread. A newer method called sentinel lymph node (SLN) mapping allows doctors to examine only the first few lymph nodes most likely to contain cancer. This can reduce the need for removing many lymph nodes and may lower the risk of complications.

Minimally invasive surgery is commonly performed using small abdominal incisions (laparoscopy). A newer technique, called vaginal natural orifice transluminal endoscopic surgery (vNOTES), allows the surgery to be performed through the vagina without any cuts on the abdomen. This approach may lead to less pain, quicker recovery, and no visible scars.

This study will compare these two surgical methods-laparoscopy and vNOTES-in patients with early-stage endometrial cancer. Researchers will look at how safe and effective each method is, how patients recover after surgery, and how well the sentinel lymph node procedure works with each technique. The study will also examine how quickly surgeons become experienced with the newer vNOTES method.

The goal of this research is to determine whether vNOTES can be a safe and effective alternative to standard laparoscopic surgery, while offering potential benefits for patients.

Endometrial cancer is one of the most common malignancies of the female genital tract, and surgical staging constitutes the cornerstone of its management. In recent years, sentinel lymph node (SLN) mapping has been increasingly used as an alternative to systematic pelvic and paraaortic lymphadenectomy. The SLN approach reduces unnecessary extensive lymph node dissections, thereby decreasing surgical morbidity while enabling reliable assessment of lymphatic spread.

With the advancement of minimally invasive surgery, conventional laparoscopy has become widely used in the surgical management of endometrial cancer. In recent years, however, transvaginal natural orifice transluminal endoscopic surgery (vNOTES) has been increasingly adopted in gynecologic surgery due to its potential advantages, including the absence of abdominal incisions, reduced postoperative pain, faster recovery, and improved cosmetic outcomes. Nevertheless, prospective data comparing the vNOTES approach with conventional laparoscopy-particularly in terms of SLN mapping success and surgical outcomes-remain limited.

The aim of this study is to comparatively evaluate the feasibility, efficacy, safety, perioperative outcomes, and impact on survival of retroperitoneal sentinel lymph node biopsy (SLNB) performed using two different minimally invasive surgical approaches-standard conventional laparoscopy and vNOTES-in patients diagnosed with endometrial cancer that is clinically and radiologically presumed to be confined to the uterus. Another objective is to assess the learning curve of surgeons for the relatively new vNOTES technique in relation to the number of cases performed.

The primary hypothesis of the study is that SLNB performed via the vNOTES approach is a safe, effective, and feasible minimally invasive surgical alternative compared to conventional laparoscopy.

Inclusion Criteria:

• Age ≥18 years
• Histologically confirmed endometrial cancer on preoperative endometrial biopsy
• Disease confirmed to be confined to the uterus based on clinical evaluation and imaging
• No evidence of lymphatic or distant metastasis on positron emission tomography/computed tomography(PET/CT) or magnetic resonance imaging (MRI)
• Surgical staging with sentinel lymph node biopsy recommended by a multidisciplinary tumor board
• Surgical treatment performed using either conventional laparoscopy or the vNOTES approach

Exclusion Criteria:

• Presence of extrauterine disease
• Detection of distant metastasis
• Surgery performed via an open (laparotomy) approach
• Incomplete medical records
• History of prior pelvic radiotherapy

Histologically confirmed endometrial cancer on preoperative endometrial biopsy