Sentinel lymph node mapping versus systematic lymphadenectomy in obese women undergoing minimally invasive surgery for endometrial cancer: A propensity-matched analysis.

OBJECTIVE

To compare perioperative outcomes and nodal assessment between sentinel lymph node (SLN) mapping and systematic lymphadenectomy (LND) in obese women undergoing minimally invasive surgery for endometrial cancer; to examine factors associated with nodal metastasis in the full cohort; and, in exploratory analyses, to describe nodal involvement across molecular subgroups and factors associated with mapping failure.

METHODS

This retrospective cohort study included 367 obese patients (BMI ≥30 kg/m2) undergoing minimally invasive surgical staging for endometrial cancer between January 2023 and December 2025. SLN mapping was attempted in 182 patients (successful in 157, failed in 25), and 185 underwent primary systematic LND. Propensity score matching (1:1) yielded 125 matched pairs.

RESULTS

The LND group had less favorable tumor characteristics. Operative time, hospital stay, and hemoglobin decline remained more favorable in the SLN group after matching. Postoperative complications were comparable in the crude and matched cohorts. Nodal metastasis was lower in the SLN-intent group (2.2% vs. 11.9%, p < 0.001) and remained less frequent after matching (2.4% vs. 9.6%, p = 0.030). Nodal metastasis occurred in 9.8% of p53abn, 10.5% of MMRd, and 5.7% of NSMP tumors. Mapping failure occurred in 13.7% of attempts and was independently associated with substantial LVSI (OR 3.58) and MMRd or p53-abnormal molecular subgroup (OR 3.02), but not with BMI or obesity class.

CONCLUSION

In obese women, SLN mapping was associated with shorter operative time and hospital stay without increasing complications. Within this uniformly obese cohort, neither BMI nor obesity class was associated with mapping failure, whereas adverse tumor characteristics were associated with both nodal metastasis and mapping failure, supporting SLN mapping as a less morbid staging strategy.