Sentinel SENECA risk factors for unsuccessful bi-lateral sentinel lymph node mapping in endometrial cancer

Objective: Our study aims to assess the risk factors associated with bi-lateral sentinel lymph node (SLN) mapping failure in endometrial cancer. Methods: The SENECA study was a retrospective multi-center international observational study that reviewed data from 2139 women with clinical stage I-to-II endometrial cancer across 64 centers in 17 countries. Between January 2021 and December 2022, patients underwent surgical treatment with SLN assessment, following the guidelines of the European Society of Gynaecological Oncology. Risk factors associated with the absence of bi-lateral mapping were analyzed using χ2 and t tests. All factors that showed statistical associations were included in a multi-variate regression analysis. Results: Among the 2139 patients, the bi-lateral lymph node detection rate was 82.7%, whereas the unilateral detection rate was 97.3%. In multi-variate analysis, 5 risk factors remained statistically associated with unsuccessful bi-lateral lymph node mapping: high-grade histology (OR 1.35, 95% CI 1.02 to 1.79, p = .03), myometrial invasion >50% (OR 1.37, 95% CI 1.07 to 1.75, p = .012), low-volume surgeon <20 cases/year (OR 2.11, 95% CI 1.55 to 2.89, p < .01), open surgical approach (OR 1.72, 95% CI 1.06 to 2.78 , p = .03), and non-indocyanine green tracer (OR 4.59, 95% CI 2.64 to 7.99, p < .01). The addition of bi-lateral pelvic lymphadenectomy and/or paraaortic lymphadenectomy to SLN biopsy caused an increased rate of intra-operative complications (2% vs 8.4%, p < .01) and all-grade post-operative complications (4.1% vs 11.2%, p < .01). Conclusions: Our study identifies 5 risk factors associated with unsuccessful lymph node mapping in endometrial cancer. Efforts should be made to perform this technique with indocyanine green, through minimally invasive surgery, and performed or supervised by an experienced surgeon with ≥20 endometrial cancer cases per year.