Role of pre-sacral sentinel lymph nodes in endometrium and cervical cancer: experience with minimally invasive indocyanine green sentinel lymph node mapping.

Objective: The aim of this study was to examine the role of pre-sacral sentinel lymph nodes (SLNs) in patients with uterine cancer.

Methods: This retrospective cohort study includes patients with endometrial or cervical cancer who underwent minimally invasive indocyanine green SLN mapping at the Bern University Hospital from December 2012 to December 2022. A complete ultra-staging of the SLNs was performed in all cases.

Results: A total of 616 patients with uterine cancer were included in this study. The mean age was 61.6 years (standard deviation ± 13.8) and mean body mass index 28.2 kg/m (standard deviation ± 7.3). Endometrial cancer was present in 466 patients, and 150 patients were diagnosed with cervical cancer. The overall SLN detection rate was 97.7%. In total, 2462 SLNs were removed, with a median number of 3 SLNs (range; 0-20) per patient. In 95 patients, the SLN showed tumor involvement comprising macro-metastasis in 74 patients (12.0%), micro-metastasis in 17 patients (2.8%), and isolated tumor cells in four patients (0.6%). In 170 patients, 384 pre-sacral SLNs were removed. Pre-sacral SLNs were more often seen in patients with cervical cancer (35.3%) than in those with endometrial cancer (25.1%) (p = .021); Three patients had macro-metastasis in the pre-sacral SLNs, accounting for 0.5% of the entire cohort. These three patients had high-grade endometrial cancer, and all had a concurrent positive pelvic SLN mapping result.

Conclusion: In our study, indocyanine green SLN mapping revealed pre-sacral SLN in one-third of patients with cervical and one-fourth of those with endometrial cancer. Pre-sacral SLN metastasis was present in 0.5% of all study patients. The relevance of pre-sacral SLNs seems to be limited to patients with high-risk endometrial cancer.