Similar distribution of pelvic sentinel lymph nodes and nodal metastases in cervical and endometrial cancer. A prospective study based on lymphatic anatomy.

Objective: Comparing the anatomical distribution of metastatic and non-metastatic pelvic sentinel lymph nodes (SLN) in cervical and endometrial cancer.

Methods: Detailed SLN mapping results were prospectively retrieved in cervical (n = 145) or high-risk endometrial cancer (n = 201) patients undergoing a robotic staging procedure. Cervically injected Indocyanine Green (ICG), allowing for reinjection in case of inadequate mapping, was used as tracer. An anatomically based definition of SLNs was adhered to evaluating the upper (UPP) and lower (LPP) paracervical lymphatic pathways. The positions of SLNs were intraoperatively depicted on an anatomical chart. A completory pelvic lymphadenectomy was performed. Mapping rates and anatomical distribution of SLNs and the location of pelvic nodal metastases were compared between groups.

Results: The bilateral mapping rate was 97.9% and 95.0% for cervical and endometrial cancer respectively (p = .16). The proportion of typically positioned (interiliac and proximal obturator fossa) SLNs along the UPP was similar between groups (78.1% vs 82.1%, p = .09), and the rate of metastatic SLNs in the obturator fossa was 54.1% and 48.6% respectively (p = .45). All pelvic node positive women (cervical cancer n = 19, endometrial cancer n = 37) had at least one metastatic SLN. Anatomically typical positions could not be defined along the LPP.

Conclusion: The anatomical location of SLNs and SLN metastases are similar in cervical and endometrial cancer suggesting that sensitivity results for an SLN concept in endometrial cancer and cervical cancer can be accumulated.