Comparison of oncologic outcome of preoveratively presumed low-risk endometrial cancer patients who underwent only bilateral pelvic sentinel lymph node (SLN) removal and those who underwent pelvic lymphadenectomy in addition to bilateral pelvic SLN removal: Turkish Gynecologic Oncology Group (TRSGO-SLN-009)

Objective: We aimed to compare the oncological outcomes of patients with bilateral sentinel lymph nodes (SLNs) detection and removed with those who underwent pelvic lymphadenectomy (PLA) in addition to bilateral SLNs removal.

Methods: This multicenter, retrospective study included cases of endometrioid type, grade I-II endometrial cancer, in which bilateral SLNs were detected and removed. Patients who had only bilateral SLNs detected and removed (group I) and patients who had bilateral SLNs detected and removed and subsequent additional bilateral PLA (group II) were included in the evaluation.

Results: In group I (n=216), SLN metastasis rate was 5.5% and in group II (n=251), it was 10.3%. The low-volume disease detection rate was 4.6% in group I and 4.8% in group II. In group II, in patients with SLN macrometastasis had also 28.6% non-SLN macrometastasis. No false-negative results occurred in group II. Recurrence was detected 1.8% in group I and 5% in group II; however, there was no significant difference (p=0.083). Disease-free survival and overall survival, were almost same between the groups (hazard ratio [HR]=2.11; 95% confidence interval [CI]=0.681-6.588; p=0.187) and (HR=1.531; 95% CI=0.392-5.975; p=0.537), respectively.

Conclusion: SLN mapping, ultrastaging, and immunohistochemical staining can identify low-volume metastases that may not be identified with classic lymphadenectomy and hematoxylin & eosin staining. It has been observed that adding PLA beyond SLN mapping did not provide an additional positive contribution to survival. For endometriod type grade I-II patients, detection of bilateral SLNs in both hemipelvis only, if detectable, is an adequate approach.