Objectives Selection of patients with endometrioid endometrial cancer (EEC), in whom systematic lymph node dissection (LND) is indicated, is an important part of management to maintain optimal oncological outcomes, while avoiding unnecessary morbidities. According to the current approach, LND is recommended for the patients with International Federation of Gynecology and Obstetrics (FIGO) grade 1 to 2 tumors and a primary tumor diameter (PTD) greater than 2 cm, even with myometrial invasion (MMI) of less than 50%. We aimed to determine incidence of LN metastasis in this particular group of patients with grade 1 tumors, superficial MMI, and a PTD greater than 2 cm.

Materials and Methods This study only focused on women with FIGO grade 1 EEC having less than 50% MMI. Therefore, women with grade 2 or 3 tumors were excluded, as well as patients with 50% or greater MMI. We also excluded women with macroscopic extrauterine disease, as well as patients with cervical stromal involvement. Patients were divided into subgroups with regard to PTD; group 1 was composed of patients with PTD of 20 mm or less, whereas group 2 was composed of patients with PTD greater than 20 mm. All clinical and pathological variables were compared between the groups.

Results Final pathology reports of 484 women with EEC who underwent surgical staging were analyzed. Among these women, there were 123 women in group 1 (PTD ≤ 20 mm) and 120 women in group 2 (PTD > 20 mm), with FIGO grade 1 tumors and superficial MMI. The median number of total LNs removed was 54 (range, 20–151). There were no women with pelvic and/or para-aortic LN metastasis in group 2, as well as in group 1.

Conclusions Our results suggest that lymphadenectomy may be omitted in women with FIGO grade 1 EEC having superficial MMI regardless of PTD. Deferral of systematic LND in this subgroup of patients may lead to reductions in costs and surgical morbidity.