Objective To explore the factors influencing adoption of the sentinel lymph node (SLN) technique for endometrial cancer staging among gynecologic oncologists. Methods A self-administered, web-based survey was sent via email (April 20 through May 21, 2017) to all members of European Society of Gynecologic Oncologists, International Gynecologic Cancer Society, and Society of Gynecologic Oncologists. Surgical and pathologic practices related to SLN and reasons for not adopting this technique were investigated. Results Overall, 489 attending physicians or consultants in gynecologic oncology from 69 countries responded: 201 (41.1%), 118 (24.1%), and 117 (23.9%) from Europe, the USA, and other countries, respectively (10.8% did not report a country). SLN was adopted by 246 (50.3%) respondents, with 93.1% injecting the cervix and 62.6 % using indocyanine green dye. The National Comprehensive Cancer Network SLN algorithm was followed by 160 (65.0%) respondents (USA 74.4%, Europe 55.4%, other countries 71.4%). However, 66.7% completed a backup lymphadenectomy in high-risk patients. When SLN biopsy revealed isolated tumor cells, 13.8% of respondents recommended adjuvant therapy. This percentage increased to 52% if micrometastases were detected. Among the 243 not adopting SLN, 50.2% cited lack of evidence and 45.3% stated that inadequate instrumentation fueled their decisions. Conclusions SLN with a cervical injection is gaining widespread acceptance for staging of endometrial cancer among gynecologic oncologists worldwide. Standardization of the surgical approach with the National Comprehensive Care Network algorithm is applied by most users. Management of isolated tumor cells and the role of backup lymphadenectomy for ‘high-risk’ cases remain areas of investigation.

Objective Endometrial cancer surgical staging includes lymph node assessment which can lead to lower extremity lymphedema. The aim of this study was to estimate prevalence after sentinel lymph node biopsy versus lymphadenectomy. Methods Consecutive patients who underwent minimally invasive surgery at the Mayo Clinic, Rochester, Minnesota, USA, between January 2009 and June 2016 for newly diagnosed endometrial cancer were mailed our validated 13 item lower extremity lymphedema screening questionnaire. We also ascertained via questionnaire whether the patient was ever diagnosed with lower extremity lymphedema. Results Among 378 patients included in the analysis, 127 (33.5%) had sentinel lymph node biopsy with or without side specific lymphadenectomy (sentinel lymph node cohort) and 251 (66.4%) underwent bilateral lymphadenectomy prior to sentinel lymph node biopsy implementation at our institution or as 'backup' after sentinel lymph node mapping (lymphadenectomy cohort). The prevalence of lower extremity lymphedema was 41.5% (157/378), with 69 patients (18.3%) self-reporting a lower extremity lymphedema diagnosis after their endometrial cancer surgery at a median of 54.3 months (interquartile range 31.2–70.1 months), and an additional 88 patients (23.3%) identified by the screening questionnaire. The prevalence of lower extremity lymphedema was significantly higher in the lymphadenectomy cohort compared with the sentinel lymph node group (49.4% (124/251) vs 26.0% (33/127); p<0.001). When the cohorts were restricted to patients surgically managed after the introduction of sentinel lymph node, the prevalence of lower extremity lymphedema was still significantly higher in the lymphadenectomy cohort compared with the sentinel lymph node cohort (39.0% (41/105) vs 26.0% (33/127); p=0.03). In a multivariable analysis adjusted for body mass index, receipt of adjuvant external beam radiation, diabetes, congestive heart failure, and International Federation of Gynecology and Obstetrics grade, the adjusted odds ratio for the association between type of nodal sampling (lymphadenectomy cohort vs sentinel lymph node cohort) and lower extremity lymphedema was 2.75 (95% confidence interval 1.69 to 4.47, p<0.001). Conclusions Sentinel lymph node biopsy was associated with a decreased risk of post-treatment lymphedema compared with lymphadenectomy in patients who underwent surgical staging for endometrial carcinoma.

Objective Ultrastaging is accurate in detecting nodal metastases, but increases costs and may not be necessary in certain low-risk subgroups. In this study we examined the risk of nodal involvement detected by sentinel lymph node (SLN) biopsy in a large population of apparent early-stage endometrial cancer and stratified by histopathologic characteristics. Furthermore, we aimed to identify a subgroup in which ultrastaging may be omitted. Methods We retrospectively included patients who underwent SLN (with bilateral mapping and no empty nodal packets on final pathology) ± systematic lymphadenectomy for apparent early-stage endometrial cancer at two referral cancer centers. Lymph node status was determined by SLN only, regardless of non-SLN findings. The incidence of macrometastasis, micrometastasis, and isolated tumor cells (ITC) was measured in the overall population and after stratification by histotype (endometrioid vs serous), myometrial invasion (none, <50%, ≥50%), and grade (G1, G2, G3). Results Bilateral SLN mapping was accomplished in 1570 patients: 1359 endometrioid and 211 non-endometrioid, of which 117 were serous. The incidence of macrometastasis, micrometastasis, and ITC was 3.8%, 3.4%, and 4.8%, respectively. In patients with endometrioid histology (n=1359) there were 2.9% macrometastases, 3.2% micrometastases, and 5.3% ITC. No macro/micrometastases and only one ITC were found in a subset of 274 patients with low-grade (G1-G2) endometrioid endometrial cancer without myometrial invasion (all <1%). The incidence of micro/macrometastasis was higher, 2.8%, in 708 patients with low-grade endometrioid endometrial cancer invading <50% of the myometrium. In patients with serous histology (n=117), the incidence of macrometastases, micrometastasis, and ITC was 11.1%, 6.0%, and 1.7%, respectively. For serous carcinoma without myometrial invasion (n=36), two patients had micrometastases for an incidence of 5.6%. Conclusions Ultrastaging may be safely omitted in patients with low-grade endometrioid endometrial cancer without myometrial invasion. No other subgroups with a risk of nodal metastasis of less than 1% have been identified.