OBJECTIVE: Management of endometrial cancer is advancing, with accurate staging crucial for guiding treatment decisions. Understanding sentinel lymph node (SLN) involvement rates across molecular subgroups is essential. To evaluate SLN involvement in early-stage (International Federation of Gynecology and Obstetrics 2009 I-II) endometrial cancer, considering molecular subtypes and new European Society of Gynaecological Oncology (ESGO) risk classification. METHODS: The SENECA study retrospectively reviewed data from 2139 women with stage I-II endometrial cancer across 66 centers in 16 countries. Patients underwent surgery with SLN assessment following ESGO guidelines between January 2021 and December 2022. Molecular analysis was performed on pre-operative biopsies or hysterectomy specimens. RESULTS: Among the 2139 patients, the molecular subgroups were as follows: 272 (12.7%) p53 abnormal (p53abn, 1191 (55.7%) non-specific molecular profile (NSMP), 581 (27.2%) mismatch repair deficient (MMRd), 95 (4.4%) POLE mutated (POLE-mut). Tracer diffusion was detected in, at least one side, in 97.2% of the cases; with a bilateral diffusion observed in 82.7% of the cases. By ultrastaging (90.7% of the cases) or one-step nucleic acid amplification (198 (9.3%) of the cases), 205 patients were identified with affected sentinel lymph nodes, representing 9.6% of the sample. Of these, 139 (67.8%) had low-volume metastases (including micrometastases, 42.9%; and isolated tumor cells, 24.9%) while 66 (32.2%) had macrometastases. Significant differences in SLN involvement were observed between molecular subtypes, with p53abn and MMRd groups having the highest rates (12.50% and 12.40%, respectively) compared with NSMP (7.80%) and POLE-mut (6.30%), (p=0.004); (p53abn, OR=1.69 (95% CI 1.11 to 2.56), p=0.014; MMRd, OR=1.67 (95% CI 1.21 to 2.31), p=0.002). Differences were also noted among ESGO risk groups (2.84% for low-risk patients, 6.62% for intermediate-risk patients, 21.63% for high-intermediate risk patients, and 22.51% for high-risk patients; p<0.001). CONCLUSIONS: Our study reveals significant differences in SLN involvement among patients with early-stage endometrial cancer based on molecular subtypes. This underscores the importance of considering molecular characteristics for accurate staging and optimal management decisions.

ASST Grande Ospedale Metropolitano Niguarda Milan Italy

Clinic of Obstetrics and Gynecology Hospital San Gerardo Monza Italy

Clinica Universidad de Navarra Pamplona Navarra Spain

Departamento de Ginecologia y Obstetricia Clinica Universidad de Navarra Pamplona Navarra Spain

Department of Gynaecologic Oncology Hospital Universitario 12 de Octubre Madrid Spain

Department of Gynaecology Son Espases University Hospital Palma de Mallorca Spain

Department of Gynecologic Oncology Basavatarakam Indo American Cancer Institute and Research Centre Hyderabad Telangana India

Department of Gynecologic Oncology Hospital Vall d'Hebron Barcelona Spain

Department of Gynecologic Oncology Nairi Medical Center Yerevan Armenia

Department of Gynecologic Oncology Universidad de Navarra Pamplona Navarra Spain

Department of Gynecologic Oncology University Hospital La Fe Valencia Valencia Spain

Department of Gynecologic Oncology; Obstetrics and Gynecology University Hospitals Leuven Leuven Vlaams Brabant Belgium

Department of Gynecological Oncology Wroclaw Medical University Wroclaw Poland

Department of Gynecology and Obstetrics Mauriziano Hospital Torino Italy

Department of Gynecology Centre Oscar Lambret Lille France

Department of Gynecology Clinica Universidad de Navarra Pamplona Navarra Spain

Department of Gynecology Hospital Universitari de Bellvitge L'Hospitalet de Llobregat Barcelona Spain

Department of Medical Oncology Clinica Universidad de Navarra Madrid Spain

Department of Medicine and Surgery University of Milan Bicocca Milano Italy

Department of Obstetrics and Gynaecology Clinico Lozano Blesa Hospital Zaragoza Spain

Department of Obstetrics and Gynaecology Semmelweis University Budapest Hungary

Department of Obstetrics and Gynecology Bezmialem Vakif Universitesi Istanbul Istanbul Turkey

Department of Obstetrics and Gynecology Brno University Hospital Brno Czech Republic Czech Republic

Department of Obstetrics and Gynecology Centro Hospitalar e Universitário de Coimbra EPE Coimbra Coimbra Portugal

Department of Obstetrics and Gynecology CHU de Liège Liege Belgium

Department of Obstetrics and Gynecology Fundación Instituto Valenciano de Oncologia Valencia Spain

Department of Obstetrics and Gynecology Hospital Clínico Universitario Virgen de la Arrixaca El Palmar Spain

Department of Obstetrics and Gynecology Hospital General Universitario Gregorio Marañón Madrid Madrid Spain

Department of Obstetrics and Gynecology Hospital Lariboisière Paris France

Department of Obstetrics and Gynecology La Paz University Hospital Madrid Madrid Spain

Department of Oncological Gynecology Lower Silesian Oncology Center Wrocław Wroclaw Poland

Department of Woman and Child Health Sciences University Hospital Agostino Gemelli Roma Lazio Italy

Department of Women Children and Public Health Sciences Gynecologic Oncology Unit Fondazione Policlinico Universitario Agostino Gemelli IRCCS Rome Italy

Endoscopica Malzoni Center for Advanced Endoscopic Gynecologic Surgery Center for Advanced Endoscopic Gynecologic Surgery Avellino Italy

Gynecologic Oncology Unit Hospital Universitario de Girona Doctor Josep Trueta Girona Catalunya Spain

Holycross Cancer Center Kielce Poland

Hospital Universitari Dexeus Barcelona Catalunya Spain

Hospital Universitario Nuestra Senora de la Candelaria Santa Cruz de Tenerife Spain

Istanbul University Cerrahpasa Cerrahpasa Faculty of Medicine Fatih Istanbul Turkey

Istituto Europeo di Oncologia Milano Anognnn Italy

Universitaria di Bologna Bologna Italy

Universitat de Barcelona Barcelona Spain

References provided by Crossref.org

Preoperative risk stratification in endometrial cancer using ESGO/ESTRO/ESP 2021 guidelines: accuracy with and without molecular classification

Sentinel Node Biopsy Using Two Concurrent Labeling Techniques (Radioactive Tracer With/Without Blue Dye vs. Indocyanin Green-ICG) in Early-Stage Endometrial Cancer Patients (TESLA-1): A Prospective Observational Study CEEGOG EX-02