RT Journal Article SR Electronic T1 414 Potential association between quantified LVSI status and molecular profile in predicting nodal metastases for patient suffering early-stage endometrial cancer JF International Journal of Gynecologic Cancer JO Int J Gynecol Cancer FD BMJ Publishing Group Ltd SP A177 OP A178 DO 10.1136/ijgc-2024-ESGO.333 VO 34 IS Suppl 1 A1 Baccus, Louis A1 Dheur, Adriane A1 Salmon, Alixe A1 Delbecque, Katty A1 Goffin, Fréderic A1 Cuypere, Marjolein De A1 Pleyers, Clémence A1 Lovinfosse, Pierre A1 Danthine, Denis A1 Thille, Alain A1 Gonne, Elodie A1 Gennigens, Christine A1 Kridelka, Frédéric A1 Kakkos, Athanasios YR 2024 UL http://ijgc.bmj.com/content/34/Suppl_1/A177.2.abstract AB Introduction/Background Endometrial cancer (EC) is the most common gynaecologic malignancy in developed countries. Molecular classification of EC includes 4 subtypes: POLE-ultramutated (POLEmut), mismatch-repair protein deficient (MMRd), p53-mutant (p53abn) and no specific molecular profile (NSMP). Lymphovascular space invasion (LVSI) appears as an independent risk factor for nodal metastases. Herein, we evaluate the impact of LVSI on nodal metastases (N+) and its association with molecular classification.Methodology We conducted a monocentric retrospective study of 171 consecutive patients treated for EC at the University Hospital of Liège between January 2019 and October 2022. LVSI data were reported for 155 patients from whom 107 had surgical nodal staging and LVSI quantification, 64 patients were thus excluded. Full IHC and molecular biology analyses were available for 89 patients (83.18%). LVSI was classified as absent (LVSI-) or present (LVSI+). LVSI+ included less than five vessels involved (LVSI<5) and equal or more than five vessels involved (substantial LVSI, LVSIsubst).Results 32 patients (35.95%) were LVSI- and none were N+, their molecular profiles were as follows: 6 MMRd (18.75%), 7 p53abn (21.88%), 2 POLEmut (6.25%) and 17 NSMP (53.12%). Thirty-seven patients (41.57) were LVSI<5 of which 2 were N+ (5.4%), the molecular profiles were as follows: 14 MMRd (37.84%), 8 p53abn (21.62%), 3 POLEmut (8.11%) and 12 NSMP (32.43%). 20 patients (22.47%) were LVSIsubst of whom 5 were N+ (25%), their molecular profiles were: 12 MMRd (60%), 5 p53abn (25%), no POLEmut and 3 NSMP (15%).Conclusion In our study, no LVSI- patient presented nodal metastases despite 40% of them being p53abn or MMRd. On the other hand, 25% of LVSIsubst patients were N+ and 85% of them were MMRd or p53abn. LVSI status seems to have a greater impact on nodal metastases risk than molecular classification.Disclosures There are no disclosures to declare.