TY - JOUR

T1 - Defining Substantial Lymphovascular Space Invasion in Endometrial Cancer

AU - Peters, Elke E.M.

AU - León-Castillo, Alicia

AU - Smit, Vincent T.H.B.M.

AU - Boennelycke, Marie

AU - Hogdall, Estrid

AU - Hogdall, Claus

AU - Creutzberg, Carien

AU - Jürgenliemk-Schulz, Ina M.

AU - Jobsen, Jan J.

AU - Mens, Jan Willem M.

AU - Lutgens, Ludy C.H.W.

AU - Van Der Steen-Banasik, Elzbieta M.

AU - Ortoft, Gitte

AU - Bosse, Tjalling

AU - Nout, Remi

N1 - Publisher Copyright: © 2022 Lippincott Williams and Wilkins. All rights reserved.

PY - 2022

Y1 - 2022

N2 - Lymphovascular space invasion (LVSI) occurs in a minority of endometrial cancer (EC) cases, and the extent of LVSI is an important risk factor for recurrence and/or metastases. Our aim was to improve the reproducibility of measuring clinically meaningful LVSI by performing a quantitative analysis of the correlation between LVSI and the risk of pelvic lymph node recurrence in EC. EC samples from PORTEC-1 and PORTEC-2 trials were retrieved and used to collect quantitative data, including the number of LVSI-positive vessels per H&E-stained slide. Using a predefined threshold for clinical relevance, the risk of pelvic lymph node recurrence risk was calculated (Kaplan-Meier method, with Cox regression) using a stepwise adjustment for the number of LVSI-positive vessels. This analysis was then repeated in the Danish Gynecological Cancer Database (DGCD) cohort. Among patients in PORTEC-1 and PORTEC-2 trials who did not receive external beam radiotherapy, the 5-yr pelvic lymph node recurrence risk was 3.3%, 6.7% (P=0.51), and 26.3% (P<0.001), respectively when 0, 1 to 3, or ≥4 vessels had LVSI involvement; similar results were obtained for the DGCD cohort. Furthermore, both the average number of tumor cells in the largest embolus and the number of LVSI-positive H&E slides differed significantly between focal LVSI and substantial LVSI. On the basis of these results, we propose a numeric threshold (≥4 LVSI-involved vessels in at least one H&E slide) for defining clinically relevant LVSI in EC, thereby adding supportive data to the semiquantitative approach. This will help guide gynecologic pathologists to differentiate between focal and substantial LVSI, especially in borderline cases.

AB - Lymphovascular space invasion (LVSI) occurs in a minority of endometrial cancer (EC) cases, and the extent of LVSI is an important risk factor for recurrence and/or metastases. Our aim was to improve the reproducibility of measuring clinically meaningful LVSI by performing a quantitative analysis of the correlation between LVSI and the risk of pelvic lymph node recurrence in EC. EC samples from PORTEC-1 and PORTEC-2 trials were retrieved and used to collect quantitative data, including the number of LVSI-positive vessels per H&E-stained slide. Using a predefined threshold for clinical relevance, the risk of pelvic lymph node recurrence risk was calculated (Kaplan-Meier method, with Cox regression) using a stepwise adjustment for the number of LVSI-positive vessels. This analysis was then repeated in the Danish Gynecological Cancer Database (DGCD) cohort. Among patients in PORTEC-1 and PORTEC-2 trials who did not receive external beam radiotherapy, the 5-yr pelvic lymph node recurrence risk was 3.3%, 6.7% (P=0.51), and 26.3% (P<0.001), respectively when 0, 1 to 3, or ≥4 vessels had LVSI involvement; similar results were obtained for the DGCD cohort. Furthermore, both the average number of tumor cells in the largest embolus and the number of LVSI-positive H&E slides differed significantly between focal LVSI and substantial LVSI. On the basis of these results, we propose a numeric threshold (≥4 LVSI-involved vessels in at least one H&E slide) for defining clinically relevant LVSI in EC, thereby adding supportive data to the semiquantitative approach. This will help guide gynecologic pathologists to differentiate between focal and substantial LVSI, especially in borderline cases.

KW - Endometrial carcinoma

KW - LVSI definition

KW - Lymphovascular space invasion

KW - Substantial LVSI

KW - Threshold

U2 - 10.1097/PGP.0000000000000806

DO - 10.1097/PGP.0000000000000806

M3 - Journal article

C2 - 34261899

AN - SCOPUS:85128800692

VL - 41

SP - 220

EP - 226

JO - International Journal of Gynecological Pathology

JF - International Journal of Gynecological Pathology

SN - 0277-1691

IS - 3

ER -