Integrated mutational landscape analysis of endometrial stromal sarcoma

T Tobias M. P. Hartwich (Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine) S Seungji Choi (Department of Biomedical Sciences, Korea University College of Medicine) A Ayoung Hwang (Department of Biomedical Sciences, Korea University College of Medicine) S Stefania Bellone (Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine) L Luca Palmieri (Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine) H Hae Seo (Department of Biomedical Sciences, Korea University College of Medicine) T Taekeun Kim (Department of Biomedical Sciences, Korea University College of Medicine) J Juhyeon Hong (Department of Biomedical Sciences, Korea University College of Medicine) C Camilla Krakstad (Centre for Cancer Biomarkers, Department of Clinical Science, University of Bergen) J Jone Trovik (Centre for Cancer Biomarkers, Department of Clinical Science, University of Bergen) I Ingunn M. Stefansson (Centre for Cancer Biomarkers, Department of Clinical Science, University of Bergen) H Hans Kristian Haugland (Department of Pathology, Haukeland University Hospital) M Michelle Greenman (Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine) V Victoria Ettorre (Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine) S Sarah Ottum (Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine) C Cem Demirkiran (Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine) Y Yang Yang-Hartwich (Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine) N Natalia Buza (Department of Pathology, Yale University School of Medicine) P Pei Hui (Department of Pathology, Yale University School of Medicine) S Salvatore Lopez (Unit of Gynecologic Oncology, Istituto di Ricovero e Cura a Carattere Scientifico Istituto Tumori “Giovanni Paolo II”) G Gennaro Cormio (Unit of Gynecologic Oncology, Istituto di Ricovero e Cura a Carattere Scientifico Istituto Tumori “Giovanni Paolo II”) M Mariantonietta Ramunno (Unit of Pathology, Istituto di Ricovero e Cura a Carattere Scientifico Istituto Tumori “Giovanni Paolo II”) A Alfredo Zito (Unit of Pathology, Istituto di Ricovero e Cura a Carattere Scientifico Istituto Tumori “Giovanni Paolo II”) E Emanuele Perrone (Unit of Gynecologic Oncology, Department Woman and Child Health Sciences and Public Health, Fondazione Policlinico Universitario A. Gemelli Istituto di Ricovero e Cura a Carattere Scientifico) A Anna Fagotti (Unit of Gynecologic Oncology, Department Woman and Child Health Sciences and Public Health, Fondazione Policlinico Universitario A. Gemelli Istituto di Ricovero e Cura a Carattere Scientifico) F Francesco Fanfani (Unit of Gynecologic Oncology, Department Woman and Child Health Sciences and Public Health, Fondazione Policlinico Universitario A. Gemelli Istituto di Ricovero e Cura a Carattere Scientifico) A Angela Santoro (Pathology Unit, Department of Woman and Child’s Health and Public Health Sciences, Fondazione Policlinico Universitario Agostino Gemelli Istituto di Ricovero e Cura a Carattere Scientifico) A Antonella Ravaggi (Division of Obstetrics and Gynecology, Azienda Socio Sanitaria Territoriale Spedali Civili di Brescia) E Eliana Bignotti (Division of Obstetrics and Gynecology, Azienda Socio Sanitaria Territoriale Spedali Civili di Brescia) F Franco Odicino (Division of Obstetrics and Gynecology, Azienda Socio Sanitaria Territoriale Spedali Civili di Brescia) L Laura Ardighieri (Unit of Pathology, Azienda Socio Sanitaria Territoriale Spedali Civili di Brescia) E Elena Ratner R Roberto Angioli (Department of Gynecology, Fondazione Policlinico Universitario Campus Bio-Medico) G Giuseppe Perrone (Operative Research Unit of Anatomical Pathology, Fondazione Policlinico Universitario Campus Bio-Medico) D Daniela Luvero (Department of Gynecology, Fondazione Policlinico Universitario Campus Bio-Medico) B Beatrice Conca (Department of Obstetrics and Gynecology, Fondazione Policlinico Universitario Campus Bio-Medico) J Jungmin Choi (Department of Genetics, Yale School of Medicine) J Joseph Schlessinger A Alessandro D. Santin (Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine)

Abstract

Endometrial stromal sarcoma (ESS) is a rare uterine malignancy with limited treatment options. We performed integrated whole-genome, whole-exome, and transcriptome sequencing on 80 ESS tumors, comprising 32 low-grade (LG) and 48 high-grade (HG) tumors, to characterize their genetic landscape. The overall mutation burden was modest, with no significant difference between grades; however, we identified six hypermutated cases (7.5%) harboring POLE or mismatch repair mutations, genomic features predictive of immunotherapy response. We identified focal RAD54B amplifications in 15 tumors (18.8%), leading to elevated RAD54B expression and significantly shorter survival. This establishes RAD54B as an oncogenic driver in ESS. Known tumor suppressors (PTEN, TP53) were frequently mutated in HG-ESS but rare in LG-ESS, highlighting distinct grade-specific drivers of malignancy. HG-ESS exhibited widespread chromosomal gains, frequent loss of cell-cycle regulators (RB1, CDKN2A), and numerous private gene fusions arising from complex DNA rearrangements. In contrast, LG-ESS were defined by canonical fusions (e.g., JAZF1–SUZ12 ) and co-occurring deletions in metabolic regulator genes (TSC2, STK11). Finally, in an activating NRAS-mutant (p.Q61R) HG-ESS xenograft, the combination of MEK and FAK inhibition dramatically suppressed tumor growth and prolonged survival, highlighting a promising targeted treatment strategy. Overall, our comprehensive analysis defines the molecular basis of ESS and provides a strong preclinical rationale for precision therapies in this aggressive cancer.

Article Details

Volume / Issue Vol. 123, Issue 5
Published February 03, 2026
ISSN 0027-8424
Publisher National Academy of Sciences

Authors (39)

T

Tobias M. P. Hartwich

Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine

S

Seungji Choi

Department of Biomedical Sciences, Korea University College of Medicine

A

Ayoung Hwang

Department of Biomedical Sciences, Korea University College of Medicine

S

Stefania Bellone

Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine

L

Luca Palmieri

Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine

H

Hae Seo

Department of Biomedical Sciences, Korea University College of Medicine

T

Taekeun Kim

Department of Biomedical Sciences, Korea University College of Medicine

J

Juhyeon Hong

Department of Biomedical Sciences, Korea University College of Medicine

C

Camilla Krakstad

Centre for Cancer Biomarkers, Department of Clinical Science, University of Bergen

J

Jone Trovik

Centre for Cancer Biomarkers, Department of Clinical Science, University of Bergen

I

Ingunn M. Stefansson

Centre for Cancer Biomarkers, Department of Clinical Science, University of Bergen

H

Hans Kristian Haugland

Department of Pathology, Haukeland University Hospital

M

Michelle Greenman

Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine

V

Victoria Ettorre

Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine

S

Sarah Ottum

Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine

C

Cem Demirkiran

Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine

Y

Yang Yang-Hartwich

Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine

N

Natalia Buza

Department of Pathology, Yale University School of Medicine

P

Pei Hui

Department of Pathology, Yale University School of Medicine

S

Salvatore Lopez

Unit of Gynecologic Oncology, Istituto di Ricovero e Cura a Carattere Scientifico Istituto Tumori “Giovanni Paolo II”

G

Gennaro Cormio

Unit of Gynecologic Oncology, Istituto di Ricovero e Cura a Carattere Scientifico Istituto Tumori “Giovanni Paolo II”

M

Mariantonietta Ramunno

Unit of Pathology, Istituto di Ricovero e Cura a Carattere Scientifico Istituto Tumori “Giovanni Paolo II”

A

Alfredo Zito

Unit of Pathology, Istituto di Ricovero e Cura a Carattere Scientifico Istituto Tumori “Giovanni Paolo II”

E

Emanuele Perrone

Unit of Gynecologic Oncology, Department Woman and Child Health Sciences and Public Health, Fondazione Policlinico Universitario A. Gemelli Istituto di Ricovero e Cura a Carattere Scientifico

A

Anna Fagotti

Unit of Gynecologic Oncology, Department Woman and Child Health Sciences and Public Health, Fondazione Policlinico Universitario A. Gemelli Istituto di Ricovero e Cura a Carattere Scientifico

F

Francesco Fanfani

Unit of Gynecologic Oncology, Department Woman and Child Health Sciences and Public Health, Fondazione Policlinico Universitario A. Gemelli Istituto di Ricovero e Cura a Carattere Scientifico

A

Angela Santoro

Pathology Unit, Department of Woman and Child’s Health and Public Health Sciences, Fondazione Policlinico Universitario Agostino Gemelli Istituto di Ricovero e Cura a Carattere Scientifico

A

Antonella Ravaggi

Division of Obstetrics and Gynecology, Azienda Socio Sanitaria Territoriale Spedali Civili di Brescia

E

Eliana Bignotti

Division of Obstetrics and Gynecology, Azienda Socio Sanitaria Territoriale Spedali Civili di Brescia

F

Franco Odicino

Division of Obstetrics and Gynecology, Azienda Socio Sanitaria Territoriale Spedali Civili di Brescia

L

Laura Ardighieri

Unit of Pathology, Azienda Socio Sanitaria Territoriale Spedali Civili di Brescia

E

Elena Ratner

R

Roberto Angioli

Department of Gynecology, Fondazione Policlinico Universitario Campus Bio-Medico

G

Giuseppe Perrone

Operative Research Unit of Anatomical Pathology, Fondazione Policlinico Universitario Campus Bio-Medico

D

Daniela Luvero

Department of Gynecology, Fondazione Policlinico Universitario Campus Bio-Medico

B

Beatrice Conca

Department of Obstetrics and Gynecology, Fondazione Policlinico Universitario Campus Bio-Medico

J

Jungmin Choi

Department of Genetics, Yale School of Medicine

J

Joseph Schlessinger

A

Alessandro D. Santin

Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine