(P 389) UNRESECTABLE AND METASTATIC DEDIFFERENTIATED LIPOSARCOMA (DDLPS): INSIGHTS FROM A MULTICENTER REAL-WORLD COHORT (RWC)

Author(s)

Diego Andres Gomez-Puerto, MD

Medical Oncologist
Vall d'Hebron Institute of Oncology / Vall d'Hebron University Hospital
Barcelona, Catalonia, Spain

Co-Author(s)

CC

Carlo Maria Cicala, MD

Vall d'Hebron Institute of Oncology / Vall d'Hebron University Hospital
Barcelona, Catalonia, Spain
RT

Raúl Terés Lleida, MD (he/him/his)

Medical Oncologist
Hospital Santa Creu i Sant Pau
Barcelona, Catalonia, Spain
Rosa Alvarez, MD

Medical Oncologist
Hospital General Universitario Gregorio Marañon. Instituto de Investigacion Sanitaria Gregorio Marañon
Madrid, Madrid, Spain
AS

Ana Sebio García, MD, PhD

Medical Oncologist
Hospital de la Santa Creu i Sant Pau, IR Sant Pau
Barcelona, Catalonia, Spain
NG

Natalia Gutierrez, MD

Hospital General Universitario Gregorio Marañon. Instituto de Investigacion Sanitaria Gregorio Marañon
Madrid, Madrid, Spain
Javier Martinez-Trufero, MD

Medical Oncologist
Hospital Universitario Miguel Servet
Zaragoza, Aragon, Spain
Carlos López-Jiménez, MD (he/him/his)

Medical Oncologist
Hospital Universitario Fundación Jiménez Díaz. Instituto de Investigación Sanitaria FJD-UAM.
Madrid, Madrid, Spain
EO

Eugenia Ortega-Izquierdo, MD

Hospital Universitario Miguel Servet
Zaragoza, Madrid, Spain
MV

Maria Angeles Vaz, N/A, MD

Hospital Universitario Ramón y Cajal
Madrid, Madrid, Spain
FP

Fernando Pikabea, MD

Hospital Universitario Basurto
Bilbao, Pais Vasco, Spain
JC

Juana María Cano, MD

Hospital General Universitario Ciudad Real
Ciudad Real, Castilla-La Mancha, Spain
MC

Marc Cucurull-Salamero, MD

ICO - Institut Català d’Oncologia Badalona, Germans Trias i Pujol University Hospital
Badalona, Andalucia, Spain
IN

Isaac Nuñez, MD

Hospital Universitario Nuestra Señora de Candelaria
Santa Cruz de Tenerife, Canarias, Spain
LC

Lucia Castillo-Portellano, MD

Hospital Universitario Virgen de la Nieves
Granada, Andalucia, Spain
AC

Anna Carbo-Bague, MD

ICO - Institut Català d’Oncologia-Girona
Girona, Catalonia, Spain
JM

Jeronimo Martinez, MD

Hospital Universitario Virgen de la Arrixaca
Murcia, Murcia, Spain
Gala Martínez-Bernal, MD

Medical Doctor
Hospital Universitario Virgen del Rocio
Sevilla, Andalucia, Spain
IS

Isabel Sevilla-Garcia, MD

Hospital Universitario Virgen de la Victoria, Clinical and Translational Cancer Research/Malaga Biomedical Research Institute (IBIMA) Málaga
Malaga, Andalucia, Spain
GM

Gloria Marquez-Gaffaro, MD

Hospital Universitario Fundación Jiménez Díaz
Madrid, Madrid, Spain
Gloria Marquina-Ospina, MD

Hospital Clinico San Carlos. Department of Medical Oncology
Hospital Clinico San Carlos. Department of Medical Oncology
Madrid, Madrid, Spain
AP

Ana Paisan, MD

Hospital Universitario Donostia
San Sebastian, Pais Vasco, Spain
MS

Maria Angeles Sala, MD

Hospital Universitario Basurto
Bilbao, Pais Vasco, Spain
César Serrano, MD, PhD

Head
Sarcoma Translational Research Program, Hospital Universitari Vall d'Hebron – Vall d'Hebron Institut d'Oncologia
Barcelona, Catalonia, Spain
Claudia M. Valverde Morales, MD (she/her/hers)

Vall d’Hebron University Hospital
Barcelona, Catalonia, Spain

Objective: DDLPS is a high-grade soft tissue sarcoma characterized by aggressive behavior and poor prognosis. Systemic treatments (Tx), such as chemotherapy (CT), have shown limited efficacy. This study evaluates Tx outcomes for unresectable/metastatic (UM) DDLPS across a multicentric RWC.

Methods: This retrospective study enrolled adult patients (pts) included in the national registry of the Spanish Sarcoma Group (GEIS) who had started systemic Tx from 1/1/18 to 1/1/24 for a confirmed UM DDLPS. Demographics and clinical data were collected. Survival endpoints were evaluated using Kaplan–Meier and log-rank tests.

Results: 155 pts were included (67% male; median age 64; 48% T4, 38.7% G3, and 17.4% metastatic). Most tumors were retroperitoneal (66%), followed by trunk (17.4%) and extremities (11%). Neoadjuvant and adjuvant Tx were given in 15% and 23%, respectively. In advanced stages, 14.8% entered clinical trials and 40% were initially treated in non-referral centers. First line (1L) Tx were Doxorubicin (D) (46.5%), anthracycline-ifosfamide (AI) (21%), trabectedin (Tr) (10.3%) brigimadlin (Bg) (7.1%) and eribulin (Er) (6.5%). Toxicity ≥ G3 occurred in 40%, mainly hematological. Median 1L progression free survival (mPFS) was 4.2 months(m) (95% CI: 0.3–0.5). PFS and response rate (RR) were: AI (7.3m, 34%), Er (7.3m, 20%), Bg (5.6m, 18%), Tr (4.7m, 19%) and D (3.5m, 10.6%). Median overall survival (OS) was 2.2 years (95% CI: 1.7–4.5). Among regimens, AI and Bg had the highest OS at 3 years (55%, 64%, respectively), though no Tx sequence demonstrated statistical significance.
Second line (2L) CT was given in 56% of pts: Tr (41.4% ; RR: 22%), DTIC-Gemcitabine DG (19.5%; RR: 5.9%), Er (16%; RR: 14%), and D (9.2%; RR: 14%), with mPFS of 3.9m. Third-line Tx (23.9% of pts) included Er (45%) and Tr (35%), with mPFS of 2.8m. About 39% received Tx beyond 2L , mostly Er (28.3%), Tr (28.3%), and DG (17%). In this latter setting, RR was minimal, with no significant differences in PFS/OS between Tx arms.

Conclusion: Tx patterns in UM DDLPS remain heterogeneous with modest outcomes. AI and Bg showed OS trends, though not statistically significant due to sample size. These data underscore the need for novel Tx strategies and randomized trials to improve care.