2272 - Pretreatment Serum Lipidomics for Identifying Sarcopenia in Esophageal Cancer Patients Receiving Radiotherapy

03:00pm - 04:00pm ET

Poster Hall - Exhibit Hall A

Screen: 26

POSTER

Presenter(s)

Jiahua Lv, MD, PhD - Sichuan Cancer Hospital and Institute, chengdu, Sichuan

Z. Xiumei¹, T. C. Xi², and J. Lv³; ¹Sichuan Clinical Research Center for Cancer, Sichuan Cancer Hospital & Institute, University of Electronic Science and Technology of China, Chengdu, China, ²Department of Radiation oncology, Sichuan Clinical ResearchCenter for Cancer, Sichuan Cancer Hospital & Institute, SichuanCancerCenter,School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China, ³Sichuan Clinical Research Center for Cancer,Sichuan Hospital Cancer & Institute, Sichuan Cancer Center, University of Electronic Science and Technology of China, Chengdu, China

Purpose/Objective(s):

To characterize serum lipidomic alterations associated with sarcopenia in EC and to evaluate a serum lipid signature for identifying sarcopenia and sarcopenic obesity prior to radiotherapy.

Materials/Methods:

We enrolled 113 patients with EC who received radiotherapy and collected pretreatment serum samples. Body composition was quantified on radiotherapy planning CT at the third lumbar (L3) level. Sarcopenia was defined using the skeletal muscle index (SMI) derived from L3 skeletal muscle area. Among sarcopenic patients, sarcopenia and sarcopenic obesity (SO) subgroups were further stratified based on visceral fat area. Untargeted serum lipidomics was performed using UHPLC–MS/MS. Multivariate analyses (PCA and OPLS-DA) were applied for pattern recognition and feature discovery, followed by differential lipid screening and correlation analyses with clinical parameters. A two-lipid panel was evaluated using a LASSO logistic model with ROC analysis.

Results:

Among the 113 patients, 45 were diagnosed with sarcopenia and 68 were non-sarcopenic. Differential analysis identified SPB 24:0;2O and DG O-17:0 as key lipids associated with sarcopenia; combined as a two-lipid panel, they showed modest discrimination with an AUC of 0.661 (95% CI 0.557–0.765). Furthermore, based on visceral fat area, sarcopenic patients were categorized into sarcopenia (n=34) and sarcopenic obesity (n=11) groups, with significant lipid differences observed between these two subgroups, including DG O-17:0, MGDG O-33:3, DGTS 34:9, SL 32:2;O2, and TG 52:0.

Conclusion:

In EC patients undergoing radiotherapy, sarcopenia is linked to a distinct serum lipidomic signature. This non-invasive lipid panel may support pre-radiotherapy screening and risk stratification, potentially informing earlier nutritional assessment and supportive care; validation in larger radiotherapy-based cohorts is warranted.