Skeletal Muscle Density as a Predictive Marker for Pathologic Complete Response in Triple-Negative Breast Cancer...

Area of Science:

• Oncology
• Radiology
• Medical Imaging Analysis

Background:

• The prognostic significance of muscle-related indicators in triple-negative breast cancer (TNBC) patients undergoing neoadjuvant chemotherapy (NAC) requires further clarification.
• This study investigates the association between skeletal muscle density (SMD) and physical reserve markers in predicting pathologic complete response (pCR) in TNBC patients.

Purpose of the Study:

• To evaluate the predictive value of skeletal muscle density (SMD) for treatment response in triple-negative breast cancer (TNBC) patients undergoing neoadjuvant chemotherapy (NAC).
• To assess the relationship between SMD and clinical variables reflecting physical reserve in relation to achieving a pathologic complete response (pCR).

Main Methods:

• Retrospective analysis of 144 TNBC patients treated with NAC (chemotherapy alone or chemoimmunotherapy) from March 2021 to March 2024.
• Skeletal muscle density (SMD) was quantified using deep learning software on CT scans at the L3 vertebral level.
• Association between SMD, clinical factors, relative dose intensity, pCR, and survival outcomes were analyzed.

Main Results:

• Higher SMD was correlated with younger age, lower BMI, and fewer comorbidities.
• In the chemoimmunotherapy group, high SMD was linked to higher relative dose intensity and improved pCR rates (63.2% vs. 44.1%).
• Multivariable analysis identified higher SMD and PD-L1 combined positive score (CPS) as independent predictors of pCR; high SMD also predicted longer event-free survival.

Conclusions:

• CT-measured SMD effectively reflects physical reserve in TNBC patients receiving NAC.
• SMD, alongside CPS, shows potential as a predictive biomarker for the efficacy of neoadjuvant chemoimmunotherapy in TNBC.
• SMD's predictive value for pCR and survival was significant in the chemoimmunotherapy group but not in the chemotherapy-alone group.