Abstract 5792
Background
Early predicting the pathologic complete response (pCR) after neoadjuvant chemotherapy in patients with locally advanced breast cancer (LABC) is closely associated with clinical outcomes. However, conventional metabolic parameters using baseline 18F-FDG PET/CT have failed to accurately predict the pCR. Breast cancer stem cells (CSCs) are known for their established role in chemoresistance. We designed a new PET parameter for CSC metabolism (MTVcsc) from pretreatment 18F-FDG PET/CT by using distinctive glucose metabolism between CSCs and differentiated cancer cells, and aimed to evaluate the prognostic value of the MTVcsc.
Methods
A total of 71 patients with LABC who underwent initial 18F-FDG PET/CT before NAC were included in this study. The SUV values of single voxels within the primary tumor were clustered by performing k-means clustering using R version 3.5.3 and MTVcsc was derived by calculating the volume of the most glycolytic cluster. The predictive values of the MTVcsc, as well as clinicopathologic and conventional metabolic parameters (SUVmax, MTV, TLG) for pCR, were analyzed by multivariable logistic regression.
Results
Seventeen patients were excluded from the final analysis due to small tumor size (< 64 voxels). The lower MTVcsc and non-luminal subtypes were significantly associated with achieving pCR following NAC (Table). The MTVcsc outperformed the conventional PET parameters in predicting pCR. Table Univariable and multivariable logistic regression model of clinicopathologic and metabolic parameters for predicting pathologic complete response.Table: 301P
Parameters | Univariable analysis | Multivariable analysis | ||||
---|---|---|---|---|---|---|
OR | 95% CI | P value | OR | 95% CI | P value | |
Ki-67 | ||||||
Low, < 20% High, ≥ 20% | 1.00 | |||||
5.57 | 1.06-29.27 | 0.043 | ||||
Molecular subtype | ||||||
Luminal A and B HER2 positive Triple negative | 1.00 | 1.00 | ||||
11.46 | 2.07-63.36 | 0.005 | 13.7 | 1.75-107.36 | 0.013 | |
6.55 | 1.05-40.67 | 0.044 | 17.42 | 1.41-215.04 | 0.026 | |
Metabolic parameters | ||||||
SUVmax Metabolic tumor volume (MTV) Total lesion glycolysis (TLG) MTVcsc | 0.98 | 0.83-1.16 | 0.814 | |||
0.98 | 0.94-1.02 | 0.281 | ||||
0.99 | 0.98-1.00 | 0.231 | ||||
0.29 | 0.10-0.89 | 0.031 | 0.21 | 0.05-0.82 | 0.025 |
Conclusions
MTVcsc, a novel PET parameter for CSC metabolism, provides predictive value for pCR. By further stratifying LABC patients with a combination of MTVcsc and molecular subtype at initial staging workup, achieving pCR after NAC can be early predicted more accurately.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
4022 - Ribociclib (RIB) plus letrozole (LET) in male patients (pts) with hormone receptor-positive (HR+), human epidermal growth factor receptor-2–negative (HER2–) advanced breast cancer (ABC) from the CompLEEment-1 trial
Presenter: Mario Campone
Session: Poster Display session 2
Resources:
Abstract
3599 - Comparative effectiveness of palbociclib plus letrozole vs letrozole for metastatic breast cancer in US real-world clinical practices
Presenter: Rachel Layman
Session: Poster Display session 2
Resources:
Abstract
901 - Pharmacokinetics (PK), safety, and efficacy of [fam-] trastuzumab deruxtecan with OATP1B/CYP3A inhibitors in subjects with HER2-expressing advanced solid tumors
Presenter: Yung-Jue Bang
Session: Poster Display session 2
Resources:
Abstract
2777 - A Phase 2 study of abemaciclib in patients (pts) with brain metastases (BM) secondary to non-small cell lung cancer (NSCLC) or melanoma (MEL).
Presenter: Solmaz Sahebjam
Session: Poster Display session 2
Resources:
Abstract
3980 - Ribociclib (RIB) + letrozole (LET) in patients (pts) with visceral metastases (VM) or bone-only metastases (BOM) in hormone receptor-positive (HR+), human epidermal growth factor receptor-2–negative (HER2–) advanced breast cancer (ABC): Subgroup analysis from the CompLEEment-1 trial
Presenter: Michelino De Laurentiis
Session: Poster Display session 2
Resources:
Abstract
4024 - Ribociclib (RIB) + letrozole (LET) in patients (pts) with hormone receptor-positive (HR+), human epidermal growth factor receptor-2–negative (HER2–) advanced breast cancer (ABC) and central nervous system (CNS) metastases: Subgroup analysis from the phase 3b CompLEEment-1 trial
Presenter: Paul Cottu
Session: Poster Display session 2
Resources:
Abstract
2151 - Clinical outcome and toxicity data in patients with advanced breast cancer treated with cyclin-dependent kinase 4/6 (CDK4/6) inhibitors combined with endocrine therapy in a real-world clinical setting.
Presenter: Elena Fountzilas
Session: Poster Display session 2
Resources:
Abstract
3994 - Safety and efficacy of Ribociclib (RIBO) + letrozole (LET) in patients (pts) with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2–) advanced breast cancer (ABC): Interim results from the Italian cohort of the CompLEEment-1 (C-1) study.
Presenter: Michele De Laurentiis
Session: Poster Display session 2
Resources:
Abstract
1370 - Interim Results From CompLEEment-1 (A Phase 3b Study of Ribociclib and Letrozole as First-Line Therapy for Advanced Breast Cancer in an Expanded Population): Spanish cohort results
Presenter: Javier Salvador
Session: Poster Display session 2
Resources:
Abstract
1109 - First Canadian Interim Analysis from the Phase IIIb CompLEEment-1 Ribociclib + Letrozole HR+ HER2- Advanced Breast Cancer Trial
Presenter: Cristiano Ferrario
Session: Poster Display session 2
Resources:
Abstract