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
1571 - Thyroid Lobectomy versus Total Thyroidectomy among Early-Stage Papillary Thyroid Carcinoma Patient
Presenter: Sara Ahmed
Session: Poster Display session 2
Resources:
Abstract
5051 - Classification of thyroid nodule using DNA methylation profiling on tissue and circulating tumor DNA
Presenter: Shubin Hong
Session: Poster Display session 2
Resources:
Abstract
4155 - Durvalumab plus Tremelimumab for the Treatment of Patients (pts) with Refractory and Progressive Advanced Thyroid Carcinoma. A Phase II Multicohort Trial (DUTHY / GETNE T1812)
Presenter: Jorge Hernando Cubero
Session: Poster Display session 2
Resources:
Abstract