Aneuploid Circulating Endothelial Cells with Prognostic Value in Locally Advanced Breast Cancer Patients After Neoadjuvant Chemotherapy.

Background: Aneuploid circulating endothelial cells (CECs) are an indicator in breast cancer (BC). Significant changes of aneuploid CECs occurred during neoadjuvant chemotherapy (NCT). This study aimed to explore the predictive and prognostic values of aneuploid CECs in locally advanced breast cancer (LABC) patients with different NCT responses.

Methods: Breast cancer patients received an EC4-T4 NCT regimen. A novel subtraction enrichment and immunostaining fluorescence in situ hybridization (SE-iFISH) strategy was applied for the detection of CECs (CD45-/CD31+/DAPI+). Receiver operating characteristic (ROC) curves were plotted to evaluate the predictive value of aneuploid CEC counts in distinguishing NCT-resistant patients from sensitive ones. All patients were observed for progression-free survival (PFS) and overall survival (OS).

Results: The CEC counts at any time point did not show the ability to predict the efficacy of NCT. The difference in the CECs between post-chemotherapy levels and baseline could be sufficient to distinguish chemotherapy-resistant cases from other cases in Hormone+Her-2-/+ (HR+) BC patients. Patients with reduction of CECs after all courses of NCT were associated with higher probability of PFS.

Conclusion: Variations in aneuploid CECs during NCT may predict chemotherapy response in patients with HR+ breast cancer. The decrease in the number of aneuploid CECs after all courses of NCT indicates better treatment outcomes in patients with LABC.