Abstract 5349
Background
ARTEMIS (A Randomized, TNBC Enrolling trial to confirm Molecular profiling Improves Survival) is a randomized trial to determine if precision guided neoadjuvant chemotherapy (NACT) impacts rates of pathologic complete response in the breast and axillary nodes (pCR). We hypothesized that CTCs in peripheral blood at the time of surgery, after completion of NACT, would be prognostic in TNBC.
Methods
Venous Blood taken following completion of NACT and immediately prior to surgery was assessed for CTCs after NACT as part of two IRB approved studies, ARTEMIS (2014 – 0185/PA15-1050) and LAB04-0698. CTCs (per 7.5 ml blood) were identified using the Cell Search® System (Menarini Silicon Biosystems). Samples with one or more cells having morphologic criteria for malignancy were deemed CTC+. Log-rank test and Cox regression analysis were applied to evaluate associations between CTC+, pCR, and overall survival.
Results
pCR was achieved in 24/68 (35%) patients with TNBC. Twenty four patients (35%) were CTC+. 3 year overall survival was evaluated in 4 groups of patients: pCR-no CTCs (n = 20), pCR-CTC + (n = 4), non-pCR-no CTCs (n = 24) and non-pCR-CTC + (n = 20). Three year OS was higher in the pCR-no CTCs cohort (100%), compared to pCR-CTC + (50%), non-pCR-no CTCs (83%), non-pCR-CTC + (19%); log rank p < 0.0001. In this data set, the presence of CTCs was associated with significant risk of death at 3 years [hazard ratio of 12.3 (95% CI 3.4-454, p = 0.00002)], whereas a favorable, but non-significant trend was noted for pCR [hazard ratio of 0.2 (95% CI 0.0, 1.4, p = 0.11)].
Conclusions
The presence of CTCs at the time of surgery after NACT has prognostic significance beyond that of pCR and should be considered in evaluation of patients for adjuvant clinical trials.
Clinical trial identification
Legal entity responsible for the study
University of Texas, MD Anderson.
Funding
University of Texas, MD Anderson.
Editorial Acknowledgement
Disclosure
All authors have declared no conflicts of interest.