Abstract Background: Circulating tumor cells (CTCs) are a well-known non-invasive blood biomarker which can stratify metastatic breast cancer (mBC) patients, especially those with highly aggressive subtypes. Initial pilot studies have characterized a distinct subtype of CTCs undergoing mitosis, whose presence correlates with worse survival outcomes than CTCs alone. However, their prognostic value and their influence in different therapeutic regimes remains unknown. In a multi-institutional prospective study, we isolated CTCs from n=138 mBC patients to categorize mitotic CTCs, evaluate their association with progression-free survival (PFS) Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 1065.
Duffy et al. (Fri,) studied this question.