M30 neoepitope expression in epithelial cancer: quantification of apoptosis in circulating tumor cells by CellSearch analysis.

Purpose: This study aimed to detect the M30 neoepitope on circulating tumor cells (CTC) as a tool for quantifying apoptotic CTC throughout disease course and treatment.

Experimental Design: An automated sample preparation and analysis platform for computing CTC (CellSearch) was integrated with a monoclonal antibody (M30) targeting a neoepitope disclosed by caspase cleavage at cytokeratin 18 (CK18) in early apoptosis. The assay was validated using cell lines and blood samples from healthy volunteers and patients with epithelial cancer.