CtDNA as a biomarker for treatment response
tumor, breast cancer
TUMOR, RESIDUAL CANCER, BREAST CANCER
Data on RCB class were available for 74 of the patients with midterm blood samples. Among patients with ctDNA positivity at midterm 12 achieved pCR (12/38, 32%), whereas 20 of 36 patients (56%) with ctDNA negativity at midterm achieved pCR (Pathological complete response according to presence of circulating tumor DNA (ctDNA) evaluated at midterm (before the 5th cycle of neoadjuvant treatment) and preoperatively in breast cancer patients.CtDNA status was evaluated using a multiplex droplet digital polymerase chain reaction assay targeting a combination of two breast tissue specific (CtDNA status at midterm and preoperatively in relation to pathological response to neoadjuvant breast cancer treatment according to histopathological assessment of the surgically removed tissue with grading according to the Residual Cancer Burden (RCB) Calculator (MD AndersonPost hoc analysis was conducted using RCB classification similar to Zhou et al.