Illustration of chemoresistance in ALDH1(+) tumors. (A) Patients who did not have pCR to NAC, there was a statistically significant rise in median ALDH1 H-score at midpoint (after four cycles) as well as at the end (after eight cycles) of NAC. (B) Patients who achieved pCR could not be stained for ALDH1 due to lack of tumor cells at the end of eight cycles; however, after four cycles, there was no significant rise in median ALDH1 H-score. Horizontal bars indicate median H score (red) with 10th to 90th percentile (black). (
= P-value <0.05, Kruskal Wallis test). ALDH1, aldehyde dehydrogenase-1; pCR, complete pathologic response; NAC, neoadjuvant chemotherapy.