Invasive ductal carcinoma. (a-f) Histology and expression of caspase-3 by immunoperoxidase. (a-b) Untreated tumor demonstrating sheets of cohesive neoplastic cells demonstrating apoptotic bodies (black arrow) and mitotic figures (red arrow), H&E at 20× and 40×, respectively. (d-e) Treated tumor demonstrating loss of cellular cohesion and increased apoptotic bodies (black arrow), H&E at 20× and 40×, respectively. (c) Untreated tumor demonstrating positivity (black arrow) for caspase-3 in up to 10% of neoplastic cells compared to 20% in treated tumor (f), immunoperoxidase (IP), 20×. (g) HPLC runs of intracellular caspase-3 activity in treated and untreated tumor specimens. The AMC peak (retention time, ~12.8 min) in treated tumor was blocked by the pancaspase inhibitor zVAD, confirming cleavage of Ac-DEVD-AMC was mediated by caspases. (h) Cellular respiration, measured on tumor arrival to the laboratory to affirm viability.