CASP3 and neoplasm: Histopathological analysis demonstrated profound PDT-induced effects, including total ablation of progesterone receptor expression in the tumor matrix and a significant increase in caspase-3-mediated apoptosis in the peritumoral zone (36.3 ± 9.6 vs. 14.8 ± 2.2 cells/mm2, p<0.0001).