Pathologic Assessment

Tumor tissue samples were fixed in 4% paraformaldehyde solution, embedded in paraffin, and sliced at 5-µm intervals. The tissue slices were stained with hematoxylin-eosin to confirm the formation of cancer nodules. Apoptosis of treated tumors was analyzed with immunohistochemical staining by using the terminal deoxynucleotidyl transferase–mediated 2ʹ-deoxyuridine, 5ʹ-triphosphate nick end labeling (TUNEL) apoptosis detection kit (R&D Systems, Minneapolis, Minn). Ki-67 antibody (Abcam, Cambridge, Mass) was used to evaluate cell proliferation according to the manufacturer protocol.