Proliferation, as one of the hallmarks and most fundamental biological processes in tumors,[1] is associated with tumor progression, response to therapy, and cancer patient survival.[2] Consequently, the evaluation of a tumor proliferative index (or growth fraction) has clinical significance in characterizing many solid tumors and hematologic malignancies.[3] This has led investigators to develop different technologies to evaluate the proliferation index in tumor samples. The most commonly used methods in evaluating a proliferative index include mitotic indexing, thymidine-labeling index, bromodeoxyuridine assay, the determination of fraction of cells in various phases of cell cycle, and the immunohistochemical evaluation of cell cycle-associated proteins.
^Yerushalmi, Rinat; Woods, Ryan; Ravdin, Peter M; Hayes, Malcolm M; Gelmon, Karen A (February 2010). "Ki67 in breast cancer: prognostic and predictive potential". The Lancet Oncology. 11 (2): 174–183. doi:10.1016/s1470-2045(09)70262-1. PMID20152769.