Measures of tumor proliferative activity.

Tumor proliferative activity, or labeling index, is of interest for gaining insight into the biologic properties of human neoplasm and for providing clinical information that might guide patient management. There has been an abundance of literature reporting experience with standard and newer techniques of measuring tumor proliferative activity. These methods are reviewed with emphasis on technical issues. Particular attention is paid to the development and use of monoclonal antibodies, Ki-67 and anti-PCNA/cyclin. These antibodies are readily available and relatively simple to use. The former has recently been shown to be of prognostic value in non-Hodgkin's large cell lymphomas. A number of studies suggest that indices using these techniques could be useful for a variety of carcinomas, soft tissue tumors, and tumors of the central nervous system.