A new method for analyzing the cell kinetics of human brain tumors by double labeling with bromodeoxyuridine in situ and with iododeoxyuridine in vitro.

BACKGROUND

Cell kinetics studies performed with immunohistochemical techniques to estimate the S-phase fraction have elucidated the proliferative potential of individual brain tumors.

METHODS

The authors developed a new double-labeling method that enables other cell kinetics variables, including the duration of the S-phase (Ts) and the potential doubling time (Tp), to be measured from a single biopsy specimen. Using this method, 100 brain tumors were labeled with bromodeoxyuridine (BUdR) in situ and with iododeoxyuridine in vitro; labeled cells were identified by double staining with immunogold-silver and alkaline phosphatase techniques.

RESULTS

Ts was fairly uniform (mean, 9.2 +/- 2.1 hour [+/- standard deviation]); range, 6.0-13.7 hours), but Tp varied from 1 day to more than 2 months. The Tp values correlated closely with the BUdR labeling index (LI), or S-phase fraction, and can be calculated from the equation: Tp = 26.9/LI1.02 (r = 0.98, P < 0.005).

CONCLUSIONS

This new method facilitates the quantitation of the proliferative potential of individual brain tumors. The S-phase fraction, Ts, and Tp can be calculated from analysis of a single biopsy specimen. This method can be used to estimate the prognosis of individual patients with brain tumors and to select treatment modalities more directly than is possible with single-labeling studies with BUdR.