The combined determination of proliferative activity and cell density in the prognosis of adult patients with supratentorial high-grade astrocytic tumors.

Tumor growth represents the ratio between cell gain (number of mitoses per unit of time, i.e., proliferative activity) and cell loss (number of cell deaths during the same unit of time). While in adults, proliferative activity parallels the level of malignancy in astrocytic tumors and therefore represents a useful diagnostic marker, cell loss has never been concomitantly assessed in tumors of this type. We hypothesize that cell density assessable on histologic slides represents the ratio between cell gain and cell loss. This hypothesis concerns only the diffuse type of astrocytic tumors. Proliferative activity (assessed by MIB1 antigen immunostain) and cell density were thus quantitatively assessed by means of a cell image processor in a series of 54 supratentorial astrocytic tumors of adult patients, which included 15 astrocytomas (ASTs), 18 anaplastic astrocytomas (ANAs), and 21 glioblastomas (GBMs). The results show that proliferative activity and cell density were highly correlated (P = .003) and that both correlated with histopathologic grade. The patients with a high-grade astrocytic tumor (i.e., ANA or GBM) that exhibited a low level of proliferative activity but high cell density survived for significantly shorter periods than did patients with a tumor that exhibited low proliferative activity and low cell density (P = .002). The patients with a high-grade astrocytic tumor that exhibited high proliferative activity and high cell density survived for significantly less time than did the patients with a tumor that exhibited high proliferative activity but low cell density (P < .05). A marked difference in survival periods was observed between the patients with a high-grade astrocytic tumor that exhibited a low level of proliferative activity and low cell density and the patients with a tumor that exhibited a high level of proliferative activity and high cell density (P < .001). The concomitant determination of proliferative activity and cell density seems likely to enable determination of the few adult patients who have high-grade astrocytic tumors and who will survive for a considerable period (several years).