TUMOUR CELL PROLIFERATION IN RELATION TO THE VASCULATURE

Abstract

The proliferation pattern of a transplantable mouse mammary carcinoma has been studied in relation to its macroscopic and microscopic struture. No significant differences were seen in the labeling or mitotic indices or in the percentage labeled mitoses curves for the peripheral 2.0 mm rim or for the central tumor core. When these parameters were scored for cells classified according to their position in relation to capillaries or to necrotic regions, marked differences were observed in all the parameters. Higher labeling and mitotic indices and higher grain counts were seen adjacent to the capillaries, resulting from a shorter cell cycle duration and a higher growth fraction. The variation in cell cycle is mainly due to a change in the duration of the G1 phase.