6th ESACP Congress, Heidelberg, April 7-11, 1999

A028
RELATIONS BETWEEN VASCULARIZATION AND PROLIFERATION IN INVASIVE BREAST CANCER
Belién JAM, Van Diest PJ, Baak JPA

Department of Pathology, Academic Hospital Vrije Universiteit, Amsterdam, Netherlands

Studies on relations between angiogenesis and tumour cell proliferation have provided conflicting results. We therefore have investigated the relations between the number and location of fully automatically identified CD31 positive microvessels and interactively segmented mitoses and necrotic compartments by image processing in 10 breast cancers in "hot spots" and in whole tumour sections. Microvessel and mitosis hot spots were topographically close or overlapping and were always located at the periphery of the tumour. The number of mitoses and microvessels per mm2 in the hot spot were strongly correlated with the respective numbers in the whole tumour section, as well as mutually. The ratio of the number of mitoses in the hot spot to the whole tumour section was significantly higher than the microvessel ratio. Mitosis were preferentially located at a distance of 50- 150 µm from microvessels. No significant difference was found between the average distance between mitoses and microvessels in the whole tumour sections and in the hot spot (79 vs 72 µm), although considerable inter-tumour differences were found (hot spot 43-106 µm, tumour 47-111 µm). The presence of necrotic areas correlated with the number of mitoses per mm2 and necrosis was in general observed at a distance >150 µm from the microvessels, suggesting that necrotic areas have outgrown their vascular system. These results indicate the usefulness of image processing of whole tumour sections for identification of proliferation and vascularization hot spots which are strong prognostic factors in breast cancer, and support the close relationship between tumour necrosis and microvessels.