Abnormal angiogenesis is a critical feature of many diseases, including cancers and their precursors. Although the association between prostate carcinogenesis and changes in microvascular architecture is well known, these changes are not well-documented from a quantitative point of view. The present work deals with stereological estimates of the number of quiescent and proliferative endothelial cells, and microvessel length in normal and prostate cancer tissues. Unbiased stereological measurements of numerical densities of proliferating cell nuclear antigen immunostained cells, nonproliferating endothelial cells, caspase 3 immunoreactive endothelial cells, and relative length (length density) of microvessels, were performed in control and cancer specimens. There were no changes in either proliferation or apoptosis in carcinoma endothelial cells. A decrease of endothelial cell density, together with an increase of microvessel length density, were detected in prostate cancer specimens. Therefore, the following conclusions can be drawn: a) The increase of angiogenetic activity in prostate carcinogenesis leads to an increment of the microvascular length; b) The amount of endothelial cells per vascular length decreases in prostate cancer; c) There is no decrease of endothelial apoptosis in cancer microvessels. d) The increase of the length density of microvessels in prostate cancer is not directly associated to an enhancement of the endothelial proliferation; and e) The blood supply of epithelium was similar in both cancerous and normal prostate.

Categorizing biologic signals by analysis of symbolic sequences was employed in the study of prostate microvessels. The estimates of the volume fraction of the vessels immunostained to Factor-VIII was mapped to binary sequences. The distance between sequences was estimated by comparing the rank and frequency of repetitive elements. These measurements were applied to detect whether there are unique microvascular patterns for each individual, and to search for patterns describing prostate microvessels of different conditions. Normal prostate, benign prostate hyperplasia and prostate carcinoma groups were studied. All the specimens were immunostained to F-VIII and strips formed by adjacent quadrats were explored. At each point of the long axis of the strip, the V(V) F-VIII was calculated. These values were processed with the information-based similarity software to estimate the dissimilarity between two space series. The following comparisons were carried out: intrasubject versus intragroup distances; intragroup distances among the groups studied and intergroup distances. The distance defined between a vessels immunostained to Factor-VIII space series and its randomized surrogate was considered as an index of the nonrandomness of the space series. These indices were compared for all the groups. We conclude that (a) The information-based similarity analysis can be adapted to vessels immunostained to Factor-VIII space series from prostate microvessels. (b) There are no unique microvascular patterns associated with each individual. (c) There are characteristic patterns describing the microvessels from normal prostate, benign prostate hyperplasia and carcinoma. (d) This method is able to account for the differences between prostate cancer and both normal and benign prostate conditions, with respect to the microvessel patterns.

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