Comparison of different immunohistochemical methods in the assessment of angiogenesis: lack of prognostic value in a group of 77 selected node-negative breast carcinomas.

There is evidence that tumor angiogenesis, as detected by immunohistochemical staining of endothelium, is of prognostic significance in breast cancer. However, little attention has been paid to possible differences between antibodies or to quantitation of the stained microvessels. We compared three endothelial cell antibodies [anti-human von Willebrand factor (anti-VWF, also termed factor VIII), anti-CD31, and anti-CD34] in archival paraffin-embedded specimens. Anti-CD34 and anti-VWF showed better staining performances than anti-CD31, although the staining results with different antibodies were comparable. Two different methods of microvessel quantitation (the highest microvessel count and percentage microvessel area) were evaluated and also showed significant correlation. From a retrospective database (n = 1000), 77 axillary node-negative invasive ductal breast carcinomas were selected on the basis of clinical outcome to maximize the prognostic power of the sample set (37 died due to a metastatic breast carcinoma, 40 showed no recurrence during 8-yr follow-up). Microvessel quantitations were related to flow cytometric DNA ploidy, c-erb-B-2 overexpression, and estrogen receptor status of the tumor. Surprisingly, neither highest microvessel counts nor microvessel area measurements quantitated with anti-CD34 or anti-VWF immunohistochemistry were able to discriminate between favorable and unfavorable outcome patients. Thus, our results suggest that further evidence is still needed on tumor angiogenesis immunohistochemistry before it can be adopted as a prognostic marker in routine, clinical practice.