An evaluation of the microvessel density (MVD) as a prognostic biomarker in adenocarcinoma of prostate

Background: To assess the angiogenetic activity in tumour areas by measuring the microvessel density (MVD) with immunohistochemistry endothelial marker CD31 and to investigate if a correlation exists between MVD and the Gleason grade groups in biopsy and prostatectomy samples of prostate cancer.

Method: The study included 20 prostate biopsies followed by the prostatectomy samples. Based on the previous pathologic reports, samples were categorised into four groups: Grade group 1 (Gleason score = 6), Grade group 2 (Gleason score 3 + 4 = 7), Grade group 3 (Gleason score 4 + 3 = 7), Grade group 4/5 (Gleason score ≥8). Tissue sections from biopsy and prostatectomy samples were stained using immunohistochemistry technique with CD31 antibody. MVD was counted under the light microscope at ×200 magnification in three hot spot areas and the mean counts were compared.

Results: Biopsy samples MVD: Grade group 1–18 ± 6.3, Grade group 2–25 ± 5.8, Grade group 3–37 ± 10.7, Grade group 4/5–27 ± 13.5.

Prostatectomy samples MVD: Grade group 1–59 ± 25.6, Grade group 2–59 ± 29.4, Grade group 3–87 ± 8.8, Grade group 4/5–59 ± 9.4.

Conclusion: We have demonstrated angiogenesis by manual counting. For both biopsy and prostatectomy samples, there was a very small difference between the Grade groups 1 and 2, but the Grade group 3 showed a higher MVD, whereas the Grade group 4/5 showed decreased MVD. From the results, the manual counting of vessels can be used as an assay to monitor the angiogenesis activity in Groups 1, 2 and 3. Additionally, our findings suggest, that the MVD assay using CD31 biomarker potentially could be included in the prognostic panel in prostate biopsy samples, when patients are inappropriate candidates for the surgery.