Comparative analysis of microvessel density quantified through the immunohistochemistry expression of CD34 and CD105 in rectal cancer.

Endothelial cells are highlighted using a variety of endothelial markers. One of the best known markers is CD34, a surface antigen. The most used immunohistochemical marker for identification of activated endothelial cells is CD105. We chose to compare these two markers in order to evaluate angiogenesis of the rectal cancers by determining the microvessel density (MVD). Our study included 31 patients with rectal cancer between 2010-2014, who underwent rectal resection at Arad and Timisoara Counties Hospitals, Romania. We used MVD quantification by highlighting the tumor blood vessels with two different endothelial markers using the immunohistochemical protocols. The CD34 evaluation of MVD was 37 vessels/field/×200 peritumoral (PT), compared with normal rectal mucosa with 17 vessels/field/×200. Intra-tumoral (IT) MVD for CD34 positive vessels was between 7 and 120 vessels/field/×200. Average IT MVD CD105+ was 13.7 vessels/field/×200, the PT MVD CD105+ was 10 vessels/field/×200. Usually, IT MVD CD105 is smaller than PT MVD CD105, a pattern that was not respected in our study. There was a statistical significant correlation between IT MVD CD34 and PT MVD CD34 with p=0.008, also IT MVD CD34 and IT MVD CD105 with p=0.009, PT MVD CD34 with PT MVD CD105, p=0.001. PT MVD CD34 had a statistical significant correlation with T, p=0.004. IT MVD CD105 associated with T, p=0.004, and with N, p=0.004. The evaluation of both CD34-CD105 showed the role of angiogenesis in the cancer proliferation and local spread, the angiogenesis level being maintained high even in the advanced stages of the disease. There was observed a difference between the intratumoral and peritumoral MVD, the study of this difference possibly leading to a better assessment of prognosis and adjusted therapies in the future.