Value of Quantifying the Intratumoral Microvessel Density
Based on Immunohistochemical Detection of PECAM-1 and
vWF in Colorectal Carcinoma from Iraqi Patients
Abstract
counting of newly formed microvessel may prove to be a useful tool in the
early detection of metastatic potential and selection of patients for whom
antiangiogenesis drugs might be beneficial.
Aim of the study: We designed this study to assess the significance of microvessel
quantification in colorectal cancer with respect to different clinicopathological
variables.
Subjects and Methods: forty archived paraffin embedded colorectal
adenocarcinoma samples and their resection margins were enrolled in our study. Thin
paraffin embedded sections (3-5μm thick) of both tumor and resection margins were
prepared for each respective biopsy and were used to detect endothelial cell surface
expression of PECAM-1 and vWF, by and immunohistochemistry technique.
Results: Based on the current outcome, there were significant differences in
microvessel density based on PECAM-1 or vWF immunostaining when each tumor
sample were compared to its respective resection margin (p<0.001and p<0.001,
respectively). In addition, tumors ≥3mm3 in size demonstrated a significant increase
in their microvessel density compared to their counterparts whether PECAM-1 or
vWF immunostaining was applied (p<0.001 and p<0.001, respectively). Moreover,
when tumor samples were analyzed based on their depth of invasion, for intratumoral
microvessel count, exclusively, vWF immunostaining analysis demonstrated
significant differences among the three groups SMP, SE, and OR since the latter came
up with the highest microvessel count (p<0.05). When tumor lymph node metastases
was questioned, exclusively, vWF immunostaining were significantly differentiated
among N0, N1, and N2 groups (p<0.05). Concerning the possible correlations
between the two investigated parameters in respect to various histopathological
variables; both PECAM-1 and vWF immunostaining demonstrated significant
positive correlations in tumor samples (r=0.37), whereas in resection margins, these
correlations were absent. Although PECAM-1 and vWF immunostaining revealed
significant and positive correlations within tumor differentiation (WD: r=0.56, MD:
r=0.57, and PD: r=0.89) as well as with tumor stage (A-B: r=0.39 and C-D: r=0.31),
still, they seem to correlate significantly and exclusively within SE group (r=0.74),
tumors <3mm3 in size (r=0.66), N0 (r=0.36), and N1 (r=0.85) groups. However,
PECAM-1 and vWF immunostaining revealed significant but negative correlation
exclusively within N2 group (r= -0.38).
Conclusions: In conclusion, microvessel count could be useful as a predictor for
tumor metastases in patients with colorectal adenocarcinoma. Possible interpretations
of the current outcome are explained thoroughly in the text.
