Prognostic Significance of Microvessel Density and Mast Cell Density for the Survival of Thai Patients with Primary Colorectal Cancer
Sirisanpang Yodavudh MD*, Siriwan Tangjitgamol MD**, Supalarp Puangsa-art MSc***
Affiliation : * Department of Pathology, Charoenkrung Pracharak Hospital, Bangkok ** Department of Anatomical Pathology and Department of Obstetrics and Gynecology, Bangkok Metropolitan Administration Medical College and Vajira Hospital, Bangkok *** Faculty of Tropical Medicine, Mahidol University, Bangkok
Background : Angiogenesis has been found to be a reliable prognostic indicator for several types of malignancies.
In colorectal cancer, however, there has been controversy as to whether there is a correlation between this
feature and the tumors’ behavior.
Objective : Determine the correlation between microvessel density (MVD) and mast cell density (MCD) in
order to evaluate these factors in terms of their prognostic relevance for primary colorectal carcinoma in Thai
patients.
Material and Method: One hundred and thirty colorectal carcinoma patients diagnosed between January
2002 and December 2004 were identified. Eleven patients were excluded from the present study due to
recurrence of colorectal carcinoma in eight cases whereas pathologic blocks were not found in three cases. One
hundred and nineteen patients met all inclusion criteria and were included in the present study. Representative
paraffin sections obtained by the tissue micro-array technique (9 x 5 arrays per slide) from areas of highest
vascular density (hot spots) were prepared. Sections were immuno-stained by monoclonal anti CD 31 for
microvessel and antibody mast cell tryptase for mast cell detections, respectively. Three readings at different
periods of time under a microscopic examination of high power magnification were examined by a pathologist
who was blinded to clinical data. The highest microvessel and mast cell counts were recorded as MVD and
MCD. Patients were then divided into groups of high and low MVD and high and low MCD by median values
(20.5 and 14.5, respectively). Overall survival of the patients in each group was estimated by the Kaplan-
Meier Method while a multivariate Cox regression backward stepwise analysis was employed to find out
independent prognostic factors.
Results : Significant positive correlation was found to exist between MVD and MCD in the hot spots (R =
0.697, p < 0.0001). Regarding their prognostic role, patients with tumors of low MVD (hypovascular) and low
MCD (low mast cell counts) had significantly longer survival rates than those with hypervascular and high
mast cell counts (p < 0.0001). The Multivariate Cox hazard showed that MVD and distance metastasis of
cancer were independent poor prognostic factors to survival (p = 0.036 and p = 0.024, respectively).The
patients with high MVD (hypervascular) tumors and with presence of distant metastasis had 1.9 and 2.5 times
higher death rates than the corresponding hypovascular and non-metastatic groups, respectively during the
period from January 2002 to September 2007.
Conclusion : Assessment of microvessel density in the invasive front of primary colorectal carcinoma could
serve as useful prognosis tool of primary colorectal carcinoma in Thai patients.
Keywords : Angiogenesis, Anti CD 31, Antibody mast cell tryptase Colorectal cancer, Survival
