A Study on Expression of Vascular Endothelial Growth Factor in Colorectal Malignancies and its Correlation with Various Clinicopathological Parameters EC01-EC04
Dr. K Ashwini,
Euphoria Apartments, Chitti babu Nagar, 3rd Cross Street, Pallikaranai, Chennai-600100, Tamil Nadu, India.
Introduction: Tumours require neovascularisation for growth and metastasis. Vascular Endothelial Growth Factor (VEGF) is an important regulator of tumour angiogenesis and is associated with metastasis and poor prognosis.
Aim: To assess the expression of VEGF in colorectal cancer by Immunohistochemistry (IHC), to compare it with the clinicopathological parameters and to determine the prognostic significance.
Materials and Methods: We received 147 cases of resected specimens of colorectal carcinomas for histopathological examination in Institute of Pathology, Madras Medical College, Chennai, Tamil Nadu, India, during the period between July 2013 to July 2015. Relevant clinical details of the patients undergoing surgery for colorectal malignancy, regarding age, gender, procedure done were collected. Four µm thick sections were taken from formalin fixed paraffin embedded tissue blocks and stained with haematoxylin and eosin. Among them, 50 random cases were selected for immunohistochemical studies.
Results: The median age at presentation was 60 years. Maximum number of cases occurred in the age group of 51-60 years. There was a male preponderance with 85 cases (57.8%). Left sided tumours were more common (104 cases, 70.7%). About 53.7% cases had tumours less than 5 cm in greatest dimension. Most common gross appearance was ulceroproliferative (92 cases, 62.6%). Most common histopathological subtype was infiltrating adenocarcinoma (123 cases, 83.7%). Most common grade was moderately differentiated (95 cases, 64.6%). Fifty three cases (36.1%) belonged to stage C2, 66 cases (44.9%) had lymph node involvement, 74 cases (50.3%) had lymphatic invasion, 67 cases (45.6%) had vascular invasion and resected margins were free in 143 (97.3%) cases; 4 cases (2.7%) had tumour infiltration in their resected margins. Among the 50 cases on which IHC was done, 9 (18%), 20 (40%) and 21 (42%) cases had 1+, 2+ and 3+ levels of VEGF expression respectively. A total of 21 cases (42%) had strong cytoplasmic staining for VEGF and 15 cases (30%) and 14 cases (28%) showed moderate and weak cytoplasmic VEGF positivity respectively. Statistically significant association was found between VEGF expression in colorectal carcinoma and factors like presence of lymphatic invasion, vascular invasion, lymph node metastasis and stage of the tumour.
Conclusion: VEGF expression in colorectal malignancies seems to be an independent prognostic marker of tumour behavior and may be used to identify patients with unfavourable clinical outcome.