Diagnostic value of vascular endothelial growth factor (VEGF) levels in gastrointestinal cancers with ascites – A cross sectional study

Introduction: Malignant ascites is suggestive of peritoneal carcinomatosis. The distinction between a malignant and non-malignant ascites in a patient with malignancy is important as it alters the management and prognosis. Current diagnostic methods are imaging, cytology and diagnostic laparoscopy, all of which have low sensitivities. The Vascular Endothelial Growth Factor (VEGF) is essential for tumour growth and hence, ascitic VEGF levels can be a method of diagnosis of malignant ascites. Methods This cross-sectional study was conducted in patients with gastrointestinal malignancies and ascites. The calculated sample size was 68 patients, who were divided into those who were truly positive and negative for malignant ascites based on a composite gold standard, comprising of cytology, CECT and laparoscopy. The ascitic VEGF levels in these patients were compared. Results A total of 84 patients were enrolled, out of which 60.71% were found to have truly malignant ascites. It was found that greater the volume of ascites, greater the statistical likelihood of finding truly malignant ascites. The ascitic VEGF levels had a non-normal distribution, with the median value being 783.64 and 41.12 pg/mL for malignant and non-malignant ascites(p < 0.001). Using a ROC Curve, a cut-off of 83.68pg/mL was obtained, with a sensitivity of 100% and a specificity of 93.94%. Conclusion This study demonstrates that ascitic VEGF levels is significantly elevated in patients with gastrointestinal malignancies and malignant ascites and hence can reliably be used for diagnosing malignant ascites. This study also shows that massive ascites and well-differentiated tumours have a higher rate of peritoneal carcinomatosis.