VEGF Levels in Women with Gynaecological Cancers
Background: High blood levels of Vascular Endothelial Growth Factor (VEGF) have been reported in patients with gynaecological cancer and have been correlated with advanced disease and poor outcome. However, results are few and varied and most studies used single measurements. There is also debate as to whether serum or plasma measurement reflects circulating VEGF. Aims: To describe and compare the properties of serum and plasma VEGF in women with ovarian and endometrial cancer. To clarify their relationships with platelets and investigate their correlation with disease activity. In addition we wished to investigate the effect of green tea (which has known angiogenic activities) consumption on blood VEGF. Methods: VEGF was measured by ELISA method in serum and plasma in women with gynaecological cancers. Serial measurements were taken in women with endometrial or ovarian cancer, and in women without cancer. Blood samples were also obtained in women before and after surgery for endometrial or ovarian cancer. The association of platelets and CRP to blood VEGF was determined using combined data. In addition, the effect of green tea on serum and plasma VEGF was evaluated in women with persistent cancer who were treated with 6 days oral green tea extracts equivalent of 900mg EGCG daily. Results: The median week to week coefficient of variance (CV) was approximately 10% for serum and 30% for plasma VEGF. There was significant overlap in VEGF concentrations between women with disease and control. Serum VEGF but not plasma correlated with platelets and CRP and there appeared to be a multiplicative relationship between plasma and serum VEGF. There was no significant difference between blood VEGF before and after surgery. Short term green tea extracts were safe but did not lead to significant changes in blood VEGF. Conclusion: Blood VEGF measurements are elevated in some women with advanced gynaecological cancers, single measurements appear a reliable indication of the levels in different patients but levels did not appear to be a good indicator of change in tumour load within individual patients. Serum VEGF varied with platelet count and CRP and may be reflection of the systemic response to advanced malignancy. It is not clear to what extent plasma VEGF reflects circulating VEGF. We did not see a reduction in blood VEGF after consumption of green tea. Future studies are needed to assess to what extent plasma VEGF reflect circulating VEGF, and the effect of green tea extracts.
Advisor: Sykes, Peter; Evans, John
Degree Name: Bachelor of Medical Science with Honours
Degree Discipline: Department of Obstetrics and Gynaecology, University of Otago Christchurch
Publisher: University of Otago
Keywords: serum VEGF; ovarian cancer; endometrial cancer; green tea; EGCG; plasma VEGF; circulating VEGF
Research Type: Thesis