Correlation of Serum VEGF Levels with Clinical Stage, Therapy Efficacy, Tumor Metastasis and Patient Survival in Ovarian Cancer

Abstract

Vascular endothelial growth factor (VEGF) has been shown to play an important role in tumor growth and progression. However, the clinical implications of VEGF expression in ovarian tumors are not fully understood. We therefore investigated the serum level of VEGF in patients with ovarian tumors and explored the potential use of VEGF as a tumor marker for diagnosis, treatment and prognosis of human ovarian cancer. The serum VEGF (sVEGF) levels in 120 patients with ovarian carcinoma, 25 patients with benign ovarian tumor and 90 healthy female blood donors were measured by an enzyme-linked immunosorbent assay in this study. We also determined the levels of sVEGF in patients with epithelial ovarian cancer before and after surgery. Our results showed that: (i) ovarian cancer patients had significantly higher levels of sVEGF compared to those of patients with benign ovarian tumor or those of healthy individuals. As a cut-off at 100 pg/ml, the sensitivity and specificity of sVEGF levels for diagnosing ovarian carcinoma were 77.1% and 87%, respectively. (ii) sVEGF levels were markedly elevated in patients with advanced stage or poorly-differentiated ovarian cancer, as well as in those with more ascites (>500 ml), as compared to patients with early stage and well-differentiated ovarian cancer, or those with less ascites (<500 ml). However, there was no significant difference in sVEGF levels among different pathological subtypes of ovarian carcinoma. (iii) The post-operative sVEGF levels were significantly lower than the pre-operative sVEGF levels. (iv) We measured significantly higher levels of sVEGF in patients with metastasis as compared to patients lacking metastasis. Lastly, (v) the average survival-time in patients with higher levels of sVEGF (>100 pg/ml) was 28 months, while the average survival-time in patients with lower levels of sVEGF (<100 pg/ml) was 35 months, indicating that the elevations in sVEGF level are correlated with patient survival and tumor metastasis in ovarian carcinoma. These data suggest that VEGF may be a useful serological biomarker for clinical diagnosis and prognosis of ovarian cancer, for follow-up of ovarian tumor metastasis and for monitoring the efficacy of therapy in patients with ovarian carcinomas.