Prevalence and Clinical Significance of Mammalian Targetof Rapamycin Phosphorylation (p-mTOR) and Vascular Endothelial Growth Factor (VEGF) in Clear Cell Carcinoma of the Ovary

Background: To determine the prevalence of mammalian target of rapamycin phosphorylation (p-mTOR)and vascular endothelial growth factor (VEGF) and any correlation with clinical characteristics and prognosisin ovarian clear cell carcinoma patients. Materials and
Method: Seventy four paraffin-embedded specimens ofsuch carcinomas frompatients who underwent surgery, received adjuvant chemotherapy and were followed upat King Chulalongkorn Memorial Hospital during January 2002 to December 2008 were stained with rabbitmonoclonal IgG p-mTOR and rabbit polyclonal IgG VEGF using immunohistochemical methods. Medicalrecords were reviewed and clinical variables were analysed.
Results: The prevalence of positive p-mTOR inovarian clear cell carcinoma was 87.9% and significantly higher in advance-stage than early-stage patients(100% versus 83.6%, P<0.05). Two-year disease free survival and 2-year overall survival in patients withpositive p-mTOR expression were 60% and 69.2% with no differences from patients with negative p-mTORexpression (p>0.05). The prevalence of VEGF expression was 63.5% and significantly higher in chemo-sensitivethan chemo-resistant patients (70.7% versus 37.5%, P<0.05). Two-year disease free survival and 2-year overallsurvival in patients with VEGF expression were 72.3% and 83% respectively which were significantly differentfrom patients with negative VEGF expression (p<0.05 ).
Conclusions: p-mTOR expression in ovarian clear cellcarcinoma was significantly correlated with the stage of disease. VEGF expression was significantly correlatedwith chemosensitivity, and survival. Further studies of related targeted therapy might be promising.