Background: Several cytokines have been associated with immune regulation and prognosis in ovarian cancer. CD4+CD25+ Tregs and CD3+CD56+ NK-like T cells are involved in the immune response against the tumor. We have investigated the association of cytokines in the ascites from patients with ovarian cancer with these populations, the platinum resistance and the prognosis of these patients.
Patients and methods: Ascites from 64 patients with ovarian cancer was analysed. Forty-two patients were studied at diagnosis (FIGO stage III in 40 cases) and were treated with cytoreductive surgery and platinum-based chemotherapy. Ascites from 9 patients with cirrhosis was used as control. Vascular endothelial growth factor (VEGF), tumor necrosis factor-alpha (TNFalpha), interferon-gamma (IFNgamma), interleukin-10 (IL10) and interleukin-12 (IL12) in ascites and serum were measured by enzyme-linked immunosorbent assay (ELISA), while lymphocytic populations were studied with three-colour flow cytometry.
Results: VEGF ascites levels were inversely correlated with CD3+CD56+ cells (rho=-0.316, p=0.012), while a similar correlation was observed between TNFalpha ascites levels and CD4+CD25+(hi) cells (rho=-0.332, p=0.041). Among patients receiving first-line chemotherapy, VEGF levels <1900 pg/ml and TNFalpha levels >35 pg/ml were associated with platinum sensitivity (p=0.021 and p=0.028, respectively) and improved progression-free survival (PFS) (p=0.007 and p=0.045, respectively). Low VEGF levels were also associated with improved overall survival (p=0.026).
Conclusion: VEGF and TNFalpha ascites levels are associated with prognosis in advanced ovarian cancer. Their prognostic significance may be due to their association with immunologically important populations, namely the NK T-like CD3+CD56+ cells and the Tregs CD4+CD25+(hi) cells.