Background: Cytokines are involved in the pathogenesis of different gynecological malignancies. Additionally, they stimulate the spread of cancer cells. Interleukin 10 (IL-10) was described as a pro-inflammatory factor and seems to be implicated in the immune deficiency of patients with cancer. The aim of this study was to determine whether the level of IL-10 in the serum and ascites was associated with the prognosis of advanced ovarian cancer (OC).
Materials and methods: In a prospective study from 2001 to 2003, the concentration of IL-10 in the serum and ascites of 117 consecutive patients with advanced OC and 30 women with benign disease who underwent surgery as a control group (CG), was analyzed by the enzyme-linked immunosorbent assay. For statistical analyses, the Chi-square test by Pearson, Fisher's exact test and the Mann-Whitney test were employed.
Results: The concentrations of IL-10 were a median of 9.87 pg/ml (range 7.8 to 500 pg/ml) in the serum and a median of 43.70 pg/ml (range 7.8 to 389.4 pg/ml) in the ascites of the OC patients. The IL-10 level in the sera of the CG was a median of 7.80 pg/ml (range 7.8 to 62.8 pg/ml) and 18.34 pg/ml (range 7.8 to 88.72 pg/ml) in the peritoneal fluid. A significant association was observed between the IL-10 serum levels (p = 0.003) and levels in the peritoneal fluid (p = 0.03) in both OC and the CG. IL-10 was significantly more expressed in the ascites of patients with OC than in their sera (p = 0.003). The concentration of IL-10 correlated significantly with proven conventional prognostic factors such as recurrence status (p = 0.005), volume of (ascites, p < 0.001, serum, p = 0.03), histological grading (p = 0.053) and histological type (ascites p = 0.005/ serum p = 0.09). There was no significant correlation between the levels of lL-10 in the ascites and/or serum and FIGO stage, residual tumor mass or age. The cut-off value of 8.0 pg/ml for IL-10 serum levels had a positive predictive value of 84% (95% CI: 76-91) and a negative predictive value of 29% (95% CI: 16-41), with a specificity and sensibility of 47% (95% CI: 29-65) and 70% (95% CI: 62-78), respectively.
Conclusion: Due to the fact that the levels of IL-10 were significantly higher in the ascites and serum of OC patients than in those of the CG, IL-10 may play an important immunosuppressive role in the pathogenesis of OC. The association between high IL-10 levels in ascites and serum and the histological type of the tumor, as well as between the levels in the peritoneal cavity and grading, suggest that IL-10 could be a prognostic factor in OC.