Long-term unresolved inflammation has been suggested as a risk factor for the development of various malignancies. The goal of this study was to examine whether the expression of interleukin (IL)-16, a proinflammatory cytokine, changes in association with ovarian cancer (OVCA) development.

In an exploratory study, changes in IL-16 expression in association with OVCA development and progression were determined using ovarian tissues and serum samples from healthy subjects (n = 10) and patients with benign (n = 10) and malignant ovarian tumors at early (n = 8) and late (n = 20) stages. In the prospective study, laying hens, a preclinical model of spontaneous OVCA, were monitored (n = 200) for 45 weeks with serum samples collected at 15-week interval. Changes in serum levels of IL-16 relative to OVCA development were examined.

The frequency of IL-16–expressing cells increased significantly in patients with OVCA (P < .001) compared to healthy subjects and patients with benign ovarian tumors. The concentration of serum IL-16 was higher in patients with benign tumors (P < .05) than in healthy subjects and increased further in patients with early-stage (P < .05) and late-stage (P < .03) OVCA. Increase in tissue expression and serum levels of IL-16 in patients with early and late stages of OVCA were positively correlated with the increase in ovarian tumor–associated microvessels. Prospective monitoring showed that serum levels of IL-16 increase significantly (P < .002) even before ovarian tumors become grossly detectable in hens.

This study showed that tissue expression and serum levels of IL-16 increase in association with malignant ovarian tumor development and progression.