High IL-23+ cells infiltration correlates with worse clinical outcomes and abiraterone effectiveness in patients with prostate cancer

Individualized treatment of prostate cancer depends on an accurate stratification of patients who are sensitive to various treatments. Interleukin-23 (IL-23) was reported to play a significant role in prostate cancer. Here, we aimed to explore the clinical value of IL-23-secreting (IL-23+) cells in prostate cancer patients. We evaluated interleukin-23A (IL-23A) expression in The Cancer Genome Atlas database and retrospectively enrolled 179 treatment-naïve metastatic prostate cancer patients diagnosed in our institute between June 2012 and December 2014. IL-23+ cells were stained and evaluated via immunohistochemistry. Further, survival and multivariate Cox regression analyses were conducted to explore the prognostic value of IL-23+ cells. We found that IL-23A expression correlated with disease progression, while IL-23+ cells were clearly stained within prostate cancer tissue. Patients with higher Gleason scores and multiple metastatic lesions tended to have more IL-23+ cell infiltration. Further analyses showed that patients with higher levels of IL-23+ cells had significantly worse overall survival (hazard ratio [HR] = 2.996, 95% confidence interval [95% CI]: 1.812–4.955; P = 0.001) and a higher risk of developing castration resistance (HR = 2.725, 95% CI: 1.865–3.981; P = 0.001). Moreover, subgroup analyses showed that when patients progressed to a castration-resistant status, the prognostic value of IL-23+ cells was observed only in patients treated with abiraterone instead of docetaxel. Therefore, we showed that high IL-23+ cell infiltration is an independent prognosticator in patients with metastatic prostate cancer. IL-23+ cell infiltration may correlate with abiraterone effectiveness in castration-resistant prostate cancer patients.