The additional value of TGF beta 1 and IL-7 to predict the course of prostate cancer progression

Background: Given the fact that prostate cancer incidence will increase in the coming years, new prognostic biomarkers are needed with regard to the biological aggressiveness of the prostate cancer diagnosed. Since cytokines have been associated with the biology of cancer and its prognosis, we determined whether transforming growth factor beta 1 (TGF beta 1), interleukin-7 (IL-7) receptor and IL-7 levels add additional prognostic information with regard to prostate cancer-specific survival. Materials and methods: Retrospective survival analysis of forty-four prostate cancer patients, that underwent radical prostatectomy, was performed (1989-2001). Age, Gleason score and pre-treatment PSA levels were collected. IL-7, IL-7 receptor and TGF beta 1 levels in prostate cancer tissue were determined by quantitative real-time RT-PCR and their additional prognostic value analyzed with regard to prostate cancer survival. Hazard ratios and their confidence intervals were estimated, and Akaike's information criterion was calculated for model comparison. Results: The predictive ability of a model for prostate cancer survival more than doubled when TGF beta 1 and IL-7 were added to a model containing only the Gleason score and pre-treatment PSA (AIC: 18.1 and AIC: 6.5, respectively). Conclusion: IL-7 and TGF beta 1 are promising markers to indicate those at risk for poor prostate cancer survival. This additional information may be of interest with regard to the biological aggressiveness of the diagnosed prostate cancer, especially for those patients screened for prostate cancer and their considered therapy.