|A Conversation with Dr. Jeri Kim |
Assistant Professor in the Department of Genitourinary Medical Oncology at The University of Texas M. D. Anderson Cancer Center
What makes this group of studies important to the broader research effort aimed at prostate cancer prevention?
The pre-prostatectomy model is important in studying the biological effects of chemopreventive agents in tissue. We have access to the entire organ and therefore the ability to study in detail the effects of a drug in different zones (areas) of the prostate. We can also study differential effects of a drug in normal tissue, in prostate intraepithelial neoplasia, and in prostate cancer. Since most prostate cancer occurs in the peripheral zone of the prostate, we are interested in effects there. If a drug of interest has no effect in the peripheral zone, it may not be useful.
How would you describe the novelty of searching for cancer prevention agents using the pre-prostatectomy model?
We are using the pre-prostatectomy model to study the biological effects of such agents as selenium and vitamin E to complement the national effort already under way to determine whether these agents can prevent prostate cancer. In this process, we will not only confirm the known mechanisms of action of these agents in prostate tissue, but we will also discover new mechanisms of action that may serve as new targets for chemoprevention or therapy for prostate cancer. Additionally, there needs to be a close collaboration among investigators from the laboratory and the clinic so new insights gained from in vitro and in vivo studies can be confirmed in the clinic and the questions raised from the clinic can be investigated in the laboratory.
What are the advantages and disadvantages of using this pre-prostatectomy cohort for studying novel agents such as selenium and vitamin E?
I think the major advantage, as mentioned, is the fact that we have access to the entire organ for correlative studies. On the other hand, there are disadvantages. Recruiting patients to a pre-postatectomy study using chemopreventive agents is difficult because patients who already have prostate cancer may not directly benefit from these agents and may be reluctant to participate in the study. Also, because chemoprevention studies in prostate cancer use biopsy as an end point (just as in the Prostate Cancer Prevention Trial, or PCPT), biomarkers studied in sections of the prostatectomy specimen will be compared with biopsy specimens of the prostate.