SUO 2017: The Effect of Agent Orange Exposure on Treatment Choice
The authors used data from the Veteran Affairs Prostate Cancer Registry, identifying 1,362 patients with NCCN low- and intermediate-risk prostate cancer (PSA < 20 ng/mL, ≤cT2, Gleason ≤7) diagnosed between 2003 and 2014. Using logistic regression, factors including age, clinical stage, Gleason Score, Agent Orange exposure, Charlson comorbidity index (CCI) and PSA at time of diagnosis were used to assess the risk of choosing active surveillance (AS) versus prostate cancer-directed therapy. Of patients who chose prostate cancer-directed treatment, the authors used the same set of variables to identify the predictors of choosing radical prostatectomy versus radiation ± hormonal therapy.
Among these 1,362 patients with low- or intermediate-risk prostate cancer, 621 (46%) patients chose AS. Of 741 patients who chose prostate cancer-directed treatment, 451 (60%) patients underwent radical prostatectomy. In multivariate analysis, Agent Orange exposure was not associated with selection of prostate cancer-directed therapy as compared to AS (p=0.09). However, Agent Orange exposure was associated with 40% less chance (OR 0.60, 95%CI 0.4-0.9) of receiving radiation ± hormonal therapy versus radical prostatectomy (p=0.02).
In summary, Agent Orange exposure was not associated with a reduced rate of acceptance of AS for low- and intermediate-risk PC when adjusting for tumor and demographic factors. Potential biases about the effect of Agent Orange exposure on medical decision making in prostate cancer do not appear to reduce the rate of acceptance of AS in appropriate patients. However, Agent Orange exposure seems to affect the choice of intervention in favor of radical prostatectomy in this population.
References:
1. Ansbaugh N, Shannon J, Mori M, et al. Agent Orange as a risk factor for high-grade prostate cancer. Cancer 2013;119(13):2399-2404.
Presented by: Hamed Ahmadi, MD
Co-Authors: Wesley Stoller BS, Ryan Kopp MD, Michael Conlin MD and Mark Garzotto MD
Affiliation: Oregon Health & Science University, Portland, OR
Written by: Zachary Klaassen, MD, Society of Urologic Oncology Fellow, University of Toronto, Princess Margaret Cancer Centre @zklaassen_md at the 18th Annual Meeting of the Society of Urologic Oncology, November 20-December 1, 2017 – Washington, DC