Background: Agent Orange exposure is a known risk factor for the development of prostate cancer; however, few studies have been conducted to evaluate prostate cancer outcomes in this patient population. This study was conducted to determine whether there is a difference in outcomes in those exposed vs not exposed to Agent Orange. The primary outcome was the time to development of castrate-resistant prostate cancer (CRPC) from date of diagnosis.
Methods: The Southern Arizona VA Health Care System electronic medical record was used for this retrospective review. Male veterans with prostate cancer aged 18 to 89 years who were treated with total androgen blockade, including orchiectomy, leuprolide, or goserelin plus bicalutamide, flutamide, or nilutamide between a specified time period, were included. Descriptive statistics were used to analyze demographic data. Student’s t test was utilized to evaluate the primary and secondary outcomes.
Results: A total of 85 veterans were included in this study, 48 with Agent Orange exposure and 37 with no Agent Orange exposure. Most veterans were treated with goserelin (97.6%) and bicalutamide (89.4%). The average age at diagnosis was 63 years in those exposed to Agent Orange and 67.9 years in those not exposed to Agent Orange. The time to development of CRPC was significantly quicker in those exposed vs not exposed to Agent Orange (52.5 mo vs 90.5 mo, P = .04). The average Gleason score at diagnosis was significantly higher in those not exposed to Agent Orange (8.1 vs 7.5, P = .02). Time to nonhormonal therapy, time to bone metastases, and time to death were quicker in those exposed to Agent Orange but were not found to be statistically significant.
Conclusions: Veterans not exposed to Agent Orange were diagnosed with higher Gleason scores than those who were exposed to Agent Orange. The time to development of CRPC was significantly quicker for Agent Orange exposed veterans. A trend toward earlier age of diagnosis, time to nonhormonal therapy, development of bone metastases, and time to death was observed in those exposed to Agent Orange.