Androgen deprivation therapy for treatment of localized prostate cancer and risk of second primary malignancies

Abstract

Background: While androgen deprivation therapy (ADT) is a common treatment for prostate cancer, little is known regarding its long-term health effects, particularly as it relates to the development of second primary malignancies. Therefore, the goal of this study was to assess the association between ADT use and second primary malignancies among men diagnosed with localized prostate cancer.

Methods: We assessed whether use of ADT (specifically, gonadotropin-releasing hormone agonists) was associated with the development of second primary malignancies in a retrospective cohort of 24,038 men ages more than 18 years who were diagnosed with localized prostate cancer between 1998 and 2007, and followed through 2009. We used proportional hazards regression to estimate the risk of developing a second primary cancer among men who were treated with ADT compared with men who were not.

Results: Men who were treated with ADT were not more likely to develop any second primary malignancy compared with those who were not treated with ADT after adjustment for age, race, date of diagnosis, utilization, clinical stage, Gleason score, and radiation therapy [HR, 1.10; 95% confidence interval (CI), 0.98-1.22)]. Radiotherapy, diabetes, and obesity did not modify the association between ADT use and second primary cancer risk.

Conclusion: Our results suggest that among men with localized prostate cancer, ADT is not associated with an increased risk of second primary malignancies.

Impact: When evaluating the risks and benefits of using ADT as a treatment for localized prostate cancer, considering the risk of second primary malignancies may not be clinically important.