Cataracts among elderly prostate cancer patients receiving androgen deprivation therapy (ADT) in the United States.

Abstract

e15068 Background: Approximately one-third of all prostate cancer patients receive some form of ADT. Side effects have been reported in patients receiving ADT, including metabolic abnormalities such as weight gain, dyslipidemia and insulin resistance. As cataracts have been linked to these components of the metabolic syndrome, an increased risk of cataract may be another adverse consequence of ADT use. Methods: Using data from the Surveillance, Epidemiology, and End Results (SEER)-Medicare linked database, we estimated the risk of cataract associated with ADT use among 64,988 prostate cancer patients aged 66 years and older diagnosed between 1996 and 2003 (with claims through 2006). Exposure to ADT was defined as having received at least one dose of a gonadotropin-releasing hormone (GnRH) agonist or orchiectomy within the first 6 months of prostate cancer diagnosis. The outcome measure was a first claim of either cataract diagnosis or surgery identified in Medicare claim files using the appropriate ICD-9 or CPT-codes. A Cox proportional hazards model was used to generate a hazard ratio (HR) associated with type of ADT. Results: Approximately 50% of prostate cancer patients had received some form of ADT within 6 months of diagnosis: 1.5% underwent an orchiectomy and 47.2% received GnRH agonists. Overall, ADT use was associated with a small increase in cataract risk (adjusted HR = 1.11, 95% CI=1.08-1.15). Cataract risk associated with GnRH agonist treatment was similar for patients with no cataract history prior to prostate cancer diagnosis (HR=1.14, 95% CI=1.10-1.19) and patients with a history of cataract (HR=1.08, 95% CI=1.03-1.12). Alternatively, orchiectomy was associated with cataract development only among patients with no prior history of cataract (HR=1.18, 95% CI=1.00-1.39). Conclusions: This is the first systematic investigation of the association between ADT and cataract. Our results suggest a modest elevation in risk of cataract among ADT users. However, the estimated risk is small and could be due to uncontrolled bias. Further study, preferably prospective in design, is needed to provide additional evidence to support or refute these findings. Author Disclosure Employment or Leadership Position Consultant or Advisory Role Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration Amgen, MedImmune Amgen Amgen Amgen