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Prostate Cancer
Volume 2014, Article ID 490315, 5 pages
Research Article

Long-Term Efficacy and Tolerability of Abdominal Once-Yearly Histrelin Acetate Subcutaneous Implants in Patients with Advanced Prostate Cancer

1Research Institute of Deaconess Clinic, 421 Chestnut Street, Evansville, IN 47713, USA
2Department of Urology, Deaconess Clinic, 421 Chestnut Street, Evansville, IN 47713, USA

Received 7 September 2014; Revised 16 November 2014; Accepted 19 November 2014; Published 4 December 2014

Academic Editor: James L. Gulley

Copyright © 2014 Sean Woolen et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Objectives. Long-term assessment of the efficacy and tolerability of subcutaneous abdominal histrelin acetate implants that have been inserted for more than two years. Materials and Methods. Retrospective data collected over a six-year period at a single center from charts of 113 patients who received the subcutaneous abdominal histrelin acetate implant. Results. Following insertion of the first implant, 92.1% and 91.8% of patients had a serum testosterone level of ≤30 ng/dL at 24 and 48 weeks, respectively. Serum testosterone levels remained at <30 ng/dL for 96% of patients at two years and for 100% of patients at 3, 4, and 5 years. The testosterone levels remained significantly less than baseline . Six patients (5.3%) had androgen-independent progression when followed up on the long term, increasing the mean serum PSA at 3, 4, and 5 years to 35.0 µg/L , 30.7 µg/L , and 132.9 µg/L , respectively. The mean serum PSA was significantly greater than baseline during these years . Eight patients (7.1%) experienced minor, but not serious, adverse events from the histrelin acetate. Conclusion. Subcutaneous abdominal histrelin acetate implants are an effective long-term and well-tolerated administration method for treating patients with advanced prostate cancer.