Adjuvant hormone therapy after radiation or surgery for localized or locally advanced prostate cancer

Abstract

Prostate cancer is being diagnosed at an earlier age and earlier disease stage than previously and increasing numbers of relatively young men are receiving potentially curative radical prostatectomy or radiotherapy for early prostate cancer. Although many of these men have an excellent outcome, a significant proportion subsequently experience disease recurrence or cancer-related death. Men with unfavorable tumor characteristics at the time of radical prostatectomy or radiotherapy are particularly at high risk of experiencing disease recurrence. One strategy to improve outcome for these men is adjuvant hormone therapy (hormone therapy administered immediately after therapy of primary curative intent). Surgical castration (bilateral orchiectomy), medical castration using the luteinizing hormone-releasing hormone (LHRH) agonist goserelin, and antiandrogen monotherapy have been investigated as adjuvant hormone therapy to radical prostatectomy and radiotherapy, and each therapy has demonstrated clinical benefits because of a significant improvement in disease-free survival. Furthermore, data are available to indicate that adjuvant hormone therapy achieved by goserelin or bilateral orchiectomy improves overall survival, particularly in men at high risk of progression. Because the effects of LHRH agonists are reversible, they provide a more acceptable method of adjuvant therapy compared to bilateral orchiectomy, particularly in the adjuvant setting, and are preferred by patients. However, the adverse effects on quality of life, in particular on sexual interest and function and bone mineral density, may limit the use of LHRH agonists in some patients. However, these parameters are maintained with nonsteroidal antiandrogens. The first data from the Early Prostate Cancer program indicate that adjuvant bicalutamide 150 mg is associated with a significant improvement in progression-free survival after radical prostatectomy or radiotherapy. Gynecomastia and breast pain are the most common side effects associated with bicalutamide therapy. Medical or surgical castration in combination with an antiandrogen (combined androgen blockade) is another option for use as an adjuvant hormone therapy. However, no study has reported on the use of combined androgen blockade in this setting. Adjuvant hormone therapy provides clinicians with another treatment option for patients with early prostate cancer and unfavorable tumor characteristics.