Table 9. Treatment Options by Stage for Prostate Cancer continued...
Antiandrogen agents used in the treatment of prostate cancer include flutamide and bicalutamide. The pure antiandrogen, flutamide, may cause diarrhea, breast tenderness, and nausea. Case reports show fatal and nonfatal liver toxic effects.
Bicalutamide may cause nausea, breast tenderness, hot flashes, loss of libido, and impotence. (Refer to the PDQ summaries on Gastrointestinal Complications; Nausea and Vomiting; Fever, Sweats, and Hot Flashes; and Sexuality and Reproductive Issues for information.)
The steroidal antiandrogen, megestrol acetate, suppresses androgen production incompletely and is generally not used as initial therapy.
Additional studies that evaluate the effects of various hormone therapies on quality of life are required.
Androgen deprivation therapy
A national Medicare survey of men who had undergone radical prostatectomy for prostate cancer and either had or had not undergone androgen depletion (either medically or surgically induced) showed a decrease with androgen depletion in all seven health-related, quality-of-life measures, including:[Level of evidence: 3iC]
- Impact of cancer and treatment.
- Concern regarding body image.
- Mental health.
- General health.
- Worries about cancer and dying.
Androgen deprivation therapy can cause osteoporosis and bone fractures. In a population-based sample of 50,613 Medicare patients aged 66 years or older followed for a median of 5.1 years, men who had been treated with either a gonadotropin-releasing hormone (GnRH) or orchiectomy had a 19.4% bone fracture rate compared with 12.6% in men who had not received hormone deprivation therapy. The effect was similar in men whether or not they had metastatic bone disease.
Placebo-controlled, randomized trials have shown that treatment of bone loss with bisphosphonates decreases the risk of bone fracture in men receiving androgen deprivation therapy for prostate cancer (RR, 0.80 in a meta-analysis of 15 trials; 95% CI, 0.69–0.94). In the meta-analysis, zoledronate appeared to have the largest effect.
The use of androgen deprivation therapy has also been associated with an increased risk of colorectal cancer.
Evidence (increased risk of colorectal cancer):
- Using the SEER Medicare database, investigators assessed the risk of subsequent colorectal cancer in 107,859 men aged 67 years and older after an initial diagnosis of prostate cancer.
- The rates of colorectal cancer per 1,000 person-years were 6.3 (95% CI, 5.3–7.5) in men who had orchiectomy, 4.4 (95% CI, 4.0–4.9) in men treated with GnRH agonists, and 3.7 (95% CI, 3.5–3.9) in men who had no androgen deprivation.
- In men treated with GnRH agonists, the risk increased with increasing duration of treatment (P for trend = .01).