A 69-year-old man comes to the physician because of a 2-month history of urinary urgency, nocturia, and progressive pain in his lower back. The pain is worse at night and does not respond to ibuprofen. Rectal examination shows an enlarged, asymmetric prostate with a nodular surface. Prostate-specific antigen concentration is 9 ng/ml (N

Question

A 69-year-old man comes to the physician because of a 2-month history of urinary urgency, nocturia, and progressive pain in his lower back. The pain is worse at night and does not respond to ibuprofen. Rectal examination shows an enlarged, asymmetric prostate with a nodular surface. Prostate-specific antigen concentration is 9 ng/ml (N < 4). A biopsy of the prostate shows a high-grade adenocarcinoma. Flutamide was then added to his initial therapy and led to significant pain relief and a decrease in the size of the primary tumor.  Which of the following mechanisms is the best explanation for the effects of flutamide in this patient?

Quizplus · Accepted Answer

Eductional Objective: Flutamide is a nonsteroidal competitive inhibitor for the binding of dihydrotestosterone and testosterone to the androgen receptor (i.e., an antiandrogen). The inhibition of androgen receptor stimulation prevents the growth of prostate cancer and its metastases.

A 69-Year-Old Man Comes to the Physician Because of a 2-Month