Free testosterone in carcinoma of the prostate

Serum concentrations of testosterone (total T), sex hormone‐binding globulin (SHBG), and albumin (A) have been measured, and from these values the free testosterone (free T) has been calculated in the following groups: 50 patients recalled 1‐2 years after prostatectomy for benign prostatic hyperplasia (BPH); 21 patients with BPH at first presentation; and 80 patients with carcinoma of the prostate (CaP) divided into 47 without clinical or radiological evidence of metastases (Mo) and 33 with metastases (M+). The Mo patients were further subdivided by the size of the prostate. Free T showed no change with age in either of the CaP groups. In both of the BPH groups free T fell with age so that in the patients aged 65 or less it was above the mean CaP level and in patients aged 75 or more it was similar to the CaP level. SHBG rose with age so that total testosterone values were a poor guide to free T. Neither presence of metastases nor prostate size in Mo patients was related to marked differences of free T.