Prognostic value of three molecular forms of prostate-specific antigen ratios in patients with prostate adenocarcinoma

Objectives. To investigate whether different molecular forms of prostate-sp ecific antigen (PSA] ratios could provide prognostic information about the stage and grade of prostate cancer, Methods. Serum specimens were examined from 53 patients who underwent radic al prostatectomy for clinically localized prostate cancer and from 94 patie nts diagnosed as having no evidence of malignancy (total PSA between 4.1 an d 20.0 ng/mL). The free/total PSA (FPSA/tPSA) ratio and complexed/total PSA (cPSA/tPSA) ratio in 18 patients with biochemical recurrence were compared with those of patients either without recurrence or with no evidence of ma lignancy. Results. The fPSA/tPSA and cPSA/tPSA ratios differed significantly (P <0.05 ) between patients with organ-confined and those with non-organ-confined di sease, but the tPSA, cPSA, and fPSA levels did not (P >0.05). The median va lues of the fPSA/tPSA ratio in patients with recurrence (7.0%) were signifi cantly lower than in the patients without recurrence (8.9%) or those withou t evidence of malignancy (15.2%) (P = 0.02 and P <0.01, respectively). The median values of the cPSA/tPSA ratio in patients with recurrence (97.4%) we re significantly higher than in patients without recurrence (92.9%) or thos e without evidence of malignancy (86.7%) (P <0.01 and P <0.01, respectively ). At the time of recurrence, 6 (33%) of 18 patients expressed higher fPSA/ tPSA ratios (15% or greater) and lower cPSA/tPSA ratios (less than 95%). Fi ve (83%) of these 6 patients appeared to have aggressive tumors according t o pathologic stage. Conclusions. The fPSA/tPSA and cPSA/tPSA ratios differed significantly amon g the three groups. Thus, a subset of tumors appears to be capable of produ cing high fPSA/tPSA and low cPSA/tPSA ratios at the time of recurrence, and some of these have an aggressive phenotype, Until this latter phenomenon c an be adequately explained, use of these ratios for prognostic purposes sho uld be approached cautiously. UROLOGY 57: 936-942, 2001. (C) 2001, Elsevier Science Inc.