The role of the complexed-to-total prostate-specific antigen ratio in predicting the final pathological stage of clinically localized prostate cancer.

Objectives: To examine the association between the complexed-to-total (C:T) prostate-specific antigen (PSA) ratio and prostate cancer pathological stage to assess whether the C:T PSA ratio may predict the final pathological stage in patients with clinically localized prostate cancer.

Patients And Methods: In a prospective study, 101 men with clinically localized prostate cancer underwent a staging pelvic lymphadenectomy and radical prostatectomy. Total PSA (tPSA) and PSA complexed to alpha(1)-antichymotrypsin (cPSA) were measured from preoperative plasma and were correlated with the clinical and pathological stage, and with surgical margin status. The pathological stage was determined as organ-confined (n=59) and extracapsular extension (n=42).

Results: The distributions of tPSA and cPSA were significantly different in men with locally confined and those with locally extended disease. This finding was not observed for the C:T PSA ratio. The area under the receiver operating characteristic (ROC) curve to predict the final pathological stage was significantly greater for tPSA (0.684) and cPSA (0.677) than for the C:T PSA ratio (p<0.032). TPSA (0.685) and cPSA (0.670) also showed areas under the ROC curve greater than that of the C:T PSA ratio (0.542) (p<0.05) for prediction of positive surgical margins.

Conclusions: Our results show that the C:T PSA ratio does not improve the performance of total PSA for predicting the final pathological stage in patients with clinically localized prostate cancer.