A Multivariate Analysis of Clinical and Pathological Factors that Predict for Prostate Specific Antigen Failure after Radical Prostatectomy for Prostate Cancer

Abstract

A Cox regression multivariate analysis was done to determine the clinical and pathological indicators that predict for prostate specific antigen (PSA) failure in 347 patients who underwent radical prostatectomy for clinically localized prostate cancer between 1989 and 1993. In the patient subgroups (PSA less than 20 ng./ml. and biopsy Gleason sum 5 to 7 or PSA more than 10 to 20 ng./ml. and biopsy Gleason sum 2 to 4) not classifiable into those at high and low risk for postoperative PSA failure using PSA and biopsy Gleason sum, the status of the seminal vesicles and prostatic capsule on endo-rectal coil magnetic resonance imaging (MRI) allowed for this categorization. Specifically, 2-year actuarial PSA failure rates were 84% versus 23% in patients with and without seminal vesicle invasion, respectively, on MRI (p < 0.0001) and 58% versus 21% in those with and without extracapsular extension, respectively (p = 0.0001). In patients with extracapsular extension but without pathological involvement of the seminal vesicle(s) or poorly differentiated tumors (pathological Gleason sum 8 to 10), the 2-year actuarial PSA failure rates were 50% (margin positive), 28% (margin negative with established extracapsular disease) and 9% (margin negative with focal microscopic extracapsular disease). Therefore, endo-rectal coil MRI showing seminal vesicle invasion or extracapsular extension when the PSA level is less than 20 ng./ml. and the biopsy Gleason sum is 5 to 7 or the PSA level is more than 10 but less than 20 ng./ml. and the biopsy Gleason sum is 2 to 4 predicted for PSA failure. In patients with extracapsular extension who had pathological Gleason sum less than 8 disease with uninvolved seminal vesicles, the margin status and extent of extracapsular disease predicted for PSA failure.

Prognostic Significance of Seminal Vesicle Invasion on the Radical Prostatectomy Specimen

“…This prognostic factor cannot be assessed preoperatively and therefore does not influence the therapeutic management of clinically localized prostatic cancer. SVI is a more significant prognostic factor than tumor volume [2] and may even be independent of the other prognostic factors [2, 6, 16]. Our results confirm these data, as tumor volume, Gleason score, the percentage of positive or doubtful margins and extracapsular extension were not significantly different between the patients with stage pT3b limited and stage pT3b extensive SVI.…”

“…However, to evaluate the own prognosis of SVI, it is essential to exclude N+ patients whose prognosis is pejorative by itself [2]. Then, SVI is a significant independent predictor of progression [2, 6, 16]. …”

Patient Selection for Magnetic Resonance Imaging of Prostate Cancer

“…Using the threshold approach, MR imaging will become more efficient and useful. The threshold approach has some similarity to the approach of d’Amico et al [9, 10]. These authors advised for radiotherapy in case of a high risk of having extracapsular disease and for surgery in case of a low risk.…”

Rising PSA after a Radical Treatment

“…However, PSA levels of >10 ng/ml, and high Gleason grade (>7) are associated with an increased risk of progression as determined by PSA failure (i.e. detectable PSA) after radical prostatectomy [7, 16, 17, 18, 19, 20, 21]. Other pathological risk factors include high clinical stage, positive surgical margins, the presence of extracapsular disease, seminal vesicle invasion, or involvement of pelvic lymph nodes (i.e.…”

“…stage > pT2N0M0) [14, 20, 22]. In addition, in patients with high Gleason grade (≥7), advanced tumour stage (>T1, T2) has been strongly associated with clinical progression [17, 20]. Tumour volume also correlates with both risk of extraprostatic disease and treatment outcomes.…”