A Nomogram for Predicting Factors of Persistently Elevated
Prostate-Specific Antigen in Patients Following Robot-Assisted Radical
Prostatectomy
Abstract
Objective:After radical prostatectomy,prostate-specific antigen(PSA)
value measuring ≥0.1ng/ml is defined as persistent PSA(pPSA) and in many
studies,it was found to be associated with aggressive disease and poor
prognosis.Our aim in this study is to point out the pathological and
clinical factors affecting pPSA among the patients who underwent
robot-assisted radical prostatectomy(RARP) in an experienced academic
center and to make a nomogram,predicting pPSA value based on operative
data,useful. Methods:We examined records of 1273 patients who underwent
RARP retrospectively. Preoperative,operative,and postoperative data were
collected.Based on the PSA values (ng/ml) measured after 4-to-8 weeks of
RARP,patients were divided into 2 groups as pPSA group (Group1)(n=97)
with PSA values ≥0.1ng/ml and undetectable PSA group (Group2)(n=778)
with PSA values <0.1ng/ml.Later on,Group1 was further divided
into Group1a (PSA:0.1-0.2ng/ml) and Group 1b (PSA≥0.2ng/ml) to evaluate
biochemical recurrence(BCR). Results:Multivariate logistic regression
analyses of the collected data revealed that
PSA>20ng/ml,operation time,a postoperative international
society of urological pathology (ISUP) grade of ≥4, pT 3-4, and pN were
independently associated with pPSA.According to the results, a nomogram
predicting pPSA was developed(Table 4).By looking at the nomogram pPSA
was found in 98.9% of the cases with a PSA value of ≥20ng/ml, an
operation time of 150 minutes, a postoperative ISUP grade of 4-5, a
positive lymphovascular invasion (LVI) status, pT3-T4, and pN+; while
pPSA was found in 25.5% of the cases with a PSA value of <20
ng/ml, an operation time of 100 minutes, a postoperative ISUP grade of
<4-5, a negative LVI status, pT<3-4, and pN-.The
estimated BCR-free survival time was 16.3 months in Group 1a and 57.0
months in Group2 (p<0.001).Adjuvant treatment ratio was 64.9%
in Group1 and 7.1% in Group2 (p<0.001). Conclusion:For the
patients who underwent RARP,factors associated with aggressive disease
can predict the PSA persistence.To plan our treatment modalities
accurately,an applicable nomogram in daily practice would be useful.