This document summarizes preliminary results from an observational study on using [-2]proPSA (p2PSA) to predict early biochemical recurrence after radical prostatectomy. The study enrolled 64 patients over 15 months to compare p2PSA to total PSA (tPSA) in detecting recurrence. After 12 months, p2PSA detected recurrence in 16 patients (48.5%) compared to only 2 (6.1%) by tPSA. All patients with tPSA recurrence also had elevated p2PSA. p2PSA detected recurrence earlier with a mean of 9 months compared to 12.4 months for tPSA. The findings suggest p2PSA may be more sensitive than

1. MP63-06
[-2]PROPSA FOR PREDICTION OF EARLY BIOCHEMICAL
RECURRENCE AFTER RADICAL PROSTATECTOMY:
PRELIMINARY RESULTS FROM AN OBSERVATIONAL COHORT
STUDY
Massimo Lazzeri*, Ferruccio Ceriotti, NicoloMaria Buffi,
Giovanni Lughezzani, Alessandro Larcher, Nicola Fossati,
Giuliana Lista, Alberto Abrate, Paolo Dell’Oglio, Francesco Mistretta,
Marina Pontillo, Milan, Italy; Vittorio Bini, Perugia, Italy;
Giorgio Guazzoni, Milan, Italy
INTRODUCTION AND OBJECTIVES: Although radical prosta-
tectomy (RP) offers a high overall cancer control rate, even in appropri-
ately selected men, up to a third undergoing RP will experience a rising
serum PSA (biochemical recurrence e BCR). The objective of the study is
to test the hypothesis that serum isoform [-2]proPSA (p2PSA) detects
BCR earlier than current reference standard test (tPSA) in patients who
underwent RP for localised prostate cancer (PCa).
METHODS: The current study is an observational, on-going,
prospective, cohort study in a contemporary cohort of consecutive
patients with localized PCa (pT2-3/N0), who had undergone RP.
Biochemical follow-up consisted of a blood sample drawn after 3-6-12
months and then every 6 months in the following two years. The primary
outcome is to determine whether or not elevation of p2PSA or kinetics in
rising of p2PSA significantly outperform the tPSA driven BCR defined
as two consecutive values of tPSA 0.2 ng/mL. Secondary outcome is
to determine whether or not results are consisting with different path-
ological outcome (stage, grade and margin status). The statistical
analysis includes both Kaplan-Meier survival analysis and the McNemar
test for comparison of paired frequencies, considering 0.8 pg/ml the
optimal threshold for p2PSA driven BCR.
RESULTS: From April 2012 to June 2013, a total of 64 patients
were enrolled in the study. The median follow-up was 10.9 months.
Over 33 patients with at least 1 year follow-up, 2 (6.1%) tPSA and 16
(48.5%) p2PSA BCR were respectively detected (p0.0001). All the
patients with tPSA BCR had a p2PSA 0.8 pg/ml. The frequencies (%)
of p2PSA positive subjects ( 0.8 pg/ml) were significantly higher than
frequencies of positive subjects identified with tPSA cut-off at 3, 6 and
12 months: 15/64 (23.4%) vs. 4/64 (6.3%), p0.0001; 18/52 (34.6%) vs.
1/52 (1.9%), p0.0001; 16/33 (48.5%) vs. 2/33 (6.1%), p0.0001,
respectively. The mean survival biochemical relapse-free time was 9.0
(95%C.I.: 7.9-10.1) months determined with p2PSA increase, and 12.4
(95%C.I.: 11.8-12.9) months recorded instead with tPSA increase,
(p0.05). Patients with pT2c-GS3+4/4+3-R1 and pT3a-R0/1 could be
considered the target categories, which would benefit more from
the study.
CONCLUSIONS: The current preliminary findings suggest that
p2PSA could be more sensitive than tPSA in detecting early BCR.
Extending observational time, increasing sample size and stratifying
patients into significant or indolent BCR are mandatory before consid-
ering p2PSA for clinical practice purposes.
Source of Funding: None
MP63-07
PROSTATE VOLUME MEASUREMENTS CAN LEAD TO LARGE
ADJUSTMENTS IN THE PROBABILITY A BIOPSY FINDS
PROSTATE CANCER OBTAINED FROM RISK CALCULATORS
Stacy Loeb*, New York, NY; Lori Rawson, Roy MacKintosh, Reno, NV;
Christopher Morrell, Baltimore, MD; Stephen Van Den Eeden, Oakland,
CA; Thomas Neville, Incline Village, NV
INTRODUCTION AND OBJECTIVES: PSA screening remains
controversial due to the downstream risk of prostate biopsy and over
diagnosis of insignificant cancer. Many of these issues stem from the
fact that total PSA alone has limited specificity. As such, many guide-
lines now emphasize a multivariable approach to prostate cancer
screening using PSA along with other predictive variables for improved
results. Although there are numerous nomograms available for this
purpose, many do not take prostate volume into consideration. The
objective of our study was to determine the incremental value of
including prostate volume for estimating the risk of prostate cancer
on biopsy.
METHODS: Utilizing the Baltimore Longitudinal Study of Aging,
we examined 204 men ages 45-75 with no history of prostate cancer
with data on age, PSA and MRI-determined prostate volume (n¼1602
data points). Probability distributions of PSA were estimated by age with
and without the additional information on prostate volume. For example,
the probability of finding cancer on prostate biopsy for a man at age 65
with a PSA of 4 ng/ml was estimated for no knowledge of prostate
volume and for various measurements of prostate volume. Statistical
analysis was used to determine the change in cancer probability on
biopsy based upon volume-adjusted probabilities.
RESULTS: The probability of finding prostate cancer on biopsy
at any given age and PSA level varied based upon prostate volume.
Specifically, volume-adjusted probabilities of prostate cancer increased
for men with prostate volumes below roughly 36cc, and decreased for
larger volumes. For example, each curve on Figure 1 shows one initial
probability from a risk calculator. For that initial probability, it then plots
the change in probability as adjusted for prostate volume.
CONCLUSIONS: Men with small to normal prostate volumes
(36cc), have volume-adjusted probabilities of cancer detection upon
biopsy that may exceed the initial probabilities from risk calculators. By
contrast, men with large prostates have a lower risk of prostate cancer
detection upon biopsy at a given age and PSA level. Prostate volume
estimation is an underutilized and important addition to prostate cancer
nomograms and risk stratification tools.
Source of Funding: NONE
MP63-08
LOW SERUM DIHYDROTESTOSTERONE IS A POWERFUL
PREDICTOR OF GLEASON SCORE 7-10 OF PROSTATE
CANCER IN MEN WITH PROSTATE-SPECIFIC ANTIGEN LEVELS
OF 3-10NG/ML
Yasuhide Miyoshi*, Susumu Umemoto, Hiroji Uemura, Yokohama,
Japan; Yasuhiro Shibata, Maebashi, Japan; Seijiro Honma, Kawasaki,
Japan; Yoshinobu Kubota, Yokohama, Japan
INTRODUCTION AND OBJECTIVES: There has been no
consensus on the role of androgen concentrations in prostate cancer
detection in men with prostate-specific antigen (PSA) levels of 3-10
ng/mL. In this study, testosterone (T) and dihydrotestosterone (DHT)
Vol. 191, No. 4S, Supplement, Monday, May 19, 2014 THE JOURNAL OF UROLOGYâ e711