Login to Access Video or Poster Abstract: MP53-09
Sources of Funding: None

Introduction

Seminal vesicle invasion (SVI) is a risk factor for poor oncologic outcome in patients with prostate cancer (PC). The total number of lymph nodes removed (lymph node yield [LNY]) during radical prostatectomy (RP) has been reported to have a diagnostic and therapeutic benefit in patients with clinically localized disease regardless of node positivity. This benefit in patients with SVI has not been previously assessed.

Methods

We identified 221 patients retrospectively from two medical centers who underwent RP without adjuvant treatment between 1990-2015 and had PC with SVI (i.e. pT3b). BCR was defined as a postoperative PSA >0.2 ng/mL, or use of salvage androgen deprivation therapy (ADT) or radiation in response to a clinical suspicion of progression. Multivariable cox proportional hazards models were used to determine if LNY was predictive of BCR. The Kaplan-Meier method was used to determine the 3-yr freedom from BCR.

Results

Median LNY was 8 (IQR: 4-13). With a median follow-up of 56.9 months, the estimated 3-year freedom from BCR for overall, N0, and N1 patients was 55.7%, 59.0% and 28.3% respectively. Results from multivariable analysis demonstrated that LNY was not significantly associated with risk of BCR for overall (HR=1.01, p=.734), for pN0 (HR=1.00, p=.825) or pN1 patients (HR=1.02=.744). PSA (HR=1.02, p<.001), pathologic Gleason sum ? 9 (HR=1.90, p=.006), more recent RP (HR=1.07, p=.004), bladder neck invasion (HR=1.98, p=.056) and N1 disease (HR=2.19, p=.003) were associated with an increased risk of BCR. Increasing LNY increased the likelihood of detecting more positive lymph nodes (?=0.19, p=.003) in pN1 patients.

Conclusions

SVI after RP is associated with a high risk of BCR. While greater LNY facilitate increased accuracy in staging, our study demonstrates that in the setting of SVI, pathologic Gleason score and PSA at diagnosis are the primary drivers of BCR.

Funding

None