Login to Access Video or Poster Abstract: MP64-06
Sources of Funding: None

Introduction

The current evidence for lymphadenectomy (LND) at the time of radical prostatectomy (RP) for Gleason 7 intermediate-risk prostate cancer (PCa) is not as robust as for high-risk prostate cancer. Current guidelines defer to various nomograms regarding the risk of lymph node involvement to dictate the need for LND. The objective of this study was to examine utilization trends and survival data for patients who underwent LND for Gleason 7 PCa.

Methods

The SEER database was queried for all patients with either Gleason 3+4 (G34) or 4+3 (G43) PCa from 2004-2013, limited to patients with no evidence of metastatic disease or prior radiotherapy. Distributions and trends of LND, cancer-specific survival (CSS) and overall-survival (OS) were calculated. Memorial-Sloan Kettering Cancer Center (MSKCC) nomogram was applied to stratify patients based on risk of nodal disease at time of RP (<5% risk or >5% risk). Finally, multivariate logistic regression analyses (MVA) were performed to determine covariates associated with the likelihood of receiving LND.

Results

A total of 78641 patients with either G34 or G43 PCa underwent RP (59194 and 19447, respectively) with mean follow-up of 57.9 months. Of these patients, 61.2% of G34 and 73.5% of G43 patients underwent LND. During this time, the proportion of G43 patients undergoing LND remained relatively stable. The proportion of G34 patients undergoing LND varied between 55.9% in 2008 and 67.9% in 2013 despite decreasing RP rates in that same time frame. On MVA, the primary contributor to the variability in LND completion was socioeconomic status (SES): patients with higher SES were less likely to receive LND when indicated (OR 0.82, p < 0.05) and more likely to receive LND when not indicated (OR 1.15, p < 0.05). Age, race and insurance status were not significant predictors of LND. The incidence of pN+ disease was 1.5% and 5.2% in the <5% and >5% risk groups, respectively. Completion of LND at time of RP did not significantly change CSS in patients with G34 PCa (99.50% with LND and 99.59% without LND, p = 0.14.) In G43 patients, however, CSS was better in patients who did not undergo LND (98.81% with LND and 99.33% without LND, p = 0.002), the difference primarily driven by pN1 patients.

Conclusions

The role of LND for Gleason 7 prostate adenocarcinoma is not yet standardized, as indicated by the variability of LND dissection rates over an 11-year period in the United States. SES was the primary predictor of LND completion at time of RP. As CSS was not affected by completion of LND for G34 PCa, further evaluation of oncologic benefit in this patient population is warranted.

Funding

None