Nationwide prevalence of lymph node metastases in Gleason score 3 + 3 = 6 prostate cancer

SummaryBased on revisions of Gleason scoring in 2005, it has been reported that nodal metastases at radical prostatectomy in Gleason 3+3=6 (GS6) prostate cancer are extremely rare, and that GS6 cancers with nodal metastases are invariably upgraded upon review by academic urological pathologists. We analysed the prevalence and determinants of nodalmetastases in a national sample of patients with GS6 cancer. We utilised the SEER database to identify patients diagnosed with GS6 prostate cancer during 2004-2010 who had radical prostatectomy and ≥1 lymph node(s) examined. We calculated the prevalence of nodal metastases and constructed a multivariable logistic regression model to identify factors associated with nodal metastases. Among 21,960 patients, the prevalence of nodal metastases was 0.48%. Older age, preoperative PSA >10 ng/mL, and advanced stage were positively associated with nodal metastases. Lymph node metastases in GS6 cancer are more prevalent in a nationwide population compared to academic centres. Revised guidelines for Gleason scoring have made GS6 cancer a more homogeneously indolent disease, which may be relevant in the era of active surveillance. We submit that lymph node metastases in GS6 cancer be used as a proxy for adherence to the 2005 ISUP consensus on Gleason grading.