Temporal trends and predictors in diagnosing pathologic node-positive prostate cancer in clinically node-negative patients.

Abstract

128 Background: The management of men with pathologically node positive (pN+) prostate cancer (PCa) is controversial. Here, we describe the temporal patterns and predictors of incidental pN+ PCa men with clinically node negative (cN0) PCa. Methods: We performed a retrospective analysis of men with nonmetastatic, cN0, PCa from the National Cancer Database from 2010 to 2017. Clinical factors included in analysis were pretreatment PSA, pre-surgical International Society of Urological Pathology (ISUP) grade group (GG), clinical T-stage, margin status, and number of nodes sampled. Patient demographic factors included in analysis were age, comorbidity index, race, insurance status, and treatment facility type. We performed univariable and multivariable logistic regression to evaluate temporal trends in the rates of cN0,pN+ prostate cancer diagnosed over time. Two-level hierarchical logistic regression was used to identify covariates associated with pN+ disease. Patients were clustered within treatment facilities to account for individual facility practice patterns. Results: We identified 304,234 men with cN0 PCa who underwent radical prostatectomy (RP) between 2010 and 2017. Within this group 10,919 (3.59%) were found to have pN+ disease. During this period, the annual rate of pN+ PCa increased from 2.02% (n=822) in 2010 to 5.12% (n=2,072) in 2017 (p<0.001). On multivariable logistic regression, ISUP GG was most strongly associated with detection of pN+ PCa. Compared to ISUP GG1, GG2 (OR 3.5, p <0.001), GG3 (OR 8.8, p <0.001), GG4 (OR 12.6, p <0.001) and GG 5 (OR 26.5, p <0.001 ) were all significantly associated with pN+ PCa. Over the study period, the rates of pN+ identification increased from 5.5% to 9.4% in men with GG4, and from 13.4% to 19.5% in men with GG5 (p <0.001). Between 2010 and 2017, the rates of RP in GG4 and GG5 similarly increased by 12% and 16%, respectively (p <0.001). Other significant covariates are depicted in Table. 22% of the total variance was explained by inter-facility variation. Conclusions: The proportion of men with cN0 found to have pN+ PCa is increasing over time, with pN+ incidentally found in nearly 1 in 10 men with GG4 and 1 in 5 men with GG5 PCa. GG4 and GG5 are the strongest independent predictors of pN+ disease, while controlling for clinical and demographic factors. As incidental pN+ results in upstaging, often requiring adjuvant treatment with radiation and systemic therapies, these data are useful for informing discussions prior to RP. [Table: see text]