Characterization of Lymph Node Tumor Burden in Node-Positive Prostate Cancer Patients after Robotic-Assisted Radical Prostatectomy with Extended Pelvic Lymph Node Dissection

Abstract

Background: Prostate cancer (PCa) nodal staging does not account for lymph node (LN) tumor burden. The LN anatomical compartment involved with the tumor or the quantified extent of extranodal extension (ENE) have not yet been studied in relation to biochemical recurrence-free survival (BRFS). Methods: Histopathological slides of 66 pN1 PCa patients who underwent extended pelvic lymph node dissection were reviewed. We recorded metrics to quantify LN tumor burden. We also characterized the LN anatomical compartments involved and quantified the extent of ENE. Results: The median follow-up time was 38 months. The median number of total LNs obtained per patient was 30 (IQR 23–37). In the risk-adjusted cox regression model, the following variables were associated with BRFS: mean size of the largest LN deposit per patient (log2: adjusted hazard ratio (aHR) = 1.91, p < 0.001), the mean total span of all LN deposits per patient (2.07, p < 0.001), and the mean percent surface area of the LN involved with the tumor (1.58, p < 0.001). There was no significant BRFS association for the LN anatomical compartment or the quantified extent of ENE. Conclusion: LN tumor burden is associated with BRFS. The LN anatomical compartments and the quantified extent of ENE did not show significant association with BRFS.

Agreement between PSMA-RADS and E-PSMA systems in classifying [18F]PSMA-1007 PET/CT lesions among prostate cancer patients: exploring the correlation between lesion size and uptake

“…Regarding discordant lesions in the lymph nodes, recent studies, such as the study by Gottlieb et al ( 30 ), revealed that histopathologically, the tumor burden in lymph node lesions is associated with BCR-free survival time in PCa patients. Furthermore, Schwartz et al ( 31 ) described that the stratification of lymph node lesions based on size and the anatomical region can hinder the serial follow-up of the lesions and potentially provide discordant findings in their classification.…”

“…Additionally, they determined that an optimal SUVmax threshold of 8.3 could be applied to identify PCa lesions through [ 18 F]PSMA-1007 PET/CT. Regarding discordant lesions in the lymph nodes, recent studies, such as the study by Gottlieb et al (30), revealed that histopathologically, the tumor burden in lymph node lesions is associated with BCR-free survival time in PCa patients. Furthermore, Schwartz et al (31) described that the stratification of lymph node (31) reported that when only the short axis of the lymph node lesion is considered, there is a better and more significant correlation with the tumor burden, and they recommend adopting the measurement of the short-axis diameter for lymph node lesions in radiological practice.…”