Assessment of Presence and Metastatic Involvement of Lymph Nodes in Anterior Periprostatic Fat (APPF) in Prostate Cancer Patients Treated with Robotic and Laparoscopic Radical Prostatectomy

Introduction: Lymph nodes (LN) in the anterior periprostatic fat (APPF) may harbour metastatic disease in patients with Prostate Cancer (PCa). We investigated the incidence and significance of LN in APPF tissue removed during robotic and laparoscopic radical prostatectomy (RP). Patients and Methods: We retrospectively analysed RP performed by a single surgeon from 2013 to 2023. A total of 670 patients underwent RP, with 407 procedures conducted laparoscopically and 263 robotically. Histological results were available for 509 patients, who were examined for the presence of LN and any evidence of metastatic involvement. Results: LN were detected in the periprostatic fat of eighty patients; however, only twelve had lymph node metastasis. Seven of the twelve patients presented with prostate-specific antigen (PSA) levels greater than 10 ug/L. All LN-positive patients had a Gleason score of seven or higher. On MRI, all patients had a PIRADS score of four or higher, and eleven were staged at T3 or higher. Additionally, all twelve patients had a Briganti score exceeding twenty. Conclusions: Our series indicates that the APPF contains LN that can harbour metastatic disease. Patients can have LN involved in APPF without the involvement of pelvic LN. Therefore, our study suggests that routine excision of APPF should be considered for appropriate LN staging and to avoid missing any metastasis, and that scoring systems like Briganti should be used to help identify this high-risk group.