Prevalence of High-Risk Prostate Cancer Metastasis to Cloquet’s Ilioinguinal Lymph Node

• Authors: Ana Plata Bello, University Hospital of Canary Islands, Tenerife, Spain; Sarah E Apatov, Memorial Sloan Kettering Cancer Center; Nicole E Benfante, Memorial Sloan Kettering Cancer Center; Ines Rivero Belenchon, Virgen del Rocio University Hospital; Natalia Picola Brau, Bellvitge University Hospital, Barcelona, Spain; Claudia Mercader Barrull, Hospital Clinic of Barcelona; Pocharapong Jenjitranant, Memorial Sloan Kettering Cancer Center; Andrew J Vickers, Memorial Sloan Kettering Cancer Center; Samson W Fine, Memorial Sloan Kettering Cancer Center; Karim A Touijer, Memorial Sloan Kettering Cancer Center
• Journal Title: JOURNAL OF UROLOGY
• Volume: Volume 207, Number 6
• Publisher: American Urological Association (AUA) | 2022-06-01, Pages 1222-1226
• Type of Work: Article | Post-print: After Peer Review
• Publisher DOI: http://doi.org/10.1097/JU.0000000000002439
• Subjects: Health Sciences, Medicine and Surgery; Health Sciences, Epidemiology
• Keywords: Prostatic neoplasms; Lymphatic metastasis; Lymph Node Excision; Inguinal Canal; Sentinel Lymph Node; Lymph Nodes

Abstract

Purpose: Cloquet’s node, located at the junction between the deep inguinal nodes and the external iliac chain, is easily accessible and commonly excised during pelvic lymph node dissection for prostate cancer. However, we hypothesize that Cloquet’s node is not part of lymphatic metastatic spread of prostate cancer. Materials and Methods: Between September 2016 and June 2019, 105 consecutive patients with high-risk prostate cancer (cT3a + or Grade Group 4 / 5 or PSA >20 ng/mL) underwent a laparoscopic radical prostatectomy and pelvic lymph node dissection. First, Cloquet’s node was identified, retrieved, and submitted separately to pathology as right and left Cloquet’s node. Next, a pelvic lymph node dissection was completed including the external iliac, obturator fossa, and hypogastric nodal packets. Each lymph node was cut in 3-mm slices which were separately embedded in paraffin, stained with hematoxylin and eosin, and examined microscopically. Results: The final analysis included 95 patients. In this high-risk population, the median number of nodes removed was 22 (IQR 18–29); 39/95 patients (41%) had lymph node metastasis. The median number of Cloquet’s nodes removed was 2 (IQR 2–3). Cloquet’s node was negative in all but one patient (1.1%), who had very high-risk features and high metastatic burden in the lymph nodes. Conclusions: In high-risk prostate cancer, metastasis to the ilio-inguinal node of Cloquet is rare. Given this low prevalence, Cloquet’s node can be safely excluded from the pelvic lymph node dissection template.