Lateral Lymph Node Size and Tumor Distance From Anal Verge Accurately Predict Positive Lateral Pelvic Lymph Nodes in Rectal Cancer: A Multi-Institutional Retrospective Cohort Study

Abstract

BACKGROUND: Lateral pelvic lymph node dissection improves oncological outcomes in rectal cancer patients with suspected lateral pelvic lymph node metastasis. However, the indication for this procedure remains unclear. OBJECTIVE: This study aimed to identify the predictive factors for lateral lymph node metastasis and the indications for lateral pelvic lymph node dissection. DESIGN: A multi-institutional retrospective study. SETTINGS: This study was conducted at 3 university hospitals. PATIENTS: This study involved 105 patients with locally advanced mid/low rectal cancer and clinically suspected lateral pelvic lymph node metastasis who underwent total mesorectal excision with lateral pelvic lymph node dissection between 2015 and 2020. MAIN OUTCOME MEASURES: Indications were set using lateral pelvic lymph node metastasis–associated preoperative factors. RESULTS: Among 105 patients, 36 (34.3%) had pathologically confirmed lateral pelvic lymph node metastasis and 77 (73.3%) underwent preoperative chemoradiation. Tumors located within 5 cm distance from the anal verge (p = 0.02) and initial node size ≥ 6 mm (p = 0.001) were significant predictors of lateral pelvic lymph node metastasis. The sensitivity was 100% (36/36) with a cutoff of 6 mm for the initial node size and 94.4% (34/36) with a cutoff of 8 mm for the initial node size. When using initial node size cutoffs of 8 mm for anal verge-to-tumor distance of >5 cm and 6 mm for anal verge-to-tumor distance of ≤5 cm, the sensitivity of lateral pelvic lymph node metastasis was found to be 100%. LIMITATIONS: The retrospective design and small sample size were the limitations of this study. CONCLUSION: Initial node size and tumor height were significant predictors of lateral pelvic lymph node metastasis. This study proposed that an initial node size of ≥8 mm with an anal verge-to-tumor distance of >5 cm and ≥6 mm with an anal verge-to-tumor distance of ≤5 cm are optimal indications for lateral pelvic lymph node dissection in rectal cancer. See Video Abstract at http://links.lww.com/DCR/C101. EL TAMAÑO DEL GANGLIO LINFÁTICO LATERAL Y LA DISTANCIA DEL TUMOR DESDE EL BORDE ANAL PREDICEN CON PRECISIÓN LOS GANGLIOS LINFÁTICOS PÉLVICOS LATERALES POSITIVOS EN EL CÁNCER DE RECTO: UN ESTUDIO DE COHORTE RETROSPECTIVO MULTIINSTITUCIONAL ANTECEDENTES: La disección de los ganglios linfáticos pélvicos laterales mejora los resultados oncológicos en pacientes con cáncer de recto con sospecha de metástasis en los ganglios linfáticos pélvicos laterales. Sin embargo, la indicación de este procedimiento sigue sin estar clara. OBJETIVO: Nuestro objetivo fue identificar los factores predictivos de la metástasis de los ganglios linfáticos laterales y las indicaciones para la disección de los ganglios linfáticos pélvicos laterales. DISEÑO: Estudio retrospectivo multiinstitucional. AJUSTES: Este estudio se realizó en tres hospitales universitarios. PACIENTES: Este estudio involucró a 105 pacientes con cáncer de recto medio/bajo localmente avanzado y sospecha clínica de metást...

Predictive factors of pathological lateral pelvic lymph node metastasis in patients with selective laparoscopic lateral lymph node dissection for rectal cancer:A retrospective Study

“…Selective LLND had a higher pathologic LPNM.A study in Korea 19 selectively performed LLND to patients with clinically suspected LPN metastasis showed that the positive rate was 34.8%. A large multicenter retrospective cohort study in China showd that positive LPN was 23.5% in patients suspected LPN metastasis based on magnetic resonance imaging (MRI) evaluation 20 .…”

Short-term outcomes of 47 selective laparoscopic lymph node dissection for rectal cancer: A Retrospective Study

“…It should be noted that this study was preventive dissection and LLND was performed on lateral lymph nodes with images less than 10mm. Another multicenter study from Korea 19 found, LPN short-axis diameter (< 5, 5-<10, and 10 mm) was signi cantly associated with LPN recurrence-free survival (5-year survival rate (5YSR), 98.2, 91.7, and 40.1%, respectively, P < 0.05), locoregional recurrence-free survival (5YSR, 95.5, 87.6, and 40.1%, respectively, P < 0.05), relapse-free survival (5YSR, 76.8, 72.5, and 30.3, respectively, P < 0.05), and overall survival (5YSR, 86.3, 83.0, and 57.5%, respectively, P < 0.05). A multicenter study from China 20 found that the 3-year OS, RFS, and LRFS in the LPN positive group were signi cantly worse than those in the LPN negative group.…”

Feasibility and limitations of combined treatment for lateral pelvic lymph node metastases in rectal cancer

“…The primary method for predicting mLLN is based on the size diagnosis of the maximum short axis diameter (SAD) of the lymph nodes on computed tomography or magnetic resonance imaging (MRI) after NACRT. However, it has recently been suggested that it is more appropriate to use the initial lateral pelvic lymph nodes (LPN) size rather than the post-chemoradiotherapy (CRT) LPN size as a predictor of mLLN, because in clinical practice, there are many cases where CRT is not performed before surgery for various reasons, such as patient rejection, old age, or complication[ 6 ]. Therefore, PLND is advocated as an adjunct to radical surgery for colorectal cancer.…”

“…Therefore, PLND should be carefully considered for such patients[ 8 ]. Studies from Japan proved that the optimal indications for PLND in rectal cancer are the initial lymph node ≥ 8 mm and the distance between the anus and the tumor edge > 5 cm or the initial lymph node ≥ 6 mm and the distance between the anus and the tumor edge ≤ 5 cm[ 6 , 9 ]. Malakorn et al [ 7 ] showed no evidence of local or distant recurrence of disease after 2 years of follow-up by using minimally invasive robot-assisted PLND to treat patients with persistent lateral pelvic lymph node enlargement after NACRT, which confirmed that Chua et al [ 5 ] The proposed robotic assistance may be a useful aid for PLND.…”