Rectal cancer lateral pelvic sidewall lymph nodes: a review of controversies and management

Abstract

Background: The management of lateral pelvic lymphadenopathy in low rectal cancer poses an oncological and technical challenge. Interpretation of the literature is confounded by different approaches to management in the East and West, and a lack of randomized data from which to draw accurate conclusions regarding the optimal approach. Recent collaboration between Eastern and Western centres has increased the standardization of care. Despite this, significant differences in international guidelines remain. The aim of this review was to appraise the available literature and propose a management algorithm. Methods: A literature review of all relevant studies was performed to summarize the historical evidence, as well as establish the significance of clinically positive lateral pelvic sidewall nodes, and the role of neoadjuvant chemoradiotherapy and lateral pelvic node dissection. A management algorithm was developed based on this review of the literature. Results: The management of pelvic sidewall lymphadenopathy in rectal cancer is non-standardized, with geographical differences. The mechanism of lateral lymphatic spread is well defined; the risk increases with lower tumour height and advanced T category. Existing data indicate that acceptable disease-free and overall survival can be achieved by neoadjuvant chemoradiotherapy with selective lateral pelvic node dissection. Conclusion: Suspicious lateral pelvic sidewall nodes, particularly in the internal iliac chain, should be considered as resectable locoregional disease, and surgery offered for enlarged nodes that do not respond to neoadjuvant chemoradiotherapy.

Radiological assessment of persistent retroperitoneal and lateral pelvic lymph nodes after neoadjuvant therapy for rectal cancer: An analysis of the United States Rectal Cancer Consortium

“…In patients who received preoperative chemoradiation and TME with mesorectal lymphadenectomy, locoregional recurrence rates have previously been reported as 4.6%–7.9% with 67.4%–82.7% of patients recurring in RLPN 7,8 . While presence of RLPN on clinical staging may indicate an increased risk for local recurrence, existing literature on its impact on long‐term oncologic outcomes is inconsistent 9,10 . As a result, clinical management and the decision to proceed with surgery remains controversial, particularly in patients with isolated, persistent RLPN disease who received neoadjuvant therapy.…”

Apparent diffusion coefficient cannot discriminate metastatic and non-metastatic lymph nodes in rectal cancer: a meta-analysis

“…For 1.5 T scanners, the calculated mean ADC value (× 10 −3 mm 2 /s) of metastatic LN was 1.09, 95%CI (0.91, 1.28), and of the non-metastatic LN, it was 1.37, 95%CI (1.09, 1.64). For 3 T scanners, the ADC value of metastatic LN was 1.01, 95%CI (0.86, 1.16), and for non-metastatic LN, it was 1.02, 95%CI (0.83, 1.22) indicated that a greater accuracy in preoperative staging is needed to select those patients that will benefit from lateral lymph node dissection surgery [29,30].…”

“…On the other hand, there is a significant risk of urinary and sexual dysfunction after surgical dissection of lateral pelvic lymph nodes [ 28 , 29 ]. Therefore, recent studies indicated that a greater accuracy in preoperative staging is needed to select those patients that will benefit from lateral lymph node dissection surgery [ 29 , 30 ].…”

Embryological Development and Topographic Anatomy of Pelvic Compartments—Surgical Relevance for Pelvic Lymphonodectomy

“…Currently it is agreed that pre-existing enlarged lymph nodes must be addressed, either by radiotherapy or surgery [13]. Recent data indicate that acceptable rates of disease-free and overall survival can be achieved by neoadjuvant chemoradiotherapy with selective lateral pelvic lymph node dissection [14].…”