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. Graphical Abstract The management of pelvic sidewall lymphadenopathy in rectal cancer is controversial and non-standardized, with significant geographical differences. Residual pelvic sidewall node involvement following neoadjuvant chemoradiotherapy (NCRT) and total mesorectal excision is associated with worse oncological outcomes. Highly selective lateral pelvic node dissection after NCRT can reduce rates of local recurrence, particularly in the pelvic sidewall. Graphical Abstract Selective resection appropriate