The following is a summary of “Prognostic Implications of Lateral Lymph Nodes in Rectal Cancer: A Population-Based Cross-sectional Study With Standardized Radiological Evaluation After Dedicated Training,” published in the January 2024 issue of Gastroenterology by Sluckin, et al.
People are still arguing about what the presence, short-axis width, and position of lateral lymph nodes mean for the prognosis. For a study, researchers sought to look at the features of lateral lymph nodes, the impact of shrinking on restaging MRI, and the rates of local recurrence in people with cT3–4 rectal cancer after re-reviewing and training the MRI—a cross-sectional study of a community that looked back over time. In 2016, 3057 people with rectal cancer had surgery. Of those, 1109 had a cT3–4 tumor placed ≤8 cm from the anorectal joint, and 891 of them got neoadjuvant treatment.
The primary outcome measures are local recurrence rates and (ipsi) lateral local recurrence. A second look showed that 314 patients (35%) had visible side lymph nodes. Of these, 30 patients had either only long-stretched obturator nodes (n = 13) or only external iliac nodes (n = 17). Neither type of node caused any lateral local recurrences. If you had internal iliac/obturator lateral lymph nodes (n = 284), you had 16.4% local recurrence and 8.8% lateral local recurrence rates 4 years later. There were higher rates of local recurrence (20.8%, 13.1%, 0%; P <.001) and lateral local recurrence (14.7%, 4.4%, 0%; P < 0.001) in people with enlarged (≥7 mm) lateral lymph nodes (n = 122) than in people with smaller or no lateral lymph nodes. In multivariate analysis, both visible lateral lymph nodes (HR 1.8 [1.1–2.8]) and larger lateral lymph nodes (HR 1.9 [1.1–3.5]) were linked to local recurrence on their own. A higher lateral local return rate of 17.0% was seen in lymph nodes that were swollen and had signs of cancer after 4 years. The lateral local recurrence rates did not change when the company was shrunk. Larger peripheral lymph nodes were linked to higher rates of distant spread over 4 years (36.4% vs. 24.4%; P = 0.021), but this wasn’t significant in adjusted analyses (HR 1.3 [0.9–1.]) and didn’t make overall survival worse. The study had some issues because it looked back at past data and looked at a large group of people with side lymph nodes. The risk of lateral local recurrence was proven when lateral lymph nodes were swollen, but shrinkage after preventive therapy did not affect the prognosis.
The results suggested that the size of the main lateral lymph nodes should be considered when planning treatment.