What To Do With Lateral Nodal Disease in Low Locally Advanced Rectal Cancer? A Call for Further Reflection and Research.

Background: There remains a lack of international consensus on the appropriate management of lateral nodal disease. Although the East manages this more aggressively with lateral lymph node dissections, the West aims to eradicate small-volume disease with neoadjuvant chemoradiotherapy and lateral nodal disease is not considered for routine surgical treatment. However, recent studies have shown that, despite neoadjuvant treatment, a significant number of patients with lateral nodal disease develop local recurrence in the lateral compartment after total mesorectal excision.

Objective: The aim of this study is to assess the role of the pretreatment features of lateral nodes on MRI in regard to local recurrence.

Design: All patients operated on for low locally advanced rectal cancer over a 5-year period were evaluated retrospectively.

Settings: This study was conducted at a single expert center.

Patients: The MRIs of a total of 313 patients were reviewed, and only those with rectal cancers up to 8 cm from the anorectal junction, measured on MRI, were selected. This left 185 patients; of these, 58 patients had clinical T1 or T2 tumors as assessed on MRI, identifying 127 patients who had cT3/T4 tumors that were included in this study.

Main Outcome Measures: The primary outcomes measured were lateral local recurrence and multivariate analyses.

Results: The lateral local recurrence rate was significantly higher (33.3% 4-year rate) in patients with nodes larger than 10 mm than in patients with smaller nodes (10.1%, p = 0.03), despite patients being irradiated in the lateral compartment.

Limitations: Because this is a relatively uncommon disease, patient numbers are low, and a multicenter study is needed to further address lateral nodal disease in low rectal cancer.

Conclusions: Chemoradiotherapy with total mesorectal excision might not be sufficient in a selected group of patients. Further research is needed about which pretreatment features of the lateral nodes predict local recurrence and what is needed to prevent these from developing. See Video Abstract at http://links.lww.com/DCR/A338.