Lateral Nodal Recurrence in Rectal Cancer

Local recurrence rates in rectal cancer have reduced dramatically since the introduction of the total mesorectal excision (TME) technique and neoadjuvant (chemo)radiotherapy (C))RT) to overall rates of 5-year local recurrence to 5-10%. However, distal rectal cancers have a tendency to spread to lateral lymph nodes and it was recently shown that patients with enlarged lateral lymph nodes of ≥7mm short-axis size have a considerable chance of a local recurrence: 15-20%. This is regardless of CRT with TME in two retrospective cohorts (Lateral Node Consortium and Snapshot Rectal Cancer 2016 study). According to the Lateral Node Consortium study, this rate was significantly reduced to \<6% when performing a lateral lymph node dissection (LLND) after (C)RT + TME. A major drawback of these recent multi-center studies is their retrospective nature. Therefore, in the Netherlands, radiologists, radiation oncologists, surgeons and pathologists have recently been educated and trained to enhance knowledge and awareness of LLNs and to implement nerve-sparing minimally invasive LLND. The LaNoReC trial is a prospective registration study aimed at evaluating oncological outcomes after multi-disciplinary training. The main question of this study is whether, after dedicated training and the performance of LLNDs, the lateral local recurrence rate in rectal cancers with enlarged nodes (≥7mm) can be reduced to below 6%.