The Study: Total mesorectal excision (TME) is the standard operation for rectal cancer, but it doesn’t typically involve an extended nodal dissection. Except, apparently in some Asian countries, more extended lateral pelvic node dissections are routine. This study looks for a benefit with lateral node dissection in T3/4 rectal cancer by pooling data from several institutions across the world. They characterized the largest size and location of any lateral nodes on over 1200 pre-op MRIs, which detected nodes in over half of cases with two-thirds in the obturator compartment. Median short axis was only 5 mm and nearly one-fifth had malignant features. Interestingly, patients with lateral nodes in the highest-size quartile (≥7 mm) by MRI had significantly higher rates of locoregional recurrence—primarily in lateral node compartments. What’s more, the small subset (n=142) of patients who underwent lateral node dissection had a 50% rate of pathologically involved nodes and enjoyed a reduction in rate of locoregional recurrence from 20 → 6%. Oh, and for kicks, see if you can spot the classic JCO “trend” statement.
Bottom Line: A lateral lymph node dissection may reduce locoregional recurrence of rectal cancer, at least in those with nodes of a short-axis ≥7 mm. | Ogura, J Clin Oncol 2018