The principal role of sentinel lymph node sampling and ultrastaging in colon cancer is enhanced staging accuracy.
The utility of this technique for patients with colon cancer remains controversial.
Dr Alexander Stojadinovic and colleagues evaluated assessment of the sentinel lymph node with step sectioning and immunohistochemistry.
The team evaluated whether it enhances the ability to stage the regional nodal basin over conventional histopathology in patients with resectable colon cancer.
The researchers conducted a multicenter randomized trial between 2002 and 2006.
|A 11% nodal upstaging was identified by evaluation of hematoxylin |
|Annals of Surgery|
The team evaluated 161 patients with stage 1 to 3 colon cancer.
The patients were randomized to standard histopathologic evaluation.
Patients were also randomized to sentinel lymph node mapping and ultrastaging with pan-cytokeratin immunohistochemistry in conjunction with standard histopathology.
The team defined sentinel lymph node-positive disease as individual tumor cells or cell aggregates identified by hematoxylin and eosin and/or immunohistochemistry.
Primary end point was the rate of nodal upstaging.
The researchers identified significant nodal upstaging with sentinel lymph node ultrastaging.
The team then excluded sentinel lymph node's with cell aggregates 0.2 mm in size or less.
Following this exclusion, no significant difference in node-positive rate was apparent between the control and sentinel lymph node arms.
A 11% nodal upstaging was identified by evaluation of hematoxylin and eosin stained step sections of sentinel lymph nodes.
These patients would have otherwise been staged node-negative by conventional pathologic assessment alone.
Dr Stojadinovic‘s team concluded, "Sentinel lymph node mapping, step sectioning, and immunohistochemistry identifies small volume nodal disease."
"It also improves staging in patients with resectable colon cancer."
"A prospective trial is ongoing to determine the clinical significance of colon cancer micrometastasis in sentinel lymph nodes."