The lymphatic infiltration identified by D2-40 monoclonal antibody predicts lymph node metastasis in submucosal invasive colorectal cancer

Background and Study Aims: Lymphatic infiltration has been recognized as a significant risk factor for lymph node metastasis of submucosal invasive colorectal cancer (SICC), but it is difficult to detect microscopically on hematoxylin and eosin (H& E)-stained slides. We therefore identified lymphatic infiltration of tumor cells with D2- 40 monoclonal antibody, which reacts specifically against the endothelium of lymphatic vessels, to make an objective and precise diagnosis. Patients and Methods: The surgical specimens of 122 consecutive patients with nonpedunculated SICC were examined for lymphatic infiltration by immunohistochemical staining with D2- 40 monoclonal antibody (LI-D) and for venous infiltration by Elastica van Gieson staining (VI-E). Results: Lymph node metastasis was found in 20 patients. Multivariate analysis showed that LI-D ( p = 0.0415) and VI-E (p = 0.0119) were significant risk factors for lymph node metastasis. Regardless of the presence of risk factors including at least either lymphatic infiltration or venous infiltration, no lymph node metastasis- positive patients were found (0%) among the 25 patients whose colorectal cancer had a sub-mucosal invasive depth of less than 1,500 m. No lymph node metastasis was found in any of the patients with a depth of submucosal invasion of less than 3,000 mu m, who had no risk factors, including LI-D or VI-E. Conclusions: Correct evaluation of lymphatic infiltration by immunohistochemical staining with D2-40 monoclonal antibody may play a crucial role in determining whether there are indications for additional treatment in the management of endoscopically resected SICC. Copyright (c) 2007 S. Karger AG, Basel.