Clinical usefulness of D2-40 in non-small cell lung cancer.

D2-40 is a recently developed monoclonal antibody that reacts with a 40 kDa O-linked sialoglycoprotein and has been used for the assessment of lymphatic invasion in tumor specimens. We have evaluated the diagnostic usefulness of D2-40 and association of its immunopositivity with clinicopathological parameters in adenocarcinoma and squamous cell carcinoma of the lung. We investigated 97 cases of surgically resected adenocarcinoma or squamous cell carcinoma of the lung for the determination of D2-40 positivity in tumor cells and peritumoral lymphatic vessel density (LVD) using an immunostaining method. D2-40 immunoreactivity in tumor cells was invariably negative in adenocarcinoma but 47% of squamous cell carcinomas were positive. D2-40 positivity in the tumor was significantly associated with high LVD in squamous cell carcinoma (P < 0.006). There was no significant association between peritumoral LVD and clinicopathologic parameters, including lymphatic vessel invasion, lymph node metastasis, and survival in adenocarcinoma and squamous cell carcinoma. These results suggest that D2-40 immunoreactivity in tumor cells can be used for distinguishing between adenocarcinoma and squamous cell carcinoma and that the reactivity of tumor cells with D2-40 is positively correlated with LVD in squamous cell carcinoma but not with lymph node metastasis in adenocarcinoma and squamous cell carcinoma.