Stainability of lung cancer cells with Leu-7 and OKT-9 monoclonal antibodies.

One hundred and one cases of lung cancer were immunohistochemically studied for stainability with Leu-7 (anti-myelin fiber associated glycoprotein) and OKT-9 (anti-transferrin receptor) monoclonal antibodies. All small cell carcinomas and carcinoid tumors were positively stained by Leu-7, and 22 of 41 differentiated adenocarcinomas were also positively stained, especially well-differentiated Clara cell-type adenocarcinoma, (11/14 cases). However, only one of 26 squamous cell carcinomas, one of six large cell carcinomas, one of six adenosquamous carcinomas and none of 16 poorly differentiated adenocarcinomas were stained by Leu-7. On the other hand, all squamous cell carcinomas (26/26 cases), 10 of the 16 poorly differentiated adenocarcinomas, four of the six large cell carcinomas showed positive membranous staining with OKT-9. However, only one of 41 differentiated adenocarcinomas and no small cell carcinomas nor carcinoid tumors were stained by OKT-9. The stainability of lung cancer by these antibodies is discussed.