Localization of CEA, beta-HCG, SP1, and keratin in the tissue of lung carcinomas. An immunohistochemical study.

One hundred and twenty seven cases of lung tumors were studied by the immunoperoxidase technique for the presence of CEA and beta-HCG. Twenty-nine of these tumors were additionally stained for keratin and SP1, CEA and SP1 could be demonstrated in 80% of the studied cases, while beta-HCG was found in only 9%. SP1 revealed an almost identical staining pattern to CEA and keratin was found only in squamous cell carcinomas. The tissue positivity of none of these three markers correlated with tumor size, lymphnodal involvement or histological type.