[CEA in lung cancer: CEA immunohistochemical study of 150 cases]

CEA (Carcinoembryonic Antigen) was examined histochemically with PAP method in 150 lung cancer cases. Positive stainings were observed in 89% of adenosquamous cancers, 79.2% of adenocarcinomas (ACs), 63.3% of squamous cell cancers (SCCs), 55.6% of large cell cancers (LCCs) and 51.6% of small cell lung cancers (SCLCs). In ACs and SCCs, the higher cancer cells differentiated, the higher positive rates were observed. The intensities from high to low as followings: ACs and adenosquamous cancers; SCLCs and SCCs; and LCCs. Cytoplasmic staining was predominantly found in ACs (76%) and adenosquamous cancers (68.8), membranous in SCCs (63%) and LCCs (60%), and intercellular in SCLCs (68.8%). The results suggests that CEA is significantly related to differential degree of lung cancers. The different staining patterns and positive rates and intensities of CEA may be helpful for the pathological classification of lung cancers. Finally, the author indicates that CEA immunohistochemical examination will be a useful measure for exactly selecting lung cancer cases suitable for radioimmunodetection and antibody-mediated therapy.