The potential usefulness of monoclonal antibodies in the determination of histologic types of lung cancer in cytologic preparations.

Two monoclonal antibodies (MAbs) were tested for their reactivity with antigens of exfoliated malignant cells in respiratory secretions of lung cancer patients. MAb CE 407 was developed from tissue culture cell line SW 756, derived from human uterine cervical squamous cell carcinoma; MAb BL 99-57 was developed from cell line T-24, derived from human transitional cell bladder cancer. MAb CE 407 reacted preferentially with squamous cell carcinomas (80%) and with some (44%) of the adenocarcinomas of the lung; BL 99-57 reacted with 76% of the adenocarcinomas, but only with 27% of the squamous cell carcinomas of the lung. The reactivity of BL 99-57 was more apparent in well-differentiated adenocarcinomas (89% positive), but less in poorly differentiated adenocarcinomas (65% positive). Neither of these antibodies reacted with antigens of small cell anaplastic carcinoma. These two MAbs may be useful in differentiating histologic types of lung cancer in cases that are difficult to diagnose morphologically and/or in which tissue is not available for study.