Detection of malignant pleural effusions by tumor marker evaluation.

Cytologic examination and determination of tumor markers (PHI, LDH, alpha-1-glycoprotein, alpha-2-HS-glycoprotein, beta 2-microglobulin, ferritin [corrected], sialic acid, IgE, fetoprotein, CEA, beta HCG and beta 1-SP-glycoprotein) were carried out in pleural fluid samples obtained from 70 patients with suspected neoplasia. Tumor markers were also determined in sera. The protein content of all pleural effusions was greater than or equal to 3 g/dl. Patients were grouped according to diagnosis as follows: (a) 42 with neoplastic diseases (7 mesotheliomas and 19 lung, 4 ovarian, 3 breast and 8 miscellaneous cancers), (b) 22 with benign inflammations and (c) 6 with congestive effusions. Of the parameters examined, only CEA and beta-HCG [corrected] gave information that the effusion was probably malignant. Using 6 ng/ml as cut-off for CEA and 10 mIU/ml for beta HCG, the sensitivity was 57.1% and 45.2%, respectively, specificity was 92.8% for both parameters and test efficiency 0.75 and 0.69, respectively. When CEA and beta HCG were considered together sensitivity increased to 73.8% and efficiency to 0.78. CEA and/or beta HCG were positive in the pleural effusions of 19 of the 20 malignant pleural effusions, all with a negative cytologic examination, which subsequently became positive in 8. Because of their high specificity, these two parameters are a useful tool and can be routinely measured to evaluate pleural effusions of dubious origin, even if CEA and beta HCG cannot, on [corrected] their own, define the primary malignancy.