Value of human chorionic gonadotropin compared to CEA in discriminating benign from malignant effusions

Human chorionic gonadotropin (HCG) is expressed in germ cell tumors and uro thelial, breast, lung and colon cancers. The aim of the study was to invest igate if the determination of HCG in comparison with CEA is able to discrim inate between malignant and benign effusions. Effusion and partially serum samples of 61 patients with benign (g.i., heart/kidney isnuff.) and 116 pat ients with malignant diseases (g.i., gynec., lung, misc., CUP) were investi gated HCG; was specifically determined by an IRMA using 2 monoclonal antibo dies, CEA by a conventional double Ab RIA. Cytological staining was preform ed using the Pappenheim-method on cytospin preparations. Significant differ ences (p<0.001) were found for HCG between benign and malignant ascitic eff usions with the best discrimination at 5 IU/l (ROC) and an overall sensitiv ity of 31.3% (spec. vs benign eff 93.4%) increasing in subgroups from hemat ol. (5.8%) <misc. (31.3%) <gynec. (32.1%) <g.i. (36%) < lung (38.1%) to CUP (50%). CEA also showed significant differences between benign and malignan t total and ascitic effusions, and weaker for the pleural subgroup (cutoff 9 ng/ml) with a total sensitivity of 44.6% (sp=100%) increasing from misc. (30.8%) <lung (47.1%) <CUP (50%) < gynec. (60%) <g.i. (60.9%). Comparative cytology and TM determinations increased the positiverate of cytology (45.2 %) to 58.3% for either cytology or HCG positive cases, or to 61.6% for eith er cytology or CEA positive cases. For the combined determination of cytolo goy and HCG and CEA, the overall TM positive rate for 33 cytology-pos. case s was 78.8%, but in 40 cytology-negative cases 37.5% for TM positive cases. in conclusion HCG is useful in ascitic > pleural effusions with high speci ficity (90% at 5 IU/l) but low sensitivity of 31% increasing in g.i., lung and gynecologic cases, CEA a more general TM with higher sensitivity of 45% increasing in g.i., gynecologic and lung cases (sp. 100% at 9 ng/ml) both adding significantly to cytology-negative effusions.