Plasma levels of 15-keto-13,14-dihydro-prostaglandin E2 in patients with bronchogenic carcinoma.

Plasma levels of the circulating metabolite of prostaglandin (PG) E2, 15-keto-13,14-dihydro-PGE2 (KH2PGE2), were determined radioimmunologically after conversion to the stable degradation product 11-deoxy-15-keto-13,14-dihydro-11,16-cyclo-PGE2 (DKH2-cyclo-PGE2). In healthy volunteers a plasma level of 25 +/- 2 pg/ml (mean +/- S.E.M., n = 24) was found. The plasma level of KH2PGE2 was significantly decreased after administration of acetylsalicylic acid (4 x 1 g/24 hours). A significant elevation of the plasma levels of the circulating metabolite of PGE2 was observed in patients with bronchogenic carcinoma as compared to healthy controls, while no elevation was found in patients with chronic myeloid leukemia, lymphatic leukemia and non-Hodgkin lymphoma. The increased plasma levels of KH2PGE2 in the patients with bronchogenic carcinoma were independent of the clinical condition, histological type of tumor, tumor spread and therapeutic regimen. The results indicate that the elevated plasma level of the circulating PGE2 metabolite in patients with bronchogenic carcinoma is not an expression of malignant disease in general. On the other hand, the results do not suggest that the increase in the plasma level of KH2 PGE2 is a biochemical tumor marker closely related to a particular clinical feature of patients with bronchogenic carcinoma.