TY - JOUR T1 - ECtopic gonadotropin in bronchogenic carcinoma AU - Rosen SW, Weintraub BD Y1 - 1969/11/03 N1 - 10.1001/jama.1969.03160310096034 JO - JAMA SP - 908 EP - 908 VL - 210 IS - 5 N2 - To the Editor:—  Your editorial "Ectopic Gonadotropin in Bronchogenic Carcinoma" (207:2094, 1969) merits additional comment.The writer noted that although Faiman and his colleagues1 had shown an arterial-venous (a-v) gradient for follicle-stimulating hormone (FSH) across a tumor, "curiously, there was no (arterial-venous) difference in the levels of luteinizing hormone (LH), even though they were above normal in the serum at the time of surgery." This may in fact not be so "curious," when one considers that the immunochemical method used by Faiman et al (and indeed all existing immunochemical methods) does not distinguish between LH and human chorionic gonadotropin (HCG). Thus, these workers may have been measuring an HCG-like polypeptide and not an LH-like polypeptide. This is pertinent because HCG is unique among polypeptide hormones thus far studied in having a long half-life in plasma (in the neighborhood of ten hours2 as opposed to 30 to 60 minutes SN - 0098-7484 M3 - doi: 10.1001/jama.1969.03160310096034 UR - http://dx.doi.org/10.1001/jama.1969.03160310096034 ER -