Pregnancy-associated plasma protein-A concentrations in men with testicular and prostatic tumors

Pregnancy-associated plasma protein-A (PAPP-A) is a macromolecular glycoprotein produced during pregnancy by the trophoblast and the decidua. It is not specific to pregnancy, since immunoreactive PAPP-A is in the circulation of normal women and men and in seminal fluid. Immunohistochemically, PAPP-A is localized in some Leydig cells, in the epididymis, in the rete testis, and in seminal vesicles. This study was conducted to learn whether circulating levels of PAPP-A can be used as a marker for the monitoring of human testicular cancer. PAPP-A was increased only in certain nonseminomatous germ cell tumor [malignant teratoma undifferentiated (MTU) + seminoma, malignant teratoma intermediate (MTI)], but the overlap with the normal values was too big for PAPP-A to have any clinical significance. After orchidectomy or prostatectomy, PAPP-A decreased but the levels were were similar to those of normal men. In men, PAPP-A can be produced by certain nonseminomatous germ cell tumors, but its origin in disease-free males is probably not the testis or the prostate.