HUMAN CHORIONIC-GONADOTROPIN (HCG) AND ITS FREE SUBUNITS IN HYDROCELEFLUIDS AND NEOPLASTIC TISSUE OF TESTICULAR CANCER-PATIENTS - INSIGHTSINTO THE IN-VIVO HCG SECRETION PATTERN
S. Madersbacher et al., HUMAN CHORIONIC-GONADOTROPIN (HCG) AND ITS FREE SUBUNITS IN HYDROCELEFLUIDS AND NEOPLASTIC TISSUE OF TESTICULAR CANCER-PATIENTS - INSIGHTSINTO THE IN-VIVO HCG SECRETION PATTERN, Cancer research, 54(19), 1994, pp. 5096-5100
To obtain insight into the secretion pattern of human chorionic gonado
tropin (hCG) and its free subunits, hCG alpha and hCG beta, in vivo, w
e analyzed hydrocele fluids of 13 patients with testicular cancer and
correlated the respective values to those of cubital vein and testicul
ar vein serum. As a control population, patients with nonmalignant hyd
roceles (n = 11) were studied. Analyses were performed with a set of h
ighly sensitive and specific time-resolved fluoroimmunoassays based on
our own panel of monoclonal antibodies. In the collective of testicul
ar cancer patients, increased hydrocele levels of either hCG or free h
CG alpha or free hCG beta mere observed in 77, 54, and 92% of cases; t
he corresponding percentages for cubital vein serum were 62, 23, and 3
1%. The cubital vein ratio of hCG:hCG alpha (546:1) and hCG:hCG beta (
51:1) decreased to 63:1 and to 7:1 in the hydrocele fluids. Surprising
ly, hydrocele fluids of five patients with pure seminoma, who were neg
ative for the three markers in the periphery, revealed an elevation of
free hCG beta in all cases, while hCG alpha and holo-hCG were elevate
d twice. Final proof that hCG beta and hCG alpha are indeed produced b
y these previously termed ''marker negative'' seminomas has been achie
ved by reverse transcripta-polmerase chain reaction with primers speci
fic for the a-subunit and the four most abundantly transcribed hCG bet
a genes 3, 5, 7, and 8. From these data, we conclude that: (a) seminom
atous and nonseminomatous testicular cancers, irrespective of histolog
y, secrete hCG and its free subunits; (b) the amount of free subunits
being secreted in vivo by these tumors has been underestimated; and (c
) the classification in marker-positive and marker-negative testicular
cancer should he reconsidered.