Detection of ovarian cancer marker CA 125 in human seminal plasma.

Ovarian cancer marker CA 125-like immunoreactivity was detected in human seminal plasma. The levels were 17-720 U/ml in specimens from normospermic men (n = 35), 22-1150 U/ml in samples from 46 men with either oligo-, astheno-, terato- or necrospermia, and 36-1096 U/ml in 7 vasectomized men. No significant differences were found in the CA 125 levels between the groups studied. Low CA 125 levels (less than 35 U/ml) were detected in male sera. Serial dilutions of seminal plasma and ovarian cancer serum gave parallel dose-response curves. No correlation was observed between the age of men, sperm count, volume of seminal plasma or percent of motile spermatozooa and CA 125 levels in seminal plasma. CA 125 in seminal plasma does not seem to be of testicular origin, as the levels in vasectomized and non-vasectomized men were similar. In gel filtration, CA 125 immunoreactivity in seminal plasma and ovarian cancer serum eluted in the same volume corresponding to a molecular weight of about 130 kD.