Alpha-fetoprotein and germ cell tumors: a possible role of yolk sac tumor in production of alpha-fetoprotein.

Abstract

Serum alpha-fetoprotein (αFP) was determined in 48 patients with germ cell tumors of the testis, ovary, and extragonadal sites. Thirty-four patients had evidence of active disease, while 14 patients were in remission. None of the latter had elevated serum αFP. Serum αFP was elevated in 10 patients. In the patients with elevated serum αFP, all the tumors which could be adequately studied histologically contained yolk sac tumor elements. As αFP is produced by normal human yolk sac, it is suggested that αFP in germ cell tumors may be produced by the yolk sac tumor elements. This may explain why only a certain number of patients with germ cell tumors have elevated serum αFP, and why in some cases serum αFP may be normal despite recurrence of the tumor. The results of the present study support the findings of other investigators, who consider that serum αFP estimation is a useful test in patients with germ cell neoplasia. Serum αFP estimation is of value in monitoring the results of therapy and assessing the presence of metastases and recurrences, although in the latter case a normal result may not always imply the absence of active disease.