Alpha-fetoprotein in malignant germ cell tumors of the ovary.

To investigate the clinical significance of alpha-Fetoprotein (AFP) in malignant germ cell tumors of the ovary, we studied 46 patients who were treated by the Tokai Ovarian Tumor Study Group. The 46 patients had the following tumors: immature teratoma (IT), 17 cases; endodermal sinus tumor (EST), 16 cases; mixed germ cell tumor containing EST, 11 cases; embryonal carcinoma, 1 case; polyembryoma, 1 case. In all 29 non-IT cases, AFP was positive, and in 27 cases (93%) the level was above 1000 ng/ml. In 11 of 17 cases of IT (64.7%), AFP levels were elevated and in 1 case the level was above 1000 ng/ml. Elevation of the AFP level above 1000 ng/ml suggested the presence of EST. AFP levels were monitored in 27 of 29 cases without IT during treatment and follow-up. It was found that AFP levels should be monitored closely for at least 1 year after induction of remission. No recurrence was observed when AFP continued to be negative longer than 1 year. The mean interval to clinical recurrence from the reelevation of AFP was 4 months (1.4-9 months). An increase in the AFP to a positive level, even without clinical signs of recurrence, should be regarded as a recurrence. AFP was found to be a useful tumor marker for the diagnosis and management of malignant germ cell tumors of the ovary.