Measurement of CA-125 in trophoblastic disease.

OBJECTIVES: Physicians treating hydatidiform mole are still seeking means of identifying those patients who will require chemotherapy. The standard accepted method is to follow human chorionic gonadotropin levels but CA-125 measurement has been suggested as a supplement that may be clinically useful. This study was undertaken to validate or refute the one previous study that addresses this issue. CA-125 was measured at the time of hydatidiform mole evacuation to determine (1) whether it would predict the need for chemotherapy and (2) whether it correlated with human chorionic gonadotropin and tumor load in following patients with hydatidiform mole and metastatic gestational trophoblastic disease.

PATIENTS AND METHODS: CA-125 was measured in serial weekly samples selected from diagnostic groups of patients with trophoblastic disease. Sixteen patients had hydatidiform mole with spontaneous resolution, fourteen had nonmetastatic gestational trophoblastic tumor, and four had low-risk metastatic disease. Six patients had high-risk metastatic disease. Ten patients had partial hydatidiform mole and one of these required chemotherapy. One patient had primary ovarian choriocarcinoma and three had placental site tumor.

RESULTS: The mean preevacuation CA-125 among the 15 patients with complete hydatidiform mole was 40.9 U/ml: 52.5 U/ml for 5 patients who required chemotherapy and 36.2 U/ml for 10 patients who did not require chemotherapy. There was no statistical difference between these values. There was no correlation of CA-125 with hCG. Frequently CA-125 became negative when hCG was still elevated. Among six patients with high-risk disease, CA-125 was elevated in four but in all six patients hCG remained elevated when CA-125 became negative. In nine patients with partial hydatidiform mole CA-125 was elevated prior to mole evacuation and then became negative. The patient with a tetraploid conceptus who required chemotherapy had negative CA-125. With placental site tumor CA-125 was negative, but it was elevated with ovarian choriocarcinoma.

CONCLUSION: CA-125 levels do not provide reliable information in the management of patients with gestational trophoblastic disease.