Evaluation of serum progesterone during treatment of malignant trophoblastic disease

Serial assays of serum progesterone and serum human chorionic gonadotropin (HCG) were performed in eight cases of choriocarcinoma before and during treatment of the disease. Serum progesterone was measured by the competitive protein-binding technique and serum HCG was measured by the hemagglutination inhibition method. Serum HCG gives a better index of response of the tumor to treatment when compared to serum progesterone. In cases where the ovaries are still present serum progesterone does not disappear completely when the disease is eradicated and fluctuates cyclically, thus reflecting ovarian activity. However, in most cases with pulmonary secondaries, serum progesterone was elevated in spite of undetectable serum HCG. With widespread metastases serum progesterone rose to pregnancy levels and remained persistently high. Cerebrospinal fluid progesterone in a case of choriocarcinoma with cerebral metastasis was 5 ng. per milliliter, which was very much higher than in normal pregnant subjects. The findings of serum progesterone in comparison to serum HCG during therapy of choriocarcinoma are discussed.