Methotrexate for prophylaxis of choriocarcinoma

The malignancy rate in 580 cases of hydatidiform mole in Singapore was 14.8 per cent. An attempt was made to reduce this rate by giving patients with moles 3 courses of prophylactin oral methotrexate totaling 150 mg. after removal of the mole. In a study involving 380 patients, including control subjects, the treatment achieved a slight reduction in malignancy rate from 8.7 to 4.5 per cent, but it produced considerable toxicity and a significantly increased mortality rate (2.2 per cent compared with 0.5 per cent in controls). However, the tumors which developed subsequent to prophylactic methotrexate were sensitive to the same drug given in larger doses. Choriocarcinomas which were recognized within a year of hydatidiform mole were highly sensitive to chemotherapy, and a 100 per cent survival rate can be expected if close follow-up and carefully supervised treatment are instituted. There was an 80 per cent mortality rate among 5 cases of choriocarcinoma which were detected later. It is suggested that closer supervision of follow-up programs, parenteral chemotherapy, a careful, decisive rotation of chemotherapeutic agents, and selective use of radiotherapy in cases of cerebral choriocarcinoma may improve the survival rate in the late cases. Routine prophylactic chemotherapy for hydatidiform mole is not recommended.