Re-evaluation of 5-fluorouracil as a single agent for gestational malignant trophoblastic neoplasms.

Large doses of 5-fluorouracil, administered by slow intravenous drip, have proven to be very effective in the treatment of malignant trophoblastic tumors. From 1964 through 1975, 5-fluorouracil was used as a single chemotherapeutic agent in 173 cases of invasive mole and 139 cases of choriocarcinoma. This series of patients was further divided into Group A (212 cases) in which 5-fluorouracil was used as initial therapy, and Group B (100 cases) in which 5-fluorouracil was given to those who developed resistance to 6-mercaptopurine and/or to methotrexate. The overall remission rate in Group A patients was 98.4% for invasive mole and 93.0% for choriocarcinoma. In Group B patients the corresponding remission rate was 93.6% and 71.7%, respectively, indicating that 5-fluorouracil is effective in patients who develop resistance to other antimetabolic agents. The rate of recurrence among 213 patients achieving complete remission during follow-up was 1.4% (3 cases). All of the remaining 210 patients had survived for more than 5 years up to the end of 1981, and 96 patients (45.7%) had survived for more than 10 years. In comparison with other antimetabolites, 5-fluorouracil has the advantages of being more effective and less toxic, and can be administered through multiple routes. Therefore, it has remained the agent of first choice in the chemotherapy of malignant trophoblastic neoplasms.