Metastatic gestational trophoblastic disease: a comparison of prognostic classification systems

The records of 53 consecutive patients with metastatic gestational trophoblastic disease (MGTD) treated at the University of Southern California/Los Angeles County Medical Center since 1970 were analyzed. Forty-eight were evaluable for this study. Treatment during the study period was based predominantly on the NIH good-prognosis-poor-prognosis system, employing single-agent therapy (methotrexate or actinomycin D) for the good-prognosis patients and methotrexate, actinomycin D, cyclophosphamide (MAC) for the poor-prognosis patients. The overall survival rate was 83.3%. The study patients were retrospectively classified according to the FIGO, NIH, and WHO systems to test each system's accuracy in predicting outcome and the appropriateness of single-agent or multiagent chemotherapy as the initial treatment in each category. None of the systems as currently used is clearly superior to the others. Analysis of the WHO scoring system showed that 21 of the 25 (84.0%) study patients with a point score less than 8 were treated primarily with a single-agent regimen. All of 21 of these patients achieved a complete sustained remission although 3 (14.3%) required multiagent chemotherapy. The 4 patients in this point category whose initial therapy was a multidrug regimen were also cured. The 23 patients in the WHO high-risk category (greater than 7) had treatment initiated with combination chemotherapy. There were no deaths among the 11 patients in the 8-12 point group, although 3 (27.3%) were salvaged by alternate multiagent chemotherapy after failing on MAC. There were 8 deaths in the 12-patient greater than 12 point WHO category (66.7%). On the basis of this analysis we recommend that the WHO scoring system be utilized for reporting results of treatment for MGTD, but the risk categories should be redefined: low, less than 8 points; medium, 8-12 points; high, greater than 12 points.