Prognostic markers and long-term outcome of placental-site trophoblastic tumours: a retrospective observational study

SummaryBackgroundPlacental-site trophoblastic tumours are a rare form of gestational trophoblastic disease and consequently information about optimum management or prognostic factors is restricted. We aimed to assess the long-term outcome of stage-adapted management by surgery, chemotherapy, or both for patients with the disorder.Methods35 550 women were registered with gestational trophoblastic disease in the UK (1976–2006), of whom 62 were diagnosed with placental-site trophoblastic tumours and included, retrospectively, in the study. Patients were treated by surgery, chemotherapy, or both. We estimated the probabilities of overall survival and survival without recurrence of disease 5 and 10 years after the date of first treatment, and calculated the association of these endpoints with prognostic factors, including time since antecedent pregnancy, serum concentration of β-human chorionic gonadotropin, and stage of disease, with both univariate and multivariate analyses.FindingsProbabilities of overall and recurrence-free survival 10 years after first treatment were 70% (95% CI 54–82) and 73% (54–85), respectively. Patients with stage I disease had a 10-year probability of overall survival of 90% (77–100) and did not benefit from postoperative chemotherapy. By contrast, patients with stage II, III, and IV disease required combined treatment with surgery and chemotherapy; probability of overall survival at 10 years was 52% (3–100) for patients with stage II disease and 49% (26–72) for stage III or IV disease. Outcome for patients who had recurrent or refractory disease was poor: only four (22%) patients achieved long-term survival beyond 60 months. Multivariate analysis showed that the only significant independent predictor of overall and recurrence-free survival was time since antecedent pregnancy. A cutoff point of 48 months since antecedent pregnancy could differentiate between patients' probability of survival (<48 months) or death (≥48 months) with 93% specificity and 100% sensitivity, and with a positive predictive value of 100% and a negative predictive value of 98%.InterpretationStage-adapted management with surgery for stage I disease, and combined surgery and chemotherapy for stage II, III, and IV disease could improve the effectiveness of treatment for placental-site trophoblastic tumours. Use of 48 months since antecedent pregnancy as a prognostic indicator of survival could help select patients for risk-adapted treatment.FundingNational Commissioning Group.