Dynamics of Gestational Trophoblastic Neoplasia Following Molar Pregnancy: A Systematic Review and Meta-Analysis

Background & Objective: Gestational Trophoblastic Disease (GTD) covers a range of conditions from noncancerous moles to malignant tumors, grouped as gestational trophoblastic Neoplasia (GTN). It's essential to monitor Human Chorionic Gonadotropin (hCG) levels after mole removal to detect potential progression to GTN, with 15% risk of malignant transformation for Complete Moles (CM) and 1-3% for Partial Moles (PM). This study was conducted with aims to estimate GTN occurrence after hCG levels normalize and identify the likely timeframe for disease reemergence to guide evidence-based follow-up recommendations.Materials & Methods: This systematic review and meta-analysis was conducted through searching in PubMed, Cochrane, Science Direct, and Google Scholar databases. Nineteen studies including 22179 CM and 18233 PM pregnancy cases with mean age of 29.7 years old and mean Gestational Age (GA) at evacuation of 11.5 weeks were included.Results: Overall pooled incidence of GTN in all types of molar pregnancy were 9.6%, incidence of GTN was higher after CM compared to PM. Most cases occurred when hCG normalization took 56 days or longer after evacuation (87.8% for CM, 60% for PM) with 72% of GTN cases in CM were above 6 months. When compared to PM, CM have higher risk of GTN (RR 4.43, 95% CI (3.89-5.05), P<0.001), significantly higher risk of GTN after 6 month of first normal hCG after evacuation (RR 6.47, 95% CI (2.77-15.11), P<0.001), which in line with significantly need longer time to achieve normal hCG (MD 1.18 weeks, 95% CI (0.62-1.75), P<0.001).Conclusion: Extended monitoring may be necessary for patients with CM and delayed hCG normalization, potentially beyond the 6-month period.