Serum β-hCG as an Indicator for Persistence in Gestational Trophoblastic Neoplasia

Open Access

Abstract

Background: Gestational trophoblastic neoplasia (GTN) is a potentially aggressive trophoblastic disorder in which persistent elevation or abnormal regression of serum beta-human chorionic gonadotropin (β-hCG) after molar evacuation may indicate persistent disease. Early identification of persistent GTN is essential to reduce morbidity and improve treatment outcomes. Aim of the study: To evaluate the role of serial serum β-hCG levels as an indicator for predicting persistence in gestational trophoblastic neoplasia during post-evacuation follow-up. Methods & Materials: This prospective observational study was conducted in the Department of Gynecological Oncology at Bangabandhu Sheikh Mujib Medical University (BSMMU), Bangladesh, from January 2021 to December 2021. Fifty patients with histopathologically confirmed hydatidiform mole who underwent suction evacuation were enrolled consecutively. Serial serum β-hCG levels were measured 48 hours after evacuation and monitored weekly for at least 8 weeks. Patients were categorized into persistent GTN (Group A, n=7) and spontaneous remission (Group B, n=43). Statistical analyses included chi-square test, unpaired t-test, ROC curve analysis, and multivariate logistic regression. Result: Persistent GTN developed in 14.0% of patients. Younger age, low socioeconomic status, low BMI, previous molar pregnancy, thyrotoxic features, uterine enlargement, expulsion of grape-like vesicles, large theca lutein cysts, and vesicular uterine appearance on ultrasonography were significantly associated with persistent GTN. All patients with persistent GTN had 48-hour post-evacuation β-hCG levels >100,000 mIU/mL (p=0.011). Mean log β-hCG values became significantly higher in persistent GTN cases from the 5th week onward (p=0.001). Diagnostic performance improved progressively over time, with the highest predictive accuracy observed at the 8th week (cutoff 1.59; sensitivity 97.7%, specificity 100%, AUC 0.997). Multivariate logistic regression identified younger age and elevated 48-hour β-hCG levels as independent predictors of persistent GTN. Conclusion: Serial serum β-hCG monitoring is a highly effective tool for early detection of persistent GTN following molar evacuation. Elevated 48-hour β-hCG levels and delayed decline of β-hCG after the 5th post-evacuation week are strong predictors of persistence. Regular β-hCG surveillance may facilitate timely intervention and improve clinical outcomes in patients with gestational trophoblastic disease.