Correlation Between Serum and Urine β-hCG in Gestational Trophoblastic Neoplasia: A Step Toward Non-Invasive Disease Monitoring

Andi Kurniadi, Aria Yusti Kusuma, Wiryawan Permadi, Gatot Nyarumenteng Adhipurnawan Winarno, Yudi Mulyana Hidayat, Febia Erfiandi, Jessica Kireina Department of Obstetrics and Gynaecology, Faculty of Medicine Universitas Padjajaran – Dr Hasan Sadikin Hospital, Bandung, IndonesiaCorrespondence: Andi Kurniadi, Department of Obstetrics and Gynaecology, Faculty of Medicine, Universitas Padjajaran – Dr Hasan Sadikin Hospital, Jl. Pasteur 38, Bandung, West Java, 40161, Indonesia, Tel +6281220286197, Email [email protected]: Gestational Trophoblastic Neoplasia (GTN) are malignant trophoblastic proliferations requiring accurate monitoring to guide treatment and assess disease progression. Serum β-hCG is the standard biomarker for GTN monitoring, but it requires blood collection, which can be invasive and resource-intensive. Urinary β-hCG testing offers a non-invasive alternative, but its clinical reliability in GTN patients remains unclear. This study evaluates the correlation between urinary and serum β-hCG levels in GTN patients, aiming to determine the feasibility of urine β-hCG as a reliable non-invasive monitoring tool.Patients and Methods: A cross-sectional study was conducted at Dr. Hasan Sadikin General Hospital, Bandung, from June 2024 to February 2025, involving 31 patients diagnosed with GTN. A total of 86 paired serum and urine β-hCG samples were analyzed using enzyme-linked immunosorbent assay (ELISA). Data normality was assessed using the Kolmogorov–Smirnov test. Pearson’s correlation and simple linear regression were used to evaluate the relationship between serum and urine β-hCG levels.Results: Serum β-hCG levels were significantly higher than urine levels (P < 0.001), but a strong positive correlation was observed between the two (r = 0.985, P < 0.001), with a coefficient of determination (r2 = 96.9%).Conclusion: Urinary β-hCG exhibits a strong correlation with serum β-hCG in GTN patients, supporting its potential as a non-invasive monitoring tool. However, hydration status, renal function, and possible assay interferences should be considered. Combining serum and urine β-hCG measurements remains the optimal approach for accurate disease monitoring.Keywords: gestational trophoblastic neoplasia, β-hCG, urine β-hCG, serum β-hCG, tumor monitoring, non-invasive biomarker