B-hCG and H-hCG levels in patients with gestational trophoblastic neoplasia

Abstract

Objective: Gestational trophoblastic disease is a term that encompasses a spectrum of disorders all arising from the placenta. Human chorionic gonadotropin (hCG) hormone has an essential role in the diagnosis and management of gestational trophoblastic neoplasia. Measuring beta-hCG (B-hCG) levels is the only standard method of monitoring treatment response in patients on chemotherapy. Serial B-hCG levels are also helpful in defining the suitable approach and the dosage of chemotherapeutic drugs. Unfortunately, this marker may not be helpful in some cases. Therefore, the present study was conducted to determine the results of the ratio of B-hCG and hyperglycosylated human chorionic gonadotropin (H-hCG) in patients with gestational trophoblastic neoplasia. Materials and methods: This was a cross-sectional study in 22 patients with gestational trophoblastic neoplasia who were referred to an oncology clinic of an academic hospital of Mashhad University of Medical Sciences in Iran from December 2017 to May 2018. Inclusion criteria were plateau level of B-hCG (during 4 weeks) or persistent low level of hCG. After ruling out other etiologies, H-hCG level was measured and the H-hCG/total hCG ratio was evaluated. If the proportion was more than 20%, active gestational trophoblastic neoplasia was diagnosed, and if it was less than 20%, quiescent gestational trophoblastic neoplasia was diagnosed. In patients with active gestational trophoblastic neoplasia, interventional procedures involved a change in the dose intensity or chemotherapy or proposing a surgery. However, only serial follow-up was recommended in patients with quiescent gestational trophoblastic neoplasia. Then, the patients were followed during the therapy and the condition of patients was followed and recorded. Results: The mean age of patients was 31.36 ± 8.01 years. Hydatidiform mole was the most common diagnosis, accounting for approximately 64% (14) of patients. A total of 81% of patients were undergoing chemotherapy. The interval time between the onset of chemotherapy until plateau or persistent low level of hCG was 11.26 ± 4.03 weeks. The mean B-hCG level was 36.6 mIU/mL and the mean H-hCG/total hCG ratio was 6.24%. This proportion was less than 20% in 82% of patients. Among these patients, 14 patients (77.8%) had spontaneously normalized levels of B-hCG during a 6-month follow-up. Two cases underwent chemotherapy due to increased B-hCG. Other patients are still under follow-up without disease progression. Among 4 patients with a H-hCG/total hCG ratio >20%, hysterectomy was recommended to one patient duo to multiparity and the fact that the tumor was localized in the uterus. In the other patients, an increase in the dose of methotrexate or a change of chemotherapy regimen was performed, which caused a decrease in B-hCG level to normal. All patients are still under follow-up without disease progression. Conclusion: The data in this study suggests the use of H-hCG as a tumor marker in patients with persistent low level of B-hCG, which is useful to distinguish between quiescence gestational trophoblastic neoplasia, which does not need treatment, from active gestational trophoblastic neoplasia. However, further studies with larger sample size are needed to confirm and generalize the above findings. Keywords: gestational trophoblastic