Next-Generation Sequencing Panel Analysis of Clinically Relevant Mutations in Circulating Cell-Free DNA from Patients with Gestational Trophoblastic Neoplasia: A Pilot Study

Gestational trophoblastic neoplasia (GTN) originates from placental tissue and exhibits the potential for invasion and metastasis. Gene alterations in GTN have not been extensively studied because of a lack of qualified tumor specimens after chemotherapy. GTN has a rapid growth rate and is highly metastatic, which makes circulating tumor DNA (ctDNA) sequencing a promising modality for gene profiling. Accordingly, in this study, we performed targeted next-generation sequencing (NGS) of 559 tumor-associated genes using circulating cell-free DNA (cfDNA) collected prior to chemotherapy from 11 patients with GTN. All sequenced genes were associated with oncogenesis, progression, and targeted therapy. The average cfDNA level was 0.43 ± 0.22 ng/μL. Significant correlations were found between cfDNA concentration and maximum lesion diameter (r = 0.625, p=0.040) and time for human chorionic gonadotropin beta subunit (β-HCG) recovering to normal level (r = 0.609, p=0.047). There were no significant correlations between cfDNA concentrations and β-HCG expression level or lung metastasis. ctDNA mutations were detected in all patients, and 73 mutant genes were detected in 11 patients. BMPR1A (27.3%), LRP1B (27.3%), ERCC4 (18.2%), FGF14 (18.2%), HSP90AA1 (18.2%), KAT6A (18.2%), KMT2D (18.2%), MAP3K1 (18.2%), RANBP2 (18.2%), and ZNF217 (18.2%) mutations were detected as overlapping mutations. The mRNA and protein levels of bone morphogenetic protein receptor type 1A were significantly downregulated in human JAR and JEG-3 choriocarcinoma cells (p