We evaluated 24 patients who were diagnosed with high-risk GTN between January 2000 and October 2019, including 15 cases of pathologically proven gestational choriocarcinomas and the causative pregnancy was investigated by STR analysis in which tumor DNA could be extracted.
In high-risk GTN without history of anteceding molar pregnancies, nonmolar pregnancy was the causative pregnancy, which was confirmed in three cases. Molar pregnancy appeared be the causative pregnancy of high-risk GTN in patients with a history of antecedent molar pregnancies either with or without interruption by subsequent nonmolar pregnancies prior to developing high-risk GTN. High-risk GTN in most of the evaluated deceased cases (three of four) was due to nonmolar pregnancy, while all but one case with molar pregnancy as the causative pregnancy survived.
STR analysis can distinguish the causative pregnancy of high-risk GTN, and nonmolar pregnancy as the causative pregnancy might have negative effects on the outcome of the disease.