Prediction of Gestational Trophoblastic Neoplasia using serum human chorionic gonadotropin concentrations longitudinal data during 21 days after evacuation mole

Gestational Trophoblastic Neoplasia (GTN) is the malignant form of gestational trophoblastic disease that has different capabilities in metastasis and invasion stance. Therefore, the aim of this study was to identify an appropriate and applicable longitudinal marker, using the serum human chorionic gonadotropin (hCG) levels during 21 days after mole evacuation for predicting the gestational trophoblastic neoplasia in women with molar pregnancy.
In the present retrospective study, documents of 201 patients with hydatidiform mole, according to their pathological reports, who from 2003 to 2013 referred to the educational and health care centers affiliated to Shahid Beheshti University of Medical Sciences were investigated. A two-stage shared random effects model was used to assess the relationship between repeated measures of β-hCG concentration (as the longitudinal marker) and occurrence of GTN. To determine the power of repeated β-hCG values for predicting GTN, a receiver operating characteristic (ROC) curve was applied in the statistical software R version 2.15.3.
In a total sample of 201 patients, 171 cases (85.1%) had spontaneous remission and GTN was detected in 30 cases (14.9%). Our modeling approach showed that the repeated measures of β-hCG concentration (in weeks 0, 1, 2 and 3) can correctly classify about 86.7% of patients with GTN and 83.0% of patients without GTN. The estimated area under curve (AUC) was 91.2%.
Our findings revealed that the repeated measures of β-hCG concentration have a high predictive accuracy for early detection of GTN. Thus, for women who suffered from molar pregnancy, monitoring the three-week trend of this marker is recommended for early detection of this malignancy.