Human chorionic gonadotropin free beta-subunit measurement as a marker of placental site trophoblastic tumors.
ABSTRACT To evaluate the utility of free human chorionic gonadotropin beta-subunit (hCGbeta) proportion of total hCG measurement to distinguish placental site trophoblastic tumor (PSTT) from more common forms of gestational trophoblastic disease (GTD).
Serum samples collected from PSTT, persistent trophoblastic disease (PTD) and choriocarcinoma patients were used for retrospective analysis of free hCGbeta-subunit. Results were reported as a percentage of total hCG using our in-house competitive radioimmunoassay.
The percentage of free hCGbeta was significantly greater in serum from 18 PSTT patients, yielding a median value of 45.5% than in a combined GTD group of 49 PTD and 12 choriocarcinoma patients. Receiver operating characteristic analysis confirms that the percentage free hCGbeta distinguishes PSTT from GTD patients. Choriocarcinoma patients had significantly higher hCGbeta measurements than PTD patients and were not well distinguished from PSTT patients.
Our findings show that an elevated proportion of free hCGbeta-subunit is a helpful but not definitive test to discriminate PSTT from other forms of GTD.
SourceAvailable from: Rosemary FisherAnnals of Oncology 09/2013; DOI:10.1093/annonc/mdt345 · 6.58 Impact Factor
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ABSTRACT: We have previously defined a new syndrome "Minimally-aggressive gestational trophoblastic neoplasms" in which choriocarcinoma or persistent hydatidiform mole has a minimal growth rate and becomes chemorefractory. Previously we described a new treatment protocol, waiting for hCG rise to >3000 mIU/ml and disease becomes more advanced, then using combination chemotherapy. Initially we found this treatment successful in 8 of 8 cases, here we find this protocol appropriate in a further 16 cases. Initially we used hyperglycosylated hCG, a limited availability test, to identify this syndrome. Here we propose also using hCG doubling rate to detect this syndrome. Minimally aggressive gestational trophoblastic disease can be detected by chemotherapy resistance or low hyperglycosylated hCG, <40% of total hCG. It can also be identified by hCG doubling rate, with doubling time greater than 2 weeks. Nineteen new cases were identified as having minimally aggressive gestational trophoblastic disease by hyperglycosylated hCG and by hCG doubling test. All were recommended to hold off further chemotherapy until hCG >3000mIU/ml. One case died prior to the start of the study, one case withdrew because of a lung nodule and one withdrew refusing the suggested combination chemotherapy. The remaining 16 women were all successfully treated. A total of 8 plus 16 or 24 of 24 women were successfully treated using the proposed protocol, holding back on chemotherapy until hCG >3000mIU/ml.Gynecologic Oncology 12/2011; 125(1):145-50. DOI:10.1016/j.ygyno.2011.12.441 · 3.69 Impact Factor
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ABSTRACT: OBJECTIVE: Currently, human chorionic gonadotropin (hCG) follow-up after evacuation of hydatidiform moles is essential to identify patients requiring chemotherapeutic treatment for gestational trophoblastic neoplasia (GTN). We propose a model based on linear regression of postevacuation serum hCG concentrations for the prediction of GTN. METHODS: One hundred thirteen patients with at least 3 serum samples from days 7 to 28 after evacuation were selected from the Dutch Central Registry for Hydatidiform Moles (1994-2009). The slopes of the linear regression lines of the first 3 log-transformed serum hCG and free β-hCG values were calculated. Receiver operating characteristic curves were constructed to calculate areas under curve (AUCs). RESULTS: The slope of the hCG regression line showed an AUC of 0.906 (95% confidence interval, 0.845-0.967). Gestational trophoblastic neoplasia could be predicted in 52% of patients with GTN at 97.5% specificity (cutoff, -0.020). Twenty-one percent of patients with GTN could be predicted before diagnosis according to the International Federation of Gynecology and Obstetrics 2000 criteria. The slope of free β-hCG showed an AUC of 0.844 (95% confidence interval, 0.752-0.935), 69% sensitivity at 97.5% specificity, and 38% of patients with GTN could be predicted before diagnosis according to the International Federation of Gynecology and Obstetrics criteria. CONCLUSIONS: The slope of the linear regression line of hCG proved to be a good test to discriminate between patients who will achieve spontaneous disease remission and patients developing GTN. The slope of free β-hCG seems to be a better predictor for GTN than the slope of hCG. Although this model needs further validation for different assays, it seems a promising way to predict the more aggressive cases of GTN.International Journal of Gynecological Cancer 05/2013; DOI:10.1097/IGC.0b013e31829703ea · 1.95 Impact Factor