Radioimmunoassay of free beta-subunit of human chorionic gonadotropin in diagnosis of high-risk and low-risk gestational trophoblastic disease

A radioimmunoassay was performed with monoclonal antibody 1E5, which distinguishes free beta-subunit of human chorionic gonadotropin in the presence of intact human chorionic gonadotrophin. Serum samples were obtained from 68 pregnant women, 9 with hydatidiform mole who underwent spontaneous remission, 12 with hydatidiform mole who developed gestational trophoblastic disease, 5 with metastatic gestational trophoblastic disease of high-risk category, and 1 with choriocarcinoma concomitant with pregnancy. The concentrations of free beta-subunit of human chorionic gonadotropin and total beta-subunit were determined on the sera. The assay data were expressed as a ratio of nanograms of free beta-subunit per 1000 mIU of total beta-subunit. The ratios, analyzed by the Wilcoxon two-sample test, indicated a highly significant correlation between high ratios and the eventual diagnosis of high-risk gestational trophoblastic disease (p = 0.0019). This study suggests that the excessive production of free beta-subunit of human chorionic gonadotrophin may identify patients with high-risk gestational trophoblastic disease much earlier and identify gestational trophoblastic disease in patients during pregnancy.     

Duration of human chorionic gonadotropin surveillance for partial hydatidiform moles

OBJECTIVE: Partial hydatidiform moles infrequently progress to gestational trophoblastic neoplasia. The purpose of this study was to determine the optimal duration of human chorionic gonadotropin surveillance. STUDY DESIGN: We retrospectively reviewed the clinical follow-up of all women who were diagnosed with partial hydatidiform mole at our institution from 1983 to 2003. RESULTS: One hundred sixty-three patients were identified with a median age of 23 years (range, 14-42 years). Seventy-four patients (45%) attained undetectable levels of human chorionic gonadotropin; none of the patients had gestational trophoblastic neoplasia. Forty patients completed the 6 months of recommended follow-up; 6 patients conceived during surveillance, and 28 patients did not return for any further office visits 1 to 5 months after achieving remission. Eighty-three patients (51%) were lost to follow-up before normalization of human chorionic gonadotropin. Six women (4%) had stage I gestational trophoblastic neoplasia during surveillance. CONCLUSION: Our results support the suggestion that a single undetectable human chorionic gonadotropin level after evacuation is sufficient follow-up to ensure remission in patients with partial hydatidiform moles.     

Expression of c-erb B-2 oncogene product in persistent gestational trophoblastic disease

OBJECTIVE: Much debate exists on the initiation of chemotherapy for women at risk for persistent gestational trophoblastic disease. This is a result of a lack of early predictors for the development of persistent gestational trophoblastic disease after evacuation of a complete hydatidiform mole, because the only current reliable method of detection and diagnosis lies in persistent or rising postmolar β-human chorionic gonadotropin values. We used immunocytochemical techniques to retrospectively study the expression of the c-erb B-2 oncogene product in formalin-fixed, paraffin-embedded trophoblastic tissues as a potential indicator of the development of persistent gestational trophoblastic disease. STUDY DESIGN: In this retrospective study 56 trophoblastic tumors were examined by means of immunocytochemical techniques to stain for the oncogene product for evidence of c-erb B-2 expression. Our 56 cases included original tissue from 20 cases of complete mole that progressed to persistent gestational trophoblastic disease, seven cases of choriocarcinoma after term pregnancy or abortion, and 29 cases of hydatidiform mole representing postevacuation, spontaneously regressing disease (including one partial mole). We also studied 11 cases of first-trimester trophoblast and 15 cases of term placenta as additional controls. RESULTS: Our results showed positive immunostaining for c-erb B-2 gene product in one case of persistent gestational trophoblastic disease, with negative staining in all other cases in the study groups and controls. CONCLUSION: Analysis for the significance of c-erb B-2 expression in persistent gestational trophoblastic disease showed that this correlation between c-erb B-2 expression and persistent gestational trophoblastic disease is not significant, suggesting that future efforts should be directed at the involvement of different oncoproteins. (AM J Obstet Gynecol 1994;170:1616-22.)     

Radioimmunoassay of free beta-subunit of human chorionic gonadotropin as a prognostic test for persistent trophoblastic disease in molar pregnancy

A new radioimmunoassay system was established with a monoclonal antibody (1E5) that distinguishes the free beta-subunit of human chorionic gonadotropin in the presence of intact human chorionic gonadotropin, showing only 0.23% cross-reactivity with the intact human chorionic gonadotropin molecule and virtually no cross-reactivity with other glycoprotein hormones or their beta-subunits. Serum samples, taken at initial diagnosis from nine patients with hydatidiform mole and spontaneous remission and 12 patients with subsequent progression to persistent trophoblastic disease, were assayed for free and total levels of the beta-subunit of human chorionic gonadotropin. The assay results were expressed as a ratio of nanograms of free beta-subunit per 1000 mIU of total beta-subunit. Eight of nine patients with mole and spontaneous remission had a ratio value less than 4 whereas 10 of 12 patients with subsequent persistent disease had a ratio value greater than 4. Statistical analysis with chi 2 showed a highly significant correlation of high ratios with eventual progressive disease (p = 0.0009). This study suggests that excessive production of the free beta-subunit of human chorionic gonadotropin may identify patients with a high likelihood of developing persistent trophoblastic disease.     

Diagnostic reliability of simultaneous measurements of beta human chorionic gonadotropin and pregnancy-specific beta-1-glycoprotein in serum of patients with trophoblastic disease

Serum levels for beta-human chorionic gonadotropin (beta-hCG) and pregnancy-specific beta 1-glycoprotein (SP1) in patients with trophoblastic disease were measured by radioimmunoassay and enzyme-linked immunosorbent assay. The beta-hCG:SP1 ratios were below 1.0 in all 22 cases of complete hydatidiform mole and in 8 of 9 cases of partial hydatidiform mole. Two (10.5%) of 19 cases of invasive mole involving metastasis had ratios that rose above 1.0 during chemotherapy. Ratios ranged from 1.6 to 29 in 11 of 15 cases of choriocarcinoma before chemotherapy. The remaining 4 cases, diagnosed within 3 months of antecedent pregnancy, had ratios below 0.99. Thus, the difference between choriocarcinoma and nonchoriocarcinoma beta-hCG:SP1 ratios may be due to trophoblastic differentiation based on the developmental stage and with trophoblast age, or due to the mass and potential activity of trophoblastic cells.     

Measurement of CA-125 in trophoblastic disease

OBJECTIVES: Physicians treating hydatidiform mole are still seeking means of identifying those patients who will require chemotherapy. The standard accepted method is to follow human chorionic gonadotropin levels but CA-125 measurement has been suggested as a supplement that may be clinically useful. This study was undertaken to validate or refute the one previous study that addresses this issue. CA-125 was measured at the time of hydatidiform mole evacuation to determine (1) whether it would predict the need for chemotherapy and (2) whether it correlated with human chorionic gonadotropin and tumor load in following patients with hydatidiform mole and metastatic gestational trophoblastic disease. PATIENTS AND METHODS: CA-125 was measured in serial weekly samples selected from diagnostic groups of patients with trophoblastic disease. Sixteen patients had hydatidiform mole with spontaneous resolution, fourteen had nonmetastatic gestational trophoblastic tumor, and four had low-risk metastatic disease. Six patients had high-risk metastatic disease. Ten patients had partial hydatidiform mole and one of these required chemotherapy. One patient had primary ovarian choriocarcinoma and three had placental site tumor. RESULTS: The mean preevacuation CA-125 among the 15 patients with complete hydatidiform mole was 40.9 U/ml: 52.5 U/ml for 5 patients who required chemotherapy and 36.2 U/ml for 10 patients who did not require chemotherapy. There was no statistical difference between these values. There was no correlation of CA-125 with hCG. Frequently CA-125 became negative when hCG was still elevated. Among six patients with high-risk disease, CA-125 was elevated in four but in all six patients hCG remained elevated when CA-125 became negative. In nine patients with partial hydatidiform mole CA-125 was elevated prior to mole evacuation and then became negative. The patient with a tetraploid conceptus who required chemotherapy had negative CA-125. With placental site tumor CA-125 was negative, but it was elevated with ovarian choriocarcinoma. CONCLUSION: CA-125 levels do not provide reliable information in the management of patients with gestational trophoblastic disease.     

Telomerase activity in complete hydatidiform mole.

OBJECTIVE: To investigate whether telomerase is activated in complete hydatidiform mole and whether it could predict the development of persistent gestational trophoblastic tumors (GTTs). STUDY DESIGN: For this prospective study, 21 patients with complete hydatidiform mole were recruited. Molar tissue was obtained for telomerase activity measurement using the telomeric repeat amplification protocol assay. Patients' clinical characteristics, telomerase activity and subsequent clinical outcome were analyzed. RESULTS: Telomerase activity was detected in 12 cases (57.1%) with varied intensity. Two of four patients who had telomerase activity, uterine size larger than expected and preevacuation serum beta-human chorionic gonadotropin (beta-hCG) levels > 10(6) mIU/mL developed persistent GTT. CONCLUSION: Telomerase activity is detectable in some complete hydatidiform moles and might be useful for predicting persistent GTT when combined with uterine size and preevacuation serum beta-hCG level.     

Factor VIII related antigen in gestational trophoblastic disease

Serum factor VIII related antigen (factor VIII R:Ag) levels were determined in 34 patients with hydatidiform mole at diagnosis and at 2, 4 and 6 weeks after evacuation of uterus and in 272 normal pregnant women. Serum factor VIII R:Ag levels in molar pregnancies before evacuation of the uterus were significantly higher than those in normal pregnancies of the same gestation age. Serum factor VIII R:Ag levels in the group of patients with residual trophoblastic disease were significantly higher than those in the group without residual trophoblastic disease before evacuation and at 6 weeks after evacuation of uterus, but there is considerable overlap in the levels of factor VIII R:Ag between the two groups of patients especially before evacuation of uterus. Factor VIII R:Ag level does not appear to be an useful marker in predicting the outcome of hydatidiform mole.     

Recurrent gestational trophoblastic disease after hCG normalization following hydatidiform mole in The Netherlands

OBJECTIVES: To determine the risk for recurrent trophoblastic disease after spontaneous normalization of human chorionic gonadotropin (hCG) levels in patients with hydatidiform mole and to determine the risk for tumor relapse after apparent remission following chemotherapy in patients with low- and high-risk persistent trophoblastic disease. METHODS: From 1994 until 2004, 355 patients with hydatidiform mole were registered at the Dutch Central Registry of Hydatidiform Mole and were monitored by sequential hCG assays in serum at the department of Chemical Endocrinology of the Radboud University Nijmegen Medical Centre. HCG regression curves were analyzed together with clinical information collected from the Hydatidiform Mole Database. RESULTS: Among the 355 registered hydatidiform mole patients, 265 patients attained spontaneous normalization following evacuation. Of the 265 patients, one patient (0.38%) subsequently required chemotherapeutic treatment for recurrent trophoblastic disease (95% confidence interval 0.0% to 2.1%). HCG levels did not decline to normal (<2.0 ng/ml) spontaneously in 90 patients; those patients were subsequently treated. Relapse rates were 8.1% (6/74) and 6.3% (1/16) for the low- and high-risk category respectively. CONCLUSION: Our analysis indicates that relapse risk in hydatidiform mole patients with spontaneous normalization is extremely low (one in 265 patients) after two normal hCG levels (<2.0 ng/ml) are achieved. Our results support the suggestion that two subsequent normal hCG levels may be sufficient to ensure sustained remission after hydatidiform mole evacuation. In contrary, in order to assure sustained remission, the relapse rates after chemotherapy in the current study emphasize the need for surveillance of trophoblastic tumor patients even after complete remission has apparently been achieved.     

Serum testosterone and dihydrotestosterone in patients with trophoblastic disease.

Serum testosterone (T) and dihydrotestosterone (DHT) were measured by radioimmunoassay in 14 patients with unaborted hydatidiform mole and in 16 patients with normal pregnancy of similar gestational age. Serum human chorionic gonadotropin (hCG) was measured by the radioreceptor assay in patients with hydatidiform mole. Serum T ranged from 0.27 to 5.39 ng/ml with a mean +/- SE of 2.21 +/- 0.45 ng/ml in patients with hydatidiform mole mole and from 0.20 to 2.40 ng/ml with a mean +/- SE of 0.80 +/- 0.14 ng/ml in patients with normal pregnancy, the difference being statistically significant (P = less than 0.005). Similarly, patients with molar pregnancies had a significantly higher (P = less than 0.005) serum DHT (range: 0.09 to 0.62 ng/ml; mean +/- SE: 0.29 +/- 0.05 ng/ml) than patients with normal pregnancies (range: 0.04 to 0.28 ng/ml; mean +/- SE 0.12 +/- 0.02 ng/ml). There was no significant correlation between uterine size or serum hCG and serum T or DHT. The possible sources of the elevated serum T and DHT and the lack of hirsutism or virilization in patients with trophoblastic disease are discussed.     

Persistent low levels of human chorionic gonadotropin: A premalignant gestational trophoblastic disease

OBJECTIVE: This study was undertaken to evaluate the significance of persistent low-level human chorionic gonadotropin (hCG) titers (usually <50 IU/L) in the absence of clinical evidence of pregnancy or gestational trophoblastic disease. STUDY DESIGN: The USA hCG Reference Service consulted on 114 cases with persistent low levels of hCG; 51 had false-positive hCG results. The remaining 63 cases had real hCG results and are presented here. RESULTS: Antecedent gestational events included hydatidiform mole (27), pregnancy (35), and gestational trophoblastic neoplasm (1). Forty of the 63 (64%) cases received therapy, including chemotherapy (38), hysterectomy (2), or both (10). Despite treatment, in all cases, low hCG titers persisted. After 1 to 4.5 years of low titers, four women had a sudden rapid increase in hCG levels, and malignant disease was confirmed or clearly suggested (gestational trophoblastic neoplasm [3] and placental site trophoblastic tumor [1]). Invasive trophoblast antigen (ITA) is a marker of invasive cytotrophoblast cells. ITA was measured in 38 of the cases with persistent low hCG, in all cases ITA accounted for less than 25% of the hCG concentration. It was also determined in the 4 cases indicated with malignant disease, accounting for more than 80% of the hCG. CONCLUSION: The presence of persistent low-level hCG titers defines a subset of women with preinvasive or quiescent gestational trophoblastic disease. ITA effectively detected the presence or absence of invasive cells in these cases. The recommended management of the quiescent disease is close surveillance without therapy until malignant disease detected.     

Hormonal contraception and trophoblastic sequelae after hydatidiform mole (a Gynecologic Oncology Group Study)

A prospective randomized study was undertaken to determine whether the administration of oral contraceptives after the evacuation of a hydatidiform mole affects the human chorionic gonadotropin serum level in a way that leads to an increased frequency in the diagnosis of postmolar trophoblastic disease. Between 1981 and 1988, 266 patients were randomly assigned to either oral contraceptives or barrier contraception after evacuation of a hydatidiform mole. Patients were followed up until serum levels of human chorionic gonadotropin were normal or until specific criteria for the diagnosis of postmolar trophoblastic disease were met. Twenty-three percent of patients receiving oral contraceptives had postmolar trophoblastic disease, whereas those using a barrier method had a rate of 33%. The median time to spontaneous regression in the oral contraceptives group was 9 weeks, whereas the median time to regression in the barrier group was 10 weeks. Twice as many patients in the barrier group became pregnant in the immediate follow-up period. We conclude that oral contraceptives are the preferred method of contraception after evacuation of a hydatidiform mole.     

Outcome of Pregnancies Occurring before Completion of Human Chorionic Gonadotropin Follow-Up in Patients with Persistent Gestational Trophoblastic Tumor

OBJECTIVE: To determine the outcome of pregnancies occurring before completion of human chorionic gonadotropin follow-up in patients treated with chemotherapy for gestational trophoblastic tumor. METHODS: Retrospective record review of patients with gestational trophoblastic tumor who conceived before standard hCG follow-up was completed during 1973-1998. RESULTS: Forty-three patients treated for gestational trophoblastic tumors conceived before human chorionic gonadotropin follow-up was completed. The antecedent pregnancy was complete mole in 31 (72.1%) and partial mole in 12 (27. 9%) patients. Of the 43 patients, 39 (90.7%) had stage I, 1 had stage II, and 3 had stage III disease. The mean interval from human chorionic gonadotropin remission to new pregnancy was 6.3 months (range 1-11 months). Ten patients underwent elective termination and four patients were lost to follow-up. Of the remaining 29 patients, 22 (75.9%) had term live births, 3 (10.3%) had preterm delivery, 3 had spontaneous abortion, and 1 (3.5%) had a repeat mole. Two cases of fetal anomalies were detected; one was inherited polydactyly and the other was hydronephrosis. One patient developed choriocarcinoma with lung involvement and underwent cesarean section at 28 weeks; a normal fetus was delivered and no choriocarcinoma was detected in the placenta. CONCLUSION: Pregnancies occurring in patients treated for gestational trophoblastic tumor before standard human chorionic gonadotropin follow-up is completed may continue under close clinical surveillance since the majority have a favorable outcome. However, patients should also be advised of the low but important risk of delayed diagnosis in case tumor relapse develops during early subsequent pregnancy.     

Radioimmunoassay of placental protein 12: levels in amniotic fluid, cord blood, and serum of healthy adults, pregnant women, and patients with trophoblastic disease

A radioimmunoassay for placental protein 12 (PP12) is described and the levels in amniotic fluid, cord blood, and serum of nonpregnant individuals, pregnant women, and patients with trophoblastic disease are presented. During pregnancy, the highest PP12 levels were found at 22 to 23 weeks (mean +/- SD, 169 +/- 123 ng/ml), and there was a transient decline at 32 to 33 weeks (63 +/- 23 ng/ml). In amniotic fluid, the levels were 100 to 1,000 times higher than in maternal serum. In cord blood at birth, the values were of the same magnitude as in maternal serum. Also healthy nonpregnant women and men had PP12-like immunoreactivity in serum. Nonpregnant women (9 to 47 ng/ml) had higher levels than men (undetectable to 21 ng/ml). Elevated levels up to 84 ng/ml were occasionally observed in trophoblastic disease, both hydatidiform mole and choriocarcinoma, but they bore no correlation with the human chorionic gonadotropin levels. On the basis of these results PP12 is not a suitable marker for trophoblastic disease. PP12 values in normal pregnancy provide the basis for the evaluation of PP12 levels in abnormal pregnancy.     

Expression of nm23-H1 in hydatidiform mole and its relationship with the development of postmolar disease.

The aim of the present study was to investigate the expression of nm23-H1 in human placenta, hydatidiform mole and choriocarcinoma cells. Nm23-H1 protein was localized in the cytotrophoblast, but not in the syncytiotrophoblast. In the hydatidiform mole cases with subsequent spontaneous remission, nm23-H1 mRNA levels were significantly lower than those in first-trimester placentas. However, its levels were elevated in the hydatidiform mole cases that progressed to persistent gestational trophoblastic disease and were comparable to those of first-trimester placentas, and they were further elevated in choriocarcinoma cells. The present data suggest an association of nm23-H1 for the proliferation activity of trophoblast, and its increased expression may influence the development of persistent trophoblastic disease.     

Partial hydatidiform mole with subsequent trophoblastic tumor; a case report.

A case of partial hydatidiform mole revealed by genetic marker analysis one maternal and two paternal chromosome complements. Levels of serum human chorionic gonadotropin were persistently elevated during follow-up. Avillous curettage specimens prior to chemotherapy were morphologically suspicious for gestational choriocarcinoma. It is still uncertain whether the risk for gestational choriocarcinoma preceded by partial mole exceeds the risk related to non-molar abortions. Careful follow-up with serial serum human chorionic gonadotropin levels is required to detect persistent disease.     

Guidelines following hydatidiform mole: a reappraisal

OBJECTIVE: The aim of this study was to determine how often patients with complete hydatidiform mole (CHM) who spontaneously achieve normal human chorionic gonadotrophin (hCG) levels subsequently develop persistent or recurrent gestational trophoblast disease. METHODS: Four hundred and fourteen cases of CHM registered at the Hydatidiform Mole Registry of Victoria were reviewed retrospectively after molar evacuation. Maternal age, gestational age, gravidity and parity were determined for each patient, as well as the need for chemotherapy. RESULTS: Among the 414 patients, 55 (13.3%) required chemotherapy for persistent trophoblastic disease. None of the patients whose hCG levels spontaneously fell to normal subsequently developed persistent molar disease. CONCLUSION: Weekly hCG measurements are recommended for all patients until normal levels are achieved. For patients who attain normal hCG levels within 2 months after evacuation, it seems safe to discontinue monitoring once normal levels are achieved. Patients who fail to achieve normal hCG levels by 2 months after evacuation should be monitored with monthly hCG measurements for 1 year after normalisation to assure sustained remission.     

Choriocarcinoma and gestational trophoblastic disease

Gestational trophoblastic disease (GTD) encompasses a unique group of uncommon but interrelated conditions derived from placental trophoblasts. For the purposes of discussion GTD is the appropriate collective name for hydatidiform mole, whereas the term gestational trophoblastic neoplasia (GTN) is reserved for cases with persistent human chorionic gonadotropin (hCG) titer elevation after evacuation of hydatidiform mole, metastatic disease, or choriocarcinoma. Although the pathology and clinical behavior of CM and PM are different, the initial management of both conditions is surgical evacuation by suction curettage, determination of the baseline, and follow-up with (hCG) titers. There are guidelines for risk-factor scoring and a staging system that classifies untreated patients into distinct prognostic categories so that treatment outcomes can be objectively compared. The rates of GTN and choriocarcinoma are decreasing and survival has dramatically improved.     

Low risk of relapse after achieving undetectable HCG levels in women with complete molar pregnancy

OBJECTIVE: Complete hydatidiform molar pregnancies occur in approximately 1 of 1,000 conceptions. After uterine evacuation of the trophoblastic tissue, women are followed up with serial serum human chorionic gonadotropin (hCG) measurements. Patients are considered to have attained remission when their hCG level spontaneously declines to an undetectable level and remains there during a 6-month follow-up period. This standard effectively detects all disease recurrence; however, it is resource intensive, delays child bearing, and is subject to significant noncompliance. Our objective was to determine the risk of disease recurrence after hCG spontaneously declines to undetectable levels. METHODS: We used a database from the New England Trophoblastic Disease Center to analyze hCG levels in patients with complete molar pregnancies. RESULTS: Among 1,029 women with complete molar pregnancy and complete data, 15% developed persistent gestational trophoblastic neoplasia. The rate of persistent neoplasm among those whose hCG level fell spontaneously to undetectable levels was 0.2% (2/876, 95% confidence interval 0-0.8%). No women developed persistent gestational trophoblastic neoplasia after their hCG level fell to undetectable levels using an assay with a sensitivity of 5 mIU/mL (n = 82, 95% confidence interval 0-4.5%). CONCLUSION: Based on our experience with women with complete hydatidiform molar pregnancies whose hCG values spontaneously fell to undetectable levels after molar evacuation, we conclude that the risk of recurrent neoplasm after hCG levels fall to less than 5 mIU/mL approaches zero.     

Detection of hCG production in trophoblastic diseases by HCG beta carboxyl-terminal peptide

A radioimmunoassay (CTP-RIA) for urinary human chorionic gonadotropin (hCG) with the use of an antiserum to be carboxyl-terminal peptide of hCG beta subunit was employed to detect hCG production in patients with gestational trophoblastic disease. In urine samples obtained from normal subjects, the upper limit of hCG-immunoactivity detected by this assay system was 1.1 IU/24h. More than 90% of the subjects tested had values lower than 0.5 IU/24h. Based on these data, we selected urinary hCG levels below 1.1 IU/24 h as the normal range for clinical applications. The utility of this new assay system was assessed in 50 cases of gestational trophoblastic disease. In patients with hydatidiform mole, invasive mole and undetermined cases, the urinary hCG level declined to be normal range following the therapy and stayed there afterwards without any sign of recurrence. However, in a woman with a long history of metastatic choriocarcinoma, we noted the reappearance of hCG even after the hCG level once declined to the normal range. It therefore seems that cell viability will persist even in the normal range determined by CTP-RIA. Therefore, therapeutic decisions should take into account these points. This specific and sensitive CTP-RIA method for the detection of hCG production was found to improve the ability to diagnose persistent or recurrent trophoblastic disease.