Early Identification of Resistance to First-Line Single-Agent Methotrexate in Patients With Persistent Trophoblastic Disease

Efficacy analysis of single-agent carboplatin AUC4 2-weekly as second-line therapy for methotrexate-resistant (MTX-R) low risk gestational trophoblastic neoplasia (GTN)

BACKGROUND

Approximately one-third of patients with low-risk Gestational Trophoblastic Neoplasia (WHO 0-6) develop methotrexate-resistance (MTX-R). In the UK, subsequent treatment with either actinomycin-D (ActD) or multi-agent combination chemotherapy has depended on whether the hCG was above or below an hCG threshold. To reduce exposure to combination chemotherapy (CC), over the years the UK service has raised this threshold as well as using single-agent carboplatin AUC6 3-weekly at MTX-R instead of CC. Updated results for carboplatin demonstrate an 86% complete hCG response (hCG CR) but associated with haematological dose-limiting toxicity.

METHODS

In 2017, single-agent carboplatin became the national standard second-line treatment following MTX-R at hCG of >3000 IU/L. Carboplatin was changed to two-weekly AUC4 scheduling and continued until normal hCG plus 3 consolidation cycles. For patients failing to respond, CC (Etoposide-Actinomycin-D or EMA-CO) was introduced.

RESULTS

22 evaluable patients with a median hCG at MTX-R of 10,147 IU/L (IQR 5527-19,639) received carboplatin AUC4 2-weekly (median no. of cycles = 6, IQR 2-8). Of these, 36% achieved a hCG CR. All 14 non-CR patients were cured with subsequent CC; 11 and 2 patients with 3rd line and 4th line CC respectively and 1 patient following 5th line CC and hysterectomy. Overall survival remains 100%.

CONCLUSION

Carboplatin is not sufficiently active in the second-line treatment of low-risk MTX-resistant GTN. New strategies are required to increase hCG CR and spare more toxic CC regimens.

Measurement of Human Chorionic Gonadotrophin in Women with Gestational Trophoblastic Disease

OBJECTIVES

The objective of this study was to collect information on human chorionic gonadotrophin (hCG) laboratory testing and reporting in women with gestational trophoblastic disease (GTD), to assess the associated challenges, and to offer perspectives on hCG testing harmonisation.

DESIGN

Information was collected from laboratories by electronic survey (SurveyMonkey) using a questionnaire designed by members of the European Organisation for the Treatment of Trophoblastic Disease (EOTTD) hCG working party.

PARTICIPANTS

The questionnaire was distributed by the EOTTD board to member laboratories and their associated scientists who work within the GTD field.

SETTING

The questionnaire was distributed and accessed via an online platform.

METHODS

The questionnaire consisted of 5 main sections. These included methods used for hCG testing, quality procedures, reporting of results, laboratory operational aspects, and non-GTD testing capability. In addition to reporting these survey results, examples of case scenarios which illustrate the difficulties faced by laboratories providing hCG measurement for GTD patient management were described. The benefits and challenges of using centralised versus non-centralised hCG testing were discussed alongside the utilisation of regression curves for management of GTD patients.

RESULTS

Information from the survey was collated and presented for each section and showed huge variability in responses across laboratories even for those using the same hCG testing platforms. An educational example was presented, highlighting the consequence of using inappropriate hCG assays on clinical patient management (Educational Example A), along with an example of biotin interference (Educational Example B) and an example of high-dose hook effect (Educational Example C), demonstrating the importance of knowing the limitations of hCG tests. The merits of centralised versus non-centralised hCG testing and use of hCG regression curves to aid patient management were discussed.

LIMITATIONS

To ensure the survey was completed by laboratories providing hCG testing for GTD management, the questionnaire was distributed by the EOTTD board. It was assumed the EOTTD board held the correct laboratory contact, and that the questionnaire was completed by a scientist with in-depth knowledge of laboratory procedures.

CONCLUSIONS

The hCG survey highlighted a lack of harmonisation of hCG testing across laboratories. Healthcare professionals involved in the management of women with GTD should be aware of this limitation. Further work is needed to ensure an appropriate, quality-assured laboratory service is available for hCG monitoring in women with GTD.

PREDICT-GTN 1: Can we improve the FIGO scoring system in gestational trophoblastic neoplasia?

Gestational trophoblastic neoplasia (GTN) patients are treated according to the eight-variable International Federation of Gynaecology and Obstetrics (FIGO) scoring system, that aims to predict first-line single-agent chemotherapy resistance. FIGO is imperfect with one-third of low-risk patients developing disease resistance to first-line single-agent chemotherapy. We aimed to generate simplified models that improve upon FIGO. Logistic regression (LR) and multilayer perceptron (MLP) modelling (n = 4191) generated six models (M1-6). M1, all eight FIGO variables (scored data); M2, all eight FIGO variables (scored and raw data); M3, nonimaging variables (scored data); M4, nonimaging variables (scored and raw data); M5, imaging variables (scored data); and M6, pretreatment hCG (raw data) + imaging variables (scored data). Performance was compared to FIGO using true and false positive rates, positive and negative predictive values, diagnostic odds ratio, receiver operating characteristic (ROC) curves, Bland-Altman calibration plots, decision curve analysis and contingency tables. M1-6 were calibrated and outperformed FIGO on true positive rate and positive predictive value. Using LR and MLP, M1, M2 and M4 generated small improvements to the ROC curve and decision curve analysis. M3, M5 and M6 matched FIGO or performed less well. Compared to FIGO, most (excluding LR M4 and MLP M5) had significant discordance in patient classification (McNemar's test P < .05); 55-112 undertreated, 46-206 overtreated. Statistical modelling yielded only small gains over FIGO performance, arising through recategorisation of treatment-resistant patients, with a significant proportion of under/overtreatment as the available data have been used a priori to allocate primary chemotherapy. Streamlining FIGO should now be the focus.

Serum human chorionic gonadotropin ratios for the detection of etoposide, methotrexate, dactinomycin, cyclophosphamide, and vincristine resistance in high‐risk gestational trophoblastic neoplasia

Aims

This study aimed to identify the optimal human chorionic gonadotropin (hCG) ratio in predicting etoposide, methotrexate, dactinomycin, cyclophosphamide, and vincristine resistance in women diagnosed with high‐risk gestational trophoblastic neoplasia (GTN) and to compare the chemoresistant disease detection rate by using the optimal hCG ratio and traditional criteria.

Methods

Seventy‐six women with primary high‐risk GTN treated with etoposide, methotrexate, dactinomycin, cyclophosphamide, and vincristine in a tertiary‐care center were included. The hCG ratio was determined by its serum pretreatment level divided by that before each cycle of chemotherapy. The traditional criteria for chemoresistance included plateau or rising of hCG or presence of new metastasis. The optimal hCG ratio was determined using receiver operating characteristics (ROC) curve analysis.

Results

Among the specificities of 90%, 92.5%, and 95%, the 90% specificity yielded the best ROC curve. At 90% specificity, the best area under curve value was at the fourth cycle with 75% sensitivity. The hCG ratio at the fourth cycle was 31.92. Using the ratio at the fourth cycle, chemoresistant disease was detected in six out of eight patients, compared to one in the traditional criteria. When combining the two diagnostic tools, the cumulative detection rate in the fourth cycle was 10/12 (83.3%) of total drug resistance. Among patients who developed drug resistance at the fourth cycle or thereafter, the use of the ratio at the fourth cycle could diagnose chemoresistance approximately two cycles earlier than that with the traditional criteria.

Conclusions

A hCG ratio of <31.9 at the fourth cycle should be considered a high‐risk for etoposide, methotrexate, dactinomycin, cyclophosphamide, and vincristine resistance and may need second‐line chemotherapy. The ratio increases the detection rate of resistance to these drugs more than the traditional criteria.

Predictive factors associated with resistance to initial methotrexate treatment in women with low-risk gestational trophoblastic neoplasia

AIM

To compare clinical characteristics and identify factors predictive of resistance to initial treatment with methotrexate-folinic acid (MTX-FA) in women with low-risk gestational trophoblastic neoplasia (GTN).

METHODS

Retrospective chart reviews were conducted in patients diagnosed with low-risk GTN who were treated with MTX-FA at Siriraj Hospital between 2002 and 2018. Demographic data, disease characteristics, treatment response, toxicity, and data of the subsequent pregnancy were collected and analyzed. Groups of patients who were responsive or resistant to treatment were compared. Stepwise logistic regression analysis was used to identify factors predictive of resistance to methotrexate chemotherapy.

RESULTS

Totally, 113 patients were eligible for analysis. The primary remission rate was 55.8% with first-line MTX-FA. All other patients achieved remission by subsequent treatment with actinomycin D or multiple-agent chemotherapy. Relapse of disease occurred in 4.4% and the overall survival rate was 99.1%. Univariate analysis showed that pretreatment serum hCG, neutrophil-to-lymphocyte ratio at baseline, and serum hCG ratio of the first three consecutive cycles (C) were significantly associated with resistance to MTX-FA. Independent factors that predict failure to respond to first-line MTX-FA were pretreatment serum hCG ≥15,000 IU/L, a less than 4.8-fold reduction of serum hCG between cycle 1 and cycle 2 (C1/C2), and a less than seven-fold reduction of serum hCG from cycle 2 to cycle 3 (C2/C3).

CONCLUSIONS

First-line MTX-FA treatment is effective in 55.8% of patients. Pretreatment serum hCG, and serum hCG ratio between consecutive treatment cycles can predict initial treatment failure.

Early prediction of post-molar gestational trophoblastic neoplasia and resistance to methotrexate, based on a single serum human chorionic gonadotropin measurement

BACKGROUND

Clinicians are unable to provide individualized counseling regarding risk of progression for patients with a complete hydatidiform mole (CHM). We developed nomograms enabling early prediction of post-molar gestational trophoblastic neoplasia (GTN) and resistance to methotrexate (MTX) based on a single serum human chorion gonadotropin (hCG) measurement.

METHODS

We generated two nomograms with logistic regression: to predict post-molar GTN, and MTX resistance. For patients with high probability to progress to post-molar GTN or MTX resistance, we determined hCG cut-offs at 97.5% specificity to select patients for additional- or adjustments in current treatment.

RESULTS

The nomograms had a good to excellent ability to distinguish either between patients with uneventful hCG regression versus progression to post molar GTN, or between patients cured by MTX versus patients in whom resistance would occur. At 97.5% specificity, we identified 66% (95%CI 56-75) of the 149 patients who would progress to post-molar GTN, four weeks after initial curettage. For patients treated with MTX, we identified 55% (95%CI 23-83) of the 43 patients who would become resistant, preceding their third course at 97.5% specificity.

CONCLUSION

The nomograms and cut-off levels can be used to assist in counseling for patients diagnosed with CHM.

Treatment of high-risk gestational trophoblastic neoplasia and chemoresistance/relapsed disease

High-risk gestational trophoblastic neoplasia (GTN) has an increased risk of developing chemoresistance to single-agent chemotherapy; therefore, the primary treatment should be a multiagent etoposide-based regimen, preferably EMA/CO. After remission (normalization of human chorionic gonadotropin - hCG), at least three consolidation courses of EMA-CO are needed to reduce the risk of relapse. Chemoresistance is diagnosed during treatment if hCG levels plateau/increase, in two consecutive values over a two-week period. When this occurs after remission, in the absence of a new pregnancy, there is a relapse. In both cases, after re-assessment of the extent of disease, EMA-EP is the most common chemotherapy choice. Even in these cases, remission rates are high. After remission is achieved, hCG should be measured monthly for a year. Pregnancy can be allowed after 12 months from remission. The follow-up of these patients in referral centers minimizes the chance of death from this disease and should be encouraged.

Treatment of low-risk gestational trophoblastic neoplasia

Low-risk gestational trophoblastic neoplasia (GTN), defined as FIGO/WHO score 0-6, is highly curable with an overall survival rate, which is approximately 100%. For most low-risk GTN patients, first-line single-agent chemotherapy with either methotrexate or actinomycin-D is recommended with overall complete human chorionic gonadotrophin (hCG) response rates of 60%-90% in mostly retrospective, non-randomised studies. The few randomised trials that exist are not appropriately powered or designed to define the optimal first-line treatment. Approximately 25%-30% of low-risk patients will develop resistance to initial single-agent chemotherapy with an increase in the FIGO score, a diagnosis of choriocarcinoma, higher pre-treatment hCG and the presence of metastatic disease being associated with an increase in the risk of resistance. The optimal treatment of patients scoring WHO 5 and 6 remains poorly defined given that approximately 70%-80% of these patients develop resistance to first-line single-agent chemotherapy, and there is an urgent need to refine the FIGO/WHO scoring system so that these patients can be identified for more intensive therapy from the outset. Despite this, almost all low-risk patients who experience treatment failure with first-line monotherapy will be cured with either sequential single-agent chemotherapy or multiagent chemotherapy with or without surgery. Given the associated increased short and longer-term toxicities associated with multi-agent chemotherapy, promising strategies to reduce the exposure of women to combination chemotherapy in low-risk disease have been investigated, including the use of carboplatin and immune check-point inhibitors. Further evaluation is required to define optimal patient selection, particularly with the use of immunotherapeutic agents given their significant increased costs and lack of longer-term safety data. Although there is a clear need to revise the FIGO/WHO (2000) scoring system, consistent international use of this is recommended to facilitate the comparison of data along with future focus in the development of international collaborative translational and clinical research, including randomised controlled trials.

Validation of an online tool for early prediction of the failure-risk in gestational trophoblastic neoplasia patients treated with methotrexate

PURPOSE

In a low-risk gestational trophoblastic neoplasia (GTN) treated with methotrexate (MTX), the modeled hCG (human chorionic gonadotropin) residual concentration (hCGres), calculated with NONMEM program® (NM) during the first 50 treatment days, is a predictor of MTX-resistance risk. This model was implemented with another algorithm on https://www.biomarker-kinetics.org/hCG . The objective was to confirm the validity of the website estimations with respect to NM.

METHODS

The consistencies of modeled hCGres estimated by NM and by the website were assessed in a dataset of 60 fictive patients with simulated hCG profiles, as well as in an independent database of 531 actual patients. Moreover, the hCGres predictive values regarding MTX failure-risk were assessed.

RESULTS

The values of hCGres obtained with both methods were highly consistent in the fictive patient and in the actual patient datasets: median relative prediction errors (RPE) were - 0.059 and 9.9 × 10^-7, respectively. The ROC AUCs for predictions of MTX failure-risk were 0.90 (95% CI 0.87,0.93) with both NM and the website. The gradual association between increasing hCGres and the 2-year MTX failure-free survival was confirmed.

CONCLUSION

There is a high consistency of hCGres estimates obtained with the two methods. The website is meant to help clinicians in the interpretation of hCG decline curves of MTX-treated GTN patients. hCGres is now validated for more than 1690 patients in four independent datasets, and its recognition as an early predictor of MTX resistance for treatment adjustment and for the future studies should be considered.

Outcomes of women diagnosed and treated for low-risk gestational trophoblastic neoplasia at the Queensland Trophoblast Centre (QTC)

BACKGROUND

Gestational trophoblastic neoplasia (GTN) is classified as a highly curable group of pregnancy-related malignancies; however, approximately 15% will be persistent and require chemotherapy. Up to 25% of these women will develop resistance and 2% will develop disease relapse after initial chemotherapy. Despite the need for further chemotherapy in these women, cure rates are high.

OBJECTIVE

To evaluate the outcomes of women diagnosed with low-risk GTN, assessing the type of treatment, the number of chemotherapy cycles received, development of resistance or disease relapse, survival, and to assess the feasibility of changing to a new drug regimen.

METHODS

From March 2012 until February 2015, a retrospective study was conducted and 38 cases with low-risk GTN were reviewed. The number of cycles, type of treatment received, duration of treatment, development of resistance and disease relapse, and adverse side effects were analysed.

RESULTS

The median duration of follow-up was 12 months. Disease-free survival was 100% and primary complete remission rates were achieved in 85.3% of patients who were treated with actinomycin D and 25% patients who were treated with methotrexate (MTX). A change in chemotherapy was required for nine patients. One patient developed disease relapse. Nausea, fatigue and constipation were the most frequent adverse events reported with actinomycin D. All women were cured of their disease.

CONCLUSION

All women were successfully treated and achieved complete remission. Changing from MTX to actinomycin D as first-line chemotherapy for women with low-risk GTN was feasible and safe.

Presence of the methylenetetrahydrofolate reductase gene polymorphism MTHFR C677T in molar tissue but not maternal blood predicts failure of methotrexate treatment for low-risk gestational trophoblastic neoplasia

Gestational trophoblastic neoplasia (GTN) is a rare tumor, and its genomic constitution is different from the maternal genome because of its gestational origin. Methotrexate (MTX) is a standard chemotherapeutic agent for low-risk GTN. An association between polymorphisms of the methylenetetrahydrofolate reductase (MTHFR) gene and MTX treatment outcome has been reported in various diseases. Thus, we examined the association between clinical outcome and MTHFR polymorphisms in both tumor and blood DNA of low-risk GTN patients. MTHFR C677T (rs1801133) and A1298C (rs1801131) were genotyped using high-resolution melting assays in 62 Japanese low-risk GTN patients and in 52 antecedent molar tissues. We compared the genotypes of MTHFR polymorphisms with the clinical outcome of 5-day MTX treatment. Twenty-five patients entered remission and 37 patients developed drug resistance or adverse effects that necessitated a drug change. The MTHFR 677T allele in molar tissue was significantly related to the need for drug change (P=0.006; odds ratio [OR], 3.13; 95% confidence interval [CI], 1.31-7.49), in contrast to MTHFR 1298C (P=0.18; OR, 0.63; 95% CI, 0.32-1.25). The MTHFR 677T and 1298C alleles obtained from patients' blood DNA were not related to MTX treatment outcome (P=0.49; OR 1.31; 95% CI, 0.61-2.91 and P=0.10; OR 0.52; 95% CI, 0.22-1.15, respectively). These data demonstrate for the first time that the genotype of MTHFR 677TT in molar tissue is associated with ineffective MTX treatment in Japanese low-risk GTN patients.

Risk adapted single-agent dactinomycin or carboplatin for second-line treatment of methotrexate resistant low-risk gestational trophoblastic neoplasia

OBJECTIVE

To evaluate the outcome of patients treated with second-line chemotherapy for methotrexate-resistant low-risk GTN at the Sheffield Centre, UK between 2001 and 2015, including the novel use of single-agent carboplatin as a strategy to reduce exposure to combination chemotherapy.

METHODS

392 low-risk GTN patients were treated with first-line methotrexate. The selection of chemotherapy regimen following methotrexate-resistance depended on the volume of residual disease as indicated by the serum hCG value at the time, with patients switching to either single-agent dactinomycin at an hCG level<150IU/L from 2001-2010 and <300IU/L since 2010, or to combination treatment with etoposide/dactinomycin (EA) above these thresholds. In order to reduce exposure to more toxic combination chemotherapy regimens, our treatment policy was revised in 2011, with the recommendation of single-agent carboplatin as an alternative to EA at hCG levels >300IU/L.

RESULTS

136 (35%) of 392 received second-line chemotherapy following methotrexate-resistance. 59 patients received single-agent dactinomycin with 53 (90%) patients achieving complete hCG response, 3 patients requiring combination chemotherapy or surgery, and 3 patients subsequently spontaneously resolving. 56 patients received EA chemotherapy with hCG complete response in 50 (89%) patients, and the remaining 6 patients were cured with further multi-agent chemotherapy or surgery. With carboplatin, 17/21 (81%) achieved an overall complete hCG response rate, with 4 patients requiring third-line EA. Carboplatin was well tolerated with no significant alopecia; myelosuppression was the most significant toxicity. Overall survival for all patients was 100%.

CONCLUSION

These data show the continued excellent outcomes for methotrexate-resistant low-risk patients treated with single-agent dactinomycin or EA. Our experience with carboplatin is promising and provides an alternative regimen for methotrexate-resistant low-risk disease that avoids alopecia and in-patient treatment.

Validation of the Predictive Value of Modeled Human Chorionic Gonadotrophin Residual Production in Low-Risk Gestational Trophoblastic Neoplasia Patients Treated in NRG Oncology/Gynecologic Oncology Group-174 Phase III Trial

OBJECTIVES

In low-risk gestational trophoblastic neoplasia, chemotherapy effect is monitored and adjusted with serum human chorionic gonadotrophin (hCG) levels. Mathematical modeling of hCG kinetics may allow prediction of methotrexate (MTX) resistance, with production parameter "hCGres." This approach was evaluated using the GOG-174 (NRG Oncology/Gynecologic Oncology Group-174) trial database, in which weekly MTX (arm 1) was compared with dactinomycin (arm 2).

METHODS

Database (210 patients, including 78 with resistance) was split into 2 sets. A 126-patient training set was initially used to estimate model parameters. Patient hCG kinetics from days 7 to 45 were fit to: [hCG(time)] = hCG7 * exp(-k * time) + hCGres, where hCGres is residual hCG tumor production, hCG7 is the initial hCG level, and k is the elimination rate constant. Receiver operating characteristic (ROC) analyses defined putative hCGRes predictor of resistance. An 84-patient test set was used to assess prediction validity.

RESULTS

The hCGres was predictive of outcome in both arms, with no impact of treatment arm on unexplained variability of kinetic parameter estimates. The best hCGres cutoffs to discriminate resistant versus sensitive patients were 7.7 and 74.0 IU/L in arms 1 and 2, respectively. By combining them, 2 predictive groups were defined (ROC area under the curve, 0.82; sensitivity, 93.8%; specificity, 70.5%). The predictive value of hCGres-based groups regarding resistance was reproducible in test set (ROC area under the curve, 0.81; sensitivity, 88.9%; specificity, 73.1%). Both hCGres and treatment arm were associated with resistance by logistic regression analysis.

CONCLUSIONS

The early predictive value of the modeled kinetic parameter hCGres regarding resistance seems promising in the GOG-174 study. This is the second positive evaluation of this approach. Prospective validation is warranted.

Optimal management of low-risk gestational trophoblastic neoplasia

Low-risk gestational trophoblastic neoplasia is a highly curable form of gestational trophoblastic neoplasia that arises largely from molar pregnancy and, on rare occasions, from other types of gestations. Risk is defined as the risk of developing drug resistance as determined by the WHO Prognostic Scoring System. All patients with non-metastatic disease and patients with risk scores <7 are considered to have low-risk disease. The sequential use of methotrexate and actinomycin D is associated with a complete remission rate of 80%. The most commonly utilized regimen for the treatment of patients resistant to single-agent chemotherapy is a multiagent regimen consisting of etoposide, methotrexate, actinomycin D, vincristine and cyclophosphamide. The measurement of human chorionic gonadotropin provides an accurate and reliable tumor marker for diagnosis, monitoring the effects of chemotherapy and follow-up to determine recurrence. Pregnancy is allowed after 12 months of normal serum tumor marker. Pregnancy outcomes are similar to those of normal population.

Human Chorionic Gonadotropin (hCG) Regression Curve for Predicting Response to EMA/CO (Etoposide, Methotrexate, Actinomycin D, Cyclophosphamide and Vincristine) Regimen in Gestational Trophoblastic Neoplasia

BACKGROUND

An hCG regression curve has been used to predict the natural history and response to chemotherapy in gestational trophoblastic disease. We constructed hCG regression curves in high-risk gestational trophoblastic neoplasia (GTN) treated with EMA/CO and identified an optimal hCG level to detect EMA/CO resistance in GTN.

MATERIALS AND METHODS

Eighty-one women with GTN treated with EMA/CO were classified as primary high-risk GTN (n=65) and single agent-resistance GTN (n=16). The hCG levels prior to each course of chemotherapy were plotted in the 10th, 50th, and 90th percentiles to construct the hCG regression curves. Diagnostic performance was evaluated for an optimal cut-off value.

RESULTS

The median hCG levels were 264,482 mIU/mL mIU/mL and 495.5 mIU/mL mIU/mL for primary high-risk GTN and single agent-resistance GTN, respectively. The 50th percentile of the hCG level in primary high-risk GTN and single agent-resistance turned to normal before the 4th and the 2nd course of chemotherapy, respectively. The 90th percentile of the hCG level in primary high-risk GTN and single agent-resistance turned to normal before the 9th and the 2nd course of chemotherapy, respectively. The hCG level of ≥118.6 mIU/mL mIU/mL at the 5thcourse of EMA/CO predicted the EMA/CO resistance in primary high-risk GTN patients with a sensitivity of 85.7% and a specificity of 100%.

CONCLUSION

EMA/CO resistance in primary high-risk GTN can be predicted by using an hCG regression curve in combination with the cut-off value of 118.6 mIU/mL at the 5thcourse of chemotherapy.

Trophoblastic disease review for diagnosis and management: a joint report from the International Society for the Study of Trophoblastic Disease, European Organisation for the Treatment of Trophoblastic Disease, and the Gynecologic Cancer InterGroup

OBJECTIVE

The objective of this study was to provide a consensus review on gestational trophoblastic disease diagnosis and management from the combined International Society for the Study of Trophoblastic Disease, European Organisation for the Treatment of Trophoblastic Disease, and the Gynecologic Cancer InterGroup.

METHODS

A joint committee representing various groups reviewed the literature obtained from PubMed searches.

RESULTS AND CONCLUSIONS

Guidelines were constructed on the basis of literature review. After initial diagnosis in local centers, centralization of pathology review and ongoing care is recommended to achieve the best outcomes.

A critical review of the analytical approaches for circulating tumor biomarker kinetics during treatment

Changes in serum tumor biomarkers may indicate treatment efficacy. Traditional tumor markers may soon be replaced by novel serum biomarkers, such as circulating tumor cells (CTCs) or circulating tumor nucleic acids. Given their promising predictive values, studies of their kinetics are warranted. Many methodologies meant to assess kinetics of traditional marker kinetics during anticancer treatment have been reported. Here, we review the methodologies, the advantages and the limitations of the analytical approaches reported in the literature. Strategies based on a single time point were first used (baseline value, normalization, nadir, threshold at a time t), followed by approaches based on two or more time points [half-life (HL), percentage decrease, time-to-events…]. Heterogeneities in methodologies and lack of consideration of inter- and intra-individual variability may account for the inconsistencies and the poor utility in routine. More recently, strategies based on a population kinetics approach and mathematical modeling have been reported. The identification of equations describing individual kinetic profiles of biomarkers may be an alternative strategy despite its complexity and higher number of necessary measurements. Validation studies are required. Efforts should be made to standardize biomarker kinetic analysis methodologies to ensure the optimized development of novel serum biomarkers and avoid the pitfalls of traditional markers.

Uterine rupture due to invasive metastatic gestational trophoblastic neoplasm

While complete molar pregnancies are rare, they are wrought with a host of potential complications to include invasive gestational trophoblastic neoplasia. Persistent gestational trophoblastic disease following molar pregnancy is a potentially fatal complication that must be recognized early and treated aggressively for both immediate and long-term recovery. We present the case of a 21-year-old woman with abdominal pain and presyncope 1 month after a molar pregnancy with a subsequent uterine rupture due to invasive gestational trophoblastic neoplasm. We will discuss the complications of molar pregnancies including the risks and management of invasive, metastatic gestational trophoblastic neoplasia.

Early prediction of treatment resistance in low-risk gestational trophoblastic neoplasia using population kinetic modelling of hCG measurements

Background:

In low-risk gestational trophoblastic neoplasia (GTN) patients, a predictive marker for early identification of methotrexate (MTX) resistance would be useful. We previously demonstrated that kinetic modelling of human chorionic gonadotrophin (hCG) measurements could provide such a marker. Here we validate this approach in a large independent patient cohort.

Methods:

Serum hCG measurements of 800 low-risk GTN patients treated with MTX were analysed. The cohort was divided into Model and Test data sets. hCG kinetics were described from initial treatment day to day 50 using: ‘(hCG(time))=hCG0*exp(–k*time)+hCGres', where hCGres is the modelled residual production, hCG0 is the baseline hCG level, and k is the rate constant. HCGres-predictive value was investigated against previously reported predictors of MTX resistance.

Results:

Declining hCG measurements were well fitted by the model. The best discriminator of MTX resistance in the Model data set was hCGres, categorised by an optimal cut-off value of >20.44 IU l⁻¹: receiver-operating characteristic (ROC) area under the curve (AUC)=0.87; Se=0.91; Sp=0.83. The predictive value of hCGres was reproducible using the Test data set: ROC AUC=0.87; Se=0.88; Sp=0.86. Multivariate analyses revealed hCGres as a better predictor of MTX resistance (HR=1.01, P<0.0001) and MTX failure-free survival (HR=13.25, P<0.0001) than other reported predictive factors.

Conclusion:

hCGres, a modelled kinetic parameter calculated after fully dosed three MTX cycles, has a reproducible value for identifying patients with MTX resistance.

Human chorionic gonadotropin (hCG) regression normograms for patients with high-risk gestational trophoblastic neoplasia treated with EMA/CO (etoposide, methotrexate, actinomycin D, cyclophosphamide and vincristine) chemotherapy

BACKGROUND

We present normograms for human chorionic gonadotropin (hCG) regression in patients with high-risk gestational trophoblastic neoplasia (GTN) successfully treated with multiagent chemotherapy in order to predict treatment resistance.

PATIENTS AND METHODS

We collected data for 46 patients with high-risk GTN treated with EMA/CO (etoposide, methotrexate, actinomycin D, cyclophosphamide and vincristine) who had hCG values available. Patients were classified as having methotrexate (MTX)-resistant disease (n = 22) or primary high-risk disease (n = 24). The 10th, 50th and 90th percentiles of the hCG before every chemotherapy course were calculated and plotted in normograms.

RESULTS

Half of the patients treated for MTX-resistant disease and primary high-risk disease had normal hCG levels before the third and sixth course of chemotherapy, respectively. In patients with MTX-resistant disease, the 90th percentile line fell below normal before the start of the fourth course, whereas in patients with primary high-risk disease this was not the case until the eighth course of chemotherapy.

CONCLUSION

Resistance to EMA/CO treatment for high-risk GTN, as illustrated by examples, could be predicted using normograms for hCG resistance. Normograms differed depending on the indication for multiagent chemotherapy due to much higher initial hCG values in patients with primary high-risk disease compared with those treated for MTX-resistant disease.

Characterisation of transient benign hCG elevations in women following chemotherapy for GTT

The occurrence of post-chemotherapy transient low level hCG elevations has been observed in a number of women treated for gestational trophoblastic tumours (GTT). The authors reviewed the records of patients treated at Charing Cross Hospital over the last 10 years and identified those with a benign rise in hCG. Stored serum samples were assayed for hCG, LH, FSH and oestradiol at varying points during patient management. The endocrine profile in patients experiencing benign hCG elevation is comparable with that seen in post-menopausal women, with low oestradiol, combined with greatly elevated LH and FSH levels. In contrast, women with genuine disease relapse as the cause of their post-chemotherapy hCG elevation had normal or only minor elevations of LH and FSH. These findings support the observation that a major rise in LH and FSH can be used as an indicator for benign pituitary hCG production in patients experiencing a low level rise in hCG levels following chemotherapy for GTT.

Predictive values of hCG clearance for risk of methotrexate resistance in low-risk gestational trophoblastic neoplasias

BACKGROUND

Early identification of patients at high risk for chemoresistance among those treated with methotrexate (MTX) for low-risk gestational trophoblastic neoplasia (GTN) is needed. We modeled human chorionic gonadotropin (hCG) decline during MTX therapy using a kinetic population approach to calculate individual hCG clearance (CL(hCG)) and assessed the predictive value of CL(hCG) for MTX resistance.

PATIENTS AND METHODS

A total of 154 patients with low-risk GTN treated with 8-day MTX regimen were retrospectively studied. NONMEM was used to model hCG decrease equations between day 0 and day 40 of chemotherapy. Receiver operating characteristic curve analysis defined the best CL(hCG) threshold. Univariate/multivariate survival analyses determined the predictive value of CL(hCG) and compared it with published predictive factors.

RESULTS

A monoexponential equation best modeled hCG decrease: hCG(t) = 3900 x e(-0.149 x t). Median CL(hCG) was 0.57 l/day (quartiles: 0.37-0.74). Only choriocarcinoma pathology [yes versus no: hazard ratio (HR) = 6.01; 95% confidence interval (CI) 2.2-16.6; P < 0.001] and unfavorable CL(hCG) quartile (< or =0.37 versus >0.37 l/day: HR = 6.75; 95% CI 2.7-16.8; P < 0.001) were significant independent predictive factors of MTX resistance risk.

CONCLUSION

In the second largest cohort of low-risk GTN patients reported to date, choriocarcinoma pathology and CL(hCG) < or =0.37 l/day were major independent predictive factors for MTX resistance risk.

Methotrexate for 2000 FIGO low-risk gestational trophoblastic neoplasia patients: efficacy and toxicity

OBJECTIVE

We sought to review efficacy and toxicity of an 8-day methotrexate (MTX) regimen in the treatment of patients with low-risk gestational trophoblastic neoplasia (GTN) from the French Trophoblastic Disease Reference Center.

STUDY DESIGN

Between 1999 and 2006, 142 low-risk GTNs were diagnosed according to International Federation of Gynecology and Obstetrics (FIGO) criteria for GTN and to the FIGO scoring system. We report their characteristics, remission/resistance/recurrence rates, and treatment toxicity.

RESULTS

The 8-day MTX regimen achieved a 77.5% remission rate. All patients but 1 (99.9%) achieved remission and remained disease free until the time of analysis. Severe (grade 3 or 4) blood/bone marrow toxicity and metabolic/laboratory toxicity was noted in 4.2% of cases, of which 2 (1.4%) were grade 4.

CONCLUSION

For patients with GTN diagnosed according to FIGO criteria and considered low risk according to the FIGO scoring system, an 8-day MTX regimen is an adequate treatment associating a high rate of remission to a low rate of toxicity.

Implantable diagnostic device for cancer monitoring

Biopsies provide required information to diagnose cancer but, because of their invasiveness, they are difficult to use for managing cancer therapy. The ability to repeatedly sample the local environment for tumor biomarker, chemotherapeutic agent, and tumor metabolite concentrations could improve early detection of metastasis and personalized therapy. Here we describe an implantable diagnostic device that senses the local in vivo environment. This device, which could be left behind during biopsy, uses a semi-permeable membrane to contain nanoparticle magnetic relaxation switches. A cell line secreting a model cancer biomarker produced ectopic tumors in mice. The transverse relaxation time (T(2)) of devices in tumor-bearing mice was 20+/-10% lower than devices in control mice after 1 day by magnetic resonance imaging (p<0.01). Short term applications for this device are numerous, including verification of successful tumor resection. This may represent the first continuous monitoring device for soluble cancer biomarkers in vivo.

External validation of serum hCG cutoff levels for prediction of resistance to single-agent chemotherapy in patients with persistent trophoblastic disease

Van Trommel et al have previously shown that serum human chorionic gonadotropin (hCG) cutoff levels can provide early prediction of resistance to first-line methotrexate (MTX) in patients with persistent trophoblastic disease (PTD). In this study, we validate this approach of prediction of resistance to single-agent chemotherapy in an independent and larger cohort of PTD patients using a different hCG assay. Receiver operating characteristics (ROC) curves were constructed to determine hCG cutoff levels and sensitivity between patients cured on single-agent chemotherapy (control group) and patients requiring change to combination chemotherapy (study group). Receiver operating characteristics analysis identified an hCG cutoff value of 737 IU l⁻¹ that enabled us to predict the subsequent development of single-agent chemotherapy resistance in 52% of patients before their fourth MTX course at 97.5% specificity. This would have enabled an earlier switch to combination chemotherapy reducing the MTX exposure by an average of 2.5 courses. The present findings confirm that serum hCG cutoff levels predict resistance to single-agent therapy earlier than traditional methods. Change to combination chemotherapy should be considered for patients whose serum hCG levels exceed these hCG cutoff values. For patients not exceeding the hCG cutoff levels, static or rising hCG levels should still be included in the criteria for change of chemotherapy.