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

Recurrence and resistance risk factors in low-risk gestational trophoblastic neoplasia

Gestational trophoblastic neoplasia (GTN) is a group of rare but highly curable pregnancy-related tumors, especially in low-risk cases. However, around 25% of patients with GTN develop either resistant or recurrent disease after initial chemotherapy. To enhance the understanding of the mechanisms driving treatment failures and to develop more personalized and effective therapeutic strategies, this review explored diverse factors influencing low-risk GTN prognosis. These factors include FIGO (International Federation of Gynecology and Obstetrics) risk score, histology, patient age, pregnancy type, human chorionic gonadotropin (hCG) levels, disease duration, tumor characteristics, metastasis, Doppler ultrasonography, and consolidation chemotherapy. Additionally, the review examined independent risk determinants for disease recurrence and resistance to single-agent chemotherapy in patients with low-risk GTN. In most previous studies on the risk factors related to low-risk GTN, resistance and recurrence have typically been examined independently, despite their overlapping and interrelated nature. Furthermore, they often involve small sample sizes, suffer from methodological shortcomings, and exhibit limited statistical power.Studies utilizing multivariate analysis have shown that independent risk determinants for resistance to first-line treatment include FIGO score, metastatic disease, pre-treatment hCG level, interval between antecedent pregnancy and GTN diagnosis, tumor size, uterine artery pulsatility index (UAPI), choriocarcinoma, lung metastases, lung nodule size, and clearance hCG quartile. The independent predictive factors associated with recurrence include lung metastases, lung nodule size, interval between antecedent pregnancy and chemotherapy, interval from first chemotherapy to hCG normalization, post-delivery low-risk GTN, number of chemotherapy courses to achieve hCG normalization, and number of consolidation chemotherapy cycles. However, while these identified predictive factors offer valuable guidance, the variability in definitions and populations across studies may have implications for the generalizability of their findings. A comprehensive approach using clear definitions and taking into account multiple predictive factors may be necessary for accurately assessing the risk of resistance and recurrence in patients with low-risk GTN.

Future Directions for Gestational Trophoblastic Disease

Gestational trophoblastic disease encompasses a spectrum of premalignant and malignant conditions. While centralized care models significantly improve survival rates, many countries still lack such specialized centers, leading to preventable deaths. Current research focuses on refining diagnostic and treatment methods, aiming to better predict the risk of malignancy and reduce the need for aggressive therapies. Immunotherapy has emerged as a promising treatment modality, offering high cure rates with fewer side effects compared to traditional chemotherapy. Global efforts must continue to expand access to specialized care and integrate new therapies to improve outcomes and reduce treatment-related harm.

Risk factors for methotrexate resistance in low-risk gestational trophoblastic neoplasia patients (FIGO score 0-4)

The challenge of methotrexate (MTX) resistance among low-risk gestational trophoblastic neoplasia (GTN) patients has always been prominent. Despite the International Federation of Gynaecology and Obstetrics (FIGO) score of 0-4 patients comprising the majority of low-risk GTN patients, a comprehensive exploration of the prevalence and risk factors associated with MTX resistance has been limited. Therefore, we aimed to identify associated risk factors in GTN patients with a FIGO score of 0-4. Between January 2005 and December 2020, 310 low-risk GTN patients received primary MTX chemotherapy in two hospitals, with 265 having a FIGO score of 0-4. In the FIGO 0-4 subgroup, 94 (35.5%) were resistant to MTX chemotherapy, and 34 (12.8%) needed multi-agent chemotherapy. Clinicopathologic diagnosis of postmolar choriocarcinoma (OR = 17.18, 95% CI: 4.64-63.70, P < 0.001) and higher pretreatment human chorionic gonadotropin concentration on a logarithmic scale (log-hCG concentration) (OR = 18.11, 95% CI: 3.72-88.15, P < 0.001) were identified as independent risk factors associated with MTX resistance according to multivariable logistic regression. The decision tree model and regression model were developed to predict the risk of MTX resistance in GTN patients with a FIGO score of 0-4. Evaluation of model discrimination, calibration and net benefit revealed the superiority of the decision tree model, which comprised clinicopathologic diagnosis and pretreatment hCG concentration. The patients in the high- and medium-risk groups of the decision tree model had a higher probability of MTX resistance. This study represents the investigation into MTX resistance in GTN patients with a FIGO score of 0-4 and disclosed a remission rate of approximately 65% with MTX chemotherapy. Higher pretreatment hCG concentration and clinicopathologic diagnosis of postmolar choriocarcinoma were independent risk factors associated with resistance to MTX chemotherapy. The decision tree model demonstrated enhanced predictive capabilities regarding the risk of MTX resistance and can serve as a valuable tool to guide the clinical treatment decisions for GTN patients with a FIGO score of 0-4.

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.

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.

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.

Guideline No. 408: Management of Gestational Trophoblastic Diseases

OBJECTIVE

This guideline reviews the clinical evaluation and management of gestational trophoblastic diseases, including surgical and medical management of benign, premalignant, and malignant entities. The objective of this guideline is to assist health care providers in promptly diagnosing gestational trophoblastic diseases, to standardize treatment and follow-up, and to ensure early specialized care of patients with malignant or metastatic disease.

INTENDED USERS

General gynaecologists, obstetricians, family physicians, midwives, emergency department physicians, anaesthesiologists, radiologists, pathologists, registered nurses, nurse practitioners, residents, gynaecologic oncologists, medical oncologists, radiation oncologists, surgeons, general practitioners in oncology, oncology nurses, pharmacists, physician assistants, and other health care providers who treat patients with gestational trophoblastic diseases. This guideline is also intended to provide information for interested parties who provide follow-up care for these patients following treatment.

TARGET POPULATION

Women of reproductive age with gestational trophoblastic diseases.

OPTIONS

Women diagnosed with a gestational trophoblastic disease should be referred to a gynaecologist for initial evaluation and consideration for primary surgery (uterine evacuation or hysterectomy) and follow-up. Women diagnosed with gestational trophoblastic neoplasia should be referred to a gynaecologic oncologist for staging, risk scoring, and consideration for primary surgery or systemic therapy (single- or multi-agent chemotherapy) with the potential need for additional therapies. All cases of gestational trophoblastic neoplasia should be discussed at a multidisciplinary cancer case conference and registered in a centralized (regional and/or national) database.

EVIDENCE

Relevant studies from 2002 onwards were searched in Embase, MEDLINE, the Cochrane Central Register of Controlled Trials, and Cochrane Systematic Reviews using the following terms, either alone or in combination: trophoblastic neoplasms, choriocarcinoma, trophoblastic tumor, placental site, gestational trophoblastic disease, hydatidiform mole, drug therapy, surgical therapy, radiotherapy, cure, complications, recurrence, survival, prognosis, pregnancy outcome, disease outcome, treatment outcome, and remission. The initial search was performed in April 2017 and updated in May 2019. Relevant evidence was selected for inclusion in the following order: meta-analyses, systematic reviews, guidelines, randomized controlled trials, prospective cohort studies, observational studies, non-systematic reviews, case series, and reports. Additional significant articles were identified through cross-referencing the identified reviews. The total number of studies identified was 673, with 79 studies cited in this review.

VALIDATION METHODS

The content and recommendations were drafted and agreed upon by the authors. The Executive and Board of Directors of the Society of Gynecologic Oncology of Canada reviewed the content and submitted comments for consideration, and the Board of Directors for the Society of Obstetricians and Gynaecologists of Canada approved the final draft for publication. The quality of evidence was rated using the criteria described in the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology framework. See the online appendix tables for key to grading and interpretation of recommendations.

BENEFITS

These guidelines will assist physicians in promptly diagnosing gestational trophoblastic diseases and urgently referring patients diagnosed with gestational trophoblastic neoplasia to gynaecologic oncology for specialized management. Treating gestational trophoblastic neoplasia in specialized centres with the use of centralized databases allows for capturing and comparing data on treatment outcomes of patients with these rare tumours and for optimizing patient care.

SUMMARY STATEMENTS (GRADE RATINGS IN PARENTHESES)

RECOMMENDATIONS (GRADE RATINGS IN PARENTHESES).

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.

Directive clinique no 408 : Prise en charge des maladies gestationnelles trophoblastiques

OBJECTIF

Cette directive passe en revue l'évaluation clinique et la prise en charge des maladies gestationnelles trophoblastiques, notamment les traitements chirurgicaux et médicamenteux des tumeurs bénignes, prémalignes et malignes. L'objectif de la présente directive clinique est d'aider les fournisseurs de soins de santé à rapidement diagnostiquer les maladies gestationnelles trophoblastiques, à normaliser les traitements et le suivi et à assurer des soins spécialisés précoces aux patientes dont l'atteinte est maligne ou métastatique. PROFESSIONNELS CONCERNéS: Gynécologues généralistes, obstétriciens, médecins de famille, sages-femmes, urgentologues, anesthésistes, radiologistes, anatomopathologistes, infirmières autorisées, infirmières praticiennes, résidents, gynécologues-oncologues, oncologues médicaux, radio-oncologues, chirurgiens, omnipraticiens en oncologie, infirmières en oncologie, pharmaciens, auxiliaires médicaux et autres professionnels de la santé qui traitent des patientes atteintes d'une maladie gestationnelle trophoblastique. La présente directive vise également à fournir des renseignements aux parties intéressées qui prodiguent des soins de suivi à ces patientes après le traitement.

POPULATION CIBLE

Femmes en âge de procréer atteintes d'une maladie gestationnelle trophoblastique.

OPTIONS

Les femmes ayant reçu un diagnostic de maladie gestationnelle trophoblastique doivent être orientées vers un gynécologue afin qu'il réalise une évaluation initiale, envisage une intervention chirurgicale primaire (évacuation ou hystérectomie) et effectue un suivi. Il y a lieu d'orienter les femmes ayant reçu un diagnostic de tumeur trophoblastique gestationnelle vers un gynécologue-oncologue afin qu'il effectue la stadification tumorale, établisse le score de risque et envisage l'intervention chirurgicale primaire ou un traitement systémique (mono- ou polychimiothérapie) et la nécessité d'éventuels traitements supplémentaires. Il est recommandé de discuter de chaque cas de néoplasie gestationnelle trophoblastique lors d'une réunion multidisciplinaire de cas oncologiques et de l'inscrire dans une base de données centralisée (régionale et/ou nationale). DONNéES PROBANTES: Des recherches ont été effectuées au moyen des bases de données Embase et MEDLINE, du Cochrane Central Register of Controlled Trials et de la Cochrane Database of Systematic Reviews afin de trouver les études publiées depuis 2002 utilisant un ou plusieurs des mots clés suivants : trophoblastic neoplasms, choriocarcinoma, trophoblastic tumor, placental site, gestational trophoblastic disease, hydatidiform mole, drug therapy, surgical therapy, radiotherapy, cure, complications, recurrence, survival, prognosis, pregnancy outcome, disease outcome, treatment outcome et remission. La recherche initiale a été effectuée en avril 2017; une mise à jour a été faite en mai 2019. Les données probantes pertinentes ont été sélectionnées aux fins d'inclusion selon l'ordre suivant : méta-analyses, revues systématiques, directives cliniques, essais cliniques randomisés, études de cohortes prospectives, études observationnelles, revues non systématiques, études de séries de cas et rapports. D'autres articles pertinents ont été trouvés en recoupant les revues répertoriées. Le nombre total d'études relevées était de 673, dont 79 études sont citées dans la présente revue. MéTHODES DE VALIDATION: Le contenu et les recommandations ont été rédigés et acceptés par les auteurs. La direction et le conseil d'administration de la Société de gynéco-oncologie du Canada ont passé en revue le contenu de la version préliminaire et ont soumis des commentaires à prendre en considération. Le conseil d'administration de la Société des obstétriciens et gynécologues du Canada a approuvé la version définitive aux fins de publication. La qualité des données probantes a été évaluée au moyen des critères de l'approche GRADE (Grading of Recommendations Assessment, Development and Evaluation). Consulter les tableaux dans l'annexe en ligne pour connaître les critères de notation et d'interprétation des recommandations. BéNéFICES, RISQUES, COûTS: Les présentes recommandations aideront les médecins à diagnostiquer rapidement les maladies gestationnelles trophoblastiques et à orienter de façon urgente les patientes ayant reçu un diagnostic de maladie gestationnelle trophoblastique en gynécologie oncologique pour une prise en charge spécialisée. Le traitement des néoplasies gestationnelles trophoblastiques en centre spécialisé combiné à l'utilisation de bases de données centralisées permet de recueillir et de comparer des données sur les résultats thérapeutiques des patientes atteintes de ces tumeurs rares et d'optimiser les soins aux patientes. DÉCLARATIONS SOMMAIRES (CLASSEMENT GRADE ENTRE PARENTHèSES): RECOMMANDATIONS (CLASSEMENT GRADE ENTRE PARENTHèSES).

Uterine artery pulsatility index and serum BMP-9 predict resistance to methotrexate therapy in gestational trophoblastic neoplasia: A cohort study

BACKGROUND

Methotrexate is the most common first-line chemotherapy for low-risk gestational trophoblastic neoplasia (GTN). Uterine artery pulsatility index (UAPI) is an ultrasound marker for tumor vascularity that has been associated with an increased risk of methotrexate resistance. The combination of circulating angiogenic factor levels with UAPI data may improve the capacity of this model to predict chemoresistance.

METHODS

This was a single-center cohort study of women newly diagnosed between January 2008 and June 2012 with low-risk GTN during postmolar surveillance and treated with single-agent methotrexate at Charing Cross Hospital, a UK national center for treatment of gestational trophoblastic disease. Two hundred seventeen women underwent an ultrasound for UAPI measurement prior to initiation of chemotherapy. To examine serologic markers of methotrexate resistance among this cohort, we performed a case-control study using archived serum from 76 patients who could be matched based on prognostic risk score. Serum samples were examined by immunoassay to measure 8 different angiogenic factors (VEGF-A, FGF-basic, PLGF-1, PDGF-BB, EGF, ANGPT2, BMP-9, and ENG). Receiver-operator characteristic area under the curve (AUC) values were calculated for the ability of each analyte to correctly classify patients as methotrexate sensitive (MTX-S) or resistant (MTX-R).

RESULTS

Total human chorionic gonadotropin levels were similar between the MTX-S and MTX-R groups. UAPI values were significantly higher in MTX-S (median 1.30 [interquartile range {IQR} = 0.80-1.90]) compared to MTX-R patients (median 0.875 [IQR = 0.60-1.30]; P < 0.0001) with AUC 0.68 (95% confidence interval 0.61-0.76; P < 0.0001). In univariate analysis, only BMP-9 concentrations were significantly different between groups, lower among MTX-S (median of 225 ng/L, IQR = 170-287) compared to MTX-R patients (median 280 ng/L [IQR = 200-339]; P= 0.03). Combining UAPI with BMP-9 concentration improved prediction for chemoresistance with AUC 0.77 (95% confidence interval 0.66-0.88; P < 0.0001).

CONCLUSION

Circulating levels of BMP-9 are elevated in newly diagnosed women with low-risk GTN destined to fail primary methotrexate therapy. A combined test using serum BMP-9 plus UAPI might improve prediction of MTX-R in low-risk GTN.

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.

A review on management of gestational trophoblastic neoplasia

BACKGROUND

The rare presence of malignant cancerous cells afar any type of pregnancy is known as gestational trophoblastic neoplasia (GTN). GTN are benign lesions which mostly happen due to the activity of extravillous trophoblast cells and the placental villous tree development. These kinds of diseases would be occurring mainly due to the following clinicopathologic conditions: (I) existence of epithelioid trophoblastic tumor (ETT), (II) rare type of choriocarcinoma cancer, (III) gestational trophoblastic tumor of mole, and (IV) the rare malignant tumor of placental site trophoblastic tumor.

OBJECTIVE

This comprehensive study is trying to review the most recent approaches in comprehension of pathogenesis, more precise diagnosis, and also the most effective therapeutic procedures for patients who suffer from GTN disorders.

MATERIALS AND METHOD

A comprehensive research was carried out on scientific databases of Science Citation Index (SCI), MEDLINE, EMBASE, HMIC, PubMed, CINAHL, Google Scholar, Cochrane Database of Systematic Reviews (CDSR), and PsycINFO over the time period of 2005 to 2019. The keywords which applied for discovering more related records were including: Gestational trophoblastic diseases (GTD), Gestational trophoblastic neoplasia (GTN), molar pregnancy, choriocarcinoma, human chorionic gonadotropin (hCG), diagnosis, management and treatment.

CONCLUSION

In spite of the fact that GTN patients are treated with conventional surgical therapies or/and chemotherapy, in some patients with resistant disease, these therapies may not be effective and patients may die. Some novel remedial agents are required for decreasing the level of toxicity caused through administering conventional chemotherapy and also treating the patients who suffer from refractory or resistant disease. The newest issues are related to GTN diagnosis, process of progression of hydatidiform mole (HM) to GTN, and the issue of GTN drug resistance. In this regard, we should have a comprehensive knowledge on GTN genetics for answering all the available questions about this disorder.

Utilization of data below the analytical limit of quantitation in pharmacokinetic analysis and modeling: promoting interdisciplinary debate

Traditionally, bioanalytical laboratories do not report actual concentrations for samples with results below the LOQ (BLQ) in pharmacokinetic studies. BLQ values are outside the method calibration range established during validation and no data are available to support the reliability of these values. However, ignoring BLQ data can contribute to bias and imprecision in model-based pharmacokinetic analyses. From this perspective, routine use of BLQ data would be advantageous. We would like to initiate an interdisciplinary debate on this important topic by summarizing the current concepts and use of BLQ data by regulators, pharmacometricians and bioanalysts. Through introducing the limit of detection and evaluating its variability, BLQ data could be released and utilized appropriately for pharmacokinetic research.

Pulse actinomycin D as first-line treatment of low-risk post-molar non-choriocarcinoma gestational trophoblastic neoplasia

Background

Little data exists predicting the resistance to actinomycin D (Act-D) single-agent for gestational trophoblastic neoplasia (GTN). The objective was to determine the overall success of pulse Act-D and the factors predictive of resistance to pulse Act-D in the treatment of low-risk, non-choriocarcinoma post-molar GTN.

Methods

From January 2013 to October 2016, according to the FIGO criteria for the diagnosis of post-molar disease and the FIGO risk-factor scoring system for GTN, a total of 135 patients with post-molar non-choriocarcinoma GTN who were chemotherapy-naive with a FIGO score < 7 were treated with single-agent pulse Act-D as a first-line regimen, in Peking Union Medical College Hospital. The pulse Act-D regimen is defined as 1.25 mg/m² (max 2 mg) IV push every other week. All patients were followed until May 2017. Epidemiological and clinical data were compared between patients with remission and resistance to Act-D to determine predictive factors by univariate and multivariate analysis.

Results

Ninety-six of 135 patients (71.1%) achieved complete remission after first-line chemotherapy of pulse Act-D. In multivariate analysis, existing invasive uterine lesions observed by pre-chemotherapy transvaginal ultrasound (odds ratio [OR] 7.5, 95% confidence intervals [CI] 2.7–20.8), FIGO score ≥ 5 (OR 15.2, 95% CI 1.5–156.1) and pre-chemotherapy levels of β-hCG ≥ 4000 IU/L (OR 3.1, 95% CI 1.2–8.3) were independent high-risk factors predicting resistance to pulse Act-D as single-agent chemotherapy. During follow-up, no relapse, treatment-associated serious adverse events, or death occurred.

Conclusions

As first-line chemotherapy, pulse Act-D was effective and tolerable for patients with low-risk post-molar non-choriocarcinoma. Existing invasive uterine lesions observed by pre-chemotherapy transvaginal ultrasound, a FIGO score ≥ 5, and pre-chemotherapy levels of β-hCG ≥ 4000 IU/L were independent factors for resistance to pulse Act-D.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4512-5) contains supplementary material, which is available to authorized users.

Evaluation and suggestions for improving the FIGO 2000 staging criteria for gestational trophoblastic neoplasia: A ten-year review of 1420 patients

BACKGROUND

To re-evaluate the efficacy of the prognostic factors currently employed in the treatment of malignant gestational trophoblastic neoplasia.

METHODS

Clinical data from the Gestational Trophoblastic Disease (GTD) Center at Peking Union Medical Hospital (PUMCH) collected between January 2002 and December 2013 were retrospectively analyzed. Univariate and multivariate analyses of prognostic factors were performed using the Cox proportional hazards model. A new hazard ratio (HR)-based prognostic scoring scale was established and compared with the original scoring system.

RESULTS

In total, 1420 cases were included in the study (median follow-up=40months, overall complete remission (CR) rate=95.8%, relapse rate=7.1%, mortality rate=5.5%, median disease-free survival (DFS)=36months). Low-risk (0-6 points) and high-risk (≥6 points) patients exhibited CR rates of 99.8% (915/917) and 88.5% (445/503) and mortality rates of 0.3% and 15.1% (P<0.001), respectively. Univariate and multivariate analyses showed that age, pretreatment serum levels of human chorionic gonadotropin beta-subunit (β-hCG) and maximum tumor diameter were not independent prognostic risk factors. Antecedent pregnancy, the interval from the index pregnancy, the number of metastases and a history of failed chemotherapy treatments were independent prognostic risk factors. By modifying the scoring system based on the variables identified in a Cox analysis, we significantly increased the area under the receiver operating characteristics (ROC) curve.

CONCLUSION

Though effective, the accuracy of the International Federation of Gynecology and Obstetrics (FIGO) 2000 Trophoblastic Neoplasia Staging System requires improvement. Irrelevant prognostic factors should be removed, and the weights of other factors should be adjusted appropriately.

SEOM clinical guidelines in gestational trophoblastic disease (2017)

Gestational trophoblastic disease (GTD) is a rare but curable disease. Recent improvements in diagnosis and molecular biology have resulted in changes in staging and treatment. These guidelines provide evidence-based recommendation on how to manage GTD.

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.

15years of progress in gestational trophoblastic disease: Scoring, standardization, and salvage

Significant improvements in treatment and the understanding of gestational trophoblastic neoplasia have occurred in the last 15years. These diseases are almost always curable, and refractory patients have more options for salvage therapy. Recent improvements in the understanding of epidemiology, diagnosis, and cell biology have resulted in changes in staging, advances in treatment options, and opportunities for fertility preservation.

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.

Predictive factors of relapse in low-risk gestational trophoblastic neoplasia patients successfully treated with methotrexate alone

BACKGROUND

Patients with 2000 FIGO low-risk gestational trophoblastic neoplasia are commonly treated with single-agent chemotherapy. Methotrexate is widely used in this indication in Europe. Analysis of relapse after treatment and identification of factors associated with relapse would help understand their potential impacts on 2000 FIGO score evolution and chemotherapy management of gestational trophoblastic neoplasia patients.

OBJECTIVE

This retrospective study analyzes the predictive factors of relapse in low-risk gestational trophoblastic neoplasia patients whose hormone chorionic gonadotropin (hCG) normalized with methotrexate alone.

STUDY DESIGN

Between 1999 and 2014, 993 patients with gestational trophoblastic neoplasia were identified in the French Trophoblastic Disease Reference Center database, of which 465 were low-risk patients whose hCG normalized with methotrexate alone. Using univariate and multivariate analysis we identified significant predictive factors for relapse after methotrexate. The Kaplan-Meier method was used to plot the outcome of patients.

RESULTS

The 5-year recurrence rate of low-risk gestational trophoblastic neoplasia patients whose hCG normalized with methotrexate alone was 5.7% (confidence interval [IC], 3.86-8.46). Univariate analysis identified an antecedent pregnancy resulting in a delivery (HR = 5.96; 95% CI, 1.40-25.4, P = .016), a number of methotrexate courses superior to 5 courses (5-8 courses vs 1-4: HR = 6.19; 95% CI, 1.43-26.8, P = .015; 9 courses and more vs 1-4: HR = 6.80; 95% CI, 1.32-35.1, P = .022), and hCG normalization delay centered to the mean as predictive factors of recurrence (HR = 1.27; 95% CI, 1.09-1.49, P = .003). Multivariate analysis confirmed the type of antecedent pregnancy and the number of methotrexate courses as independent predictive factors of recurrence. A low-risk gestational trophoblastic neoplasia arising after a normal delivery had an 8.66 times higher relapse risk than that of a postmole gestational trophoblastic neoplasia (95% CI, 1.98-37.9], P = .0042). A patient who received 5-8 courses of methotrexate had a 6.7 times higher relapse risk than a patient who received 1-4 courses (95% CI, 1.54-29.2, P = .011). A patient who received 9 courses or more had an 8.1 times higher relapse risk than a patient who received 1-4 courses of methotrexate (95% CI, 1.54-42.6, P = .014).

CONCLUSION

Low-risk gestational trophoblastic neoplasia following a delivery and patients who need more than 4 courses of methotrexate to normalization are at a higher risk of relapse than other low-risk patients. Allotting a higher score to the "antecedent pregnancy" FIGO item should be considered for postdelivery gestational trophoblastic neoplasia. Further analysis of the need for consolidation courses is warranted.

Establishing the Quantitative Relationship Between Lanreotide Autogel®, Chromogranin A, and Progression-Free Survival in Patients with Nonfunctioning Gastroenteropancreatic Neuroendocrine Tumors

The objective of this work was to establish the quantitative relationship between Lanreotide Autogel® (LAN) on serum chromogranin A (CgA) and progression-free survival (PFS) in patients with nonfunctioning gastroenteropancreatic neuroendocrine tumors (GEP-NETs) through an integrated pharmacokinetic/pharmacodynamic (PK/PD) model. In CLARINET, a phase III, randomized, double-blind, placebo-controlled study, 204 patients received deep subcutaneous injections of LAN 120 mg (n = 101) or placebo (n = 103) every 4 weeks for 96 weeks. Data for 810 LAN and 1298 CgA serum samples (n = 632 placebo and n = 666 LAN) were used to develop a parametric time-to-event model to relate CgA levels and PFS (76 patients experienced disease progression: n = 49 placebo and n = 27 LAN). LAN serum profiles were described by a one-compartment disposition model. Absorption was characterized by two parallel pathways following first- and zero-order kinetics. As PFS data were considered informative dropouts, CgA and PFS responses were modeled jointly. The LAN-induced decrease in CgA levels was described by an inhibitory E MAX model. Patient age and target lesions at baseline were associated with an increment in baseline CgA. Weibull model distribution showed that decreases in CgA from baseline reduced the hazard of disease progression significantly (P < 0.001). Covariates of tumor location in the pancreas and tumor hepatic tumor load were associated with worse prognosis (P < 0.001). We established a semimechanistic PK/PD model to better understand the effect of LAN on a surrogate endpoint (serum CgA) and ultimately the clinical endpoint (PFS) in treatment-naive patients with nonfunctioning GEP-NETs.

Bringing Model-Based Prediction to Oncology Clinical Practice: A Review of Pharmacometrics Principles and Applications

Despite much investment and progress, oncology is still an area with significant unmet medical needs, with new therapies and more effective use of current therapies needed. The emergent field of pharmacometrics combines principles from pharmacology (pharmacokinetics [PK] and pharmacodynamics [PD]), statistics, and computational modeling to support drug development and optimize the use of already marketed drugs. Although it has gained a role within drug development, its use in clinical practice remains scarce. The aim of the present study was to review the principal pharmacometric concepts and provide some examples of its use in oncology. Integrated population PK/PD/disease progression models as part of the pharmacometrics platform provide a powerful tool to predict outcomes so that the right dose can be given to the right patient to maximize drug efficacy and reduce drug toxicity. Population models often can be developed with routinely collected medical record data; therefore, we encourage the application of such models in the clinical setting by generating close collaborations between physicians and pharmacometricians.

IMPLICATIONS FOR PRACTICE

The present review details how the emerging field of pharmacometrics can integrate medical record data with predictive pharmacological and statistical models of drug response to optimize and individualize therapies. In order to make this routine practice in the clinic, greater awareness of the potential benefits of the field is required among clinicians, together with closer collaboration between pharmacometricians and clinicians to ensure the requisite data are collected in a suitable format for pharmacometrics analysis.

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.

Early Prediction of Disease Progression in Small Cell Lung Cancer: Toward Model-Based Personalized Medicine in Oncology

Predictive biomarkers can play a key role in individualized disease monitoring. Unfortunately, the use of biomarkers in clinical settings has thus far been limited. We have previously shown that mechanism-based pharmacokinetic/pharmacodynamic modeling enables integration of nonvalidated biomarker data to provide predictive model-based biomarkers for response classification. The biomarker model we developed incorporates an underlying latent variable (disease) representing (unobserved) tumor size dynamics, which is assumed to drive biomarker production and to be influenced by exposure to treatment. Here, we show that by integrating CT scan data, the population model can be expanded to include patient outcome. Moreover, we show that in conjunction with routine medical monitoring data, the population model can support accurate individual predictions of outcome. Our combined model predicts that a change in disease of 29.2% (relative standard error 20%) between two consecutive CT scans (i.e., 6-8 weeks) gives a probability of disease progression of 50%. We apply this framework to an external dataset containing biomarker data from 22 small cell lung cancer patients (four patients progressing during follow-up). Using only data up until the end of treatment (a total of 137 lactate dehydrogenase and 77 neuron-specific enolase observations), the statistical framework prospectively identified 75% of the individuals as having a predictable outcome in follow-up visits. This included two of the four patients who eventually progressed. In all identified individuals, the model-predicted outcomes matched the observed outcomes. This framework allows at risk patients to be identified early and therapeutic intervention/monitoring to be adjusted individually, which may improve overall patient survival.

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.