Effectiveness and toxicity of second-line actinomycin D in patients with methotrexate-resistant postmolar low-risk gestational trophoblastic neoplasia

Initial Diagnosis and Treatment of Low-Risk Gestational Trophoblastic Neoplasia

Gestational trophoblastic neoplasia (GTN) is a rare form of cancer that is treated according to the World Health Organization (WHO) risk score, which predicts responsiveness to single-agent chemotherapy. Patients with WHO risk scores ≤6 have low-risk GTN, for which cure rates near 100%. Most women with low-risk GTN will respond to single-agent chemotherapy, which is given with either methotrexate or dactinomycin, and allows women to retain their fertility. This article also discusses less common treatment paradigms including second dilation and curettage and hysterectomy, as well as the emerging role of immunotherapy in managing low-risk GTN.

Clinical features of gestational choriocarcinoma: A retrospective bicentric study

OBJECTIVE

To investigate the clinicopathological features, prognostic factors, treatment, clinical response, and outcome of gestational choriocarcinoma (GCC).

MATERIALS AND METHODS

A retrospective review was made of the clinicopathological and survival data of 13 patients who were diagnosed and treated for GCC in two referral centers in Turkey between 1992 and 2020.

RESULTS

The median age of patients was 36 years (range, 27-54 years), and seven were ≤39 years. The antecedent pregnancy was a term in nine (69.2%) cases, and the risk score was ≥7 in 11 (84.6%). According to the International Federation of Gynecology and Obstetrics 2009 staging, eight cases were in stage I, two in stage III, and three in stage IV. With the exception of one patient, all the others received combination chemotherapy (CT), and two of those were also treated with radiotherapy. Chemoresistance developed in 50% (6/12), and second-line CT was given to four of these. The overall complete response rate was 69.2%. Four patients died of chemoresistance and disease progression, all of them were with antecedent-term pregnancy, had high scores ≥7, and had metastases.

CONCLUSION

GCC is a unique subtype of gestational trophoblastic neoplasia, which differs from others in terms of poor prognosis, a frequent tendency to early metastasis, and resistance to treatment. To be able to achieve the most efficient therapy and prognosis, histopathology-based risk models should be developed.

Immunotherapy in the treatment of chemoresistant gestational trophoblastic neoplasia - systematic review with a presentation of the first 4 Brazilian cases

OBJECTIVE

To evaluate the efficacy of immunotherapy for GTN treatment after methotrexate-resistance or in cases of multiresistant disease, through a systematic review, as well as to present the first 4 Brazilian cases of immunotherapy for GTN treatment.

METHODS

Three independent researchers searched five electronic databases (EMBASE, LILACS, Medline, CENTRAL and Web of Science), for relevant articles up to February/2023 (PROSPERO CRD42023401453). The quality assessment was performed using the Newcastle Ottawa scale for case series and case reports. The primary outcome of this study was the occurrence of complete remission. The presentation of the case reports was approved by the Institutional Review Board.

RESULTS

Of the 4 cases presented, the first was a low-risk GTN with methotrexate resistance unsuccessfully treated with avelumab, which achieved remission with sequential multiagent chemotherapy. The remaining 3 cases were high-risk multiagent-resistant GTN that were successfully treated with pembrolizumab, among which there were two subsequent gestations, one of them with normal pregnancy and healthy conceptus. Regarding the systematic review, 12 studies were included, only one of them on avelumab, showing a 46.7% complete remission rate. The remaining 11 studies were on pembrolizumab, showing an 86.7% complete remission rate, regardless of tumor histology. Both immunotherapies showed good tolerability, with two healthy pregnancies being recorded: one after avelumb and another after pembrolizumab.

CONCLUSION

Immunotherapy showed effectiveness for GTN treatment and may be especially useful in cases of high-risk disease, where pembrolizumab achieves a high therapeutic response, regardless of the histological type, and despite prior chemoresistance to multiple lines of treatment.

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.

Current chemotherapeutic options for the treatment of gestational trophoblastic disease

INTRODUCTION

Gestational trophoblastic neoplasia (GTN) is a rare tumor that arises from trophoblastic tissues with high remission rates after chemotherapy treatment. GTN can develop from any gestational events, such as miscarriage, ectopic pregnancy, and preterm/term pregnancy, but is more frequent after hydatidiform mole. The sensitivity of this tumor to chemotherapy and the presence of an exceptional tumor marker allow high remission rates, especially when patients are treated in referral centers.

AREAS COVERED

Observational, retrospective, prospective, systematic reviews, and meta-analysis studies focusing on GTN treatment. We searched PubMed, Medline, and the Library of Congress from January 1965 to May 2022.

EXPERT OPINION

Early GTN diagnosis allows low-toxic and highly effective treatment. Even multimetastatic disease has high rates of remission with multiagent regimen chemotherapy. Surgery is reserved for uterine disease in patients who have completed childbearing, in cases of chemoresistance to multiagent regimens or in the rare cases of placental site trophoblastic tumor or epithelioid trophoblastic tumor. While resistance is managed by salvage chemotherapy, cases with limited clinical response to sequential regimens have been successfully treated with immunotherapy.

Clinical Presentation, Treatment Outcomes, and Resistance-related Factors in South American Women with Low-risk Postmolar Gestational Trophoblastic Neoplasia

OBJECTIVE

 There are few multinational studies on gestational trophoblastic neoplasia (GTN) treatment outcomes in South America. The purpose of this study was to assess the clinical presentation, treatment outcomes, and factors associated with chemoresistance in low-risk postmolar GTN treated with first-line single-agent chemotherapy in three South American centers.

METHODS

 Multicentric, historical cohort study including women with International Federation of Gynecology and Obstetrics (FIGO)-staged low-risk postmolar GTN attending centers in Argentina, Brazil, and Colombia between 1990 and 2014. Data were obtained on patient characteristics, disease presentation, and treatment response. Logistic regression was used to assess the relationship between clinical factors and resistance to first-line single-agent treatment. A multivariate analysis of the clinical factors significant in univariate analysis was performed.

RESULTS

 A total of 163 women with low-risk GTN were included in the analysis. The overall rate of complete response to first-line chemotherapy was 80% (130/163). The rates of complete response to methotrexate or actinomycin-D as first-line treatment, and actinomycin-D as second-line treatment postmethotrexate failure were 79% (125/157), 83% (⅚), and 70% (23/33), respectively. Switching to second-line treatment due to chemoresistance occurred in 20.2% of cases (33/163). The multivariate analysis demonstrated that patients with a 5 to 6 FIGO risk score were 4.2-fold more likely to develop resistance to first-line single-agent treatment (p = 0.019).

CONCLUSION

 1) At presentation, most women showed clinical characteristics favorable to a good outcome, 2) the overall rate of sustained complete remission after first-line single-agent treatment was comparable to that observed in developed countries, 3) a FIGO risk score of 5 or 6 is associated with development of resistance to first-line single-agent chemotherapy.

Current Evidence on Immunotherapy for Gestational Trophoblastic Neoplasia (GTN)

Simple Summary

Gestational trophoblastic neoplasia (GTN) is a rare tumor group that arises from the malignant transformation of placental tissue. Based on the evaluation of International Federation of Gynecology and Obstetrics (FIGO) anatomic staging and FIGO prognostic score, GTN is divided into low-, high-, and ultra-high-risk groups if the score obtained is less than or equal to 6, greater than 6 or greater than 12, respectively. The standard treatment is chemotherapy, using a single agent in low-risk disease and multiagent chemotherapy in high- and ultra-high-risk GTN. In chemoresistant forms of GTN, the use of immune checkpoint inhibitors, such as anti-PD-1 or anti-PD-L1/2, could represent a new therapeutic strategy. In this study, we evaluate the available evidence on immune checkpoint inhibitors for GTN treatment.

Abstract

Background: Gestational trophoblastic disease includes a rare group of benign and malignant tumors derived from abnormal trophoblastic proliferation. Malignant forms are called gestational trophoblastic neoplasia (GTN) and include invasive mole, choriocarcinoma, placental site trophoblastic tumor and epithelioid trophoblastic tumor. Standard treatment of GTN is chemotherapy. The regimen of choice mainly depends on the FIGO prognostic score. Low-risk and high-risk GTN is treated with single-agent or multiagent chemotherapy, respectively. In the case of chemoresistance, immunotherapy may represent a new therapeutic strategy. Methods: Literature obtained from searches on PubMed concerning GTN and immunotherapy was reviewed. Results: Programmed cell death 1 (PD-1) and its ligands (PD-L1/2) are expressed in GTN. Published data on PD-1/PD-L1 inhibitors alone in GTN were available for 51 patients. Pembrolizumab is an anti-PD-1 inhibitor used in chemoresistant forms of GTN. In the TROPHIMMUN trial, Avelumab, a monoclonal antibody inhibiting PD-L1, showed promising results only in patients with GTN resistant to monochemotherapy. Conversely, in patients with resistance to multiagent chemotherapy, treatment with Avelumab was discontinued due to severe toxicity and disease progression. The association of Camrelizumab and Apatinib could represent a different treatment for forms of GTN refractory to polychemotherapy or for relapses. Conclusions: Anti-PD-1 or anti-PD-L1 might represent an important new treatment strategy for the management of chemoresistant/refractory GTN.

Ten steps to establish a national centre for gestational trophoblastic disease

PURPOSE OF REVIEW

Gestational trophoblastic disease (GTD) is a group of heterogeneous disorders characterized by abnormal proliferation of trophoblastic tissue. GTD is a rare disease that is curable in the vast majority of patients when managed appropriately. The aim of the review is to discuss the important steps necessary to establish a center of excellence for GTD.

RECENT FINDINGS

Care of patients with a rare disease is complicated by lack of strong evidence, scattering of patients across the country and limited expertise of medical professionals. The establishment of a center of excellence requires awareness of its benefit, funding, a solid business case and most of all dedicated clinicians. A multidisciplinary team and formulation of national guidelines are important steps before clinical pathways can be developed and treatment can be evaluated for improvement of care and research purposes. International embedding can facilitate the process and lead to the development of a (inter) national acknowledged sustainable center of excellence.

SUMMARY

Centers of excellence could optimize the care of patients with GTD and promote research.

Predictors for single-agent resistance in FIGO score 5 or 6 gestational trophoblastic neoplasia: a multicentre, retrospective, cohort study

BACKGROUND

Patients with gestational trophoblastic neoplasia who have an International Federation of Gynaecology and Obstetrics (FIGO) risk score of 5 or 6 usually receive non-toxic single-agent chemotherapy as a first-line treatment. Previous studies suggest that only a third of patients have complete remission, with the remaining patients requiring toxic multiagent chemotherapy to attain remission. As stratification factors are unknown, some centres offer multiagent therapy upfront, resulting in overtreatment of many patients. We aimed to identify predictive factors for resistance to single-agent therapy to inform clinicians on which patients presenting with a FIGO score of 5 or 6 are likely to benefit from upfront multiagent chemotherapy.

METHODS

We did a multicentre, retrospective, cohort study of patients with gestational trophoblastic neoplasia presenting with a FIGO score of 5 or 6, who received treatment at three gestational trophoblastic neoplasia reference centres in the UK, Brazil, and the USA between Jan 1, 1964, and Dec 31, 2018. All patients who had been followed up for at least 12 months after remission were included. Patients were excluded if they had received a non-standard single-agent treatment (eg, etoposide); had been given a previously established first-line multiagent chemotherapy regimen; or had incomplete data for our analyses. Patient data were retrieved from medical records. The primary outcome was the incidence of chemoresistance after first-line or second-line single-agent chemotherapy. Variables associated with chemoresistance to single-agent therapies were identified by logistic regression analysis. In patient subgroups defined by choriocarcinoma histology and metastatic disease status, we did bootstrap modelling to define thresholds of pretreatment human chorionic gonadotropin concentrations and identify groups of patients with a greater than 80% risk (ie, a positive predictive value [PPV] of 0·8) of resistance to single-agent chemotherapy.

FINDINGS

Of 5025 patients with low-risk gestational trophoblastic neoplasia, we identified 431 patients with gestational trophoblastic neoplasia presenting with a FIGO risk score of 5 or 6. All patients were followed up for a minimum of 2 years. 141 (40%) of 351 patients developed resistance to single-agent treatments and required multiagent chemotherapy to achieve remission. Univariable and multivariable logistic regression revealed metastatic disease status (multivariable logistic regression analysis, odds ratio [OR] 1·9 [95% CI 1·1-3·2], p=0·018), choriocarcinoma histology (3·7 [1·9-7·4], p=0·0002), and pretreatment human chorionic gonadotropin concentration (2·8 [1·9-4·1], p<0·0001) as significant predictors of resistance to single-agent therapies. In patients with no metastatic disease and without choriocarcinoma, a pretreatment human chorionic gonadotropin concentration of 411 000 IU/L or higher yielded a PPV of 0·8, whereas in patients with either metastases or choriocarcinoma, a pretreatment human chorionic gonadotropin concentration of 149 000 IU/L or higher yielded the same PPV for resistance to single-agent therapy.

INTERPRETATION

Approximately 60% of women with gestational trophoblastic neoplasia presenting with a FIGO risk score of 5 or 6 achieve remission with single-agent therapy; almost all remaining patients have complete remission with subsequent multiagent chemotherapy. Primary multiagent chemotherapy should only be given to patients with metastatic disease and choriocarcinoma, regardless of pretreatment human chorionic gonadotropin concentration, or to those defined by our new predictors.

FUNDING

None.

TRANSLATION

For the Portuguese translation of the abstract see Supplementary Materials section.

Increasing the human chorionic gonadotrophin cut-off to ≤1000 IU/l for starting actinomycin D in post-molar gestational trophoblastic neoplasia developing resistance to methotrexate spares more women multi-agent chemotherapy

Background

A human chorionic gonadotropin (hCG) cut-off of ≤300 IU/l for starting actinomycin D (ActD) in post-molar gestational trophoblastic neoplasia (GTN) patients developing methotrexate resistance (MTX-R) reduced the number of women needing toxic multi-agent chemotherapy (etoposide, MTX and ActD alternating weekly with cyclophosphamide and vincristine; EMA/CO) without affecting survival. Here we assess whether an increased hCG cut-off of ≤1000 IU/l spares more women EMA/CO.

Patients and methods

All post-molar GTN patients treated with first-line methotrexate and folinic acid (MTX/FA) were identified in a national cohort between 2009 and 2016. Data collected included age, FIGO score, the hCG levels at MTX-R, and treatment outcomes.

Results

In total, 609 GTN patients commenced treatment with MTX/FA achieving a complete response in 57% (348/609). Resistance developed in 25.1% (153/609) at an hCG ≤ 1000 IU/l and switching to ActD achieved remission in 92.8% without any major toxicity with the remaining 7.2% remitting on EMA/CO. Comparative analysis of patients switching at an hCG <100 versus 100-300 versus 300-1000 IU/l revealed a significant fall in the cure rate with second-line ActD from 97% (93/96) to 87% (34/39) to 78% (14/18), respectively, P = 0.009. However, by increasing the hCG cut-off from ≤300 to ≤1000 IU/l, 14 patients were spared EMA/CO chemotherapy. Moreover, in the present series, all post-molar GTN remain in remission.

Conclusion

This study demonstrates that increasing the hCG cut-off from ≤300 to ≤1000 IU/l for choosing patients for ActD following MTX-R spares more women with GTN from the greater toxicity of EMA/CO without compromising 100% survival outcomes.

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An hCG cut-off of ≤1000 IU/l for ActD over EMA/CO treatment in MTX-R GTN spares women toxicity without affecting survival.

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On developing MTX-R, as the hCG cut-off for selecting ActD versus EMA/CO rises, the complete response rate for ActD falls.

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Half of FIGO-7 patients were cured on single-agent treatment (MTX/FA or sequential ActD), warranting further investigation.

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.

Outcomes for relapsed versus resistant low risk gestational trophoblastic neoplasia following single-agent chemotherapy

OBJECTIVE

To compare outcomes for relapsed versus resistant low risk gestational trophoblastic neoplasia (GTN) following single-agent chemotherapy.

METHODS

This was a single center retrospective study of low risk GTN. Cases failing to achieve a normal hCG with first-line therapy were defined as chemotherapy resistance. Cases achieving hCG remission, but recurring, were defined as relapse. Primary endpoints were remission rate with second-line therapy and time to remission. Univariate and multivariate analyses were performed to define prognostic factors.

RESULTS

Among 877 low risk GTN patients there were 124 (14.8%) chemotherapy resistant and 22 (2.6%) relapse cases. Complete remission rates with second-line therapy were similar between relapse (77.3%) and resistant (76.6%) cases (p = 0.95), but resistance was associated with a longer time to reach complete remission with second-line therapy (median 8.3 vs 4.9 weeks; p = 0.024). In multivariate analysis, the significant prognostic factors for second-line therapy remission and time to second-line therapy remission were use of multi-agent chemotherapy (OR of 9.45; 95%CI, 2.13-41.97; p = 0.003) and primary chemo-resistance (HR of 0.27; 95%CI, 0.12-0.59; p = 0.001), respectively. With additional therapies, sustained remission rates rose to 90% (18/20) for relapse and 99.2% (120/121) for chemo-resistance (p = 0.053).

CONCLUSIONS

Although second-line therapy for resistant or relapsed low risk GTN is able to achieve complete remission in most cases, time to complete remission for relapsed disease was shorter than for resistant disease. Further studies on the biologic differences between resistant and relapsed disease may clarify the optimal treatment for these clinical situations.