Sonographic characteristics of post-molar gestational trophoblastic neoplasia at diagnosis and during follow-up, and relationship with methotrexate resistance

Rapid progression from complete molar pregnancy to post-molar gestational trophoblastic neoplasia: a rare case report and literature review

Background

Post-molar gestational trophoblastic neoplasia (pGTN) develops in about 15% to 20% of complete hydatidiform mole (CMH). Commonly, pGTN is diagnosed based on hCG monitoring following the molar evacuation. To date, no detailed information is available on how fast can pGTN develop from CHM. However, the concurrence of CHM and pGTN is extremely rare.

Case presentation

A 29-year-old woman presented to the gynecology department with irregular vaginal bleeding and an elevated hCG serum level. Both ultrasound and MRI showed heterogeneous mass in uterine cavity and myometrium. Suction evacuation was performed and histologic examination of the evacuated specimen confirmed complete hydatidiform mole. Repeated ultrasound showed significant enlargement of the myometrium mass one week after the evacuation. pGTN with prognostic score of 4 was then diagnosed and multi-agent chemotherapy regimen implemented with a good prognosis.

Conclusion

In rare cases, CMH can rapidly progress into pGTN. Imaging in combination with hCG surveillance seems to play a vital role guiding timely diagnosis and treatment in the specific condition. Low-risk gestational trophoblastic neoplasia (GTN) should be managed stratified according to the individual situation.

Gestational choriocarcinoma

Gestational choriocarcinoma accounts for 5% of gestational trophoblastic neoplasms. Approximately 50%, 25%, and 25% of gestational choriocarcinoma occur after molar pregnancies, term pregnancies, and other gestational events, respectively. The FIGO scoring system categorizes patients into low (score 0 to 6) and high risk (score 7 or more) choriocarcinoma. Single-agent and multi-agent chemotherapy are used in low- and high-risk patients, respectively. Chemotherapy for localized disease has a goal of eradication of disease without surgery and is associated with favorable prognosis and fertility preservation. Most patients with gestational choriocarcinoma are cured with chemotherapy; however, some (<5.0%) will die as a result of multi-drug resistance, underscoring the need for novel approaches in this group of patients. Although there are limited data due to its rarity, the treatment response with immunotherapy is high, ranging between 50-70%. Novel combinations of immune checkpoint inhibitors with targeted therapies (including VEGFR-2 inhibitors) are under evaluation. PD-L1 inhibitors are considered a potential important opportunity for chemo-resistant patients, and to replace or de-escalate chemotherapy to avoid or minimize chemotherapy toxicity. In this review, the Rare Tumor Working Group and the European Organization for Research and Treatment of Cancer evaluated the current landscape and further perspective in the management of patients diagnosed with gestational choriocarcinoma.

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.

Use of Methotrexate in Gynecologic and Obstetric Practice: What the Radiologist Needs to Know

Methotrexate (MTX) is the primary pharmaceutical agent that is used for management of disorders arising from trophoblastic tissue. Its widespread international use is mostly attributable to its noninvasive, safe, and effective characteristics as a treatment option for ectopic pregnancy (EP) and gestational trophoblastic disease (GTD), with the large added benefit of fertility preservation. Although the effects of MTX usage are well documented in the gynecologic and obstetric literature, there is a scarcity of radiologic literature on the subject. Depending on the type of EP, the route of MTX administration and dosage may vary. US plays an essential role in the diagnosis and differentiation of various types of EPs, pregnancy-related complications, and complications related to MTX therapy, as well as the assessment of eligibility criteria for MTX usage. A knowledge of expected imaging findings following MTX treatment, including variability in echogenicity and shape of the EP, size fluctuations, changes in vascularity and gestational sac content, and the extent of hemoperitoneum, is essential for appropriate patient management and avoidance of unnecessary invasive procedures. A recognition of sonographic findings associated with pregnancy progression and complications such as tubal or uterine rupture, severe hemorrhage, septic abortion, and development of arteriovenous communications ensures prompt patient surgical management. The authors discuss the use of MTX in the treatment of disorders arising from trophoblastic tissue (namely EP and GTD), its mechanism of action, its route of administration, and various treatment regimens. The authors also provide a focused discussion of the role of US in the detection and diagnosis of EP and GTD, the assessment of the eligibility criteria for MTX use, and the identification of the sonographic findings seen following MTX treatment, with specific emphasis on imaging findings associated with MTX treatment success and failure. Online supplemental material is available for this article. ^©RSNA, 2021.

Doppler-based predictive model for methotrexate resistance in low-risk gestational trophoblastic neoplasia with myometrial invasion: prospective study of 147 patients

OBJECTIVES

This prospective clinical study aimed to evaluate the vascularization characteristics of low-risk gestational trophoblastic neoplasia (GTN) using Doppler imaging and to develop a predictive model for resistance to methotrexate (MTX).

METHODS

Patients with low-risk GTN receiving primary MTX treatment were enrolled from the Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China, from September 2012 to August 2018. The primary endpoint was to develop and internally validate a predictive model for resistance to MTX therapy in these patients. In the training set, clinical features and Doppler hemodynamic parameters before MTX therapy were analyzed using logistic regression to identify independent predictors of MTX resistance, which were integrated into the model. The predictive performance of the model was evaluated by leave-one-out cross-validation in the training dataset and internal validation in an independent-sample test dataset.

RESULTS

The entire imaging protocol was completed by 147 eligible patients, of which 110 comprised the training set and 37 the test set. In the training set, cases with myometrial invasion (81.8%; 90/110) showed vascular-enriched areas in the myometrium and high velocity and low impedance ratios of the uterine artery (UtA) compared to cases without myometrial invasion (18.2%; 20/110). On multivariate logistic regression analysis, time-averaged mean velocity in UtA (UtA-TAmean) and the International Federation of Gynecology and Obstetrics (FIGO) score were identified as independent predictors (P = 0.009 and P = 0.043, respectively) of MTX resistance. The Doppler-based predictive model, developed based on the 90 cases with myometrial invasion, was y = -2.95332 + 0.41696 × FIGO score + 0.03551 × UtA-TAmean. The model showed an area under the curve of 0.757 (95% CI, 0.653-0.862) and the optimal cut-off value was 0.50622, which had 45.2% sensitivity and 96.6% specificity. The model stratified patients with low-risk GTN into low (< 10%), intermediate (10-90%) and high (> 90%) probability of MTX resistance, based on the threshold values of -1.59544 and 0.10046. The model had an accuracy of 74.4% (95% CI, 64.5-82.3%) in the cross-validation and 72.7% (95% CI, 55.8-84.9%) in the internal validation.

CONCLUSIONS

The Doppler-based predictive model, combining a non-invasive marker of tumor vascularity with the FIGO scoring system, can differentiate cases with low from those with high probability of developing MTX resistance and therefore has the potential to guide treatment options in patients with low-risk GTN and myometrial invasion. © 2020 Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

The Role of Contrast-Enhanced Ultrasound in Evaluating Gestational Trophoblastic Neoplasia: A Preliminary Study

Objective

We aimed to compare the imaging features of gestational trophoblastic neoplasias (GTNs) and benign pregnancy-related uterine diseases on contrast-enhanced ultrasound (CEUS) to explore the clinical value of CEUS in differentiating these two types of uterine lesions.

Materials and Methods

In this prospective study, patients with GTNs before and after chemotherapy and benign pregnancy-related uterine lesions received conventional US and CEUS. The imaging features and parameters of CEUS of the lesions were assessed.

Results

A total of 73 patients were enrolled in this study, including 48 with GTNs and 25 with benign lesions. The enhancement pattern of newly diagnosed GTNs was mainly diffuse enhancement (70.8%), with a non-enhanced area of less than 1/3 of the entire lesion. For the benign group, the enhancement pattern was mainly ring-shaped enhancement (72.0%), and the non-enhanced area was more than 1/2 (68.0%), significantly different from that of GTNs (P = 0.000 and 0.002, respectively). Forty-one lesions demonstrated unclear boundaries on greyscale US but clearly displayed on CEUS. In both the benign and malignant groups, the measurements of lesion size on CEUS were larger than those on greyscale US (P = 0.000). The measurement differences (ΔD: D2-D1) of the malignant cases were higher than those of the benign cases (P = 0.001).

Conclusion

GTNs and benign pregnancy-related uterine diseases have different imaging characteristics on CEUS. The boundary and involved range of the lesion can be clearly demonstrated on CEUS. CEUS possesses clinical value in diagnosing and evaluating GTNs and benign pregnancy-related diseases.