Practical guidelines of the EOTTD for pathological and genetic diagnosis of hydatidiform moles

Hydatidiform moles are rare and thus most pathologists and geneticists have little experience with their diagnosis. It is important to promptly and correctly identify hydatidiform moles given that they are premalignant disorders associated with a risk of persistent gestational trophoblastic disease and gestational trophoblastic neoplasia. Improvement in diagnosis can be achieved with uniformization of diagnostic criteria and establishment of algorithms. To this aim, the Pathology and Genetics Working Party of the European Organisation for Treatment of Trophoblastic Diseases has developed guidelines that describe the pathological criteria and ancillary techniques that can be used in the differential diagnosis of hydatidiform moles. These guidelines are based on the best available evidence in the literature, professional experience and consensus of the experts' group involved in its development.

Short tandem repeats genotyping of gestational choriocarcinoma - our experiences

OBJECTIVE

This short communication demonstrates how short tandem repeat genotyping can identify the origin of gestational choriocarcinoma.

MATERIALS AND METHODS

The origin of gestational choriocarcinoma in our three cases was determined using the short tandem repeats genotyping technique, which involved quantitative fluorescent PCR and fragmentation analysis.

RESULTS

In Case 1 despite no medical history of molar pregnancy, DNA analysis indicated that the choriocarcinoma originated from a homozygous complete hydatidiform mole. We conclude, that the patient's complete abortion 10 years prior to the choriocarcinoma diagnosis was an undiagnosed complete hydatidiform mole. In Case 2 and Case 3 the clinically presumed origin of choriocarcinoma was confirmed.

CONCLUSION

Determining the origin of choriocarcinoma is essential for clinical application, as it affects the FIGO scoring system for gestational trophoblastic neoplasia, which determines the patient's prognosis and treatment approach.

Extrauterine epithelioid trophoblastic tumour and its somatic carcinoma mimics: short tandem repeat genotyping meets the diagnostic challenges

AIMS

While epithelioid trophoblastic tumour (ETT) primarily arises from the uterus, cases have been increasingly documented at extrauterine sites, originating from an ectopic gestation or presenting as a metastatic tumour, leading to the major differential diagnosis of somatic carcinoma with trophoblastic differentiation. The precise separation of a gestational trophoblastic tumour from its somatic carcinoma mimics is highly relevant and crucial for patient management and prognosis.

METHODS AND RESULTS

We summarise the clinicopathological and molecular features of four challenging epithelioid malignancies presenting at extrauterine sites, with ETT as the main differential diagnosis. All four tumours demonstrated histological and immunohistochemical features overlapping between a somatic carcinoma and an ETT, combined with inconclusive clinical and imaging findings. Serum beta-hCG elevation was documented in two cases. Short tandem repeat (STR) genotyping was performed and was informative in all cases. The presence of a unique paternal allelic pattern in the tumour tissue confirmed the diagnosis of ETT in two cases with an initial consideration of either somatic carcinoma or suspicion of a gestational trophoblastic tumour. The presence of matching genetic profile with the patient's paired normal tissue was seen in two other cases (both initially considered as ETT), confirming their somatic origin, including one metastatic triple-negative breast carcinoma and one primary lung carcinoma.

CONCLUSIONS

Diagnostic separation of ETT at an extrauterine site from its somatic carcinoma mimics can be difficult at the histological and immunohistochemical levels. STR genotyping offers a robust ancillary tool that precisely separates ETT from somatic carcinomas with trophoblastic differentiation.

Impact of molecular genotyping on the diagnosis and treatment of human chorionic gonadotropin-producing tumors

OBJECTIVES

To assess the use of molecular genotyping to accurately diagnose and treat human chorionic gonadotropin (hCG)-producing tumors and to evaluate the discriminating capacity of molecular testing on prognosis and overall survival.

METHODS

We conducted a retrospective descriptive study of patients registered with the French Reference Center for Trophoblastic Disease between 1999 and 2021. We included all patients with hCG-producing tumors for whom results of molecular genotyping were available.

RESULTS

Fifty-five patients with molecular genotyping were included: 81.2 % (n = 45) had tumors of gestational origin, 12.7 % (n = 7) of non-gestational origin and 5.5 % (n = 3) of undetermined origin. The results of molecular genotyping influenced the treatment decisions for 17 % of patients in this cohort. Overall survival was 93.3 % for patients with gestational tumors (after a median follow-up of 74 months) compared to 71.4 % for patients with non-gestational tumors (after a median follow-up of 23 months).

CONCLUSION

In atypical presentations of hCG-producing tumors, molecular genotyping is a valuable tool to guide diagnosis and tailor treatment recommendations.

Claudin-6 enhances the malignant progression of gestational trophoblastic neoplasm by promoting proliferation and metastasis

PURPOSE

Choriocarcinoma (CC) is a rare and highly malignant epithelial tumour. However, the mechanism underlying its occurrence and development remains unknown. We aimed to reveal the biological significance and prognostic value of Claudin-6 (CLDN6) in gestational trophoblastic disease (GTD).

PATIENTS AND METHODS

We collected clinical GTD specimens from 2011 to 2019 and measured CLDN6 gene expression by immunohistochemistry (IHC). High-throughput mRNA sequencing (RNA-seq) revealed a GTD progression-associated gene. CCK-8, wound healing, and flow cytometry assays were used to assess the biological effects of CLDN6 overexpression and knockdown. The medical records of 118 GTD patients from 2011 to 2019 were retrospectively analysed to identify correlations between CLDN6 expression and GTD patient clinical-pathological parameters; these correlations were analysed using the chi-square test and one-way ANOVA. Univariate logistic regression was used to analyse various prognostic parameters of patients with post-molar GTN.

RESULTS

CLDN6 had the second highest fold change in gene expression between GTN and normal samples. CLDN6 was highly expressed in GTN tissues and CC cell lines, and silencing CLDN6 inhibited the proliferation and migration and promoted the apoptosis of CC cells. CLDN6 overexpression was significantly correlated with uterine size (p = 0.01) and ovarian cysts > 6 cm (p = 0.027), CLDN6 expression was significantly higher in HR-GTNs than in low-risk GTNs (LR-GTNs) (p = 0.008), and logistic regression analysis showed that CLDN6 expression in hydatidiform moles (HMs) was related to a high risk of developing post-molar GTN (OR = 2.393, p = 0.03).

CONCLUSION

We propose that CLDN6 participates in the development of GTD and may become a new therapeutic target for CC.

Molecular Analyses of Chorionic-Type Intermediate Trophoblastic Lesions: Atypical Placental Site Nodules are Closer to Placental Site Nodules Than Epithelioid Trophoblastic Tumors

Gestational trophoblastic diseases derived from the chorionic-type intermediate trophoblast include benign placental site nodule (PSN) and malignant epithelioid trophoblastic tumor (ETT). Among PSNs, the World Health Organization classification introduced a new entity named atypical placental site nodule (APSN), corresponding to an ETT precursor, for which diagnostic criteria remain unclear, leading to a risk of overdiagnosis and difficulties in patient management. We retrospectively studied 8 PSNs, 7 APSNs, and 8 ETTs to better characterize this new entity and performed immunohistochemical analysis (p63, human placental lactogen, Cyclin E, and Ki67), transcriptional analysis using the NanoString method to quantify the expression of 760 genes involved in the main tumorigenesis pathways, and RNA sequencing to identify fusion transcripts. The immunohistochemical analysis did not reveal any significant difference in Cyclin E expression among the 3 groups (P = .476), whereas the Ki67 index was significantly (P < .001) higher in ETT samples than in APSN and PSN samples. None of the APSN samples harbored the LPCAT1::TERT fusion transcripts, in contrast to 1 of 6 ETT samples, as previously described in 2 of 3 ETT samples. The transcriptomic analysis allowed robust clustering of ETTs distinct from the APSN/PSN group but failed to differentiate APSNs from PSNs. Indeed, only 7 genes were differentially expressed between PSN and APSN samples; CCL19 upregulation and EPCAM downregulation were the most distinguishing features of APSNs. In contrast, 80 genes differentiated ETTs from APSNs, establishing a molecular signature for ETT. Gene set analysis identified significant enrichments in the DNA damage repair, immortality and stemness, and cell cycle signaling pathways when comparing ETTs and APSNs. These results suggested that APSN might not represent a distinct entity but rather a transitional stage between PSN and ETT. RNA sequencing and the transcriptional signature of ETT described herein could serve as triage for APSN from curettage or biopsy material, enabling the identification of cases that need further clinical investigations.

Gestational Trophoblastic Disease: Contemporary Diagnostic Approach

Pathologic diagnosis of gestational trophoblastic disease (GTD)-hydatidiform moles and gestational trophoblastic neoplasms-underwent a major shift in the past decade from morphology-based recognition to precise molecular genetic classification of entities, which also allows for prognostic stratification of molar gestations. This article highlights these recent advances and their integration into the routine pathology practice. The traditional gross and histomorphologic features of each entity are also reviewed with special focus on differential diagnoses and their clinical implications.

Epithelioid Trophoblastic Tumour: A Case with Genetic Linkage to a Child Born over Seventeen Years Prior, Successfully Treated with Surgery and Pembrolizumab

Epithelioid trophoblastic tumours are rare neoplasms showing differentiation towards the chorion leave-type intermediate cytotrophoblast, with only a handful of cases being reported in the literature. These tumours are slow-growing and are typically confined to the uterus for extended periods of time. While the pathogenesis is unclear, they are thought to arise from a remnant intermediate trophoblast originating from prior normal pregnancies or, less frequently, gestational trophoblastic tumours. A protracted time period between the gestational event and tumour development is typical. This case describes a 49-year-old previously healthy female who presented with a completely asymptomatic uterine mass, discovered incidentally during a routine gynaecological assessment. The pathological analysis of the hysterectomy specimen confirmed an epithelioid trophoblastic tumour, involving the uterus and cervix. This is a rare gynaecological tumour. A comparative short tandem repeat analysis revealed genetic similarities to a previous healthy gestation seventeen years prior. She was successful treated with adjuvant pembrolizumab, with no evidence of disease recurrence to date.

Application of next-generation sequencing to preimplantation genetic testing for recurrent hydatidiform mole patients

PURPOSE

To study the application of next-generation sequencing on preimplantation genetic testing for recurrent hydatidiform mole patients.

METHODS

A total of ten recurrent hydatidiform mole patients aged 27-34 years with a history of at least twice hydatidiform moles and no normal pregnancy were collected from 2019 to 2020. The diagnosis of hydatidiform mole type was clarified using short tandem repeat genotyping on products of conception, and whole-exome sequencing was applied for all patients and their partners. Seven recurrent hydatidiform mole patients with complete hydatidiform mole/partial hydatidiform mole type among previous hydatidiform mole tissues and no Pathogenetic/Likely pathogenetic/Uncertain significance variants in NLRP7/KHDC3L/MEI1/C11orf80 underwent a procedure of preimplantation genetic testing. Next-generation sequencing for analyzing the copy number variants and the numbers of heterozygous single nucleotide polymorphism was adopted to clarify the ploidy and parental origin of the embryo chromosomes in vitro. Embryos with biparental diploidy were selected for transfer.

RESULTS

Seven patients have undergone the procedure of preimplantation genetic testing, and twenty-three embryos were obtained, among which 82.6% (n = 19) were identified transferrable and 17.4% (n = 4) were identified aneuploid. Two patients have delivered healthy babies and another is currently in the second trimester after transfer.

CONCLUSION

Analyzing the copy number variants and the numbers of heterozygous single nucleotide polymorphism on the basis of next-generation sequencing can be utilized in the procedure of preimplantation genetic testing among part of recurrent hydatidiform mole patients. The current study is effective to reduce the occurrence of hydatidiform mole with improved clinical strategy, the advanced testing technology and analysis methods, as three of seven patients have conceived or delivered successfully.

[Expressions of NF-κBp65 and IκBα in gestational trophoblastic disease and clinical significance]

AIM

To investigate the roles of nuclear factor κB p65 (NF-κBp65) and inhibitor of nuclear factor κB α (IκBα) in the development and metastasis of gestational trophoblastic neoplasia (GTN) by analyzing the expressions of NF-κBp65 and IκBα in normal early pregnancy villi and gestational trophoblastic diseases, and to reveal the relationship of NF-κBp65 and IκBα with age and clinical stage of GTN patients.

METHODS

The expressions of NF-κBp65 and IκBα were detected by immunohistochemistry in normal pregnancy villi (20 cases), hydatidiform moles (HM, 30 cases), invasive hydatidiform moles (IHM, 13 cases) and chorionic carcinomas (CCA, 15 cases).

RESULTS

NF-κBp65 expression was statistically different (P<0.05) between normal pregnancy villi and IHM (P=0.013), normal pregnancy villi and CCA(P=0.018), HM and IHM(P=0.026), HM and CCA (P=0.035). Differences in IκBα expression were statistically significant between normal pregnancy villi and IHM, normal pregnancy villi and CCA, HM and IHM, HM and CCA (P<0.01). The expressions of NF-κBp65 and IκBα were correlated to clinical stage (P=0.043, 0.042, P<0.05), but not to patients' ages. Spearman correlation analysis revealed that there was a negative association between the protein expressions of NF-κBp65 and IκBα in GTN (r=-0.403, P=0.034, P<0.05).

CONCLUSION

Up-regulated expression of NF-κBp65 and down-regulated expression of IκBα may be related to the development, invasion and metastasis of GTN. The expressions of NF-κBp65 and IκBα are negatively correlated in gestational trophoblastic tumor tissues.

Genetic variation in TGF-beta 1 gene promoter and risk of gestational trophoblastic disease

OBJECTIVE

To examine the relationship of transforming growth factor beta 1 (TGF-beta 1) gene polymorphisms at promoter positions -509 (C/T) and -800 (G/A) with the risk of gestational trophoblastic disease (GTD) as compared to normal controls

STUDY DESIGN

Polymerase chain reaction-restriction fragment length polymorphism was performed on peripheral blood of 102 patients with GTD and 124 normal, healthy, pregnant women as the control group.

RESULTS

In this study, TGF-beta 1 gene polymorphisms at positions -509 (C/T) and -800 (G/A) failed to correlate with GTD.

CONCLUSION

Our findings suggest that promoter gene polymorphisms of TGF-beta 1 do not play major roles in GTD and may not be risk factors for this disease.

Diagnostic and prognostic significance of circulating tumor suppressor gene p53 autoantibodies in patients with gestational trophoblastic tumors

Seventy-two patients with gestational trophoblastic tumors (GTTs) and 20 first-trimester healthy pregnant women (controls) participated in this study. According to the WHO scoring system, GTTs were subgrouped into 24 hydatiform mole spontaneous regression (HMSR), 18 postmolar high-risk (PMHR) and 16 low- and 14 high-risk cases of choriocarcinoma. Patients with choriocarcinoma were treated with hysterectomy and methotrexate chemotherapy, whereas molar pregnancy was managed by either oxytocin infusion followed by suction evacuation or by hysterectomy. Serum p53 autoantibodies were determined by enzyme-linked immunosorbant assay and serum hCGbeta was determined by radioimmunoassay before and throughout the 12 months after treatment. p53 autoantibodies were not detected in normal pregnancy and cases of HMSR but were detected in all cases of PMHR and choriocarcinoma. Concentrations of p53 autoantibodies were higher in choriocarcinoma than in PMHR cases. Serial measurements of p53 autoantibodies dropped to an undetectable level within 1 and 6 months after treatment in cases of PMHR and low-risk choriocarcinoma, respectively. Decreasing values of p53 autoantibodies in high-risk choriocarcinoma remained higher than the cut-off level of controls. There was a significant positive correlation between p53 autoantibodies and serum hCGbeta concentration in GTTs. In conclusion, detection of p53 autoantibodies has a high potential for the differential diagnosis of GTTs and their serial measurements are clinically useful to monitor disease progression and to assess response to therapy in GTTs.

Indoleamine 2,3-dioxygenase expression in gestational trophoblastic disease: implications for development of immunotherapeutic approaches

OBJECTIVE

To examine the immunoexpression of indoleamine 2,3-dioxygenase (IDO) in gestational trophoblastic neoplasia (GTN), including hydatidiform moles and gestational trophoblastic tumors.

STUDY DESIGN

GTN cases were identified from a referral center for trophoblastic disease, and sections were immunostained with anti-IDO antibody and classified as positive or negative for trophoblast staining relative to normal chorionic villi.

RESULTS

Fifty-two cases were included: 10 nonmolar hydropic miscarriages (HA), 11 partial moles (PHM), 9 complete moles (CHM), 15 choriocarcinoma cases (CC) and 7 placental site trophoblastic tumors (PSTT). All HA, PHM and CHM demonstrated IDO staining; 2 of 15 CC were strongly positive, 6 demonstrated focal positivity (< 10% of tumor cells), and the remainder were negative. Of the 7 PSTT, only 2 showed focal weak positivity; the others were negative.

CONCLUSION

Hydatidiform moles express IDO, but the majority of gestational trophoblastic tumors, despite arising from villous or nonvillous trophoblast, do not express this enzyme, suggesting that IDO-mediated immunoregulation is unlikely to be a major component of the malignant phenotype in these tumors. Immunotherapeutic approaches involving IDO might represent ancillary approaches in a minority of patients with GTN.

Assessment of Her-2/neu expression in hydatidiform moles for prediction of subsequent gestational trophoblastic neoplasia

OBJECTIVE

The aim of the present study was to asses the ability of Her-2/neu immunohistochemical staining of the molar tissue to predict the risk of developing gestational trophoblastic neoplasia (GTN).

METHODS

Sections prepared from 33 consecutive formalin-fixed paraffin-embedded archival reconfirmed hydatidiform mole tissue blocks were immunohistochemically stained for Her-2/neu. The staining was scored according to the subjectively evaluated intensity of staining and the proportion of stained villous cytotrophoblastic cells. Clinical data were abstracted from medical files.

RESULTS

23 patients had a complete and 10 a partial mole. Nine patients (27.3%) were diagnosed with GTN [7 of 23 patients with a complete mole (30.4%) and 2 of the 10 (20.0%) with a partial mole]. A positive immunohistochemical Her-2/neu stain was found in 6 (18.2%) of the patients with hydatidiform mole (3 with a complete mole). The rate of Her-2/neu expression was somewhat higher in moles with subsequent GTN than in moles with an uneventful course (22.2% vs. 16.6%, respectively). The difference did not reach significance (Fisher's Exact Test, P=0.55) possibly due to the small number of cases (power of <5%). The sensitivity and specificity of Her-2/neu expression for prediction of GTN was 22.2% and 83.3%, respectively, and the positive and negative predictive value 33.3% and 74.1%, respectively.

CONCLUSION

While the specificity of Her-2/neu immunohistochemical staining for prediction of GTN is relatively high, the low sensitivity and low positive and negative predictive value precludes its practical clinical use for prediction of post-molar GTN. The quest for a precise predictor of post-molar GTN should continue.

[MMP-2/TIMP-2 expression in the trophoblasts of patients with gestational trophoblastic disease]

OBJECTIVE

To explore the role of matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of MMP-2 (TIMP-2) in the pathogenesis, development and prognosis of gestational trophoblastic disease (GTD).

METHODS

In situ hybridization and immunohistochemistry were utilized for MMP-2/TIMP-2 mRNA and protein detection in normal chorion of women with early gestation, hydatidiform mole, invasive mole, or choricarcinoma.

RESULTS

The results revealed that specific staining for mRNA and protein of MMP-2 and the expression of TIMP-2 was reduced in normal chorion of early gestation. In GTD ranging from hydatidiform mole, invasive mole to choricarcinoma, MMP-2 expression tended to increase while TIMP-2 expression underwent an invert change. The positivity rate of MMP-2 and TIMP-2 in gestational trophoblastic tumor group was higher than that of the normal chorion of early gestation group and hydatiform mole group (P<0.05 and P<0.001, respectively).

CONCLUSION

A disrupted balance between the activation and inhibition of MMP-2 plays a critical role in the pathogenesis, progression and metastasis of GTD.

Evaluation of deletions in 7q11.2 and 8p12–p21 as prognostic indicators of tumour development following molar pregnancy

OBJECTIVES

Previous studies have identified loss of chromosomal regions 7p12-q11.2 and 8p12-p21 in choriocarcinoma suggesting that suppressor genes involved in tumour development may be located within these regions. Our objectives were to refine the regions of loss and evaluate these deletions as prognostic indicators of trophoblastic tumour development following molar pregnancy.

METHODS

Fluorescent microsatellite genotyping was used to perform deletion mapping in a series of thirty-nine gestational trophoblastic tumours (GTT) including both choriocarcinoma and placental site trophoblastic tumours.

RESULTS

Significant loss of heterozygosity (LOH) was found for both regions in GTT that originated in non-molar pregnancies. Although no common interval of loss was found in those GTT with LOH for the 7q11.2 region, for the 8p12-p21 locus, markers D8S1731 and NEFL defined a minimal region of loss in all tumours showing LOH. However, complete LOH of either region occurred in only a minority of tumours (20%; chromosome 7: 24%; chromosome 8) suggesting that loss of neither region is likely to be a primary event in the development of GTT. This was further supported by the observation that no deletions were found in either region for the fourteen GTT that followed complete molar pregnancies.

CONCLUSIONS

While we have defined a minimal interval in 8p12-p21 in which tumour suppressor genes involved in GTT are likely to be located, the data suggest that deletions in 7q11.2 or 8p12-p21 are unlikely to be useful prognostic indicators in the management of patients with molar pregnancies.

Detection of HASH2 (ASCL2) gene expression in gestational trophoblastic disease

OBJECTIVE

To examine the expression of HASH2 in gestational trophoblastic disease (GTD).

STUDY DESIGN

DNA and RNA were isolated from 54 cases of GTD comprising 27 complete hydatidiform moles (CMs), 12 invasive moles (IvMs), 1 placental site trophoblastic tumor (PSTT) and 14 choriocarcinomas (ChCas). Reverse transcriptase polymerase chain reaction and polymerase chain reaction were performed using 2 sets of primers. One pair was used to detect a 190-base pair (bp) segment of the coding region of HASH2 and the other a 68-bp segment of the 3'UTR of the gene that contains a SacII polymorphism.

RESULTS

HASH2 was expressed in all normal placenta but not in any of the 27 CMs. In contrast, samples of IvM, PSTT and ChCa, the malignant forms of GTD, all expressed HASH2. Amplification of the 68-bp segment, in the 3'UTR, revealed a product in malignant disease that was larger than 68 bps and resistant to digestion with SacII.

CONCLUSION

Negative expression of HASH2 in CM but positive expression in malignant tumors suggests the presence of a specific mechanism for inactivation of the HASH2 gene in CM and reactivation in IvM or ChCa. Based on our data, we speculate that the 3' end of the gene might play an important role in regulating transcription of HASH2.

Heterogeneity in the origin of recurrent complete hydatidiform moles: not all women with multiple molar pregnancies have biparental moles

Hydatidiform moles of two women, each with three molar pregnancies, were examined in order to study their origin. Multiple recurrences have previously been associated with women who have biparental complete hydatidiform moles (CHM). However, all the moles examined in this study were androgenetic CHM (AnCHM), indicating that recurrent (>2) moles, particularly in the absence of a positive family history, may be androgenetic rather than biparental. These data suggest that some women have a specific liability for having AnCHM. Making the distinction between a biparental or an androgenetic origin of recurrent moles is of relevance for counselling and when considering therapeutic options. Therefore, we propose that all recurrent moles should be investigated using molecular techniques.

Expression of maspin in gestational trophoblastic disease

BACKGROUND

Maspin is a tumor suppressor gene whose expression is altered in neoplasia and malignancies of many tissues. In the human placenta, the maspin gene is expressed in trophoblastic cells and might act as an inhibitory regulator of trophoblastic invasion. Hence, in gestational trophoblastic disease (GTD), where there is increased propensity for invasion in the trophoblastic tissue, we hypothesized that maspin expression would be decreased. The present study aimed at investigating the expression of maspin in GTD and its prognostic significance.

METHODS

Using immunohistochemical staining, we firstly studied the expression of maspin in hydatidiform moles, with gestational age-matched normal first trimester placenta used as control. A total of 38 cases of hydatidiform moles were studied, including 20 complete moles (CM) and 18 partial moles (PM). Among them, 10 cases of the CM group and 8 cases of the PM group subsequently developed gestational trophoblastic neoplasia (GTN). Immunostaining was also performed on tissue from 4 cases of choriocarcinoma and 5 cases of placental site trophoblastic tumor. Reverse transcriptase-polymerase chain reaction (RT-PCR) was further performed on RNA extracted from 10 hydatidiform moles (5 with GTN and 5 without) and 6 normal first-trimester placentae.

RESULTS

In all tissue sections, nuclear expression of immunostaining signal was demonstrated, mainly in the cytotrophoblasts. The percentage of trophoblastic nuclei stained in both complete and partial moles was significantly lower than that in normal first-trimester placenta (P < 0.001). However, there was no significant difference in immunostaining between complete and partial moles (P > 0.05). There was also significantly lower expression of maspin in those cases subsequently developing GTN than those which did not (P = 0.01). Immunostaining on choriocarcinoma and placental site trophoblastic tumor showed reduced expression of maspin in all the tumor cells. Reverse transcriptase-polymerase chain reaction revealed that the expression of maspin was consistently down-regulated in all the hydatidiform mole samples.

CONCLUSIONS

Our results suggest that there is down-regulated expression of maspin in gestational trophoblastic diseases, and the down-regulation is more prominent in cases developing gestational trophoblastic neoplasia. This may play a role with prognostic significance in the pathogenesis and malignant transformation of hydatidiform moles.

Telomerase activity and the subunit of telomerase in hydatidiform mole and their relationship with the development of postmolar tumor

OBJECTIVES

To investigate the pattern of telomerase activity and the subunit of telomerase in normal placentae and GTD, and to determine the prognostic significance of telomerase activity and the subunit of telomerase in GTD.

METHODS

Telomerase activity human telomerase (hTERT) and human telomerase (hTR) expression were analyzed in the initial uterine evacuation specimen of 63 hydatidiform moles (HMs), 42 normal human placental tissues, 17 malignant gestational trophoblastic tumors, primary cultures of normal villi and JAR cell lines by use of the polymerase chain reaction-based telomeric repeat amplification protocol (TRAP) assay and reverse transcription-polymerase chain reaction (RT-PCR) methods.

RESULTS

Telomerase activity was 100% in primary cultures of normal villi and JAR cell lines and in less than 60-day early placental villi, while only 9.1% in greater than 60-day placental villi, 27% in HMs and 58% in malignant trophoblastic tumors. High levels of hTR could be found in all groups. hTR expression was detected in all cases of < 60-day placental villi, in 72.7% > 60-day placental villi, in 87.3% in HMs and 100% in malignant trophoblastic tumors. Telomerase activity and hTERT expression had significant differences among the groups. Telomerase activity was associated with serum hCG levels but not related to other clinical risk factors.

CONCLUSIONS

Telomerase activity may be correlated with the development of trophoblastic tumors, and hTERT may be a useful diagnostic marker for detecting the existence of malignant trophoblastic cells.

Expression pattern of the activating protein-1 family of transcription factors in gestational trophoblastic lesions

The human placenta is an endocrine tissue with a unique capacity for rapid, but tightly controlled, proliferation and invasion. Gestational trophoblastic diseases (GTDs) are placental pathologies with endocrine activity and partially malignant potential and include hydatidiform moles, placental site nodules, and tumors such as placental site trophoblastic tumor and choriocarcinomas. The activating protein-1 (AP-1) family of transcription factors is composed of the cellular homologs of the Jun and Fos oncoproteins, which are immediately involved in cellular proliferation, differentiation, and invasion processes and in the regulation of endocrine genes. The expression pattern of the AP-1 family in the normal human placenta has been recently described, where most of the factors were found in the extravillous (invasive) trophoblast. Their systematic expression in GTD has not been studied thus far. For this reason in this study, we investigated the expression pattern of the AP-1 family in GTDs and compared it with the expression in normal placenta using immunohistochemistry with specific polyclonal antibodies against all members of the AP-1 family (JunB, JunD, c-Jun, c-Fos, FosB, Fra-1, Fra-2). Immunohistochemistry was performed on normal human placentas (positive control) and on 28 cases of GTD including 7 choriocarcinomas and 21 hydatidiform moles. In the normal placenta and in hydatidiform molar samples, most AP-1 factors (especially c-Jun, JunD, and Fra2) were expressed in the intermediate (extravillous) trophoblast. In addition, in molar lesions, strong expression was found in trophoblasts proliferating from the surface of villi. There was only a weak expression of JunB and Fra2 in small fractions of villous cyto- and syncytiotrophoblast nuclei. In choriocarcinomas, there was a strong expression for c-Jun, JunD, Fra1, and Fra2. The specific localization to extravillous trophoblasts and their expression pattern in GTDs indicate that the AP-1 family of transcription factors might be implicated in regulating proliferation and invasion of trophoblasts and play a role in the pathogenesis of GTDs.

Osteopontin Expression in Gestational Trophoblastic Diseases: Correlation With Expression of the Adhesion Molecule, CEACAM1

The human placenta is a complex tissue with multiple endocrine and nutritional functions and a unique capacity for rapid proliferation but tightly controlled invasion, differentiating it from malignant tumors. Osteopontin (OPN) is a glycoprotein of the extracellular matrix, which has been shown to mediate cellular migration and invasion and to contribute to tumorigenesis in several types of cancers. OPN also could be implicated in regulating implantation and placentation by promoting cellular migration and invasion in a placenta-specific fashion. We could demonstrate the expression pattern of OPN in the normal human placenta in which it is localized in the extravillous (intermediate) trophoblast and the villous cytotrophoblast. CEACAM1 is an adhesion molecule, which we have recently found to be expressed at the maternal-fetal interface of the normal placenta with a localization to the extravillous (invasive) trophoblast and in gestational trophoblastic disease (GTD) and also to be potentially implicated in trophoblast invasion and tumorigenesis. Both OPN and CEACAM1 have been shown to interact with integrin beta3. The purpose of this study was to investigate the expression pattern of OPN in GTD and to correlate it with the expression of CEACAM1. To analyze the expression of OPN, we performed immunohistochemistry on a total of 27 cases of GTD, including 21 hydatidiform moles and 6 choriocarcinomas, which had previously been characterized with respect to their CEACAM1 expression. Hydatidiform moles showed a positivity for OPN in villous cytotrophoblast and in the trophoblast proliferations on the villous surface. The strongest OPN expression could be observed in the choriocarcinomas with a heterogenous OPN expression pattern. CEACAM1 had shown similar results and was found to be expressed in choriocarcinoma. The expression pattern of osteopontin in gestational trophoblastic diseases indicates that it might play a role in the pathogenesis of GTD (possibly as a functional complex with CEACAM1 and integrin beta3) and might be useful as an additional diagnostic marker for such lesions.

[Use of flow cytometry in the diagnosis of gestational trophoblastic disease]

INTRODUCTION

Histopathologic analysis of aborted tissue in molar pregnancy is frequently complicated by scarcity of tissue as well as by the fact that ultrasound and biochemistry permit the clinical diagnosis of gestational trophoblastic disease at the very beginning of pregnancy, when all classical morphologic features have not yet developed. Flow cytometry is today a widely used method that can help the pathologist reach a correct diagnosis, having implications for the patient.

AIM

To show the role of flow cytometry in addition to classical histopathologic methods in the early diagnosis of gestational trophoblastic disease, i. e. molar pregnancy.

PATIENTS AND METHODS

A total of 103 consecutively received placental tissue samples from spontaneous/medically induced abortions were histopathologically examined and submitted to flow cytometry analysis.

RESULTS

The patient mean age was 31 (range 19-50) years, and mean gestational age was 10 (range 5-19) weeks. Residual placental tissue with or without degenerative changes was found in 51.5% of the samples; in 8.7% embryonal/fetal tissues were identified as well. The histopathologic diagnosis of partial hydatiform mole was made in 34% and of complete hydatiform mole in 5.8% of cases. The difference in mean age of women according to histopathologic findings or placental ploidy was not significant. Flow cytometry revealed 42.7% of diploid samples, 58.3% of aneuploid samples and 1% of tetraploid samples. Of 53 samples showing normal morphology or degenerative hydropic changes, 60.4% were diploid and 39.6% aneuploid; of 9 samples containing fetal tissues 44.4% were diploid and 55.5% aneuploid (NS). A significant difference (p < 0.01) was found between the placental tissue ploidy with histopathologic diagnosis of residual placental tissue, and with histopathologic diagnosis of partial hydatiform mole (p < 0.001); when fetal tissues were present the difference was not significant

CONCLUSION

This study confirmed the partial hydatiform mole to be a common but clinically underdiagnosed condition. Except for the knowledge whether the abortion was caused by cytogenetic factors, flow cytometry helps the pathologist reach an accurate diagnosis and has a place in daily practice.

Mcl-1 expression in gestational trophoblastic disease correlates with clinical outcome

BACKGROUND

Hydatidiform moles (HMs) are abnormal pregnancies with a propensity for developing persistent disease in the form of gestational trophoblastic neoplasia (GTN), which requires chemotherapy. In previous studies, the authors demonstrated that low apoptotic activity was correlated with the progression of HM to GTN, and they hypothesized that some apoptosis-related genes may determine this progression.

METHODS

The differential expression of apoptotic genes in HMs that subsequently developed into GTN was compared with the same expression in HMs that spontaneously regressed using a human apoptosis array; then, the expression was evaluated with real-time quantitative polymerase chain reaction analysis and immunohistochemistry using 54 clinical samples from patients with HMs who had follow-up data available.

RESULTS

Using an apoptosis array, greater expression of Mcl-1, which is an antiapoptotic gene, was detected in HMs that subsequently developed into GTN. It was confirmed that the levels of Mcl-1 RNA expression (P = 0.017) and Mcl-1 protein expression (P < 0.001) in HMs that developed into persistent disease and required chemotherapy were significantly greater compared with the levels in HMs that regressed. Moreover, Mcl-1 immunoreactivity, which was detected predominantly in cytotrophoblasts, was correlated with the apoptotic index, as assessed with M30 cytoDeath immunohistochemistry, which is a good indicator of apoptotic events in the early-stage disease.

CONCLUSIONS

The current results demonstrated that Mcl-1, as identified by a cyclic DNA array, may play a role in the pathogenesis of HMs and may have potential as a useful marker for predicting the clinical behavior of HMs.

Molecular biology of gestational trophoblastic neoplasia: a review

Gestational trophoblastic diseases are interrelated conditions characterized by abnormal growth of chorionic tissues with varying propensitiesfor local invasion and metastases. These diseases are characterized by altered expression of several growth regulatory factors and oncogenes. On the basis of the expression of various oncogenes and growth factors, partial mole appears to be more like normal placenta, while complete mole seems to be more like choriocarcinoma. These results may have both prognostic and therapeutic consequences and provide insight into the relationship between normal placenta and gestational trophoblastic diseases.

Genetics and molecular markers in gestational trophoblastic disease with special reference to their clinical application

Gestational trophoblastic disease (GTD) encompasses a diverse group of lesions with specific cytogenetic and molecular pathogenesis. Although cytogenetic studies have been extensively reported, the molecular pathogenesis is poorly understood. We will summarize some of the recent molecular observations and correlate them with the pathology of GTD. Complete mole is androgenetic in origin. Thus, if a monoallelic contribution can be shown in complete mole, this would render the gene susceptible to functional inactivation by 'one-hit' kinetics. Alternatively, uniparental transmission of genes that are subject to parental imprinting in humans would impair their regulation. Loss of NECC1 expression, biallelic deletions at the critical (7p12-7q11.23) region and enhanced H19 expression in choriocarcinoma would reflect the genetic features exhibited by the putative forerunner, complete mole. In addition to the unique genetic features shown in GTD, alterations in gene expression profiles accompanied by malignant conversion of trophoblasts would facilitate the development of choriocarcinogenesis from complete mole. With recent advances in molecular techniques, further work is still necessary to provide a better understanding and useful markers for persistent trophoblastic disease. These may provide useful prognostic indications that may guide the different diagnosis of GTD.

Epidemiology of gestational trophoblastic diseases

The epidemiology of gestational trophoblastic diseases is unclear. Problems with collection and interpretation of differing data abound. Hydatidiform mole (HM) is associated with abnormal gametogenesis and/or fertilization. This is further influenced by age, ethnicity and a prior history of an HM suggesting a genetic basis for its aetiology. Whilst a prior HM is significant in the development of trophoblastic neoplasia there is no clear explanation for the development of gestational trophoblastic neoplasia in association with a normal gestation. The development and improvements in suction curettage, termination of pregnancy, contraceptive techniques, diagnostic imaging and biochemical testing have been associated not only with a fall in the birth rate, but also with a reduction in the incidence of trophoblastic diseases. Future study should examine the mechanism of malignant change in normal and abnormal trophoblast.

The management of recurrent and drug-resistant gestational trophoblastic neoplasia (GTN)

Gestational trophoblastic neoplasia (GTN) comprises a spectrum of disease from low-risk disease which can be cured with simple relatively non-toxic treatment, to extremely aggressive tumours which require specialized management. The prognostic variables in patients with GTN are different from those in other gynaecological malignancies, and the major adverse prognostic variables include long interval from antecedent pregnancy, high concentrations of the pregnancy hormone, human chorionic gonadotrophin, metastases in brain and liver and failure of prior treatment. Patients who relapse after their prior treatment can also be categorized into different risk groups. Salvage treatment can vary from single agent actinomycin D to combination chemotherapy and, in selected cases, surgery. With appropriate management, the majority of patients can achieve long-term remission and, in most cases, preserve fertility. The late side-effects of more intensive treatment are a small risk of inducing second tumours and also of bringing forward the age of menopause.

Methylation status and expression of E-cadherin and cadherin-11 in gestational trophoblastic diseases

The clinical significance of cadherins in gestational trophoblastic diseases (GTD) is not fully understood. In this study, the expression of E-cadherin and cadherin-11 in 12 normal placentas, 32 cases of hydatidiform mole (HM) including 15 complete HMs and 17 partial HMs, and five choriocarcinomas was investigated by immunohistochemistry and correlated with follow-up of HMs. Cases with available frozen blocks were further analyzed by western blot and semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR). Methylation of E-cadherin was investigated by methylation-specific PCR in six normal first trimester placentas, 19 HMs and their associated deciduas. E-cadherin expression was localized to cytotrophoblast and intermediate trophoblast whereas cadherin-11 was expressed in syncytiotrophoblast, intermediate trophoblast, and decidua. Immunoreactivity of E-cadherin was reduced in choriocarcinoma and complete HM when compared with that in normal first trimester placenta (P < 0.01, P = 0.04). Hypermethylation of E-cadherin was demonstrated in three complete HMs with the lowest level of E-cadherin. Compared with normal first trimester placenta, immunoreactivity of cadherin-11 was higher in complete HM (P = 0.02), but lower in choriocarcinoma (P = 0.02). Such differential expression was confirmed by western blot and semiquantitative RT-PCR. No obvious association was observed between the development of persistent trophoblastic disease with the expression of E-cadherin and cadherin-11.

[DNA analysis in gestational trophoblastic disease]

OBJECTIVE

DNA analysis of different forms of gestational trophoblastic disease.

DESIGN

Retrospective clinical study.

SETTING

Slovak Center of Trophoblastic Disease, Bratislava, Slovak Republic.

METHODS

In the period of September 1993 to April 2003, eighty-nine cases of gestational trophoblastic disease were analysed. There were 22 cases of partial hydatidiform moles, 58 cases of complete hydatidiform mole, 5 cases of invasive mole and 4 cases of gestational choriocarcinomas. Southern hybridization and polymerase chain reaction were used for DNA analysis.

RESULTS

From 22 analyzed cases of partial hydatidiform moles 19 (86.4%) were triploid and 3 (13.6%) diploid ones. There were 58 cases of complete hydatidiform mole and out of them 29 (50%) were homozygous, 28 (48.3%) heterozygous, and in one case (1.7%) both paternal and maternal genome was detected. In 8 cases of heterozygous and in one case of homozygous complete hydatidiform mole occurred a malignant transformation to gestational choriocarcinoma.

CONCLUSIONS

Molecular analysis can determine the nuclear DNA origin of complete hydatidiform mole and allow us to define the patients with higher risk of malignant transformation usually to gestational choriocarcinoma.

Detection of mitochondrial DNA mutations in gestational trophoblastic disease

Mitochondrial DNA (mtDNA) mutations have been implicated in a wide range of human disease. However, its role in gestational trophoblastic disease remains unclear. In this study, the entire mitochondrial genome of 10 hydatidiform moles (HM) and one choriocarcinoma were examined by automated DNA sequencing after amplification by polymerase chain reaction. MtDNA sequences obtained separately from disease tissues (HM and choriocarcinoma) and patients' tissues were compared. Of the 133 neutral sequence variants identified, 41 have not been reported to date. Large or small-scale deletion or insertion was not detected in any of the samples studied. A total of six (five in the D-loop and one in the 16S rRNA gene) somatic point mutations were detected in the choriocarcinoma sample, in contrast to none being detected in the HM samples. Somatic mtDNA instability was detected in the D-loop region in three cases of HM as well as in the choriocarcinoma sample. Somatic mtDNA instability appeared in the same nucleotide position, from 303 to 309, within the Conserved Sequence Block II resulting in alteration in length of the homopolymorphic C-tract, reflecting microsatellite instability. The results suggest that mtDNA instability may be an early event occurring at a premalignant stage. Occurrence of multiple somatic mtDNA mutations in choriocarcinoma suggests that mtDNA mutations might play an important role in the molecular pathogenesis of invasive gestational trophoblastic disease.

Genomic imprinting in gestational trophoblastic disease--a review

The abnormal pregnancy hydatidiform mole (HM) can be classified as complete (CHM) or partial (PHM) on the basis of both morphology and genetic origin. PHM are diandric triploids while almost all CHM are androgenetic. Thus the characteristic trophoblastic hyperplasia seen in both CHM and PHM is usually associated with the presence of two paternal genomes. Very occasionally CHM may be diploid, but biparental, in origin. These rare BiCHM are found in patients with recurrent HM and appear to be associated with an autosomal recessive condition predisposing to molar pregnancies. Since they are pathologically indistinguishable from androgenetic CHM, BiCHM are also likely to result from defects in genomic imprinting. There is evidence that the gene mutated in this condition, provisionally mapped to 19q13.3-13.4, may be important in setting the maternal imprint in the ovum. Women with BiCHM have a much higher risk of recurrent HM than women with AnCHM and an appreciable risk of persistent trophoblastic disease. Investigation of these unusual BiCHM and isolation of the defective gene will lead to a greater understanding of the function of genomic imprinting in early development.

Diagnostic aspects of hydatidiform mole with persistence of polymorphic trophoblastic hyperplasia

The persistence of polymorphic trophoblastic hyperplasia in a hydatidiform mole is an extremely rare condition. Its early recognition is essential since such cases can transform into invasive types of tumors.

MATERIALS AND METHODS

The biopsies were routinely processed in paraffin, embedded and stained with HE. Immunohistochemical staining reactions were performed with the following monoclonal antibodies for hydatidiform mole: beta-hCG, HPL, MIB1, CK18, HER-2/neu, p53 and carbohydrate antibodies, Thomsen-Friedenreich antigen, Glycodelin A, Mucl and Mucl-cor.

RESULTS

Large villi and hydatidiform villi with wide-ranged syncyctio- and cytotrophoblasts were seen. Intervillous proliferating trophoblasts showed cell- and nuclear polymorphy with a wall invasion of the myometrium. The immunohistochemistry exhibited strong positivity for the membrane-associated HER-2/neu and for the beta-hCG in syncytiotrophoblast and in multinuclear giant cells of intervillus trophoblasts. A weakly positive reaction with hPL was seen in most cells of the trophoblasts. The rest of the immunohistochemistry served as a diagnostic support.

CONCLUSION

A complete hydatidiform mole with hyperplasia and proliferation of polymorphic trophoblasts presents a high risk of developing a persistent (eventually metastatic) trophoblastic disorder and, in up to 15% of the cases, an invasive mole. In 2.5% of the cases it can transform into a choriocarcinoma.

Altered imprinting, promoter usage, and expression of insulin-like growth factor-II gene in gestational trophoblastic diseases

OBJECTIVE

We aimed to understand the involvement of imprinted genes in the pathogenesis of gestational trophoblastic diseases (GTD) such as hydatidiform mole (H-mole) and gestational trophoblastic tumors (GTT).

METHODS

An allelic-typing assay was performed using a PCR-RFLP-based method for identification of heterozygous informative cases. The usage of insulin-like growth factor-II (IGF2) promoters was examined by RT-PCR using promoter-specific primers. The mRNA expression of IGF2 and H19 was quantified using a densitometer.

RESULTS

The imprinting of IGF2 and H19 was maintained in all normal placenta tissues (n = 15) but relaxed in GTD (n = 47). Loss of imprinting (LOI) of IGF2 was in the order of GTT (57%) > complete H-mole (43%) > partial H-mole (25%). Similarly, LOI of H19 was in the order of GTT (40%) > complete H-mole (18%) > partial H-mole (0%). Promoter usage pattern of IGF2 changed with gestation stage of normal placentae and GTD. In normal placentae, the usage of promoter P1 was higher than that of P4 in the first trimester but lowered in the full term. H-mole and GTT predominantly used promoter P1 with relative silencing of promoter P4. Although normal early placenta and various GTD tissues showed the similar usage of IGF2 promoter P1, GTT tissues revealed the higher expression levels of IGF2 but a down-regulation of H19 relative to the normal early placentae.

CONCLUSIONS

These results suggest that LOI, deregulation of IGF2 promoters, and the altered expression levels of IGF2 and H19 genes might be associated with the progression of GTD.

Recent advances in molecular biology of gestational trophoblastic diseases. A review

Gestational trophoblastic diseases are interrelated conditions characterized by abnormal growth of chorionic tissues with various propensities for local invasion and metastasis. Complete mole is a unique conception in that all nuclear DNA is paternally derived and all cytoplasmic DNA is maternally derived. In contrast, partial mole generally has a triploid karyotype, where the extra haploid set of chromosomes is paternally derived: Gestational trophoblastic diseases are characterized by altered expression of several growth regulatory factors and oncogenes. While differences in expression of oncoproteins may be important to the development of gestational trophoblastic disease, the precise molecular changes that are critical to pathogenesis remain unknown.