Following metastatic placental site trophoblastic tumor with urine beta-core fragment

The results of treatment with high-dose chemotherapy and peripheral blood stem cell support for gestational trophoblastic neoplasia

OBJECTIVE

The objective of the study was to evaluate the effect of high-dose chemotherapy (HDC) with peripheral blood stem cell support (PBSCS) on survival of patients with gestational trophoblastic neoplasia (GTN) with either refractory choriocarcinomas or a poor-prognosis placental site/epithelioid trophoblastic tumours (PSTT/ETTs).

METHODS

Databases of two referral centres for gestational trophoblastic disease were searched, and 32 patients treated with HDC between 1994 and 2015 were identified. Tissue samples were retrieved for genetic evaluation. Cox regression analyses were performed to identify possible predictors of overall survival (OS).

RESULTS

HDC induced a sustained complete response in 7 patients. Overall, 41% (13/32) of the patients remained disease free after HDC with or without additional treatment. Patients who survived had much lower human chorionic gonadotropin (hCG) values (all ≤12 IU/L) before and after HDC than those who died of disease. Univariable Cox regression analysis demonstrated that hCG >12 IU/L before or after HDC, International Federation of Gynaecology and Obstetrics (FIGO) stage II-IV and presence of metastases at the time of diagnosis were significantly associated with adverse OS. However, only hCG values before HDC remained significant in a multivariable model (p < 0.001). Five of 11 (45%) patients with PSTT/ETT presenting ≥48 months after antecedent pregnancy and 6 of 14 (43%) patients with refractory choriocarcinoma were in remission. Three treatment-related deaths occurred.

CONCLUSIONS

Despite 3 treatment-induced deaths, HDC with PBSCS appears to be active in salvaging selected patients with poor-prognosis PSTT/ETTs and refractory choriocarcinomas. Low hCG values before HDC seems a beneficial predictor of OS and may suggest that HDC acts more like a consolidation therapy.

High-dose chemotherapy with autologous peripheral blood stem cell transplantation for choriocarcinoma: A case report and literature review

Choriocarcinoma is a malignant gestational trophoblastic neoplasia (GTN) and one of the curable types of gynecological cancer. However, 10% of choriocarcinoma patients have a poor prognosis, particularly when they have metastasis, apart from pulmonary metastasis, or do not go into remission by the second chemotherapeutic regimen. We herein present the case of a 36-year-old patient who had choriocarcinoma with metastases to the lungs, liver and kidneys. The 5th and 6th regimens with cisplatin for choriocarcinoma failed and the patient developed brain metastases. She was then treated with four cycles of high-dose ifosfamide, carboplatin and etoposide (ICE) with blood progenitor cell support after confirming the effectiveness of ICE at normal doses. The serum human chorionic gonadotropin (hCG) level was 140,009 mIU/ml at the start of high-dose ICE and the patient tolerated this regimen well. However, the beneficial effect was decreasing with each successive course of treatment, with the lowest level of hCG at 103 mIU/ml after the fourth course. The patient did not achieve complete remission and succumbed to the disease 4 months after the last chemotherapy. The findings of the present case and a review of the related literature suggest that high-dose ICE with stem cell rescue may be considered as a viable treatment option for a multi-drug resistant choriocarcinoma or GTN.

USA hCG reference service, 10-year report

INTRODUCTION

The USA hCG Reference Service has been dealing with cases of persistent low levels of hCG and gestational trophoblastic diseases for 10years. Here we present the complete experience.

METHODS

Total hCG in serum and urine was measured using the Siemen's Immulite 1000 assay. Hyperglycosylated hCG, nicked hCG, free ss-subunit and ss-core fragment were measured using microtiterplate assays with antibodies B152, B151, FBT11 and B210, respectively.

RESULTS

The USA hCG Reference Service has identified 83 cases of false-positive hCG, 71 cases of aggressive gestational trophoblastic disease (GTD), 52 cases of minimally invasive GTD, 168 cases of quiescent GTD and 22 cases of placenta site trophoblastic tumor (PSTT). In addition, 103 cases of pituitary hCG have been identified, 60 cases of nontrophoblastic tumor, 4 cases of inherited hCG and 2 cases of Munchausen's syndrome. This is 565 cases total. Multiple new methods are described and tested for diagnosing all of these disorders.

CONCLUSIONS

The USA hCG Reference Service experience shows new methods for detecting multiple hCG-related disorders and recommends new approaches for detecting these hCG-related disorders.

New discoveries on the biology and detection of human chorionic gonadotropin

Human chorionic gonadotropin (hCG) is a glycoprotein hormone comprising 2 subunits, alpha and beta joined non covalently. While similar in structure to luteinizing hormone (LH), hCG exists in multiple hormonal and non-endocrine agents, rather than as a single molecule like LH and the other glycoprotein hormones. These are regular hCG, hyperglycosylated hCG and the free beta-subunit of hyperglycosylated hCG. For 88 years regular hCG has been known as a promoter of corpus luteal progesterone production, even though this function only explains 3 weeks of a full gestations production of regular hCG. Research in recent years has explained the full gestational production by demonstration of critical functions in trophoblast differentiation and in fetal nutrition through myometrial spiral artery angiogenesis. While regular hCG is made by fused villous syncytiotrophoblast cells, extravillous invasive cytotrophoblast cells make the variant hyperglycosylated hCG. This variant is an autocrine factor, acting on extravillous invasive cytotrophoblast cells to initiate and control invasion as occurs at implantation of pregnancy and the establishment of hemochorial placentation, and malignancy as occurs in invasive hydatidiform mole and choriocarcinoma. Hyperglycosylated hCG inhibits apoptosis in extravillous invasive cytotrophoblast cells promoting cell invasion, growth and malignancy. Other non-trophoblastic malignancies retro-differentiate and produce a hyperglycosylated free beta-subunit of hCG (hCG free beta). This has been shown to be an autocrine factor antagonizing apoptosis furthering cancer cell growth and malignancy. New applications have been demonstrated for total hCG measurements and detection of the 3 hCG variants in pregnancy detection, monitoring pregnancy outcome, determining risk for Down syndrome fetus, predicting preeclampsia, detecting pituitary hCG, detecting and managing gestational trophoblastic diseases, diagnosing quiescent gestational trophoblastic disease, diagnosing placental site trophoblastic tumor, managing testicular germ cell malignancies, and monitoring other human malignancies. There are very few molecules with such wide and varying functions as regular hCG and its variants, and very few tests with such a wide spectrum of clinical applications as total hCG.

Determination of hyperglycosylated human chorionic gonadotropin produced by malignant gestational trophoblastic neoplasias and male germ cell tumors using a lectin-based immunoassay and surface plasmon resonance

The ability to reliably detect aberrant glycosylation of human chorionic gonadotropin (hCG) may have profound implications for the diagnosis and monitoring of malignant gestational trophoblastic neoplasia, germ cell tumors, other malignancies, and pregnancy complications. To become a clinically useful assay, however, this discrimination of glycoforms should be possible on minimally treated biological specimens. Towards this end, we have developed a lectin-based sandwich-type immunoassay to compare the glycosylation patterns of hCG among urine specimens from patients presenting with a normal pregnancy, invasive mole, choriocarcinoma, and male germ cell tumors using carbohydrate-free antibody fragments as capture reagents and a panel of eight lectins, five recognizing neutral sugars and three recognizing sialic acid. There was no significant difference in the binding of any of the lectins to hCG in the urine of women over the gestational range of 6-38 weeks. Three lectins, however, exhibited differential binding to urinary hCG derived from these normal pregnant controls and that from patients with malignant forms of gestational trophoblastic disease and male germ cell tumors. Galanthus nivalis agglutinin and Maackia amurensis lectin, which bind terminal mannose and alpha(2-3)sialic acid, respectively, preferentially bound pregnancy-derived hCG, whereas the lectin, wheat germ agglutinin, which binds sialic acid and beta(1-4)N-acetylglucosamine, exhibited decreased binding to pregnancy-derived hCG compared to that from patients with male germ cell tumors and malignant gestational trophoblastic neoplasia. The differential binding observed with these three promising lectins is most encouraging and warrants further examination. The experimental paradigm also holds promise for the development of comparable assays for other glycosylated tumor markers.

Gestational trophoblastic diseases: 3. Human chorionic gonadotropin-free β-subunit, a reliable marker of placental site trophoblastic tumors

OBJECTIVES

Placental site trophoblastic tumor (PSTT) commonly presents with low and variable concentration of hCG immunoreactivity in serum which can be difficult to differentiate from early stage choriocarcinoma/gestational trophoblastic neoplasm (GTN) or quiescent gestational trophoblastic disease (quiescent GTD). Nontrophoblastic malignancies such as germ cell tumors or other tumors secreting low hCG must also be considered in the differential diagnosis. Because treatments for these conditions are different, a means of differentiating PSTT from other diagnoses is important. We investigate the usefulness of hCG-free beta-subunit to make this discrimination.

METHODS

Data collected on cases referred to the USA hCG Reference Service for consultation served as a basis for this retrospective analysis. There were 13 cases with histology proven PSTT and 12 with nontrophoblastic malignancy. hCG-free beta-subunit was measured by immunoassay and reported as a proportion of total hCG (hCG-free beta-subunit(%)). hCG-free beta-subunit(%) results were determined for all histologically proven cases of PSTT and for the nontrophoblastic malignancies. Comparisons of hCG-free beta-subunit(%) were made and compared with those of the 82 choriocarcinoma/GTN cases and 69 quiescent GTD cases. The accuracy of hCG-free beta-subunit(%) to discriminate these malignancies was analyzed by investigating the areas under receiver-operating characteristics curve +/- standard error.

RESULTS

hCG-free beta-subunit(%) was the predominant hCG form in cases of PSTT (mean +/- standard deviation, 60 +/- 19%) and nontrophoblastic malignancies (91 +/- 11%), thus discriminating these diagnoses from choriocarcinoma/GTN (9.3 +/- 9.2%) and from quiescent GTD (5.4 +/- 7.8%). The cutoff of >35% free beta-subunit is proposed. At this cutoff, 100% detection at 0% false-positive is achieved. The accuracy of hCG-free beta-subunit(%) for this discrimination is 100 +/- 0%. At a proposed cutoff of >80%, the free beta-subunit test will also distinguish PSTT from nontrophoblastic malignancy, with 77% detection at 23% false-positive or an accuracy of 92 +/- 3.2%.

CONCLUSION

Measurement of the proportion hCG-free beta-subunit(%) was found to be useful in the diagnosis of PSTT using proposed cutoff values of >35% and >80%. While this finding needs to be confirmed by larger studies, it would be reasonable to measure hCG-free beta-subunit(%) whenever the diagnosis of PSTT is considered.

Gestation trophoblastic diseases: management of cases with persistent low human chorionic gonadotropin results

The finding of persistent low levels of human chorionic gonadotropin (hCG) raises concern, regardless of the antecedent history, and often provokes the evaluating physician to embark on further work-up. The USA hCG Reference Service was started in 1998 to aid physicians with these persistent low hCG cases. This article reviews the observations of the USA hCG Reference Service for 134 cases with persistent low hCG results. Examination of these cases provides clear insight for the appropriate management of those presenting with persistent low levels of hCG. Three distinct sources are discussed for persistent low hCG results: quiescence gestational trophoblastic disease, false-positive hCG results, and pituitary hCG.

Placental site trophoblastic tumor: A study of 55 cases and review of the literature emphasizing factors of prognostic significance

OBJECTIVE

The placental site trophoblastic tumor is a rare form of gestational trophoblastic disease. Fifteen percent of reported cases have been fatal, but predicting behavior in individual patients has been challenging.

METHODS

The clinical, gross and histopathological features of 55 cases and 180 cases in the literature were analyzed for their effect on survival and in relation to tumor stage.

RESULTS

The 55 patients in our series were 20 to 62 (average 32) years of age. The tumors occurred on an average of 34 months after the last known gestation. 84% were stage I, 2% stage II, 5% stage III, and 9% stage IV. Serum levels of human chorionic gonadotropin (hCG) were elevated (average 691 mIU/ml) in 77% of the cases. The tumors were on average 5 cm in greatest dimension and were composed microscopically of infiltrative sheets of intermediate (extravillous) trophoblastic cells. The mitotic rate ranged from 0 to 20 (average 5.0) per 10 high power fields. The follow-up interval averaged 4.6 years. Eight patients (15%) died from metastatic tumor, and nine additional patients had metastases or a recurrence but were alive at last contact. The most common metastatic sites were the lungs, liver, and vagina.

CONCLUSIONS

Significant factors associated with adverse survival in the present series were age over 35 years (P = 0.025), interval since the last pregnancy of over 2 years (P = 0.014), deep myometrial invasion (P = 0.006), stage III or IV (P < 0.0005), maximum hCG level > 1000 mIU/ml (P = 0.034), extensive coagulative necrosis (P = 0.024), high mitotic rate (P = 0.005), and the presence of cells with clear cytoplasm (P < 0.0005). Only stage and clear cytoplasm were independent predictors of overall survival, while stage and age were the only independent predictors of time to recurrence or disease-free survival. In the literature, factors associated with survival were stage (P < 0.005), interval from preceding pregnancy of over 2 years (P = 0.029), previous term pregnancy (P = 0.046), high mitotic rate (P < 0.0005), and high hCG level (P = 0.037).

Advances in the clinical laboratory detection of gestational trophoblastic disease

BACKGROUND

Gestational trophoblastic disease (GTD) consists of a spectrum of disorders that are characterized by an abnormal proliferation of trophoblastic tissue. Gestational trophoblastic neoplasia (GTN) refers to a subset of GTD with a persistently elevated serum hCG in the absence of a normal pregnancy and with a history of normal or abnormal pregnancy. Although previously a lethal disease, GTN is considered today the most curable gynecologic cancer. However, a delay in the diagnosis may increase the patient's risk of developing malignant GTN, and therefore the prompt identification of GTN is important.

SERUM MARKERS

hCG test is essential for detection of GTN. It has emerged that there are problems with hCG tests. In addition to regular hCG, at least five major variants of hCG are present in serum samples. False-positive hCG (phantom hCG) can occur in the absence of GTN. Low-level real hCG may occasionally persist in the absence of clinical evidence of pregnancy or GTD. Alternatively, low-level real hCG may be due to pituitary hCG. Other placental hormones, human placental lactogen (hPL), inhibin and activin, and progesterone have also been evaluated as tumor markers for GTD.

CONCLUSION

hCG has high diagnostic sensitivity, approaching 100% sensitivity, for managing the treatment of GTN and for detecting recurrences of disease. It is recommended to use hCG test that recognizes all forms of the hCG molecule. In cases where low-level hCG persists, it must be differentiated whether it is real or false. Real-hCG may be due to quiescent gestational trophoblastic disease or pituitary hCG. It has not yet been established whether measurement of markers other than hCG (hPL, inhibin, activin, and progesterone) is useful in the detection and follow-up of GTD.

[Gestational trophoblastic disease. Non-villous forms of gestational trophoblastic disease]

The non-villous forms of gestational trophoblastic disease (GTD) include a wide range of morphologic different lesions and cover a wide range of differential diagnosis. Choriocarcinomas (CCA) represent the most malignant form displaying a dimorphic pattern with proliferation of syncytio- and zytotrophoblast. An early start of chemotherapy is of great prognostic impact. Placental site nodule (PSN) and exaggerated placental site (EPS) are non-neoplastic lesions of the intermediate trophoblast without tumorous appearance, whereas placental site trophoblastic tumor (PSTT) and epitheloid trophoblastic tumor (ETT) represent tumorous neoplasms with a potential for local invasion and metastases. PSNs are incidental findings of highly polymorphic cells. In EPS chorionic villi are almost present, endometrial glands and spiral arteries are completely engulfed by intermediate trophoblastic cells without necroses. In PSTT the monomorphic, occasional multinucleated giant cells separating individual muscle fibers and charactersitically blood vessel walls are extensively replaced by trophoblastic cells and fibrinoid material. The ETT consists large necrotic areas with hyalinisation. Typically small blood vessels with preserved walls are located within the center of glycogen-rich monomorphous proliferation of trophoblastic cells.

Utility of Commonly Used Commercial Human Chorionic Gonadotropin Immunoassays in the Diagnosis and Management of Trophoblastic Diseases

Background: Patients with trophoblastic diseases produce ordinary and irregular forms of human chorionic gonadotropin (hCG; e.g., nicked hCG, hCG missing the β-subunit C-terminal segment, hyperglycosylated hCG, and free β subunit) that are recognized to differing extents by automated immunometric hCG (or hCGβ) assays. This has led to low or false-negative results and misdiagnosis of persistent disease. False-positive hCG immunoreactivity has also been detected, leading to needless therapy for trophoblastic diseases. Here we compare seven commonly used hCG assays.

Methods: Standards for five irregular forms hCG produced in trophoblastic diseases, serum samples from 59 patients with confirmed trophoblastic diseases, and serum samples from 12 women with previous false-positive hCG results (primarily in the Abbott AxSYM assay) were blindly tested by commercial laboratories in the Beckman Access hCGβ, the Abbott AxSYM hCGβ, the Chiron ACS:180 hCGβ, the Baxter Stratus hCG test, the DPC Immulite hCG test, the Serono MAIAclone hCGβ tests, and in the hCGβ RIA.

Results: Only the RIA and the DPC appropriately detected the five irregular hCG standards. Only the Beckman, DPC, and Abbott assays gave results similar to the RIA in the patients with confirmed trophoblastic diseases (values within 25% of RIA in 49, 49, and 54 of 59 patients, respectively). For samples that were previously found to produce false-positive hCG results, no false-positive results were detected with the DPC and Chiron tests (5 samples, median &lt;2 IU/L), but up to one-third of samples were false positive (&gt;10 IU/L) in the Beckman (1 of 5), Serono (2 of 9), and Baxter assays (1 of 5), and the hCGβ RIA (3 of 9; median for all assays, &lt;5 IU/L). These samples, which produced false-positive results earlier in the Abbott AxSYM assay, continued to produce high values upon reassessment (median, 81 IU/L).

Conclusions: Of six frequently used hCG immunometric assays, only the DPC detected the five irregular forms of βhCG, agreed with the RIA, and avoided false-positive results in the samples tested. This assay, and similarly designed assays not tested here, seem appropriate for hCG testing in the diagnosis and management of trophoblastic diseases.

The pathology of intermediate trophoblastic tumors and tumor-like lesions

An intermediate trophoblast is a distinctive trophoblastic cell population from which four trophoblastic lesions are thought to arise: exaggerated placental site (EPS), placental site nodule (PSN), placental site trophoblastic tumor (PSTT), and epithelioid trophoblastic tumor (ETT). EPSs and PSTTs are related to the differentiation of the intermediate trophoblast in the implantation site (implantation site intermediate trophoblast), whereas PSNs and ETTs are related to the intermediate trophoblast of the chorion laeve (chorionic-type intermediate trophoblast). EPSs and PSNs are nonneoplastic lesions, whereas PSTTs and ETTs are neoplasms with a potential for local invasion and metastasis. Microscopically, intermediate trophoblastic lesions can be confused with a variety of trophoblastic and nontrophoblastic tumors, but an appreciation of the morphologic features and immunophenotype allows their diagnosis to be relatively straightforward in most instances. Correct diagnosis is important because each of these lesions may require different therapeutic approaches.