Human chorionic gonadotropin free β-subunit measurement as a marker of placental site trophoblastic tumors

Charing Cross Oncology Laboratory and Trophoblastic Disease Centre, Charing Cross Hospital Campus of Imperial College Healthcare National Health Service Trust, London, UK.
The Journal of reproductive medicine (Impact Factor: 0.7). 09/2008; 53(8):643-8.
Source: PubMed


To evaluate the utility of free human chorionic gonadotropin beta-subunit (hCGbeta) proportion of total hCG measurement to distinguish placental site trophoblastic tumor (PSTT) from more common forms of gestational trophoblastic disease (GTD).
Serum samples collected from PSTT, persistent trophoblastic disease (PTD) and choriocarcinoma patients were used for retrospective analysis of free hCGbeta-subunit. Results were reported as a percentage of total hCG using our in-house competitive radioimmunoassay.
The percentage of free hCGbeta was significantly greater in serum from 18 PSTT patients, yielding a median value of 45.5% than in a combined GTD group of 49 PTD and 12 choriocarcinoma patients. Receiver operating characteristic analysis confirms that the percentage free hCGbeta distinguishes PSTT from GTD patients. Choriocarcinoma patients had significantly higher hCGbeta measurements than PTD patients and were not well distinguished from PSTT patients.
Our findings show that an elevated proportion of free hCGbeta-subunit is a helpful but not definitive test to discriminate PSTT from other forms of GTD.

8 Reads
  • [Show abstract] [Hide abstract]
    ABSTRACT: Gestational trophoblastic neoplasia (GTN) encompasses several entities including complete (CHM) and partial (PHM) hydatidiform mole (HM) and the malignant gestational trophoblastic tumors (GTTs), choriocarcinoma (CC), and placental-site trophoblastic tumor (PSTT), including epithelioid trophoblastic tumor (ETT). To detect pGTN, postmolar surveillance by measurement of maternal human chorionic gonoadotropin (hCG) levels should be performed. With such a protocol, many cases of pGTN are identified early at a presymptomatic stage based on plateuing or rising hCG concentrations and subsequently treated successfully with chemotherapy. In such cases, histopathological confirmation of the precise nature of the pGTN usually is not available. However, GTT also may present clinically with primary or metastatic disease, either following and unrecognized HM or developing from a nonmolar gestation. Due to their distinctive clinical and histological features, malignant GTTs are generally clearly subdivided into CC and PSTT (including ETT). CC essentially represents malignant trophoblastic tumors with differentiation toward villous trophoblast, with extensive hematogenous spread and high hCG levels, which are highly chemoresponsive. However, PSTTs, represent malignant differentiation toward implantation-site type trophoblast, with lower hCG levels and less response to chemotherapy. Current issues regarding the clinical and histological features of CC and PSTT/ETT are discussed.
    No preview · Article · Jan 2010 · Fetal and pediatric pathology
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Gestational trophoblastic neoplasia (GTN) refers to a unique and heterogeneous group of conditions demonstrating differentiation towards various components of gestational trophoblast. Variants of hydatidiform mole (HM) are considered benign, whilst choriocarcinoma (CC), placental site trophoblastic tumour (PSTT) and the more recently described epithelioid trophoblastic tumour (ETT), a variant of PSTT, are malignant gestational trophoblastic tumours (GTT). The early and reproducible pathologic diagnosis of the various forms of GTN has been aided by recent developments in tumour markers, laboratory technology and new insights into our understanding of these different gestational diseases. Whilst CC is usually exquisitely chemosensitive, the much rarer PSTT and ETT require primary surgical management for optimal outcome. This dichotomous approach to the management of malignant GTT, determined by FIGO stage and differing tumour biology based on histology, has ensured an overall cure rate in excess of 90% for this group of tumours.
    Preview · Article · Jan 2010
  • [Show abstract] [Hide abstract]
    ABSTRACT: During the 9-month time period of human pregnancy, the placenta is a pleiotropic regulator of the intrauterine environment. The principle cell type of the placenta, trophoblast, produces a wide variety of hormones that signal maternal, placental, and fetal tissues in an autocrine, paracrine, and endocrine fashion. The placenta can be separated into three distinct compartments. The implantation site is where trophoblast invades the uterine vessels to form a maternal circulation. The interhemal membrane is where trophoblast modulates maternal metabolism, transports substrates to the fetus, and protects the fetus from potentially harmful maternal agents. The extraplacental membranes regulate prostaglandins and other mediators that trigger labor. In addition to their involvement in normal physiology at these maternal–fetal interfaces, the evaluation of placental hormones also plays a critical role in the detection of Down syndrome, in the prediction of pregnancy complications such as preeclampsia and preterm labor, and in understanding the long-term complications of intrauterine deprivation. Finally, as with specific cellular lineages in other organs, trophoblast can undergo neoplastic transformation (gestational trophoblastic disease). Diagnostic immunohistochemistry for placental hormones and measurement of serum levels of placental hormones following therapy play important roles in diagnosis and treatment of specific tumors and precursor lesions arising at each of these three locations. KeywordsGestational trophoblastic disease-Hormones-Invasion-Labor-Placenta-Transport-Trophoblast
    No preview · Chapter · Jan 2010
Show more