The role of surgery in the management of women with gestational trophoblastic disease

A review on management of gestational trophoblastic neoplasia

BACKGROUND

The rare presence of malignant cancerous cells afar any type of pregnancy is known as gestational trophoblastic neoplasia (GTN). GTN are benign lesions which mostly happen due to the activity of extravillous trophoblast cells and the placental villous tree development. These kinds of diseases would be occurring mainly due to the following clinicopathologic conditions: (I) existence of epithelioid trophoblastic tumor (ETT), (II) rare type of choriocarcinoma cancer, (III) gestational trophoblastic tumor of mole, and (IV) the rare malignant tumor of placental site trophoblastic tumor.

OBJECTIVE

This comprehensive study is trying to review the most recent approaches in comprehension of pathogenesis, more precise diagnosis, and also the most effective therapeutic procedures for patients who suffer from GTN disorders.

MATERIALS AND METHOD

A comprehensive research was carried out on scientific databases of Science Citation Index (SCI), MEDLINE, EMBASE, HMIC, PubMed, CINAHL, Google Scholar, Cochrane Database of Systematic Reviews (CDSR), and PsycINFO over the time period of 2005 to 2019. The keywords which applied for discovering more related records were including: Gestational trophoblastic diseases (GTD), Gestational trophoblastic neoplasia (GTN), molar pregnancy, choriocarcinoma, human chorionic gonadotropin (hCG), diagnosis, management and treatment.

CONCLUSION

In spite of the fact that GTN patients are treated with conventional surgical therapies or/and chemotherapy, in some patients with resistant disease, these therapies may not be effective and patients may die. Some novel remedial agents are required for decreasing the level of toxicity caused through administering conventional chemotherapy and also treating the patients who suffer from refractory or resistant disease. The newest issues are related to GTN diagnosis, process of progression of hydatidiform mole (HM) to GTN, and the issue of GTN drug resistance. In this regard, we should have a comprehensive knowledge on GTN genetics for answering all the available questions about this disorder.

Challenges in the diagnosis and treatment of gestational trophoblastic neoplasia worldwide

Gestational trophoblastic neoplasia (GTN) is a rare tumor that originates from pregnancy that includes invasive mole, choriocarcinoma (CCA), placental site trophoblastic tumor and epithelioid trophoblastic tumor (PSTT/ETT). GTN presents different degrees of proliferation, invasion and dissemination, but, if treated in reference centers, has high cure rates, even in multi-metastatic cases. The diagnosis of GTN following a hydatidiform molar pregnancy is made according to the International Federation of Gynecology and Obstetrics (FIGO) 2000 criteria: four or more plateaued human chorionic gonadotropin (hCG) concentrations over three weeks; rise in hCG for three consecutive weekly measurements over at least a period of 2 weeks or more; and an elevated but falling hCG concentrations six or more months after molar evacuation. However, the latter reason for treatment is no longer used by many centers. In addition, GTN is diagnosed with a pathological diagnosis of CCA or PSTT/ETT. For staging after a molar pregnancy, FIGO recommends pelvic-transvaginal Doppler ultrasound and chest X-ray. In cases of pulmonary metastases with more than 1 cm, the screening should be complemented with chest computed tomography and brain magnetic resonance image. Single agent chemotherapy, usually Methotrexate (MTX) or Actinomycin-D (Act-D), can cure about 70% of patients with FIGO/World Health Organization (WHO) prognosis risk score ≤ 6 (low risk), reserving multiple agent chemotherapy, such as EMA/CO (Etoposide, MTX, Act-D, Cyclophosphamide and Oncovin) for cases with FIGO/WHO prognosis risk score ≥ 7 (high risk) that is often metastatic. Best overall cure rates for low and high risk disease is close to 100% and > 95%, respectively. The management of PSTT/ETT differs and cure rates tend to be a bit lower. The early diagnosis of this disease and the appropriate treatment avoid maternal death, allow the healing and maintenance of the reproductive potential of these women.

A promising therapeutic strategy for metastatic gestational trophoblastic disease: Engineered anticancer gene-expressing stem cells to selectively target choriocarcinoma

Gestational trophoblastic disease (GTD) is an unusual disease occurring in pregnancy that originates from abnormal trophoblastic cells and comprises a group of diseases with different properties of invasion, metastasis and recurrence. The GTD group includes hydatidiform moles and gestational trophoblastic neoplasms (GTNs), with GTNs being divided into invasive moles, choriocarcinoma, placental site trophoblastic tumors and epithelioid trophoblastic tumors. The present review focuses on current effective treatments for GTD, including conventional and novel promising direct enzyme prodrug therapies (DEPTs). Conventional therapies, such as chemotherapy and hysterectomy, are currently used in a clinical setting; however, the use of diverse DEPTs, including antibody-DEPT and gene-DEPT is also being attempted to cure GTNs. In addition, gene delivery tools using genetically engineered neural stem cells (NSCs) are presently being examined for the treatment of GTNs. The tumor-tropism of NSCs by chemoattractant factors is a unique characteristic of these cells and can serve as a vehicle to deliver anticancer agents. Previous studies have demonstrated that injection with NSC-expressing suicide genes into xenograft animal models has a significant inhibitory effect on tumor growth. Stem cells can be genetically engineered to express anticancer genes, which migrate to the metastatic sites and selectively target cancer cells, and are considered to effectively target metastatic GTNs. However, the safety issue of stem cell therapy, such as tumorigenesis, remains a challenge. Novel therapies comprising a combination of conventional and novel promising treatments are anticipated to be definitive treatments for metastasized and/or recurrent patients with GTNs.