Epithelioid trophoblastic tumor: an outcome-based literature review of 78 reported cases

Epithelioid trophoblastic tumor (ETT) is very rare; and therefore, a substantially increased data set is unlikely to be obtained in the near future. This analysis aimed to assess the effects of current management on clinical outcomes and to identify potential prognostic indicators in ETT.

We applied a literature search using PubMed to analyze the clinical data of 78 published cases of ETT.

Women with ETT present at reproductive age (mean ± SD, 37.1 ± 8.7 years) and have a slightly to moderately elevated serum β-human chorionic gonadotropin (median, 665 IU/L). Epithelioid trophoblastic tumor is frequently present in the lower uterine segment/cervix (26/58 cases) and can be misdiagnosed as squamous cell carcinoma (6/26). Lung is the most common extrauterine site of ETT (5/11 with uterine ETT and 10/20 without uterine ETT). Kaplan-Meier analysis indicates that chemotherapy (surgery with postoperative chemotherapy vs surgery alone) is associated with increased ETT relapse (P = 0.005), even after stratification by International Federation of Gynecology and Obstetrics (FIGO) stage (P = 0.008); but FIGO stage remains the only significant prognostic indicator for ETT (P = 0.015).

This analysis confirms the hypothetical chemotherapy resistance and prognostic value of FIGO staging in ETT. These findings remain tentative given the small data set available for analysis and the reporting bias from these published cases; however, they may confer a risk-adapted therapy. Finally, both gynecologists and pathologists should be alert to the potential misdiagnosis of squamous cell carcinoma when ETT is present in the lower uterine segment/cervix.