Abstract 15P
Background
Due to the scarcity of cases of Placental site trophoblastic tumor (PSTT) and Epithelioid trophoblastic tumor (ETT), their clinicopathological characteristics and prognosis have not been well summarized. Consequently, we conducted the largest to date series sample of both types to investigate the outcomes and prognostic factors in patients with PSTT and ETT. We set gestational choriocarcinoma (GCC) as a control group to show the clinical features of PTSS and ETT.
Methods
Female patients with a confirmed diagnosis of PTSS, ETT and GCC as their only primary tumor were extracted from the Surveillance, Epidemiology, and End Result (SEER) database (2000-2019). Patients were analyzed for age, race, marital status, stage, tumor size, treatment, and long-term survival. Dichotomous variables were analyzed using chi-square tests. The Kaplan–Meier method and the Cox proportional hazards regression model were used to evaluate overall survival (OS) and cancer-specific survival (CSS).
Results
We included 728 patients; 142(19.5%) had ETT, 107(14.7%) had PSTT and 479(65.8%) had GCC. Most patients were 30 years old or above with the predominant race being White (n=462). Primary surgical resection was performed on 58.2% of patients (n=424), while 75.5% had undergone chemotherapy and 4.3% were administered radiotherapy. There is no significant difference in OS and CSS between the different tumor groups and the median OS and CSS were not reached in any of the gestational trophoblastic neoplasms (GTN)groups. After multivariate adjusting, older age, not undergoing primary surgical resection, radiotherapy and/or chemotherapy, and metastasis of the primary tumor were all significant prognostic factors for adverse OS and CSS. Being unmarried was only a significant prognostic factor for worse CSS.On the contrary, tumor size, stage and race did not have any significant effect on OS/CSS. Between the GTN groups, there was no significant difference in the effects of chemotherapy and/or primary surgical resection on OS/CSS.
Conclusions
There was no discernable survival benefit difference detected in ETT and PSTT compared to GCC. But due to the scarcity of the data available on GTN, more research is needed to deepen our understanding of these rare cancers.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.