Presentation, progression, and survival in placental site trophoblastic tumors: A population-based analysis and review of the literature.

e17658 Background: Placental Site Trophoblastic Tumors (PSTT) are an extremely rare subtype of Gestational Trophoblastic Disease (GTD), accounting for 0.23% to 3% of all cases. According to the current literature, approximately two-thirds of PSTTs exhibit indolent behavior, while the remainder may metastasize and result in mortality. Limited data exists on the presentation and treatment of PSTT. Methods: We review the literature of this rare form of GTD. In addition, patients diagnosed with PSTT between 2000 and 2021 were identified using the Surveillance, Epidemiology, and End Results (SEER) Program database. Statistical significance of key variables was assessed using the log-rank test. Results: A total of 8 cases were identified, underscoring the rarity of this cancer. The patients' ages ranged from 25 to 54 years, with 75% being between 25–39 years old. All patients identified as white race, and 62.5% identified as Spanish-Hispanic-Latino. The majority of patients had a household income between $45,000 and $85,000 (88%). All patients resided in urban areas, with 75% living in metropolitan areas with populations exceeding 1 million. Stage at diagnosis was reported for half of the cases (4), with 3 presenting with distant metastases and only 1 with localized disease. Notably, all patients were alive at last follow-up. Surgical intervention was performed in 62.5% of cases and 50% of patients underwent both surgery and chemotherapy. Conclusions: PSTT is an exceedingly rare cancer, making it challenging to draw prognostic conclusions. Interestingly, 62.5% of the cases in this cohort identified as Spanish-Hispanic-Latino and all where white race. All cases were diagnosed in urban settings, suggesting access to tertiary care and the majority were from low-middle income households. Despite most patients presented with metastatic disease, none succumbed to their illness, indicating a favorable prognosis regardless of stage. Since all patients were alive at last follow up, no specific clinical or demographic variables were significantly associated with long-term survival, highlighting the need for further studies to enhance understanding of this rare disease.